conf: rename

56 files changed, 5320 insertions, 0 deletions

diff --git a/Year_1/Programming_2/algorithms/binarysearch.cc b/Year_1/Programming_2/algorithms/binarysearch.cc
new file mode 100644
index 0000000..c9b4cd7
--- /dev/null
+++ b/Year_1/Programming_2/algorithms/binarysearch.cc
@@ -0,0 +1,33 @@
+#include<iostream>
+
+using namespace std;
+
+bool bs(int a[], int i, int j, int x) {
+    if(j<i) return false;
+    int mid = i+(j-i)/2;
+    if(a[mid] == x)
+        return true;
+    if(a[mid] > x)
+        return bs(a, i, mid-1, x);
+    return bs(a, mid+1, j, x);
+}
+
+bool bs2(int a[], int i, int j, int x) {
+    while(i <= j) {
+        int mid = i+(j-i)/2;
+        if(a[mid] == x) return true;
+        if(a[mid] < x)
+            i = mid+1;
+        else
+            j = mid-1;
+    }
+    return false;
+}
+
+int main() {
+    int a[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
+    for(int i = 0; i < 12; ++i)
+        cout << i << ' '<<bs(a, 0, 9, i) << ' ' << bs2(a, 0, 9, i) << endl;
+    return 0;
+}
+
diff --git a/Year_1/Programming_2/algorithms/cbrt.cc b/Year_1/Programming_2/algorithms/cbrt.cc
new file mode 100644
index 0000000..30c7792
--- /dev/null
+++ b/Year_1/Programming_2/algorithms/cbrt.cc
@@ -0,0 +1,37 @@
+#include<iostream>
+
+using namespace std;
+
+int cbrt(int n) {
+    int i = 0;
+    int j = n;
+    int q = (i+j)/2;
+    while(q*q*q != n) {
+        q = (i+j)/2;
+        if(q*q*q < n)
+            i=q;
+        else
+            j=q;
+    }
+    return q;
+}
+
+double cbrt2(int n) {
+    int i = 1;
+    while(i*i*i <= n)
+        ++i;
+    // precision
+    
+    --i;
+    while(i*i*i < n)
+        i+=0.000001;
+    
+    return i;
+}
+
+int main() {
+    int i;
+    cin >> i;
+    cout << i << ' ' << cbrt(i) << endl;
+    return 0;
+}
diff --git a/Year_1/Programming_2/algorithms/insertionsort.cc b/Year_1/Programming_2/algorithms/insertionsort.cc
new file mode 100644
index 0000000..9b309d6
--- /dev/null
+++ b/Year_1/Programming_2/algorithms/insertionsort.cc
@@ -0,0 +1,42 @@
+#include<iostream>
+
+using namespace std;
+
+void insertionsort(int a[], int n) {
+    for(int i = 1; i < n; ++i) {
+        int j = i-1;
+        int key = a[i];
+        while(j > -1 && a[j] > key) {
+            swap(a[j+1], a[j]);
+            --j;
+        }
+        a[j+1] = key;
+    }
+}
+
+void insertionsort_rec(int a[], int n) {
+    if(n < 2) return;
+    insertionsort_rec(a, n-1);
+ 
+    int key = a[n-1];
+    int j = n-2;
+
+    while(j > -1 && a[j] > key) {
+        swap(a[j+1], a[j]);
+        --j;
+    }
+
+    a[j+1] = key;
+
+}
+
+int main() {
+    int arr[10] = {3, 450, 12, 4, -1, 0, 24, 95, 123, 0};
+    for(int i = 0; i < 10; ++i)
+        cout << *(arr+i) << ' ';
+    cout << endl;
+    insertionsort_rec(arr, 10);
+    for(int i = 0; i < 10; ++i)
+        cout << *(arr+i) << ' ';
+    return 0;
+}
diff --git a/Year_1/Programming_2/algorithms/log.cc b/Year_1/Programming_2/algorithms/log.cc
new file mode 100644
index 0000000..1e49a2e
--- /dev/null
+++ b/Year_1/Programming_2/algorithms/log.cc
@@ -0,0 +1,25 @@
+#include<iostream>
+
+using namespace std;
+
+double log(double n) {
+    if(n <= 2) return 1.0;
+    return 1.0 + log(n/2);
+}
+
+int log2(double n) {
+    int a = 1;
+
+    while(n > 2) {
+        n /= 2;
+        ++a;
+    }
+
+    return a;
+}
+
+int main() {
+    for(int i = 0; i < 25; ++i)
+        cout << i << ' ' << log(i) << ' ' << log2(i) << endl;
+    return 0;
+}
diff --git a/Year_1/Programming_2/algorithms/mergesort.cc b/Year_1/Programming_2/algorithms/mergesort.cc
new file mode 100644
index 0000000..68d28cb
--- /dev/null
+++ b/Year_1/Programming_2/algorithms/mergesort.cc
@@ -0,0 +1,52 @@
+#include<iostream>
+
+using namespace std;
+
+void merge(int A[], int l, int q, int r) {
+    int i = l;
+    int j = q+1;
+    int k = l;
+    int B[r];
+
+    while((i <= q) && (j <= r)) {
+        if(A[i] <= A[j])
+            B[k] = A[i++];
+        else
+            B[k] = A[j++];
+
+        k++;
+    }
+
+    while(i <= q)
+        B[k++] = A[i++];
+
+    while(j <= r)
+        B[k++] = A[j++];
+
+    for(k = l; k <= r; ++k) 
+        A[k] = B[k];
+}
+
+void mergesort(int A[], int l, int r) {
+    if(l < r) {
+        int q = (l+r)/2;
+        mergesort(A, l, q);
+        mergesort(A, q+1, r);
+        merge(A, l, q, r);
+    }
+}
+
+
+int main() {
+    int a[] = {7,1,22,3,2,12,27,31,6};
+    for(int i = 0; i < 9; ++i) {
+        cout << a[i] << ' ';
+    }
+    cout << endl;
+    mergesort(a, 0, 8);
+    for(int i = 0; i < 9; ++i) {
+        cout << a[i] << ' ';
+    }
+
+    return 0;
+}
diff --git a/Year_1/Programming_2/algorithms/pow.cc b/Year_1/Programming_2/algorithms/pow.cc
new file mode 100644
index 0000000..16cf419
--- /dev/null
+++ b/Year_1/Programming_2/algorithms/pow.cc
@@ -0,0 +1,25 @@
+#include<iostream>
+
+using namespace std;
+
+int pow(int x, int y) {
+    int a = 1;
+    
+    for(int i = 0; i < y; ++i)
+        a*=x;
+    
+    return a;
+}
+
+
+int pow2(int x, int y) {
+    if(y < 1) return 1;
+    
+    return x*pow(x, y-1);
+}
+
+int main() {
+    cout << pow(2, 5) << endl;
+    cout << pow2(2, 5) << endl;
+    return 0;
+}
diff --git a/Year_1/Programming_2/algorithms/quicksort.cc b/Year_1/Programming_2/algorithms/quicksort.cc
new file mode 100644
index 0000000..795bd7b
--- /dev/null
+++ b/Year_1/Programming_2/algorithms/quicksort.cc
@@ -0,0 +1,38 @@
+#include<iostream>
+
+using namespace std;
+
+int partition(int A[], int l, int r) {
+    int x = A[r];
+    int i = l-1;
+
+    for(int j = l; j < r; ++j) {
+        if(A[j] <= x) {
+            swap(A[++i], A[j]);
+        }
+    }
+    swap(A[++i], A[r]);
+    return i;
+}
+
+void quicksort(int A[], int l, int r) {
+    if(l < r) {
+        int q = partition(A, l, r);
+        quicksort(A, l, q-1);
+        quicksort(A, q+1, r);
+    }
+}
+
+int main() {
+    int a[] = {7,1,22,3,2,12,27,31,6};
+    for(int i = 0; i < 9; ++i) {
+        cout << a[i] << ' ';
+    }
+    cout << endl;
+    quicksort(a, 0, 8);
+    for(int i = 0; i < 9; ++i) {
+        cout << a[i] << ' ';
+    }
+
+    return 0;
+}
diff --git a/Year_1/Programming_2/algorithms/selectionsort.cc b/Year_1/Programming_2/algorithms/selectionsort.cc
new file mode 100644
index 0000000..57dcc17
--- /dev/null
+++ b/Year_1/Programming_2/algorithms/selectionsort.cc
@@ -0,0 +1,46 @@
+#include<iostream>
+#include<algorithm>
+
+using namespace std;
+
+void selectionsort(int a[], int n) {
+    for(int i = 0; i < n-1; ++i) {
+        int min = i;
+        for(int j = i+1; j < n; ++j) {
+            if(a[j] < a[min])
+                min = j;
+        }
+
+        swap(a[min], a[i]);
+    }
+}
+
+int min_i(int a[], int i, int j) {
+    if(i == j) return i;
+
+    int k = min_i(a, i+1, j);
+    return (a[i] < a[k]) ? i : k;
+}
+
+void selectionsort_rec(int* a, int b, int e=0) {
+    if(b == e) return;
+
+    int key = min_i(a, e, b-1);
+    if(key != e)
+        swap(a[key], a[e]);
+
+    selectionsort_rec(a, b, e+1);
+}
+
+int main() {
+    int arr[] = {3,450,12,4,-1,0,24,95,123,0};
+    for(int i = 0; i < 10; ++i) {
+        cout << *(arr+i) << ' ';
+    }
+    cout << endl;
+    selectionsort_rec(arr, 10);
+    for(int i = 0; i < 10; ++i) {
+        cout << *(arr+i) << ' ';
+    }
+    return 0;
+}
diff --git a/Year_1/Programming_2/algorithms/sqrt.cc b/Year_1/Programming_2/algorithms/sqrt.cc
new file mode 100644
index 0000000..aa6b032
--- /dev/null
+++ b/Year_1/Programming_2/algorithms/sqrt.cc
@@ -0,0 +1,46 @@
+#include<iostream>
+
+using namespace std;
+
+double abs(double n) {
+    if(n < 0) return -n;
+
+    return n;
+}
+
+
+double sq(int n) {
+    double x = n;
+    double y = 1;
+    while(x-y > 0.0000001) {
+        x = (x+y)/2;
+        y = n/x;
+    }
+    return x;
+}
+
+double sq2_n(double n, double a) {
+    if(abs(a*a - n) <= 0.000001) {
+        return a;
+    }
+
+    return sq2_n(n, (a+n/a)/2);
+}
+
+double sq2(int n) {
+    return sq2_n(n, n/2);
+}
+
+double sqrt_d(int n) {
+    double x = 1;
+    while(abs(x*x-n)>=0.0000001) {
+        x = ((n/x)+x)/2;
+    }
+    return x;
+}
+
+int main() {
+    cout << sq(81) << endl;
+    cout << sq2(81) << endl;
+    return 0;
+}
diff --git a/Year_1/Programming_2/coding_contest/dolcetti.cpp b/Year_1/Programming_2/coding_contest/dolcetti.cpp
new file mode 100644
index 0000000..c3409a4
--- /dev/null
+++ b/Year_1/Programming_2/coding_contest/dolcetti.cpp
@@ -0,0 +1,51 @@
+#include<iostream>
+#include<fstream>
+#include<queue>
+#include<vector>
+
+using namespace std;
+
+int main() {
+    using tii = tuple<int, int, int>;
+    ifstream in("input.txt");
+    ofstream out("output.txt");
+
+    for(int ts = 0; ts < 100; ++ts) {
+        int N;
+        in >> N;
+
+        priority_queue<tii, vector<tii>> pq;
+        tii qq;
+        for(int i = 0; i < N; ++i) {
+            int e1, e2;
+            in >> e1 >> e2;
+            get<0>(qq) = e1-e2;
+            get<1>(qq) = e1;
+            get<2>(qq) = e2;
+
+            pq.push(qq);
+        }
+        
+        int counter = N;
+        int sum{};
+
+        while(counter-- > N/2) {
+            qq = pq.top();
+            sum += get<1>(qq);
+            pq.pop();
+        }
+
+        while(!pq.empty()) {
+            qq = pq.top();
+            sum += get<2>(qq);
+            pq.pop();
+        }
+
+        out << sum << endl;
+    }
+
+    in.close();
+    out.close();
+    return 0;
+}
+
diff --git a/Year_1/Programming_2/coding_contest/gita.cpp b/Year_1/Programming_2/coding_contest/gita.cpp
new file mode 100644
index 0000000..cbb4910
--- /dev/null
+++ b/Year_1/Programming_2/coding_contest/gita.cpp
@@ -0,0 +1,46 @@
+#include<iostream>
+#include<fstream>
+#include<vector>
+#include<map>
+
+using namespace std;
+
+int main() {
+    ifstream in("input.txt");
+    ofstream out("output.txt");
+    
+    for(int c = 0; c < 100; ++c) {
+        int N, L;
+        in >> N >> L;
+        vector<pair<short, int>> students;
+        for(int i = 0; i < N; ++i) {
+            int num;
+            in >> num;
+            students.push_back({num, 0});
+        }
+
+        int index, val;
+        for(int i = 0; i < L; ++i) {
+            in >> index >> val;
+            students[index].second += val;
+        }
+
+        vector<pair<short, int>> errors;
+        short _j{};
+        for(auto const& i : students) {
+            if(i.second < i.first) {
+                errors.push_back({_j, i.first-i.second});
+            }
+            _j++;
+        }
+
+        out << errors.size() << ' ';
+        for(auto const& i : errors) {
+            out << i.first << ' ' << i.second << ' ';
+        }
+        out << endl;
+    }
+    out.close();
+    in.close();
+    return 0;
+}
diff --git a/Year_1/Programming_2/coding_contest/gribaudo.cpp b/Year_1/Programming_2/coding_contest/gribaudo.cpp
new file mode 100644
index 0000000..39d0e42
--- /dev/null
+++ b/Year_1/Programming_2/coding_contest/gribaudo.cpp
@@ -0,0 +1,47 @@
+#include<iostream>
+#include<vector>
+#include<fstream>
+
+using namespace std;
+
+int maxpath(vector<vector<int>>& v) {
+    for(int i = v.size()-2; i >= 0; --i) {
+        for(int j = 0; j <= i; ++j) {
+            if(v[i+1][j] > v[i+1][j+1]) {
+                v[i][j] += v[i+1][j];
+            } else {
+                v[i][j] += v[i+1][j+1];
+            }
+        }
+    }
+
+    return v[0][0];
+}
+
+int main() {
+    ifstream in("input.txt");
+    ofstream out("output.txt");
+
+    for(int ts = 0; ts < 1; ++ts) {
+        int N;
+        in >> N;
+        vector<vector<int>> triangle;
+
+        for(int i = 0; i < N; ++i) {
+            int e;
+            triangle.push_back(vector<int>{});
+            int j;
+            for(j = 0; j <= i; ++j) {
+                in >> e;
+                triangle[i].push_back(e);
+            }
+            for(; j < N; ++j) 
+                triangle[i].push_back(0);
+        }
+        out << maxpath(triangle) << endl;
+    }
+
+    in.close();
+    out.close();
+    return 0;
+}
diff --git a/Year_1/Programming_2/coding_contest/gualtieri.cpp b/Year_1/Programming_2/coding_contest/gualtieri.cpp
new file mode 100644
index 0000000..f8a0ecf
--- /dev/null
+++ b/Year_1/Programming_2/coding_contest/gualtieri.cpp
@@ -0,0 +1,46 @@
+#include<iostream>
+#include<fstream>
+#include<map>
+
+using namespace std;
+
+int main() {
+    ifstream in("input.txt");
+    ofstream out("output.txt");
+
+    for(int ts = 0; ts < 100; ++ts) {
+        string P{}, L{};
+        in >> P;
+        in >> L;
+        map<char, int> chars;
+
+        for(auto const& c : P) {
+            (chars.find(c) == chars.end()) ? chars[c] = 1 : chars[c]+=1;
+        }
+        int lenn = L.length();
+        int lenp = P.length();
+        int counter{};
+
+        for(int i = 0; i < lenn-lenp+1; ++i) {
+            map<char, int> tmp;
+            bool check{true};
+            for(int j = i; j < i+lenp; ++j) {
+                (tmp.find(L[j]) == tmp.end()) ? tmp[L[j]] = 1 : tmp[L[j]]+=1;
+            }
+            for(auto const &i : tmp) {
+                if(chars[i.first] != tmp[i.first]) {
+                    check = false;
+                    break;
+                }
+            }
+            if(check)
+                ++counter;
+        }
+        out << counter << endl;
+
+    }
+
+    out.close();
+    in.close();
+    return 0;
+}
diff --git a/Year_1/Programming_2/coding_contest/ladri.cpp b/Year_1/Programming_2/coding_contest/ladri.cpp
new file mode 100644
index 0000000..04e8e65
--- /dev/null
+++ b/Year_1/Programming_2/coding_contest/ladri.cpp
@@ -0,0 +1,53 @@
+#include<iostream>
+#include<fstream>
+#include<vector>
+
+using namespace std;
+
+int main() {
+    ifstream in("input.txt");
+    ofstream out("output.txt");
+
+    for(short _ = 0; _ < 100; ++_) {
+        int N, K, M;
+        in >> N >> K >> M;
+        int* path = new int[N+1];
+        int i;
+        for(i = 0; i < N; ++i)
+            in >> path[i];
+
+        path[i] = M;
+        int start = 0;
+        vector<int> values;
+        /* 1 31 33 38 62 69 93 97 98 99 */
+        /* x x     x  x   x          x       
+         * K = 30
+         */
+        for(int i = 0; i < N+1; ++i) {
+            if(path[i] - start > K) {
+                for(int j = i-1; j >= 0; --j) {
+                    if(path[i] - path[j] <= K) {
+                        values.push_back(path[j]);
+                        start = path[j];
+                        i = j;
+                        break;
+                    }
+                }
+            }
+        }
+
+        // Stampa la path corretta per debug
+        for(auto const& i: values) 
+            cout << i << ' ';
+
+        cout << endl;
+        out << values.size() << endl;
+        delete[] path;
+    }
+
+
+    out.close();
+    in.close();
+
+    return 0;
+}
diff --git a/Year_1/Programming_2/coding_contest/pizzini.cpp b/Year_1/Programming_2/coding_contest/pizzini.cpp
new file mode 100644
index 0000000..4fcb4ab
--- /dev/null
+++ b/Year_1/Programming_2/coding_contest/pizzini.cpp
@@ -0,0 +1,48 @@
+#include<iostream>
+#include<fstream>
+#include<vector>
+
+using namespace std;
+
+void get_fib(vector<int> &v, int N) {
+    int a = v.at(0);
+    int b = v.at(1);
+    while(b <= N) {
+        a += b;
+        v.push_back(a);
+        swap(a, b);
+    }
+    v.pop_back();
+}
+
+int main() {
+    ifstream in("input.txt");
+    ofstream out("output.txt");
+
+    for(short _ = 0; _ < 100; ++_) {
+        int N;
+        in >> N;
+        vector<int> fib {1, 2};
+        get_fib(fib, N);
+        vector<int> seq(fib.size(), 0);
+
+        int sum{};
+        for(int i = fib.size()-1; i >= 0; --i) {
+            if(fib.at(i) + sum > N) continue;
+
+            sum += fib.at(i);
+            seq[i] = 1;
+        }
+
+
+        for(auto const& i : seq)
+            out << i;
+
+        out << endl;
+    }
+
+    out.close();
+    in.close();
+    
+    return 0;
+}
diff --git a/Year_1/Programming_2/coding_contest/scheletri.cpp b/Year_1/Programming_2/coding_contest/scheletri.cpp
new file mode 100644
index 0000000..2389d25
--- /dev/null
+++ b/Year_1/Programming_2/coding_contest/scheletri.cpp
@@ -0,0 +1,56 @@
+#include<iostream>
+#include<fstream>
+#include<vector>
+#include<algorithm>
+
+using namespace std;
+
+int find_i(int index, vector<int> cms) {
+    for(int i = index; i < cms.size(); ++i) {
+        if(cms.at(i) != 0)
+            return i;
+    }
+    
+    return 0;
+}
+
+int find_j(int index, vector<int> cms) {
+    for(int j = index; j < cms.size()-1; ++j) {
+        if(cms.at(j+1) == 0)
+            return j+1;
+    }
+    
+    return cms.size();
+}
+
+int main() {
+    ifstream in("input.txt");
+    ofstream out("output.txt");
+
+    short N;
+    for(int __c = 0; __c < 100; ++__c) {
+        in >> N;
+        vector<int> cms;
+        int el;
+        for(short i = 0; i < N; ++i) {
+            in >> el;
+            cms.push_back(el);
+        }
+        
+        int counter{};
+        int i{}, j{};
+        while(count_if(begin(cms), end(cms), [](int num) { return num == 0; } ) != cms.size() ) {
+            i = find_i(i, cms);
+            j = find_j(i, cms);
+            for(int ii = i; ii < j; ++ii) {
+                --cms[ii];
+            }
+            ++counter;
+        }
+        out << counter << endl;
+    }
+
+    out.close();
+    in.close();
+    return 0;
+}
diff --git a/Year_1/Programming_2/coding_contest/stazioni.cpp b/Year_1/Programming_2/coding_contest/stazioni.cpp
new file mode 100644
index 0000000..29ede44
--- /dev/null
+++ b/Year_1/Programming_2/coding_contest/stazioni.cpp
@@ -0,0 +1,82 @@
+#include<iostream>
+#include<fstream>
+#include<algorithm>
+#include<vector>
+
+using namespace std;
+
+int main() {
+    ifstream in("input.txt");
+    ofstream out("output.txt");
+
+    for(int ts = 0; ts < 1; ++ts) {
+        int N, S;
+        in >> N >> S;
+        vector<long> st;
+        vector<vector<long>> paths;
+        vector<vector<long>> paths2;
+        vector<vector<long>> paths3;
+
+        int e;
+        for(int i = 0; i < N; ++i) {
+            in >> e;
+            st.push_back(e);
+        }
+
+        int index{};
+        for(int i = 0; i < N-S+1; ++i) {
+            for(int j = 0; j < N; ++j) {
+                paths.push_back(vector<long>{});
+                paths[index].push_back(i);
+                for(int k = j; paths[index].size() < S; ++k) {
+                    int t = (k == N) ? 0 : k;
+                    if(k > N) break;
+                    paths[index].push_back(t);
+                }
+                sort(begin(paths[index]), end(paths[index]));
+                if(paths[index].size() == S)
+                    paths2.push_back(paths[index]);
+                ++index;
+            }
+        }
+        for(int i = 0; i < paths2.size(); ++i) {
+            bool check{true};
+            if(paths2[i].size() != S) continue;
+            for(int j = 0; j < paths2[i].size()-1; ++j) {
+                if(paths2[i].at(j) == paths2[i].at(j+1)) {
+                    check = false;
+                    break;
+                }
+            }
+            if(check)
+                paths3.push_back(paths2[i]);
+        }
+
+        for(auto const& i : paths3) {
+            for(auto const& j : i) 
+                cout << st[j] << ' ';
+
+            cout << endl;
+        }
+        cout << endl;
+
+        int major{};
+        for(int i = 0; i < paths3.size(); ++i) {
+            vector<long> diffs;
+            for(int j = 0; j < paths3[i].size()-1; ++j) {
+                int p1 = st[paths3[i][j+1]];
+                int p2 = st[paths3[i][j]];
+                diffs.push_back(p1 - p2);
+            }
+            int miner = *min_element(begin(diffs), end(diffs));
+            if(miner > major)
+                major = miner;
+        }
+        cout << ts << ' ' << major << endl;
+        out << major << endl;
+    }
+
+    in.close();
+    out.close();
+    return 0;
+}
diff --git a/Year_1/Programming_2/coding_contest/tastevin.cpp b/Year_1/Programming_2/coding_contest/tastevin.cpp
new file mode 100644
index 0000000..301ebcf
--- /dev/null
+++ b/Year_1/Programming_2/coding_contest/tastevin.cpp
@@ -0,0 +1,38 @@
+#include<iostream>
+#include<fstream>
+#include<vector>
+#include<algorithm>
+
+using namespace std;
+
+int main() {
+    ifstream in("input.txt");
+    ofstream out("output.txt");
+
+    for(int ts = 0; ts < 100; ++ts) {
+        int N;
+        in >> N;
+        vector<int> arr(N);
+        for(int i = 0; i < N; ++i) {
+            in >> arr.at(i);
+        }
+
+        vector<int> paths(N, 1);
+
+        for(int i = N-2; i >= 0; --i) {
+            int mx = 0;
+            for(int j = i+2; j < N; ++j) {
+                if(mx < paths[j] && arr[j] >= arr[i]) {
+                    mx = paths[j];
+                }
+            }
+            paths[i] += mx;
+        }
+
+        out << *max_element(begin(paths), end(paths)) << '\n';
+    }
+
+    in.close();
+    out.close();
+    return 0;
+}
diff --git a/Year_1/Programming_2/coding_contest/tastevin_paths.cpp b/Year_1/Programming_2/coding_contest/tastevin_paths.cpp
new file mode 100644
index 0000000..eb7da54
--- /dev/null
+++ b/Year_1/Programming_2/coding_contest/tastevin_paths.cpp
@@ -0,0 +1,67 @@
+// It prints all possible paths
+
+#include<iostream>
+#include<fstream>
+#include<vector>
+
+using namespace std;
+
+int main() {
+    ifstream in("input.txt");
+    ofstream out("output.txt");
+
+    for(int ts = 0; ts < 100; ++ts) {
+        int N;
+        in >> N;
+        vector<int> arr;
+        int e;
+        for(int i = 0; i < N; ++i) {
+            in >> e;
+            arr.push_back(e);
+        }
+
+        int max_value{};
+        int value;
+
+        for(int i = 0; i < N; ++i) {
+            vector<int> tmp;
+            tmp.push_back(i);
+            value = arr[i];
+            for(int j = i+2; j < N; ++j) {
+                if(arr[j] >= value) {
+                    tmp.push_back(j);
+                    value = arr[j];
+                    ++j;
+                }
+            }
+            while(!tmp.empty()) {
+                if(tmp.size() > max_value) {
+                    for(auto const&i : tmp) {
+                        cout << i << ' ';
+                    }
+                    cout << endl;
+                    max_value = tmp.size();
+                }
+                int k = tmp.back();
+                tmp.pop_back();
+                if(tmp.size() > 0)
+                    value = arr[tmp.back()];
+                else
+                    value = arr[k];
+                for(int j = k+1; j < N; ++j) {
+                    if(arr[j] >= value) {
+                        value = arr[j];
+                        tmp.push_back(j);
+                        ++j;
+                    }
+                }
+            }
+        }
+
+        out << max_value << '\n';
+    }
+
+    in.close();
+    out.close();
+    return 0;
+}
diff --git a/Year_1/Programming_2/data_structures/bfs.cc b/Year_1/Programming_2/data_structures/bfs.cc
new file mode 100644
index 0000000..2b4efbd
--- /dev/null
+++ b/Year_1/Programming_2/data_structures/bfs.cc
@@ -0,0 +1,186 @@
+#include<iostream>
+#include<vector>
+#include<queue>
+#define W -1
+#define G 0
+#define B 1
+
+using namespace std;
+
+template<class H>
+class node {
+public:
+    explicit node(H key, node<H>* next) : _key{key}, _next(next) {}
+    const H& key() const { return _key; }
+    H& key() { return _key; }
+    const node<H>*& next() const { return _next; }
+    node<H>*& next() { return _next; }
+private:
+    H _key;
+    node<H>* _next;
+};
+
+template<class H>
+class list {
+public:
+    list() : _head{nullptr} {}
+    ~list() {
+        while(_head) {
+            auto tmp = _head;
+            _head = _head->next();
+            delete tmp;
+        }
+    }
+    list<H>* push(H val) {
+        auto iter = _head;
+        while(iter && iter->next())
+            iter = iter->next();
+
+        if(!iter)
+            _head = new node<H>{val, nullptr};
+        else
+            iter->next() = new node<H>{val, nullptr};
+
+        return this;
+    }
+    void print() {
+        auto iter = _head;
+        while(iter) {
+            cout << iter->key() << ' ';
+            iter = iter->next();
+        }
+    }
+    vector<H> as_vector() {
+        vector<H> v;
+        auto iter = _head;
+        while(iter) {
+            v.push_back(iter->key());
+            iter = iter->next();
+        }
+        return v;
+    }
+    node<H>* search(H val) {
+        auto iter = _head;
+        while(iter && iter->key() != val) {
+            iter = iter->next();
+        }
+
+        return iter;
+    }
+private:
+    node<H>* _head;
+};
+
+template<class H>
+class graph {
+public:
+
+private:
+    int _len, _nodes, _edges;
+    int* _parents;
+    int* _distances;
+    H** _k; // it works like a dictionary, it saves the keys
+    list<int>** _adj;
+    int _index(H val) {
+        for(int i = 0; i < _nodes; ++i)
+            if(*_k[i] == val) return i;
+
+        return -1;
+    }
+public:
+    graph(int len) : _len{len}, _nodes{0}, _edges{0} {
+        _k = new H*[len];
+        _adj = new list<int>*[_len];
+        _parents = new int[_len];
+        _distances = new int[_len];
+        for(int i = 0; i < _len; ++i) {
+            _k[i] = nullptr;
+            _adj[i] = new list<int>{};
+        }
+    }
+
+    graph<H>* add_node(H k) {
+        if(_nodes == _len) return this;
+        if(_index(k) >= 0) return this; // node is already there
+
+        _k[_nodes++] = new H(k);
+
+        return this;
+    }
+
+    void bfs(int s) {
+        int colors[_len];
+        queue<int> q;
+
+        for(int i = 0; i < _nodes; ++i) {
+            colors[i] = W;
+            _parents[i] = -1;
+            _distances[i] = 999999999;
+        }
+        q.push(s);
+        colors[s] = G;
+        _distances[s] = 0;
+        while(!q.empty()) {
+            int x = q.front();
+            q.pop();
+            for(auto const& j : _adj[x]->as_vector()) {
+                if(colors[j] == W) {
+                    colors[j] = G;
+                    q.push(j);
+                    _parents[j] = x;
+                    _distances[j] = _distances[x] + 1;
+                }
+            }
+            colors[x] = B;
+        }
+
+        for(int i = 0; i < _nodes; ++i) {
+            cout << "[" << i << "]->";
+            if(_distances[i]==999999999) cout << "inf." << endl;
+            else cout << _distances[i] << endl;
+        }
+    }
+
+    void bfs(H x) {
+        int s = _index(x);
+        if(s != -1)
+            bfs(s);
+    }
+
+    graph<H>* add_edge(H x, H y) {
+        int i = _index(x);
+        int j = _index(y);
+        if(i < 0 || j < 0) return this;
+
+        if(!_adj[i]->search(j)) {
+            _adj[i]->push(j);
+            _edges++;
+        }
+
+        return this;
+    }
+
+    void print() {
+        for(int i = 0; i < _nodes; ++i) {
+            cout << "(" << i << ", " << *_k[i] << "): ";
+            for(auto const& j : _adj[i]->as_vector())
+                cout << "(" << j << ", " << *_k[j] << "), ";
+            cout << '\n';
+        } 
+    }
+};
+
+
+int main() {
+    graph<string>* g = new graph<string>(5);
+    g->add_node("hello")->add_node("greg")->add_node("yes");
+    g->add_node("nop")->add_node("ok");
+    g->add_edge("hello", "ok");
+    g->add_edge("ok", "yes")->add_edge("yes", "ok")->add_edge("yes", "yes");
+    g->add_edge("yes", "nop");
+    g->print();
+    g->bfs("hello");
+
+    delete g;
+    return 0;
+}
diff --git a/Year_1/Programming_2/data_structures/bst.cc b/Year_1/Programming_2/data_structures/bst.cc
new file mode 100644
index 0000000..9223e04
--- /dev/null
+++ b/Year_1/Programming_2/data_structures/bst.cc
@@ -0,0 +1,225 @@
+#include<iostream>
+
+using namespace std;
+
+template<class T>
+struct node {
+    T key;
+    node<T>* prev;
+    node<T>* right;
+    node<T>* left;
+};
+
+template<class T>
+class bst {
+public:
+    bst() : root{nullptr} {}
+
+    ~bst() {
+        // TODO
+    }
+
+    bst<T>* insert(initializer_list<T>&& list) {
+        for(auto const& i : list)
+            insert(i);
+
+        return this;
+    }
+
+    bst<T>* insert(T k) {
+        node<T>* nodus = new node<T>{k, nullptr, nullptr, nullptr};
+        node<T>* iter = root;
+        node<T>* prev = nullptr;
+
+        while(iter) {
+            prev = iter;
+            iter = (k < iter->key) ? iter->left : iter->right;
+        }
+
+        nodus->prev = prev;
+        if(!prev)
+            root = nodus;
+        else if(k < prev->key)
+            prev->left = nodus;
+        else
+            prev->right = nodus;
+
+        return this;
+    }
+
+    bst<T>* remove(initializer_list<T>&& list) {
+        for(auto const& i : list)
+            remove(i);
+
+        return this;
+    }
+
+    bst<T>* remove(T k) {
+        node<T>* nodus = search(k);
+        if(!nodus) return this;
+
+        if(!nodus->left) {
+            _transplant(nodus, nodus->right);
+        } else if(!nodus->right) {
+            _transplant(nodus, nodus->left);
+        } else {
+            node<T>* iter = _min(nodus->right);
+            if(iter->prev != nodus) {
+                _transplant(iter, iter->right);
+                iter->right = nodus->right;
+                iter->right->prev = iter;
+            }
+            _transplant(nodus, iter);
+            iter->left = nodus->left;
+            iter->left->prev = iter;
+        }
+
+        delete nodus;
+        return this;
+    }
+
+    node<T>* min() {
+        return _min(root);
+    }
+
+    node<T>* min(node<T>* nodus) {
+        return _min(nodus);
+    }
+
+    node<T>* max() {
+        return _max(root);
+    }
+
+    node<T>* max(node<T>* nodus) {
+        return _max(nodus);
+    }
+
+    node<T>* search(T k) {
+        node<T>* iter = root;
+        while(iter && iter->key != k)
+            iter = (iter->key > k) ? iter->left : iter->right;
+
+        return iter;
+    }
+
+    node<T>* successor(T k) {
+        node<T>* nodus = search(k);
+        if(!nodus) return nullptr;
+
+        if(nodus->right)
+            return min(nodus->right);
+
+        node<T>* prev = nodus->prev;
+        while(prev && nodus == prev->right) {
+            nodus = prev;
+            prev = prev->prev;
+        }
+
+        return prev;
+
+    }
+    node<T>* predecessor(T k) {
+        node<T>* nodus = search(k);
+        if(!nodus) return nullptr;
+
+        if(nodus->left)
+            return max(nodus->left);
+
+        node<T>* prev = nodus->prev;
+        while(prev && nodus == prev->left) {
+            nodus = prev;
+            prev = prev->prev;
+        }
+
+        return prev;
+    }
+
+    friend ostream& operator<<(ostream& os, bst<T>* tree) {
+        tree->_preorder(os, tree->root);
+        return os;
+    }
+private:
+    void _transplant(node<T>* u, node<T>* v) {
+        if(!u->prev) {
+            root = v;
+        } else if(u == u->prev->left) {
+            u->prev->left = v;
+        } else {
+            u->prev->right = v;
+        }
+
+        if(v)
+            v->prev = u->prev;
+    }
+
+    node<T>* _min(node<T>* root) {
+        node<T>* iter = root;
+        while(iter && iter->left)
+            iter = iter->left;
+
+        return iter;
+    }
+
+    node<T>* _max(node<T>* root) {
+        node<T>* iter = root;
+        while(iter && iter->right)
+            iter = iter->right;
+
+        return iter;
+    }
+
+    void _inorder(ostream& os, node<T>* root) {
+        if(root) {
+            _inorder(os, root->left);
+            os << root->key << ' ';
+            _inorder(os, root->right);
+        }
+    }
+
+    void _preorder(ostream& os, node<T>* root) {
+        if(root) {
+            os << root->key << ' ';
+            _inorder(os, root->left);
+            _inorder(os, root->right);
+        }
+    }
+
+    void _postorder(ostream& os, node<T>* root) {
+        if(root) {
+            _inorder(os, root->left);
+            _inorder(os, root->right);
+            os << root->key << ' ';
+        }
+    }
+    node<T>* root;
+};
+
+int main() {
+    bst<int>* b = new bst<int>{};
+
+    // b->insert(12)->insert(5)->insert(18)->insert(2)->insert(9);
+    // b->insert(15)->insert(13)->insert(17)->insert(19);
+
+    b->insert({12, 5, 18, 2, 9, 15, 13, 17, 19});
+    cout << b << endl;
+    cout << (b->search(5) != nullptr) << endl;
+    cout << (b->search(1) != nullptr) << endl;
+    cout << b->max()->key << ' ' << b->min()->key << endl;
+    for(auto const& i : {12, 9, 14, 18}) {
+        auto elem = b->successor(i);
+        if(elem)
+            cout << "(" << i << ", " << elem->key << ") ";
+    }
+    cout << endl;
+
+    for(auto const& i : {9, 2, 5, 15, 18, 12, 19}) {
+        auto elem = b->predecessor(i);
+        if(elem)
+            cout << "(" << i << ", " << elem->key << ") ";
+    }
+    cout << endl;
+    b->remove({5, 12});
+    cout << b << endl;
+
+    return 0;
+}
diff --git a/Year_1/Programming_2/data_structures/circle_double_list.cc b/Year_1/Programming_2/data_structures/circle_double_list.cc
new file mode 100644
index 0000000..f162e57
--- /dev/null
+++ b/Year_1/Programming_2/data_structures/circle_double_list.cc
@@ -0,0 +1,185 @@
+#include<iostream>
+
+using namespace std;
+
+template<typename T>
+struct node {
+    T value;
+    node* prev;
+    node* next;
+};
+
+
+template<typename T>
+class list {
+public:
+    list() : _head{nullptr} {}
+
+    ~list() {
+        node<T>* iter = _head;
+        while(iter->next != _head) {
+            node<T>* tmp = iter;
+            delete tmp;
+            iter = iter->next;
+        }
+        node<T>* tmp = iter;
+        delete tmp;
+    }
+
+    list* push_front(T val) {
+        auto elem = _last();
+        if(!_head) {
+            _head = new node<T>{val, nullptr, nullptr};
+            _head->prev = _head->next = _head;
+        } else {
+            _head = new node<T>{val, elem, _head};
+            elem->next = _head->next->prev = _head;
+        }
+
+        return this;
+    }
+
+    list* push_back(T val) {
+        if(!_head) return this->push_front(val);
+
+        auto last_e = _last();
+        last_e->next = new node<T>{val, last_e, _head};
+        _head->prev = last_e->next;
+
+        return this;
+    }
+
+    list* push_after_value(T val, T newval) {
+        node<T>* iter = _search(val);
+        if(iter) {
+            node<T>* nod = new node<T>{newval, iter, iter->next};
+            iter->next = nod;
+            nod->next->prev = nod;
+        }
+
+        return this;
+    }
+
+    list* push_before_value(T val, T newval) {
+        node<T>* elem = _search(val);
+        if(!elem) return this;
+
+        node<T>* iter = _head;
+
+        if(iter->value == val)
+            return this->push_front(newval);
+
+        while(iter->next != elem)
+            iter = iter->next;
+
+        node<T>* nod = new node<T>{newval, iter, iter->next};
+        iter->next = nod;
+        nod->next->prev = nod;
+
+        return this;
+    }
+
+    list* pop(int val) {
+        node<T>* elem = _search(val);
+        if(!elem) return this;
+
+        if(elem == _head) return this->pop_front();
+
+        node<T>* iter = elem->prev;
+        node<T>* temp = iter->next;
+        iter->next = iter->next->next;
+        iter->next->prev = iter;
+        delete temp;
+
+        return this;
+    }
+
+    list* pop_front() {
+        if(!_head)
+            return this;
+
+        auto last_e = _last();
+        node<T>* elem = _head;
+        _head = _head->next;
+        _head->prev = last_e;
+        last_e->next = _head;
+        delete elem;
+
+        return this;
+    }
+
+    list* pop_back() {
+        if(!_head)
+            return this;
+
+        auto last_e = _last();
+
+        if(last_e == _head) {
+            delete _head;
+            _head = nullptr;
+        } else {
+            auto iter = last_e->prev;
+            delete iter->next;
+            iter->next = _head;
+            _head->prev = iter;
+        }
+
+        return this;
+    }
+
+    void print() {
+        node<T>* iter = _head;
+        while(iter != nullptr) {
+            cout << iter->value << ' ';
+            cout << "[[ " << iter->prev->value << ", ";
+            cout << iter->next->value << " ]],  ";
+            iter = iter->next;
+            if(iter == _head) break;
+        }
+    }
+private:
+    node<T>* _last() {
+        node<T>* iter = _head;
+        while(iter && iter->next != _head) {
+            iter = iter->next;
+        }
+
+        return iter;
+    }
+
+    node<T>* _search(T val) {
+        node<T>* iter = _head;
+        if(iter->value == val) return iter;
+
+        while(iter && iter->value != val) {
+            iter = iter->next;
+            if(iter == _head) return nullptr;
+        }
+
+        return iter;
+    }
+
+    node<T>* _head;
+};
+
+int main() {
+    list<int>* l = new list<int>{};
+    l->push_front(2);
+    l->push_back(1)->push_back(3);
+    l->push_front(5)->push_front(9);
+    l->push_back(0)->push_back(6);
+    l->print(); cout << '\n';
+    l->push_after_value(7, -2);
+    l->push_before_value(9, 10);
+    l->print(); cout << '\n';
+    l->pop_front();
+    l->pop_front();
+    l->pop_back();
+    l->pop_front();
+    l->print(); cout << '\n';
+    l->pop(2);
+    l->print(); cout << '\n';
+
+    delete l;
+    return 0;
+}
diff --git a/Year_1/Programming_2/data_structures/circle_list.cc b/Year_1/Programming_2/data_structures/circle_list.cc
new file mode 100644
index 0000000..2143ac1
--- /dev/null
+++ b/Year_1/Programming_2/data_structures/circle_list.cc
@@ -0,0 +1,189 @@
+#include<iostream>
+
+using namespace std;
+
+template<typename T>
+struct node {
+    T value;
+    node* next;
+};
+
+
+template<typename T>
+class list {
+public:
+    list() : _head{nullptr} {}
+
+    ~list() {
+        node<T>* iter = _head;
+        while(iter->next != _head) {
+            node<T>* tmp = iter;
+            delete tmp;
+            iter = iter->next;
+        }
+        node<T>* tmp = iter;
+        delete tmp;
+    }
+
+    list* push_front(T val) {
+        auto elem = _last();
+        _head = new node<T>{val, _head};
+        if(!elem)
+            elem = _head;
+
+        elem->next = _head;
+
+        return this;
+    }
+
+    list* push_back(T val) {
+        if(!_head) return this->push_front(val);
+
+        auto last_e = _last();
+        last_e->next = new node<T>{val, _head};
+
+        return this;
+    }
+
+    list* push_after_value(T val, T newval) {
+        node<T>* iter = _search(val);
+        if(iter)
+            iter->next = new node<T>{newval, iter->next};
+
+        return this;
+    }
+
+    list* push_before_value(T val, T newval) {
+        node<T>* elem = _search(val);
+        if(!elem) return this;
+
+        node<T>* iter = _head;
+
+        if(iter->value == val)
+            return this->push_front(newval);
+
+        while(iter->next != elem)
+            iter = iter->next;
+
+        iter->next = new node<T>{newval, iter->next};
+
+        return this;
+    }
+
+    list* pop(int val) {
+        node<T>* elem = _search(val);
+        if(!elem) return this;
+
+        node<T>* iter = _head;
+        if(iter == elem) return this->pop_front();
+
+        while(iter->next != elem)
+            iter = iter->next;
+
+        node<T>* temp = iter->next;
+        iter->next = iter->next->next;
+        delete temp;
+
+        return this;
+    }
+
+    list* pop_front() {
+        if(!_head)
+            return this;
+
+        auto last_e = _last();
+
+        if(last_e == _head) {
+            delete _head;
+            _head = nullptr;
+        } else {
+            node<T>* elem = _head;
+            _head = _head->next;
+            last_e->next = _head;
+            delete elem;
+        }
+
+        return this;
+    }
+
+    list* pop_back() {
+        if(!_head)
+            return this;
+
+        node<T>* iter = _head;
+        auto last_e = _last();
+
+        if(last_e == _head) {
+            delete iter;
+            _head = nullptr;
+        } else {
+            while(iter->next != last_e) {
+                iter = iter->next;
+            }
+
+            delete iter->next;
+            iter->next = _head;
+        }
+
+        return this;
+    }
+
+    void print() {
+        node<T>* iter = _head;
+        while(iter) {
+            cout << iter->value << ' ';
+            iter = iter->next;
+            if(iter == _head) break;
+        }
+    }
+private:
+    node<T>* _last() {
+        node<T>* iter = _head;
+        while(iter && iter->next != _head) {
+            iter = iter->next;
+        }
+
+        return iter;
+    }
+
+    node<T>* _search(T val) {
+        node<T>* iter = _head;
+        if(iter->value == val) return iter;
+
+        while(iter && iter->value != val) {
+            iter = iter->next;
+            if(iter == _head) return nullptr;
+        }
+
+        return iter;
+    }
+
+    node<T>* _head;
+};
+
+int main() {
+    list<int>* l = new list<int>{};
+    l->push_before_value(4, 1);
+    l->push_back(4);
+    l->push_back(1);
+    l->push_back(0);
+    l->push_front(2);
+    l->print(); cout << endl;
+    l->pop_back();
+    l->print(); cout << endl;
+    l->pop_front();
+    l->print(); cout << endl;
+    l->pop_back();
+    l->print(); cout << endl;
+    l->push_front(3);
+    l->print(); cout << endl;
+    l->push_after_value(4, 7);
+    l->print(); cout << endl;
+    l->push_before_value(3, 5);
+    l->print(); cout << endl;
+    l->pop(5);
+    l->print(); cout << endl;
+
+    delete l;
+    return 0;
+}
diff --git a/Year_1/Programming_2/data_structures/dfs.cc b/Year_1/Programming_2/data_structures/dfs.cc
new file mode 100644
index 0000000..744f153
--- /dev/null
+++ b/Year_1/Programming_2/data_structures/dfs.cc
@@ -0,0 +1,191 @@
+#include<iostream>
+#include<vector>
+#include<queue>
+#define W -1
+#define G 0
+#define B 1
+
+using namespace std;
+
+template<class H>
+class node {
+public:
+    explicit node(H key, node<H>* next) : _key{key}, _next(next) {}
+    const H& key() const { return _key; }
+    H& key() { return _key; }
+    const node<H>*& next() const { return _next; }
+    node<H>*& next() { return _next; }
+private:
+    H _key;
+    node<H>* _next;
+};
+
+template<class H>
+class list {
+public:
+    list() : _head{nullptr} {}
+    ~list() {
+        while(_head) {
+            auto tmp = _head;
+            _head = _head->next();
+            delete tmp;
+        }
+    }
+    list<H>* push(H val) {
+        auto iter = _head;
+        while(iter && iter->next())
+            iter = iter->next();
+
+        if(!iter)
+            _head = new node<H>{val, nullptr};
+        else
+            iter->next() = new node<H>{val, nullptr};
+
+        return this;
+    }
+    void print() {
+        auto iter = _head;
+        while(iter) {
+            cout << iter->key() << ' ';
+            iter = iter->next();
+        }
+    }
+    vector<H> as_vector() {
+        vector<H> v;
+        auto iter = _head;
+        while(iter) {
+            v.push_back(iter->key());
+            iter = iter->next();
+        }
+        return v;
+    }
+    node<H>* search(H val) {
+        auto iter = _head;
+        while(iter && iter->key() != val) {
+            iter = iter->next();
+        }
+
+        return iter;
+    }
+private:
+    node<H>* _head;
+};
+
+template<class H>
+class graph {
+private:
+    int _len, _nodes, _edges;
+    int* _parents;
+    int* _radixes;
+    int* _distances;
+    int* _finishes;
+    int* _colors;
+    int _time;
+    int _current;
+    H** _k; // it works like a dictionary, it saves the keys
+    list<int>** _adj;
+    int _index(H val) {
+        for(int i = 0; i < _nodes; ++i)
+            if(*_k[i] == val) return i;
+
+        return -1;
+    }
+    void _dfsvisit(int u) {
+        _colors[u] = G;
+        _distances[u] = _time++;
+        _radixes[u] = _current;
+        for(auto const& v : _adj[u]->as_vector()) {
+            if(_colors[v] == W) {
+                _parents[v] = u;
+                _dfsvisit(v);
+            }
+        }
+        _colors[u] = B;
+        _finishes[u] = _time++;
+    }
+public:
+    graph(int len) : _len{len}, _nodes{0}, _edges{0} {
+        _k = new H*[len];
+        _adj = new list<int>*[_len];
+        _parents = new int[_len];
+        _radixes = new int[_len];
+        _distances = new int[_len];
+        _finishes = new int[_len];
+        _colors = new int[_len];
+        for(int i = 0; i < _len; ++i) {
+            _k[i] = nullptr;
+            _adj[i] = new list<int>{};
+        }
+    }
+
+    graph<H>* add_node(H k) {
+        if(_nodes == _len) return this;
+        if(_index(k) >= 0) return this; // node is already there
+
+        _k[_nodes++] = new H(k);
+
+        return this;
+    }
+
+
+    void dfs() {
+        _time = 0;
+        for(int i = 0; i < _nodes; ++i) {
+            _colors[i] = W;
+            _parents[i] = -1;
+        }
+
+        for(int i = 0; i < _nodes; ++i) {
+            if(_colors[i] == W) {
+                _current = i;
+                _dfsvisit(i);
+            }
+        }
+        for(int i = 0; i < _nodes; ++i) {
+            cout << *_k[i] << "(" << _distances[i]+1 << ',' << _finishes[i]+1 << ")" << endl;
+        }
+    }
+
+    graph<H>* add_edge(H x, H y) {
+        int i = _index(x);
+        int j = _index(y);
+        if(i < 0 || j < 0) return this;
+
+        if(!_adj[i]->search(j)) {
+            _adj[i]->push(j);
+            _edges++;
+        }
+
+        return this;
+    }
+
+    void print() {
+        for(int i = 0; i < _nodes; ++i) {
+            cout << "(" << i << ", " << *_k[i] << "): ";
+            for(auto const& j : _adj[i]->as_vector())
+                cout << "(" << j << ", " << *_k[j] << "), ";
+            cout << '\n';
+        } 
+    }
+};
+
+
+int main() {
+    graph<char>* g = new graph<char>(6);
+    g->add_node('u')->add_node('v')->add_node('x')->add_node('y');
+    g->add_node('w')->add_node('z');
+    g->add_edge('u', 'v');
+    g->add_edge('u', 'x');
+    g->add_edge('x', 'v');
+    g->add_edge('y', 'x');
+    g->add_edge('v', 'y');
+    g->add_edge('w', 'y');
+    g->add_edge('w', 'z');
+    g->add_edge('z', 'z');
+
+    g->print();
+    g->dfs();
+
+    delete g;
+    return 0;
+}
diff --git a/Year_1/Programming_2/data_structures/graph.cc b/Year_1/Programming_2/data_structures/graph.cc
new file mode 100644
index 0000000..12837be
--- /dev/null
+++ b/Year_1/Programming_2/data_structures/graph.cc
@@ -0,0 +1,164 @@
+#include<iostream>
+#include<vector>
+
+using namespace std;
+
+template<class H>
+class node {
+public:
+    explicit node(H key, node<H>* next) : _key{key}, _next(next) {}
+    const H& key() const { return _key; }
+    H& key() { return _key; }
+    const node<H>*& next() const { return _next; }
+    node<H>*& next() { return _next; }
+private:
+    H _key;
+    node<H>* _next;
+};
+
+template<class H>
+class list {
+public:
+    list() : _head{nullptr} {}
+    ~list() {
+        while(_head) {
+            auto tmp = _head;
+            _head = _head->next();
+            delete tmp;
+        }
+    }
+    list<H>* push(H val) {
+        auto iter = _head;
+        while(iter && iter->next())
+            iter = iter->next();
+
+        if(!iter)
+            _head = new node<H>{val, nullptr};
+        else
+            iter->next() = new node<H>{val, nullptr};
+
+        return this;
+    }
+    list<H>* pop(H val) {
+        auto elem = search(val);
+        if(!elem)
+            return this;
+
+        auto iter = _head;
+        // This is the case when head is the element we want to pop
+        if(iter == elem) {
+            delete _head;
+            _head = nullptr;
+            return this;
+        }
+
+        while(iter && iter->next() != elem)
+            iter = iter->next();
+
+        auto tmp = iter->next();
+        if(iter->next()->next()) { 
+            iter->next() = iter->next()->next();
+        } else { // the element we want to pop is the tail
+            iter->next() = nullptr;
+        }
+        delete tmp;
+
+        return this;
+    }
+    void print() {
+        auto iter = _head;
+        while(iter) {
+            cout << iter->key() << ' ';
+            iter = iter->next();
+        }
+    }
+    vector<H> as_vector() {
+        vector<H> v;
+        auto iter = _head;
+        while(iter) {
+            v.push_back(iter->key());
+            iter = iter->next();
+        }
+        return v;
+    }
+    node<H>* search(H val) {
+        auto iter = _head;
+        while(iter && iter->key() != val) {
+            iter = iter->next();
+        }
+
+        return iter;
+    }
+private:
+    node<H>* _head;
+};
+
+template<class H>
+class graph {
+public:
+
+private:
+    int _len, _nodes, _edges;
+    H **_k;
+    list<int> **_adj;
+    int _index(H val) {
+        for(int i = 0; i < _nodes; ++i)
+            if(*_k[i] == val) return i;
+
+        return -1;
+    }
+public:
+    graph(int len) : _len{len}, _nodes{0}, _edges{0} {
+        _k = new H*[len];
+        _adj = new list<int>*[_len];
+        for(int i = 0; i < _len; ++i) {
+            _k[i] = nullptr;
+            _adj[i] = new list<int>{};
+        }
+    }
+
+    graph<H>* add_node(H k) {
+        if(_nodes == _len) return this;
+        if(_index(k) >= 0) return this; // node is already there
+
+        _k[_nodes++] = new H(k);
+
+        return this;
+    }
+
+    graph<H>* add_edge(H x, H y) {
+        int i = _index(x);
+        int j = _index(y);
+        if(i < 0 || j < 0) return this;
+
+        if(!_adj[i]->search(j)) {
+            _adj[i]->push(j);
+            _edges++;
+        }
+
+        return this;
+    }
+
+    void print() {
+        for(int i = 0; i < _nodes; ++i) {
+            cout << "(" << i << ", " << *_k[i] << "): ";
+            for(auto const& j : _adj[i]->as_vector())
+                cout << "(" << j << ", " << *_k[j] << "), ";
+            cout << '\n';
+        } 
+    }
+};
+
+
+int main() {
+    graph<string>* g = new graph<string>(5);
+    g->add_node("hello")->add_node("greg")->add_node("yes");
+    g->add_node("nop")->add_node("ok");
+    g->add_edge("hello", "ok");
+    g->add_edge("ok", "yes")->add_edge("yes", "ok")->add_edge("yes", "yes");
+    g->add_edge("yes", "nop");
+    g->print();
+
+    delete g;
+    return 0;
+}
diff --git a/Year_1/Programming_2/data_structures/graph_stl.cc b/Year_1/Programming_2/data_structures/graph_stl.cc
new file mode 100644
index 0000000..5381747
--- /dev/null
+++ b/Year_1/Programming_2/data_structures/graph_stl.cc
@@ -0,0 +1,221 @@
+#include<iostream>
+#include<vector>
+#include<algorithm>
+#include<queue>
+#include<stack>
+#define INF 99999999
+#define W -1
+#define G 0
+#define B 1
+
+using namespace std;
+
+template<class H>
+class graph {
+public:
+    graph(int len) : _len{len}, _nodes{0}, _edges{0} {
+        _k = new H*[len];
+        _adj = new vector<int>[len];
+        _colors = new int[len];
+        _d = new int[len];
+        _f = new int[len];
+        _p = new int[len];
+
+        for(int i = 0; i < len; ++i) {
+            _k[i] = nullptr;
+        }
+    }
+    ~graph() {
+        delete[] _k;
+        delete[] _adj;
+    }
+
+    graph<H>* add_node(H x) {
+        if(_index(x) > -1) return this;
+        if(_nodes == _len) return this;
+        _k[_nodes++] = new H(x);
+
+        return this;
+    }
+    graph<H>* add_edge(H u, H v) {
+        int i = _index(u);
+        int j = _index(v);
+        if(i < 0 || j < 0) return this;
+
+        if(find(_adj[i].begin(), _adj[i].end(), j) == _adj[i].end()) {
+            _adj[i].push_back(j);
+        }
+        return this;
+    }
+    void print() {
+        for(int i = 0; i < _nodes; ++i) {
+            cout << "(" << *_k[i] << ", " << i << "): ";
+            for(auto const& j : _adj[i]) {
+                cout << "(" << *_k[j] << ", " << j << ") ";
+            }
+            cout << endl;
+        }
+    }
+    void dfsvisit(int u, bool visited[]) {
+        visited[u] = true;
+        cout << "(" << *_k[u] << ", " << u << ") ";
+        for(auto const& i : _adj[u]) {
+            if(!visited[i])
+                dfsvisit(i, visited);
+        }
+    }
+    int dfsvisit(int u) {
+        int cycle = 0;
+        _colors[u] = G;
+        _d[u] = _time++;
+
+        for(auto const& j : _adj[u]) {
+            if(_colors[j] == W)
+                cycle |= dfsvisit(j);
+        }
+
+        _colors[u] = B;
+        _stack.push(u);
+        _f[u] = _time++;
+        return cycle;
+    }
+    int dfs() {
+        int cycle = 0;
+        for(int i = 0; i < _nodes; ++i) {
+            _colors[i] = W;
+        }
+        _time = 0;
+        for(int i = 0; i < _nodes; ++i) {
+            if(_colors[i] == W)
+                cycle |= dfsvisit(i);
+            else if(_colors[i] == G)
+                cycle = 1;
+        }
+        for(int i = 0; i < _nodes; ++i) {
+            cout << "(" << *_k[i] << ", " << i << "): [" << _d[i] << "," << _f[i] << "]" << endl;
+        }
+        return cycle;
+    }
+
+    void top_sort() {
+        int cycle = dfs();
+        if(cycle) {
+            cout << "cyclic graph!" << endl;
+            return;
+        }
+        int* s = new int[_nodes];
+        for(int i = 0; i < _nodes; ++i) s[i] = i;
+        _sort(s, _nodes, _f);
+        for(int i = 0; i < _nodes; ++i) {
+            cout << "(" << s[i] << ", " << _f[s[i]] << ") ";
+        }
+
+    }
+
+    void bfs(H v) {
+        int s = _index(v);
+        if(s < 0) return;
+
+        for(int i = 0; i < _nodes; ++i) {
+            _colors[i] = W;
+            _d[i] = INF;
+            _p[i] = -1;
+        }
+        _colors[s] = G;
+        _d[s] = 0;
+        queue<int> q;
+        q.push(s);
+        while(!q.empty()) {
+            int u = q.front();
+            q.pop();
+            for(auto const& j : _adj[u]) {
+                if(_colors[j] == W) {
+                    _colors[j] = G;
+                    _d[j] = _d[u]+1;
+                    _p[j] = u;
+                    q.push(j);
+                }
+            }
+            _colors[u] = B;
+        }
+        for(int i = 0; i < _nodes; ++i) {
+            cout << "(" << *_k[i] << ", " << i << "): [" << _d[i] << "]" << endl;
+        }
+    }
+    void ssc() {
+        dfs();
+        cout << endl << endl;
+        auto gr = _transpose();
+        bool* visited = new bool[_nodes];
+        for(int i = 0; i < _nodes; ++i)
+            visited[i] = false;
+
+        while(!_stack.empty()) {
+            int v = _stack.top();
+            _stack.pop();
+            if(!visited[v]) {
+                gr->dfsvisit(v, visited);
+                cout << endl;
+            }
+        }
+        delete[] visited;
+    }
+private:
+    graph<H>* _transpose() {
+        graph<H>* g = new graph<H>{_len};
+        for(int i = 0; i < _nodes; ++i) {
+            g->add_node(*_k[i]);
+        }
+
+        for(int i = 0; i < _nodes; ++i) {
+            for(auto const& j : _adj[i]) {
+                g->add_edge(j, i);
+            }
+        }
+
+        return g;
+    }
+    void _sort(int* d, int n, int* s) {
+        for(int i = -1; i < n; ++i) {
+            int j = i-1;
+            while(j > -1 && s[d[j+1]]>s[d[j]]) {
+                swap(d[s[j+1]], d[s[j]]);
+                --j;
+            }
+        }
+    }
+    int _index(H x) {
+        for(int i = 0; i < _nodes; ++i)
+            if(*_k[i] == x) return i;
+
+        return -1;
+    }
+    stack<int> _stack;
+    H** _k;
+    vector<int>* _adj;
+    int _len, _nodes, _edges;
+    int* _colors;
+    int _time;
+    int* _d;
+    int* _f;
+    int* _p;
+};
+
+int main() {
+    graph<int>* g = new graph<int>{5};
+    for(auto const& i : {0, 1, 2, 3, 4})
+        g->add_node(i);
+    g->add_edge(1, 0);
+    g->add_edge(2, 1);
+    g->add_edge(0, 2);
+    g->add_edge(0, 3);
+    g->add_edge(3, 4);
+    //g->print();
+    cout << endl;
+    //g->top_sort();
+    g->ssc();
+    cout << endl;
+    //g->bfs(0);
+    delete g;
+    return 0;
+}
diff --git a/Year_1/Programming_2/data_structures/list.cc b/Year_1/Programming_2/data_structures/list.cc
new file mode 100644
index 0000000..8ddcbf9
--- /dev/null
+++ b/Year_1/Programming_2/data_structures/list.cc
@@ -0,0 +1,164 @@
+#include<iostream>
+
+using namespace std;
+
+template<typename T>
+struct node {
+    T value;
+    node* next;
+};
+
+
+template<typename T>
+class list {
+public:
+    list() : _head{nullptr} {}
+
+    ~list() {
+        while(_head) {
+            node<T>* tmp = _head->next;
+            delete tmp;
+            _head = tmp;
+        }
+    }
+
+    list* push_front(T val) {
+        _head = new node<T>{val, _head};
+
+        return this;
+    }
+
+    list* push_back(T val) {
+        if(!_head) return this->push_front(val);
+
+        node<T>* iter = _head;
+        while(iter->next) {
+            iter = iter->next;
+        }
+        iter->next = new node<T>{val, nullptr};
+
+        return this;
+    }
+
+    list* push_after_value(T val, T newval) {
+        node<T>* iter = _search(val);
+        if(iter)
+            iter->next = new node<T>{newval, iter->next};
+
+        return this;
+    }
+
+    list* push_before_value(T val, T newval) {
+        node<T>* elem = _search(val);
+        if(!elem) return this;
+
+        node<T>* iter = _head;
+
+        if(iter->value == val)
+            return this->push_front(newval);
+
+        while(iter->next != elem)
+            iter = iter->next;
+
+        iter->next = new node<T>{newval, iter->next};
+
+        return this;
+    }
+
+    list* pop(int val) {
+        node<T>* elem = _search(val);
+        if(!elem) return this;
+
+        node<T>* iter = _head;
+        if(iter == elem) return this->pop_front();
+
+        while(iter->next != elem)
+            iter = iter->next;
+
+        node<T>* temp = iter->next;
+        iter->next = iter->next->next;
+        delete temp;
+
+        return this;
+    }
+
+    list* pop_front() {
+        if(!_head)
+            return this;
+
+        node<T>* elem = _head;
+        _head = _head->next;
+        delete elem;
+
+        return this;
+    }
+
+    list* pop_back() {
+        if(!_head)
+            return this;
+
+        node<T>* iter = _head;
+
+        while(iter->next && iter->next->next) {
+            iter = iter->next;
+        }
+
+        if(!iter->next) {
+            delete iter;
+            _head = nullptr;
+        } else if(iter->next->next) {
+            delete iter->next->next;
+        } else {
+            delete iter->next;
+        }
+
+        iter->next = nullptr;
+
+        return this;
+    }
+
+    void print() {
+        node<T>* iter = _head;
+        while(iter) {
+            cout << iter->value << ' ';
+            iter = iter->next;
+        }
+    }
+private:
+    node<T>* _search(T value) {
+        node<T>* iter = _head;
+        while(iter && iter->value != value)
+            iter = iter->next;
+
+        return iter;
+    }
+
+    node<T>* _head;
+};
+
+int main() {
+    list<int>* l = new list<int>{};
+    l->push_front(2)->push_front(1);
+    l->print(); cout << endl;
+    l->push_back(5);
+    l->print(); cout << endl;
+    l->push_back(10)->push_back(15);
+    l->print(); cout << endl;
+    l->push_after_value(5, 6);
+    l->print(); cout << endl;
+    l->push_before_value(5, 4);
+    l->print(); cout << endl;
+    l->push_before_value(4, 3);
+    l->print(); cout << endl;
+    l->pop_back();
+    l->print(); cout << endl;
+    l->pop_front();
+    l->print(); cout << endl;
+    l->push_front(1);
+    l->print(); cout << endl;
+    l->pop(1);
+    l->print(); cout << endl;
+
+    delete l;
+    return 0;
+}
diff --git a/Year_1/Programming_2/data_structures/list_double.cc b/Year_1/Programming_2/data_structures/list_double.cc
new file mode 100644
index 0000000..fa0af26
--- /dev/null
+++ b/Year_1/Programming_2/data_structures/list_double.cc
@@ -0,0 +1,182 @@
+#include<iostream>
+
+using namespace std;
+
+template<typename T>
+struct node {
+    T value;
+    node* prev;
+    node* next;
+};
+
+
+template<typename T>
+class list {
+public:
+    list() : _head{nullptr} {}
+
+    ~list() {
+        while(_head != nullptr) {
+            node<T>* tmp = _head->next;
+            delete tmp;
+            _head = tmp;
+        }
+    }
+
+    list* push_front(T val) {
+        if(!_head) {
+            _head = new node<T>{val, nullptr, nullptr};
+        } else {
+            _head = new node<T>{val, nullptr, _head};
+            _head->next->prev = _head;
+        }
+
+        return this;
+    }
+
+    list* push_back(T val) {
+        if(!_head) return this->push_front(val);
+
+        node<T>* iter = _head;
+        while(iter->next) {
+            iter = iter->next;
+        }
+        iter->next = new node<T>{val, iter, nullptr};
+
+        return this;
+    }
+
+    list* push_after_value(T val, T newval) {
+        node<T>* elem = _search(val);
+        if(elem) {
+            node<T>* nod = new node<T>{newval, elem, elem->next};
+            elem->next = nod;
+            nod->next->prev = nod;
+        }
+
+        return this;
+    }
+
+    list* push_before_value(T val, T newval) {
+        node<T>* elem = _search(val);
+        if(!elem) return this;
+
+        node<T>* iter = _head;
+
+        if(iter->value == val)
+            return this->push_front(newval);
+
+        while(iter->next != elem)
+            iter = iter->next;
+
+        node<T>* nod = new node<T>{newval, iter, iter->next};
+        iter->next = nod;
+        nod->next->prev = nod;
+
+        return this;
+    }
+
+    list* pop(int val) {
+        node<T>* elem = _search(val);
+        if(!elem) return this;
+
+        if(elem == _head) return this->pop_front();
+
+        node<T>* iter = elem->prev;
+        node<T>* temp = iter->next;
+        iter->next = iter->next->next;
+        iter->next->prev = iter;
+        delete temp;
+
+        return this;
+    }
+
+    list* pop_front() {
+        if(!_head)
+            return this;
+
+        node<T>* elem = _head;
+        _head = _head->next;
+        _head->prev = nullptr;
+        delete elem;
+
+        return this;
+    }
+
+    list* pop_back() {
+        if(!_head)
+            return this;
+
+        node<T>* iter = _last()->prev;
+
+        if(iter->next == nullptr) {
+            delete iter;
+            _head = nullptr;
+        } else if(iter->next->next) {
+            delete iter->next->next;
+        } else {
+            delete iter->next;
+        }
+
+        iter->next = nullptr;
+
+        return this;
+    }
+
+    void print() {
+        node<T>* iter = _head;
+        while(iter) {
+            cout << iter->value << ' ';
+            cout << "[[ " << (iter->prev!=nullptr ? iter->prev->value : -1) << ", ";
+            cout << (iter->next!=nullptr ? iter->next->value : -1) << " ]],  ";
+            iter = iter->next;
+        }
+    }
+private:
+    node<T>* _last() {
+        node<T>* iter = _head;
+        while(iter->next) {
+            iter = iter->next;
+        }
+
+        return iter;
+    }
+
+    node<T>* _search(T value) {
+        node<T>* iter = _head;
+        while(iter && iter->value != value)
+            iter = iter->next;
+
+        return iter;
+    }
+
+    node<T>* _head;
+};
+
+int main() {
+    list<int>* l = new list<int>{};
+    l->push_front(2)->push_front(1);
+    l->print(); cout << endl;
+    l->push_back(5);
+    l->print(); cout << endl;
+    l->push_back(10)->push_back(15);
+    l->print(); cout << endl;
+    l->push_after_value(5, 6);
+    l->print(); cout << endl;
+    l->push_after_value(5, 7);
+    l->print(); cout << endl;
+    l->push_before_value(5, 4);
+    l->print(); cout << endl;
+    l->push_before_value(5, 3);
+    l->print(); cout << endl;
+    l->pop_back();
+    l->print(); cout << endl;
+    l->pop_front();
+    l->print(); cout << endl;
+    l->pop(2);
+    l->print(); cout << endl;
+
+    delete l;
+
+    return 0;
+}
diff --git a/Year_1/Programming_2/data_structures/matrix-graph.cc b/Year_1/Programming_2/data_structures/matrix-graph.cc
new file mode 100644
index 0000000..a644ec1
--- /dev/null
+++ b/Year_1/Programming_2/data_structures/matrix-graph.cc
@@ -0,0 +1,81 @@
+#include<iostream>
+#include<list>
+
+using namespace std;
+
+template<class H>
+class matrix_graph {
+public:
+    ~matrix_graph() {
+        delete[] _m;
+        delete[] _k;
+    }
+    matrix_graph(int len) : _len{len}, _nodes{0}, _edges{0} {
+        _m = new int*[len];
+        _k = new H*[len];
+        for(int i = 0; i < len; ++i) {
+            _m[i] = new int[len];
+            _k[i] = nullptr;
+            for(int j = 0; j < len; ++j)
+                _m[i][j] = 0;
+        }
+    }
+
+    matrix_graph<H>* add_node(H k) {
+        if(_len == _nodes) return this; // no more space for new nodes
+        if(_index(k) > -1) return this; // nodes already exists
+
+        _k[_nodes++] = new H(k);
+
+        return this;
+    }
+
+    matrix_graph<H>* add_edge(H x, H y) {
+        int i = _index(x);
+        int j = _index(y);
+        if(i < 0 || j < 0) return this;
+        if(!_m[i][j]) {
+            _m[i][j] = 1;
+            _edges++;
+        }
+        return this;
+    }
+    void print() {
+        for(int i = 0; i < _len; ++i) {
+            cout << i << ' ' << *_k[i] << ": ";
+            for(int j = 0; j < _len; ++j) {
+                if(_m[i][j])
+                    cout << *_k[j] << ' ';
+            }
+            cout << '\n';
+        }
+        cout << endl;
+        for(int i = 0; i < _len; ++i) {
+            for(int j = 0; j < _len; ++j) {
+                cout << _m[i][j] << ' ';
+            }
+            cout << '\n';
+        }
+    }
+private:
+    int _len, _nodes, _edges;
+    int** _m;
+    H** _k;
+    int _index(H x) {
+        for(int i = 0; i < _nodes; ++i)
+            if(*_k[i] == x) return i;
+        return -1;
+    }
+};
+
+int main() {
+    matrix_graph<string>* g = new matrix_graph<string>(5);
+    g->add_node("hello")->add_node("greg")->add_node("yes");
+    g->add_node("nop")->add_node("ok");
+    g->add_edge("hello", "ok");
+    g->add_edge("ok", "yes")->add_edge("yes", "ok")->add_edge("yes", "yes");
+    g->add_edge("yes", "nop");
+    g->print();
+    delete g;
+    return 0;
+}
diff --git a/Year_1/Programming_2/data_structures/queue.cc b/Year_1/Programming_2/data_structures/queue.cc
new file mode 100644
index 0000000..8398459
--- /dev/null
+++ b/Year_1/Programming_2/data_structures/queue.cc
@@ -0,0 +1,72 @@
+#include<iostream>
+
+using namespace std;
+
+template<typename T>
+struct node {
+    T value;
+    node<T>* next;
+};
+
+template<class T>
+class queue {
+public:
+    queue() : _head{nullptr} {}
+
+    ~queue() {
+        auto iter = _head;
+        while(iter) {
+            delete iter;
+            iter = iter->next;
+        }
+    }
+
+    queue<T>* enqueue(T val) {
+
+        if(!_head) {
+            _head = new node<T>{val, nullptr};
+            _tail = _head;
+        } else {
+            _tail->next = new node<T>{val, nullptr};
+            _tail = _tail->next;
+        }
+
+        return this;
+    }
+
+    node<T>* dequeue() {
+        if(!_head) return nullptr;
+        auto iter = _head;
+        delete _head;
+        _head = iter->next;
+        return iter;
+    }
+
+    void print() {
+        auto iter = _head;
+        while(iter) {
+            cout << iter->value << ' ';
+            iter = iter->next;
+        }
+        cout << endl;
+    }
+private:
+    node<T>* _head;
+    node<T>* _tail;
+};
+
+int main() {
+    queue<int>* q = new queue<int>();
+
+    q->dequeue();
+    q->enqueue(4)->enqueue(2)->enqueue(8);
+    q->print();
+    auto e = q->dequeue();
+    if(e)
+        cout << e->value << endl;
+    q->enqueue(1);
+    q->print();
+
+    delete q;
+    return 0;
+}
diff --git a/Year_1/Programming_2/data_structures/queue_w_array.cc b/Year_1/Programming_2/data_structures/queue_w_array.cc
new file mode 100644
index 0000000..fb92d68
--- /dev/null
+++ b/Year_1/Programming_2/data_structures/queue_w_array.cc
@@ -0,0 +1,66 @@
+#include<iostream>
+
+using namespace std;
+
+template<class H>
+class queue {
+public:
+    queue(int n) : _size{n}, _counter{0}, _head{0}, _tail{0} {
+        _arr = new H[n];
+    }
+    ~queue() {
+        delete _arr;
+    }
+    bool is_empty() {
+        return _counter == 0;
+    }
+    bool is_full() {
+        return _counter == _size;
+    }
+
+    queue<H>* enqueue(H x) {
+        if(!is_full()) {
+            _arr[_tail] = x;
+            if(_tail == _size-1)
+                _tail = 0;
+            else
+                ++_tail;
+            _counter++;
+        }
+
+        return this;
+    }
+    H dequeue() {
+        if(is_empty()) return -1;
+        H x = _arr[_head];
+
+        if(_head == _size-1)
+            _head = 0;
+        else
+            ++_head;
+
+        _counter--;
+        return x;
+    }
+private:
+    H* _arr;
+    int _size;
+    short _counter;
+    short _head;
+    short _tail;
+};
+
+int main() {
+    queue<int>* q = new queue<int>{4};
+    q->enqueue(5)->enqueue(13)->enqueue(3);
+    cout << q->dequeue() << '\n';
+    q->enqueue(4)->enqueue(6)->enqueue(7);
+    q->dequeue();
+    q->enqueue(7);
+
+    for(int i = 0; i < 6; ++i) {
+        cout << q->dequeue() << ' ';
+    }
+    delete q;
+    return 0;
+}
diff --git a/Year_1/Programming_2/data_structures/stack.cc b/Year_1/Programming_2/data_structures/stack.cc
new file mode 100644
index 0000000..ffff780
--- /dev/null
+++ b/Year_1/Programming_2/data_structures/stack.cc
@@ -0,0 +1,70 @@
+#include<iostream>
+
+using namespace std;
+
+template<typename T>
+struct node {
+    T value;
+    node<T>* next;
+};
+
+template<class T>
+class stack {
+public:
+    stack() : _head{nullptr} {}
+
+    ~stack() {
+        auto iter = _head;
+        while(iter) {
+            delete iter;
+            iter = iter->next;
+        }
+    }
+
+    stack<T>* push(T val) {
+
+        if(!_head) {
+            _head = new node<T>{val, nullptr};
+        } else {
+            _head = new node<T>{val, _head};
+        }
+
+        return this;
+    }
+
+    node<T>* pop() {
+        if(!_head) return nullptr;
+        node<T>* elem = _head;
+        delete _head;
+        _head = elem->next;
+
+        return elem;
+    }
+
+    void print() {
+        auto iter = _head;
+        while(iter) {
+            cout << iter->value << ' ';
+            iter = iter->next;
+        }
+        cout << endl;
+    }
+private:
+    node<T>* _head;
+};
+
+int main() {
+    stack<int>* s = new stack<int>();
+
+    s->pop();
+    s->push(4)->push(2)->push(8);
+    s->print();
+    auto e = s->pop();
+    if(e)
+        cout << e->value << endl;
+    s->push(1);
+    s->print();
+
+    delete s;
+    return 0;
+}
diff --git a/Year_1/Programming_2/data_structures/stack_w_array.cc b/Year_1/Programming_2/data_structures/stack_w_array.cc
new file mode 100644
index 0000000..c20db90
--- /dev/null
+++ b/Year_1/Programming_2/data_structures/stack_w_array.cc
@@ -0,0 +1,50 @@
+#include<iostream>
+
+using namespace std;
+
+template<class H>
+class stack {
+public:
+    stack(int n) : _size{n}, _top{-1} {
+        _arr = new H[n];
+    }
+    ~stack() {
+        delete _arr;
+    }
+    bool is_empty() {
+        return _top == -1;
+    }
+    bool is_full() {
+        return _top == _size-1;
+    }
+    stack<H>* push(H x) {
+        if(!is_full()) {
+            _arr[++_top] = x;
+        }
+        return this;
+    }
+    H pop() {
+        if(is_empty()) 
+            return -1;
+        _top--;
+        return _arr[_top+1];
+    }
+private:
+    int _size;
+    H* _arr;
+    short _top;
+};
+
+int main() {
+    stack<int>* s = new stack<int>{7};
+
+    s->push(15)->push(6)->push(2)->push(9)->push(17)->push(3);
+    cout << s->pop() << '\n';
+    s->push(18)->push(19)->push(12);
+
+    for(int i = 0; i < 7; ++i)
+        cout << s->pop() << ' ';
+
+    delete s;
+    return 0;
+}
diff --git a/Year_1/Programming_2/data_structures/top-sort.cc b/Year_1/Programming_2/data_structures/top-sort.cc
new file mode 100644
index 0000000..7441ee9
--- /dev/null
+++ b/Year_1/Programming_2/data_structures/top-sort.cc
@@ -0,0 +1,212 @@
+
+#include<iostream>
+#include<vector>
+#include<queue>
+#define W -1
+#define G 0
+#define B 1
+
+using namespace std;
+
+template<class H>
+class node {
+public:
+    explicit node(H key, node<H>* next) : _key{key}, _next(next) {}
+    const H& key() const { return _key; }
+    H& key() { return _key; }
+    const node<H>*& next() const { return _next; }
+    node<H>*& next() { return _next; }
+private:
+    H _key;
+    node<H>* _next;
+};
+
+template<class H>
+class list {
+public:
+    list() : _head{nullptr} {}
+    ~list() {
+        while(_head) {
+            auto tmp = _head;
+            _head = _head->next();
+            delete tmp;
+        }
+    }
+    list<H>* push(H val) {
+        auto iter = _head;
+        while(iter && iter->next())
+            iter = iter->next();
+
+        if(!iter)
+            _head = new node<H>{val, nullptr};
+        else
+            iter->next() = new node<H>{val, nullptr};
+
+        return this;
+    }
+    void print() {
+        auto iter = _head;
+        while(iter) {
+            cout << iter->key() << ' ';
+            iter = iter->next();
+        }
+    }
+    vector<H> as_vector() {
+        vector<H> v;
+        auto iter = _head;
+        while(iter) {
+            v.push_back(iter->key());
+            iter = iter->next();
+        }
+        return v;
+    }
+    node<H>* search(H val) {
+        auto iter = _head;
+        while(iter && iter->key() != val) {
+            iter = iter->next();
+        }
+
+        return iter;
+    }
+private:
+    node<H>* _head;
+};
+
+template<class H>
+class graph {
+private:
+    int _len, _nodes, _edges;
+    int* _parents;
+    int* _radixes;
+    int* _distances;
+    int* _finishes;
+    int* _colors;
+    int _time;
+    int _current;
+    H** _k; // it works like a dictionary, it saves the keys
+    list<int>** _adj;
+    int _index(H val) {
+        for(int i = 0; i < _nodes; ++i)
+            if(*_k[i] == val) return i;
+
+        return -1;
+    }
+    bool _dfsvisit(int u) {
+        bool cycle = false;
+        _colors[u] = G;
+        _distances[u] = _time++;
+        _radixes[u] = _current;
+        for(auto const& v : _adj[u]->as_vector()) {
+            if(_colors[v] == W) {
+                _parents[v] = u;
+                _dfsvisit(v);
+            } else if(_colors[v] == G) {
+                cycle = true;
+            }
+        }
+        _colors[u] = B;
+        _finishes[u] = _time++;
+        return cycle;
+    }
+public:
+    graph(int len) : _len{len}, _nodes{0}, _edges{0} {
+        _k = new H*[len];
+        _adj = new list<int>*[_len];
+        _parents = new int[_len];
+        _radixes = new int[_len];
+        _distances = new int[_len];
+        _finishes = new int[_len];
+        _colors = new int[_len];
+        for(int i = 0; i < _len; ++i) {
+            _k[i] = nullptr;
+            _adj[i] = new list<int>{};
+        }
+    }
+
+    graph<H>* add_node(H k) {
+        if(_nodes == _len) return this;
+        if(_index(k) >= 0) return this; // node is already there
+
+        _k[_nodes++] = new H(k);
+
+        return this;
+    }
+
+
+    bool dfs() {
+        bool cycle = 0;
+        _time = 0;
+        for(int i = 0; i < _nodes; ++i) {
+            _colors[i] = W;
+            _parents[i] = -1;
+        }
+
+        for(int i = 0; i < _nodes; ++i) {
+            if(_colors[i] == W) {
+                _current = i;
+                cycle |= _dfsvisit(i);
+            }
+        }
+        for(int i = 0; i < _nodes; ++i) {
+            cout << *_k[i] << "(" << _distances[i]+1 << ',' << _finishes[i]+1 << ")" << endl;
+        }
+        return cycle;
+    }
+
+    void top_sort() {
+        bool cycle = dfs();
+        if(cycle) {
+            cerr << "Grafo ciclico\n";
+            return;
+        }
+        vector<int> s(_finishes, _finishes+_nodes);
+        sort(begin(s), end(s));
+        for(auto const& i : s) {
+            cout << "(" << i << ", " << _finishes[i] << ") ";
+        }
+    }
+
+    graph<H>* add_edge(H x, H y) {
+        int i = _index(x);
+        int j = _index(y);
+        if(i < 0 || j < 0) return this;
+
+        if(!_adj[i]->search(j)) {
+            _adj[i]->push(j);
+            _edges++;
+        }
+
+        return this;
+    }
+
+    void print() {
+        for(int i = 0; i < _nodes; ++i) {
+            cout << "(" << i << ", " << *_k[i] << "): ";
+            for(auto const& j : _adj[i]->as_vector())
+                cout << "(" << j << ", " << *_k[j] << "), ";
+            cout << '\n';
+        } 
+    }
+};
+
+
+int main() {
+    graph<char>* g = new graph<char>(6);
+    g->add_node('u')->add_node('v')->add_node('x')->add_node('y');
+    g->add_node('w')->add_node('z');
+    g->add_edge('u', 'v');
+    g->add_edge('u', 'x');
+    g->add_edge('x', 'v');
+    g->add_edge('y', 'x');
+    g->add_edge('v', 'y');
+    g->add_edge('w', 'y');
+    g->add_edge('w', 'z');
+    g->add_edge('z', 'z');
+
+    g->print();
+    g->dfs();
+    g->top_sort();
+
+    delete g;
+    return 0;
+}
diff --git a/Year_1/Programming_2/exercises/carattere-maggiore.cc b/Year_1/Programming_2/exercises/carattere-maggiore.cc
new file mode 100644
index 0000000..2e89fcd
--- /dev/null
+++ b/Year_1/Programming_2/exercises/carattere-maggiore.cc
@@ -0,0 +1,40 @@
+#include<iostream>
+#include<map>
+#include<fstream>
+
+using namespace std;
+
+
+
+int main() {
+    ifstream in("input.txt");
+    ofstream out("output.txt");
+
+    for(int ts = 0; ts < 100; ++ts) {
+        string line;
+        getline(in, line);
+        map<char, int> chs;
+        for(auto const& c : line) {
+            if(c == ' ') continue;
+            if(chs.find(c) != chs.end())
+                chs[c]++;
+            else
+                chs[c] = 1;
+        }
+        int n = 0;
+        char c = 'a';
+        for(auto const& i : chs) {
+            if(i.second >= n) {
+                if(i.first >= c) {
+                    n = i.second;
+                    c = i.first;
+                }
+            }
+        }
+        out << c << ' ' << n << endl;
+    }
+
+    out.close();
+    in.close();
+    return 0;
+}
diff --git a/Year_1/Programming_2/exercises/dequeue.cc b/Year_1/Programming_2/exercises/dequeue.cc
new file mode 100644
index 0000000..4b012c4
--- /dev/null
+++ b/Year_1/Programming_2/exercises/dequeue.cc
@@ -0,0 +1,137 @@
+
+#include<iostream>
+#include<fstream>
+
+using namespace std;
+
+template<class T>
+class node {
+public:
+    node(T key, node<T>* next) : _key{key}, _next{next} {}
+    node(T key) : _key{key}, _next{nullptr} {}
+    const T& key() const { return _key; }
+    T& key() { return _key; }
+    const node<T>*& next() const { return _next; }
+    node<T>*& next() { return _next; }
+private:
+    T _key;
+    node<T>* _next;
+};
+
+template<class T>
+class Coda {
+public:
+    Coda() : _head{nullptr}, _tail{nullptr} {}
+    ~Coda() {
+
+    }
+    Coda<T>* enqueue(T val) {
+        if(!_head) {
+            _head = new node<T>{val, nullptr};
+            _tail = _head;
+        } else {
+            _tail->next() = new node<T>{val, nullptr};
+            _tail = _tail->next();
+        }
+
+        return this;
+    }
+    node<T>* dequeue() {
+        if(!_head) return nullptr;
+        node<T>* elem = _head;
+        delete _head;
+        _head = elem->next();
+
+        return elem;
+    }
+
+    bool is_empty() { return _head == nullptr; }
+private:
+    node<T>* _head;
+    node<T>* _tail;
+};
+
+int main() {
+    ifstream in("input.txt");
+    ofstream out("output.txt");
+
+    for(int ts = 0; ts < 100; ++ts) {
+        string t;
+        int n;
+        in >> t;
+        switch(t.at(0)) {
+        case 'b': {
+            Coda<bool>* queue = new Coda<bool>{};
+            in >> n;
+            string s;
+            for(int i = 0; i < n; ++i) {
+                in >> s;
+                if(s.at(0) == 'i') {
+                    queue->enqueue(s.at(1) - '0');
+                } else {
+                    queue->dequeue();
+                }
+            }
+            while(!queue->is_empty())
+                out << queue->dequeue()->key() << ' ';
+            out << endl;
+            break;
+        }
+        case 'd': {
+            Coda<double>* queue = new Coda<double>{};
+            in >> n;
+            string s;
+            for(int i = 0; i < n; ++i) {
+                in >> s;
+                if(s.at(0) == 'i') {
+                    queue->enqueue(stod(s.substr(1, s.length()-1)));
+                } else {
+                    queue->dequeue();
+                }
+            }
+            while(!queue->is_empty())
+                out << queue->dequeue()->key() << ' ';
+            out << endl;
+            break;
+        }
+        case 'c': {
+            Coda<char>* queue = new Coda<char>{};
+            in >> n;
+            string s;
+            for(int i = 0; i < n; ++i) {
+                in >> s;
+                if(s.at(0) == 'i') {
+                    queue->enqueue(s.at(1));
+                } else {
+                    queue->dequeue();
+                }
+            }
+            while(!queue->is_empty())
+                out << queue->dequeue()->key() << ' ';
+            out << endl;
+            break;
+        }
+        case 'i': {
+            Coda<int>* queue = new Coda<int>{};
+            in >> n;
+            string s;
+            for(int i = 0; i < n; ++i) {
+                in >> s;
+                if(s.at(0) == 'i') {
+                    queue->enqueue(stoi(s.substr(1, s.length()-1)));
+                } else {
+                    queue->dequeue();
+                }
+            }
+            while(!queue->is_empty())
+                out << queue->dequeue()->key() << ' ';
+            out << endl;
+            break;
+        }
+        }
+    }
+    in.close();
+    out.close();
+    return 0;
+}
+
diff --git a/Year_1/Programming_2/exercises/doppioni.cc b/Year_1/Programming_2/exercises/doppioni.cc
new file mode 100644
index 0000000..fdd3e88
--- /dev/null
+++ b/Year_1/Programming_2/exercises/doppioni.cc
@@ -0,0 +1,77 @@
+#include<iostream>
+#include<fstream>
+
+using namespace std;
+
+template<class T>
+class node {
+public:
+    node(T key, node* parent, node* right, node* left) : _key{key}, _parent{parent}, _right{right}, _left{left} {}
+    T& key() { return _key; }
+    const T& key() const { return _key; }
+    node<T>*& parent() { return _parent; }
+    const node<T>*& parent() const { return _parent; }
+    node<T>*& right() { return _right; }
+    const node<T>*& right() const { return _right; }
+    node<T>*& left() { return _left; }
+    const node<T>*& left() const { return _left; }
+private:
+    T _key;
+    node<T>* _parent;
+    node<T>* _right;
+    node<T>* _left;
+};
+
+class bst {
+public:
+    bst() : _duplicates{0}, _root{nullptr} {}
+    bst* add(int val) {
+        node<int>* iter = _root;
+        node<int>* prev = nullptr;
+        while(iter) {
+            prev = iter;
+            if(iter->key() == val) {
+                _duplicates++;
+                return this;
+            }
+
+            if(iter->key() > val)
+                iter = iter->right();
+            else
+                iter = iter->left();
+        }
+
+        node<int>* nodus = new node<int>{val, prev, nullptr, nullptr};
+        if(!prev)
+            _root = nodus;
+        else if(prev->key() > val)
+            prev->right() = nodus;
+        else
+            prev->left() = nodus;
+
+        return this;
+    }
+    const int& duplicates() const { return _duplicates; }
+private:
+    int _duplicates;
+    node<int>* _root;
+};
+
+int main() {
+    ifstream in("input.txt");
+    ofstream out("output.txt");
+    for(int ts = 0; ts < 100; ++ts) {
+        bst* b = new bst{};
+        int n;
+        in >> n;
+        int e;
+        for(int i = 0; i < n; ++i) {
+            in >> e;
+            b->add(e);
+        }
+        out << b->duplicates() << endl;
+    }
+    in.close();
+    out.close();
+    return 0;
+}
diff --git a/Year_1/Programming_2/exercises/estremi-uguali.cc b/Year_1/Programming_2/exercises/estremi-uguali.cc
new file mode 100644
index 0000000..63ac019
--- /dev/null
+++ b/Year_1/Programming_2/exercises/estremi-uguali.cc
@@ -0,0 +1,32 @@
+#include<iostream>
+#include<string>
+#include<fstream>
+
+using namespace std;
+
+int result(string s) {
+    if(s.at(0) == s.at(s.length()-1))
+        return 1;
+
+    return 0;
+}
+
+int main() {
+    ifstream in("input.txt");
+    ofstream out("output.txt");
+
+    for(int ts = 0; ts < 100; ++ts) {
+        int _;
+        string s;
+        int size{};
+        for(int i = 0; i < 3; ++i) {
+            in >> _ >> s;
+            size += result(s);
+        }
+        out << size << '\n';
+    }
+
+    in.close();
+    out.close();
+    return 0;
+}
diff --git a/Year_1/Programming_2/exercises/even-length.cc b/Year_1/Programming_2/exercises/even-length.cc
new file mode 100644
index 0000000..2d3d6a4
--- /dev/null
+++ b/Year_1/Programming_2/exercises/even-length.cc
@@ -0,0 +1,27 @@
+#include<iostream>
+#include<string>
+#include<fstream>
+
+using namespace std;
+
+string result(string s) {
+    if(s.length() % 2 == 0)
+        return s;
+
+    return s.substr(0, s.length()-1);
+}
+
+int main() {
+    ifstream in("input.txt");
+    ofstream out("output.txt");
+
+    for(int ts = 0; ts < 100; ++ts) {
+        string s;
+        in >> s;
+        out << result(s) << '\n';
+    }
+
+    in.close();
+    out.close();
+    return 0;
+}
diff --git a/Year_1/Programming_2/exercises/exam_08_10_14.cc b/Year_1/Programming_2/exercises/exam_08_10_14.cc
new file mode 100644
index 0000000..c9c33be
--- /dev/null
+++ b/Year_1/Programming_2/exercises/exam_08_10_14.cc
@@ -0,0 +1,202 @@
+#include<iostream>
+
+using namespace std;
+
+template<class H> class MultiBST {
+    virtual MultiBST<H>* ins(H x) = 0;
+    virtual int multiplicity(H x) = 0;
+    virtual void inorder() = 0;
+};
+
+template<class H>
+class node {
+public:
+    node(H val) : _key{val}, _parent{nullptr}, _left{nullptr}, _right{nullptr}, _rk{1} {}
+    H& key() { return _key; }  
+    const H& key() const { return _key; }  
+    node<H>*& parent() { return _parent; }
+    const node<H>*& parent() const { return _parent; }
+    node<H>*& left() { return _left; }
+    const node<H>*& left() const { return _left; }
+    node<H>*& right() { return _right; }
+    const node<H>*& right() const { return _right; }
+    int& rk() { return _rk; }
+    const int& rk() const { return _rk; }
+private:
+    H _key;
+    node<H>* _parent;
+    node<H>* _left;
+    node<H>* _right;
+    int _rk;
+};
+
+template<class H>
+class MyMultiBST : public MultiBST<H> {
+public:
+    MyMultiBST() : _root{nullptr} {}
+    node<H>*& root() { return _root; }
+    const node<H>*& root() const { return _root; }
+    int multiplicity(H x) {
+        auto elem = _search(x);
+        if(elem)
+            return elem->rk();
+        return 0;
+    }
+    MyMultiBST<H>* ins(H x) {
+        auto iter = _search(x);
+        if(iter) {
+            iter->rk() = iter->rk()+1;
+        } else {
+            iter = _root;
+            node<H>* y{nullptr};
+
+            while(iter) {
+                y = iter;
+                if(iter->key() > x) 
+                    iter = iter->left();
+                else
+                    iter = iter->right();
+            }
+
+            node<H>* nodus = new node<H>{x};
+            nodus->parent() = y;
+            if(!y) {
+                _root = nodus;
+            } else if(y->key() > x) {
+                y->left() = nodus;
+            } else {
+                y->right() = nodus;
+            }
+        }
+
+        return this;
+    }
+    void inorder() {
+       _inorder(_root);
+    }
+    MyMultiBST<H>* del(H x) {
+        node<H>* y;
+        node<H>* z = _search(x);
+
+        if(!z) return this;
+
+        if(z->rk() > 1) {
+            z->rk() = z->rk()-1;
+        } else {
+            if(!z->left()) {
+                _transplant(z, z->right());
+            } else if(!z->right()) {
+                _transplant(z, z->left());
+            } else {
+                y = _min(z->right());
+                if(y->parent() != z) {
+                    _transplant(y, y->right());
+                    y->right() = z->right();
+                    y->right()->parent() = y;
+                }
+                _transplant(z, y);
+                y->left() = z->left();
+                y->left()->parent() = y;
+                delete z;
+            }
+        }
+
+        return this;
+    }
+    node<H>* predecessor(H x) {
+        auto iter = _search(x);
+        if(!iter) return nullptr;
+        if(iter->left())
+            return _max(iter->left());
+
+        auto y = iter->parent();
+        while(y && iter == y->left()) {
+            iter = y;
+            y = y->parent();
+        }
+
+        return y;
+    }
+    int rank(H x) {
+        auto iter = predecessor(x);
+        int sum{1};
+        while(iter) {
+            sum+=iter->rk();
+            iter = predecessor(iter->key());
+        }
+        return sum;
+    }
+private:
+    void _transplant(node<H>* u, node<H>* v) {
+        if(!u->parent()) _root = v;
+        else if(u == u->parent()->left())
+            u->parent()->left() = v;
+        else
+            u->parent()->right() = v;
+
+        if(v)
+            v->parent() = u->parent();
+    }
+    node<H>* _max(node<H>* x) {
+        if(!x) return nullptr;
+
+        auto iter = x;
+        while(iter->right()) {
+            iter = iter->right();
+        }
+
+        return iter;
+    }
+    node<H>* _min(node<H>* x) {
+        if(!x) return nullptr;
+
+        auto iter = x;
+        while(iter->left()) {
+            iter = iter->left();
+        }
+
+        return iter;
+    }
+    void _inorder(node<H>* p) {
+        if(p) {
+            _inorder(p->left());
+            for(int i = 0; i < p->rk(); ++i) {
+                cout << p->key() << ' ';
+            }
+            _inorder(p->right());
+        }
+    }
+    node<H>* _search(H val) {
+        auto iter = _root;
+        while(iter && iter->key() != val) {
+            if(iter->key() > val)
+                iter = iter->left();
+            else
+                iter = iter->right();
+        }
+
+        return iter;
+    }
+    node<H>* _root;
+};
+
+int main() {
+    MyMultiBST<int>* t = new MyMultiBST<int>{};
+
+    for(auto const& i : {10, 7, 7, 23, 30, 4, 1, 5, 9, 5, 1, 7, 1, 9})
+        t->ins(i);
+
+    t->inorder();
+    cout << '\n';
+    for(auto const& i : {5, 7, 17})
+        cout << i << ": " << t->multiplicity(i) << endl;
+
+    for(auto const& i : {7, 4, 23, 7, 7})
+        t->del(i);
+    t->inorder();
+    cout << '\n';
+    for(auto const& i: {5, 9, 30})
+        cout << t->rank(i) << ' ';
+    delete t;
+    return 0;
+}
diff --git a/Year_1/Programming_2/exercises/exam_20_07_20/ex1.cpp b/Year_1/Programming_2/exercises/exam_20_07_20/ex1.cpp
new file mode 100644
index 0000000..4f08a74
--- /dev/null
+++ b/Year_1/Programming_2/exercises/exam_20_07_20/ex1.cpp
@@ -0,0 +1,39 @@
+#include<iostream>
+#include<sstream>
+#include<fstream>
+#include<vector>
+
+using namespace std;
+int insertionsort(vector<int>& a, int n) {
+    int c = 0;
+    for(int i = 1; i < n; ++i) {
+        int j = i-1;
+        int key = a[i];
+        while(j > -1 && a[j] > key) {
+            swap(a[j+1], a[j]);
+            --j;
+            c++;
+        }
+        a[j+1] = key;
+    }
+    return c;
+}
+int main() {
+    ifstream in("input.txt");
+    ofstream out("output.txt");
+
+    for(int ts = 0; ts < 100; ++ts) {
+        int N;
+        in >> N;
+        int a, b;
+        vector<int> v;
+        for(int i = 0; i < N; ++i) {
+            in >> a >> b;
+            v.push_back(a+b);
+        }
+        out << insertionsort(v, v.size()) << endl;
+    }
+    in.close();
+    out.close();
+    return 0;
+}
diff --git a/Year_1/Programming_2/exercises/exam_20_07_20/ex2.cpp b/Year_1/Programming_2/exercises/exam_20_07_20/ex2.cpp
new file mode 100644
index 0000000..aed25e4
--- /dev/null
+++ b/Year_1/Programming_2/exercises/exam_20_07_20/ex2.cpp
@@ -0,0 +1,63 @@
+#include<iostream>
+#include<sstream>
+#include<fstream>
+#include<queue>
+
+using namespace std;
+using pi = tuple<int, int, vector<int>>;
+
+class comp {
+public:
+    bool operator()(const pi& lhs, const pi& rhs) const {
+        auto xl = get<0>(lhs);
+        auto yl = get<0>(rhs);
+
+        auto il = get<1>(lhs);
+        auto jl = get<1>(rhs);
+        if(xl == yl)
+            return il > jl;
+        return xl > yl;
+    }
+};
+
+int main() {
+    ifstream in("input.txt");
+    ofstream out("output.txt");
+
+    for(int ts = 0; ts < 100; ++ts) {
+        int R, C;
+        in >> R >> C;
+        vector<vector<int>> v;
+        priority_queue<pi, vector<pi>, comp> pq;
+        int k;
+        for(int i = 0; i < R; ++i) {
+            v.push_back(vector<int>{});
+            for(int j = 0; j < C; ++j) {
+                in >> k;
+                v[i].push_back(k);
+            }
+        }
+
+        int index = 0;
+        for(auto const& i : v) {
+            int s = 0;
+            pi qq;
+            for(auto const& j : i)
+                s += j;
+            get<0>(qq) = s;
+            get<1>(qq) = index++;
+            get<2>(qq) = i;
+            pq.push(qq);
+        }
+        while(!pq.empty()) {
+            auto q = pq.top();
+            pq.pop();
+            for(auto const& i : get<2>(q))
+                out << i << ' ';
+        }
+        out << endl;
+    }
+    in.close();
+    out.close();
+    return 0;
+}
diff --git a/Year_1/Programming_2/exercises/exam_20_07_20/ex3.cpp b/Year_1/Programming_2/exercises/exam_20_07_20/ex3.cpp
new file mode 100644
index 0000000..71f9c65
--- /dev/null
+++ b/Year_1/Programming_2/exercises/exam_20_07_20/ex3.cpp
@@ -0,0 +1,284 @@
+#include<iostream>
+#include<sstream>
+#include<fstream>
+
+using namespace std;
+
+template<class T>
+struct node {
+    T key;
+    node<T>* prev;
+    node<T>* right;
+    node<T>* left;
+};
+
+template<class T>
+class bst {
+public:
+    bst() : root{nullptr} , _val{0}{}
+
+    ~bst() {
+        // TODO
+    }
+
+    bst<T>* insert(initializer_list<T>&& list) {
+        for(auto const& i : list)
+            insert(i);
+
+        return this;
+    }
+
+    bst<T>* insert(T k) {
+        node<T>* nodus = new node<T>{k, nullptr, nullptr, nullptr};
+        node<T>* iter = root;
+        node<T>* prev = nullptr;
+
+        while(iter) {
+            prev = iter;
+            iter = (k < iter->key) ? iter->left : iter->right;
+        }
+
+        nodus->prev = prev;
+        if(!prev)
+            root = nodus;
+        else if(k < prev->key)
+            prev->left = nodus;
+        else
+            prev->right = nodus;
+
+        return this;
+    }
+
+    bst<T>* remove(initializer_list<T>&& list) {
+        for(auto const& i : list)
+            remove(i);
+
+        return this;
+    }
+
+    bst<T>* remove(T k) {
+        node<T>* nodus = search(k);
+        if(!nodus) return this;
+
+        if(!nodus->left) {
+            _transplant(nodus, nodus->right);
+        } else if(!nodus->right) {
+            _transplant(nodus, nodus->left);
+        } else {
+            node<T>* iter = _min(nodus->right);
+            if(iter->prev != nodus) {
+                _transplant(iter, iter->right);
+                iter->right = nodus->right;
+                iter->right->prev = iter;
+            }
+            _transplant(nodus, iter);
+            iter->left = nodus->left;
+            iter->left->prev = iter;
+        }
+
+        delete nodus;
+        return this;
+    }
+
+    node<T>* min() {
+        return _min(root);
+    }
+
+    node<T>* min(node<T>* nodus) {
+        return _min(nodus);
+    }
+
+    node<T>* max() {
+        return _max(root);
+    }
+
+    node<T>* max(node<T>* nodus) {
+        return _max(nodus);
+    }
+
+    node<T>* search(T k) {
+        node<T>* iter = root;
+        while(iter && iter->key != k)
+            iter = (iter->key > k) ? iter->left : iter->right;
+
+        return iter;
+    }
+
+    node<T>* successor(T k) {
+        node<T>* nodus = search(k);
+        if(!nodus) return nullptr;
+
+        if(nodus->right)
+            return min(nodus->right);
+
+        node<T>* prev = nodus->prev;
+        while(prev && nodus == prev->right) {
+            nodus = prev;
+            prev = prev->prev;
+        }
+
+        return prev;
+
+    }
+    node<T>* predecessor(T k) {
+        node<T>* nodus = search(k);
+        if(!nodus) return nullptr;
+
+        if(nodus->left)
+            return max(nodus->left);
+
+        node<T>* prev = nodus->prev;
+        while(prev && nodus == prev->left) {
+            nodus = prev;
+            prev = prev->prev;
+        }
+
+        return prev;
+    }
+
+    friend ostream& operator<<(ostream& os, bst<T>* tree) {
+        tree->_inorder(os, tree->root);
+        return os;
+    }
+    T sol(T k) {
+        return _max(search(k))->key;
+    }
+private:
+    int _val;
+    void _transplant(node<T>* u, node<T>* v) {
+        if(!u->prev) {
+            root = v;
+        } else if(u == u->prev->left) {
+            u->prev->left = v;
+        } else {
+            u->prev->right = v;
+        }
+
+        if(v)
+            v->prev = u->prev;
+    }
+
+    node<T>* _min(node<T>* root) {
+        node<T>* iter = root;
+        while(iter && iter->left)
+            iter = iter->left;
+
+        return iter;
+    }
+
+    node<T>* _max(node<T>* root) {
+        node<T>* iter = root;
+        while(iter && iter->right)
+            iter = iter->right;
+
+        return iter;
+    }
+
+    void _inorder(ostream& os, node<T>* root) {
+        if(root) {
+            if(root->right && root->left) {
+                _val++;
+            }
+            _inorder(os, root->left);
+            os << root->key << ' ';
+            _inorder(os, root->right);
+        }
+    }
+
+    void _preorder(ostream& os, node<T>* root) {
+        if(root) {
+            os << root->key << ' ';
+            _inorder(os, root->left);
+            _inorder(os, root->right);
+        }
+    }
+
+    void _postorder(ostream& os, node<T>* root) {
+        if(root) {
+            _inorder(os, root->left);
+            _inorder(os, root->right);
+            os << root->key << ' ';
+        }
+    }
+    node<T>* root;
+};
+
+int main() {
+    ifstream in("input.txt");
+    ofstream out("output.txt");
+
+    for(int ts = 0; ts < 100; ++ts) {
+        string t, comm;
+        in >> t;
+        int n;
+        switch(t.at(0)) {
+        case 'd':
+            {
+                bst<double>* b = new bst<double>{};
+                in >> n;
+                double k;
+                for(int i = 0; i < n; ++i) {
+                    in >> comm;
+                    stringstream tcomm(comm);
+                    int ex= 0;
+                    while(getline(tcomm, comm, ':')) {
+                        if(ex == 0) {
+                            if(comm == "ins")
+                                ex = 1;
+                            else
+                                ex = 2;
+                        } else {
+                            if(ex == 1)
+                                b->insert(stod(comm));
+                            else
+                                b->remove(stod(comm));
+                            ex = 0;
+                        }
+                    }
+                }
+                in >> k;
+                cout << b << endl;
+                out << b->sol(k) << endl;
+ 
+                delete b;
+                break;
+            }
+        case 'i':
+            {
+                bst<int>* b = new bst<int>{};
+                in >> n;
+                int k;
+                for(int i = 0; i < n; ++i) {
+                    in >> comm;
+                    stringstream tcomm(comm);
+                    int ex= 0;
+                    while(getline(tcomm, comm, ':')) {
+                        if(ex == 0) {
+                            if(comm == "ins")
+                                ex = 1;
+                            else
+                                ex = 2;
+                        } else {
+                            if(ex == 1)
+                                b->insert(stoi(comm));
+                            else
+                                b->remove(stoi(comm));
+                            ex = 0;
+                        }
+                    }
+                }
+                in >> k;
+                cout << b << endl;
+                out << b->sol(k) << endl;
+ 
+                delete b;
+                break;
+            }
+        }
+    }
+
+    in.close();
+    out.close();
+    return 0;
+}
+
diff --git a/Year_1/Programming_2/exercises/exam_20_07_20/ex4.cpp b/Year_1/Programming_2/exercises/exam_20_07_20/ex4.cpp
new file mode 100644
index 0000000..e234363
--- /dev/null
+++ b/Year_1/Programming_2/exercises/exam_20_07_20/ex4.cpp
@@ -0,0 +1,293 @@
+#include<iostream>
+#include<sstream>
+#include<fstream>
+
+using namespace std;
+
+template<class T>
+struct node {
+    T key;
+    node<T>* prev;
+    node<T>* right;
+    node<T>* left;
+};
+
+template<class T>
+class bst {
+public:
+    bst() : root{nullptr} , _val{0}{}
+
+    ~bst() {
+        // TODO
+    }
+
+    bst<T>* insert(initializer_list<T>&& list) {
+        for(auto const& i : list)
+            insert(i);
+
+        return this;
+    }
+
+    bst<T>* insert(T k) {
+        node<T>* nodus = new node<T>{k, nullptr, nullptr, nullptr};
+        node<T>* iter = root;
+        node<T>* prev = nullptr;
+
+        while(iter) {
+            prev = iter;
+            iter = (k < iter->key) ? iter->left : iter->right;
+        }
+
+        nodus->prev = prev;
+        if(!prev)
+            root = nodus;
+        else if(k < prev->key)
+            prev->left = nodus;
+        else
+            prev->right = nodus;
+
+        return this;
+    }
+
+    bst<T>* remove(initializer_list<T>&& list) {
+        for(auto const& i : list)
+            remove(i);
+
+        return this;
+    }
+
+    bst<T>* remove(T k) {
+        node<T>* nodus = search(k);
+        if(!nodus) return this;
+
+        if(!nodus->left) {
+            _transplant(nodus, nodus->right);
+        } else if(!nodus->right) {
+            _transplant(nodus, nodus->left);
+        } else {
+            node<T>* iter = _min(nodus->right);
+            if(iter->prev != nodus) {
+                _transplant(iter, iter->right);
+                iter->right = nodus->right;
+                iter->right->prev = iter;
+            }
+            _transplant(nodus, iter);
+            iter->left = nodus->left;
+            iter->left->prev = iter;
+        }
+
+        delete nodus;
+        return this;
+    }
+
+    node<T>* min() {
+        return _min(root);
+    }
+
+    node<T>* min(node<T>* nodus) {
+        return _min(nodus);
+    }
+
+    node<T>* max() {
+        return _max(root);
+    }
+
+    node<T>* max(node<T>* nodus) {
+        return _max(nodus);
+    }
+
+    node<T>* search(T k) {
+        node<T>* iter = root;
+        while(iter && iter->key != k)
+            iter = (iter->key > k) ? iter->left : iter->right;
+
+        return iter;
+    }
+
+    node<T>* successor(T k) {
+        node<T>* nodus = search(k);
+        if(!nodus) return nullptr;
+
+        if(nodus->right)
+            return min(nodus->right);
+
+        node<T>* prev = nodus->prev;
+        while(prev && nodus == prev->right) {
+            nodus = prev;
+            prev = prev->prev;
+        }
+
+        return prev;
+
+    }
+    node<T>* predecessor(T k) {
+        node<T>* nodus = search(k);
+        if(!nodus) return nullptr;
+
+        if(nodus->left)
+            return max(nodus->left);
+
+        node<T>* prev = nodus->prev;
+        while(prev && nodus == prev->left) {
+            nodus = prev;
+            prev = prev->prev;
+        }
+
+        return prev;
+    }
+
+    friend ostream& operator<<(ostream& os, bst<T>* tree) {
+        tree->_inorder(os, tree->root);
+        return os;
+    }
+    T sol(T k) {
+        auto x = search(k);
+        auto m = _max(x)->key;
+        auto mnn = _min(x);
+        T mn;
+        if(mnn->right)
+            mn = _min(mnn->right)->key;
+        else
+            mn = mnn->key;
+        cout << m << ' ' << mn << endl;
+        return m - mn;
+    }
+private:
+    int _val;
+    void _transplant(node<T>* u, node<T>* v) {
+        if(!u->prev) {
+            root = v;
+        } else if(u == u->prev->left) {
+            u->prev->left = v;
+        } else {
+            u->prev->right = v;
+        }
+
+        if(v)
+            v->prev = u->prev;
+    }
+
+    node<T>* _min(node<T>* root) {
+        node<T>* iter = root;
+        while(iter && iter->left)
+            iter = iter->left;
+
+        return iter;
+    }
+
+    node<T>* _max(node<T>* root) {
+        node<T>* iter = root;
+        while(iter && iter->right)
+            iter = iter->right;
+
+        return iter;
+    }
+
+    void _inorder(ostream& os, node<T>* root) {
+        if(root) {
+            if(root->right && root->left) {
+                _val++;
+            }
+            _inorder(os, root->left);
+            os << root->key << ' ';
+            _inorder(os, root->right);
+        }
+    }
+
+    void _preorder(ostream& os, node<T>* root) {
+        if(root) {
+            os << root->key << ' ';
+            _inorder(os, root->left);
+            _inorder(os, root->right);
+        }
+    }
+
+    void _postorder(ostream& os, node<T>* root) {
+        if(root) {
+            _inorder(os, root->left);
+            _inorder(os, root->right);
+            os << root->key << ' ';
+        }
+    }
+    node<T>* root;
+};
+
+int main() {
+    ifstream in("input.txt");
+    ofstream out("output.txt");
+
+    for(int ts = 0; ts < 100; ++ts) {
+        string t, comm;
+        in >> t;
+        int n;
+        switch(t.at(0)) {
+        case 'd':
+            {
+                bst<double>* b = new bst<double>{};
+                in >> n;
+                double k;
+                for(int i = 0; i < n; ++i) {
+                    in >> comm;
+                    stringstream tcomm(comm);
+                    int ex= 0;
+                    while(getline(tcomm, comm, ':')) {
+                        if(ex == 0) {
+                            if(comm == "ins")
+                                ex = 1;
+                            else
+                                ex = 2;
+                        } else {
+                            if(ex == 1)
+                                b->insert(stod(comm));
+                            else
+                                b->remove(stod(comm));
+                            ex = 0;
+                        }
+                    }
+                }
+                in >> k;
+                cout << b << endl;
+                out << b->sol(k) << endl;
+ 
+                delete b;
+                break;
+            }
+        case 'i':
+            {
+                bst<int>* b = new bst<int>{};
+                in >> n;
+                int k;
+                for(int i = 0; i < n; ++i) {
+                    in >> comm;
+                    stringstream tcomm(comm);
+                    int ex= 0;
+                    while(getline(tcomm, comm, ':')) {
+                        if(ex == 0) {
+                            if(comm == "ins")
+                                ex = 1;
+                            else
+                                ex = 2;
+                        } else {
+                            if(ex == 1)
+                                b->insert(stoi(comm));
+                            else
+                                b->remove(stoi(comm));
+                            ex = 0;
+                        }
+                    }
+                }
+                in >> k;
+                cout << b << endl;
+                out << b->sol(k) << endl;
+ 
+                delete b;
+                break;
+            }
+        }
+    }
+
+    in.close();
+    out.close();
+    return 0;
+}
+
diff --git a/Year_1/Programming_2/exercises/exam_20_07_20/ex5.cpp b/Year_1/Programming_2/exercises/exam_20_07_20/ex5.cpp
new file mode 100644
index 0000000..dd8fc98
--- /dev/null
+++ b/Year_1/Programming_2/exercises/exam_20_07_20/ex5.cpp
@@ -0,0 +1,285 @@
+#include<iostream>
+#include<vector>
+#include<algorithm>
+#include<queue>
+#include<stack>
+#include<fstream>
+#define INF 99999999
+#define W -1
+#define G 0
+#define B 1
+
+using namespace std;
+
+template<class H>
+class graph {
+public:
+    graph(int len) : _len{len}, _nodes{0}, _edges{0} {
+        _k = new H*[len];
+        _adj = new vector<int>[len];
+        _colors = new int[len];
+        _d = new int[len];
+        _f = new int[len];
+        _p = new int[len];
+
+        for(int i = 0; i < len; ++i) {
+            _k[i] = nullptr;
+        }
+    }
+    ~graph() {
+        delete[] _k;
+        delete[] _adj;
+    }
+
+    graph<H>* add_node(H x) {
+        if(_index(x) > -1) return this;
+        if(_nodes == _len) return this;
+        _k[_nodes++] = new H(x);
+
+        return this;
+    }
+    graph<H>* add_edge(H u, H v) {
+        int i = _index(u);
+        int j = _index(v);
+        if(i < 0 || j < 0) return this;
+
+        if(find(_adj[i].begin(), _adj[i].end(), j) == _adj[i].end()) {
+            _adj[i].push_back(j);
+        }
+        return this;
+    }
+    void print() {
+        for(int i = 0; i < _nodes; ++i) {
+            cout << "(" << *_k[i] << ", " << i << "): ";
+            for(auto const& j : _adj[i]) {
+                cout << "(" << *_k[j] << ", " << j << ") ";
+            }
+            cout << endl;
+        }
+    }
+    void dfsvisit(int u, bool visited[]) {
+        visited[u] = true;
+        cout << "(" << *_k[u] << ", " << u << ") ";
+        for(auto const& i : _adj[u]) {
+            if(!visited[i])
+                dfsvisit(i, visited);
+        }
+    }
+    int dfsvisit(int u) {
+        int cycle = 0;
+        _colors[u] = G;
+        _d[u] = _time++;
+
+        for(auto const& j : _adj[u]) {
+            if(_colors[j] == W)
+                cycle |= dfsvisit(j);
+        }
+
+        _colors[u] = B;
+        _stack.push(u);
+        _f[u] = _time++;
+        return cycle;
+    }
+    int dfs() {
+        int cycle = 0;
+        for(int i = 0; i < _nodes; ++i) {
+            _colors[i] = W;
+        }
+        _time = 0;
+        for(int i = 0; i < _nodes; ++i) {
+            if(_colors[i] == W)
+                cycle |= dfsvisit(i);
+            else if(_colors[i] == G)
+                cycle = 1;
+        }
+        for(int i = 0; i < _nodes; ++i) {
+            cout << "(" << *_k[i] << ", " << i << "): [" << _d[i] << "," << _f[i] << "]" << endl;
+        }
+        return cycle;
+    }
+
+    void top_sort() {
+        int cycle = dfs();
+        if(cycle) {
+            cout << "cyclic graph!" << endl;
+            return;
+        }
+        int* s = new int[_nodes];
+        for(int i = 0; i < _nodes; ++i) s[i] = i;
+        _sort(s, _nodes, _f);
+        for(int i = 0; i < _nodes; ++i) {
+            cout << "(" << s[i] << ", " << _f[s[i]] << ") ";
+        }
+
+    }
+
+    void bfs(H v) {
+        int s = _index(v);
+        if(s < 0) return;
+
+        for(int i = 0; i < _nodes; ++i) {
+            _colors[i] = W;
+            _d[i] = INF;
+            _p[i] = -1;
+        }
+        _colors[s] = G;
+        _d[s] = 0;
+        queue<int> q;
+        q.push(s);
+        while(!q.empty()) {
+            int u = q.front();
+            q.pop();
+            for(auto const& j : _adj[u]) {
+                if(_colors[j] == W) {
+                    _colors[j] = G;
+                    _d[j] = _d[u]+1;
+                    _p[j] = u;
+                    q.push(j);
+                }
+            }
+            _colors[u] = B;
+        }
+        for(int i = 0; i < _nodes; ++i) {
+            cout << "(" << *_k[i] << ", " << i << "): [" << _d[i] << "]" << endl;
+        }
+    }
+    int ssc() {
+        dfs();
+        cout << endl << endl;
+        bool* visited = new bool[_nodes];
+        for(int i = 0; i < _nodes; ++i)
+            visited[i] = false;
+        int count = 0;
+        while(!_stack.empty()) {
+            int v = _stack.top();
+            _stack.pop();
+            if(!visited[v]) {
+                dfsvisit(v, visited);
+                count++;
+                cout << endl;
+            }
+        }
+        delete[] visited;
+        return count;
+    }
+private:
+    graph<H>* _transpose() {
+        graph<H>* g = new graph<H>{_len};
+        for(int i = 0; i < _nodes; ++i) {
+            g->add_node(*_k[i]);
+        }
+
+        for(int i = 0; i < _nodes; ++i) {
+            for(auto const& j : _adj[i]) {
+                g->add_edge(j, i);
+            }
+        }
+
+        return g;
+    }
+    void _sort(int* d, int n, int* s) {
+        for(int i = -1; i < n; ++i) {
+            int j = i-1;
+            while(j > -1 && s[d[j+1]]>s[d[j]]) {
+                swap(d[s[j+1]], d[s[j]]);
+                --j;
+            }
+        }
+    }
+    int _index(H x) {
+        for(int i = 0; i < _nodes; ++i)
+            if(*_k[i] == x) return i;
+
+        return -1;
+    }
+    stack<int> _stack;
+    H** _k;
+    vector<int>* _adj;
+    int _len, _nodes, _edges;
+    int* _colors;
+    int _time;
+    int* _d;
+    int* _f;
+    int* _p;
+};
+
+int main() {
+    ifstream in("input.txt");
+    ofstream out("output.txt");
+
+    for(int ts = 0; ts < 100; ++ts) {
+        int n, e;
+        in >> n>>e;
+        string t;
+        in >> t;
+        char _t;
+        switch(t.at(0)){
+            case 'd':{
+                graph<double>* g = new graph<double>{n};
+                double x, y;
+                for(int i = 0; i < n; ++i) {
+                    in >> x;
+                    g->add_node(x);
+                }
+                for(int i = 0; i < e; ++i) {
+                    in >>_t;
+                    in >> x >> y;
+                    in >> _t;
+                    g->add_edge(x, y);
+                    g->add_edge(y, x);
+                }
+                g->print();
+                cout << endl << endl;
+                out << g->ssc()<<endl;
+                delete g;
+                break;
+             }
+            case 'i':{
+
+                graph<int>* g = new graph<int>{n};
+                int x, y;
+                for(int i = 0; i < n; ++i) {
+                    in >> x;
+                    g->add_node(x);
+                }
+                for(int i = 0; i < e; ++i) {
+                    in >>_t;
+                    in >> x >> y;
+                    in >> _t;
+                    g->add_edge(x, y);
+                    g->add_edge(y, x);
+                }
+                g->print();
+                cout << endl << endl;
+                out << g->ssc()<<endl;
+                delete g;
+                break;
+                     }
+            case 'c': {
+
+                graph<char>* g = new graph<char>{n};
+                char x, y;
+                for(int i = 0; i < n; ++i) {
+                    in >> x;
+                    g->add_node(x);
+                }
+                for(int i = 0; i < e; ++i) {
+                    in >>_t;
+                    in >> x >> y;
+                    in >> _t;
+                    g->add_edge(x, y);
+                    g->add_edge(y, x);
+                }
+                g->print();
+                cout << endl << endl;
+                out << g->ssc()<<endl;
+                delete g;
+                break;
+                      }
+        }
+    }
+    in.close();
+    out.close();
+    return 0;
+}
+
diff --git a/Year_1/Programming_2/exercises/inizia-con.cc b/Year_1/Programming_2/exercises/inizia-con.cc
new file mode 100644
index 0000000..97f0c39
--- /dev/null
+++ b/Year_1/Programming_2/exercises/inizia-con.cc
@@ -0,0 +1,33 @@
+#include<iostream>
+#include<string>
+#include<fstream>
+
+using namespace std;
+
+string result(string s, char c) {
+    if(s.at(0) == c)
+        return s + ' ';
+
+    return "";
+}
+
+int main() {
+    ifstream in("input.txt");
+    ofstream out("output.txt");
+
+    for(int ts = 0; ts < 100; ++ts) {
+        int _;
+        string s;
+        char c;
+        in >> c;
+        for(int i = 0; i < 3; ++i) {
+            in >> _ >> s;
+            out << result(s, c);
+        }
+        out << '\n';
+    }
+
+    in.close();
+    out.close();
+    return 0;
+}
diff --git a/Year_1/Programming_2/exercises/inserimento-coda.cc b/Year_1/Programming_2/exercises/inserimento-coda.cc
new file mode 100644
index 0000000..6775ca2
--- /dev/null
+++ b/Year_1/Programming_2/exercises/inserimento-coda.cc
@@ -0,0 +1,119 @@
+#include<iostream>
+#include<fstream>
+
+using namespace std;
+
+template<class T>
+class node {
+public:
+    node(T key, node<T>* next) : _key{key}, _next{next} {}
+    node(T key) : _key{key}, _next{nullptr} {}
+    const T& key() const { return _key; }
+    T& key() { return _key; }
+    const node<T>*& next() const { return _next; }
+    node<T>*& next() { return _next; }
+private:
+    T _key;
+    node<T>* _next;
+};
+
+template<class T>
+class Coda {
+public:
+    Coda() : _head{nullptr}, _tail{nullptr} {}
+    ~Coda() {
+
+    }
+    Coda<T>* enqueue(T val) {
+        if(!_head) {
+            _head = new node<T>{val, nullptr};
+            _tail = _head;
+        } else {
+            _tail->next() = new node<T>{val, nullptr};
+            _tail = _tail->next();
+        }
+
+        return this;
+    }
+    node<T>* pop() {
+        if(!_head) return nullptr;
+        node<T>* elem = _head;
+        delete _head;
+        _head = elem->next();
+
+        return elem;
+    }
+
+    bool is_empty() { return _head == nullptr; }
+private:
+    node<T>* _head;
+    node<T>* _tail;
+};
+
+int main() {
+    ifstream in("input.txt");
+    ofstream out("output.txt");
+
+    for(int ts = 0; ts < 100; ++ts) {
+        string t;
+        int n;
+        in >> t;
+        switch(t.at(0)) {
+        case 'b': {
+            Coda<bool>* queue = new Coda<bool>{};
+            in >> n;
+            bool e;
+            for(int i = 0; i < n; ++i) {
+                in >> e;
+                queue->enqueue(e);
+            }
+            while(!queue->is_empty())
+                out << queue->pop()->key() << ' ';
+            out << endl;
+            break;
+        }
+        case 'd': {
+            Coda<double>* queue = new Coda<double>{};
+            in >> n;
+            double e;
+            for(int i = 0; i < n; ++i) {
+                in >> e;
+                queue->enqueue(e);
+            }
+            while(!queue->is_empty())
+                out << queue->pop()->key() << ' ';
+            out << endl;
+            break;
+        }
+        case 'c': {
+            Coda<char>* queue = new Coda<char>{};
+            in >> n;
+            char e;
+            for(int i = 0; i < n; ++i) {
+                in >> e;
+                queue->enqueue(e);
+            }
+            while(!queue->is_empty())
+                out << queue->pop()->key() << ' ';
+            out << endl;
+            break;
+        }
+        case 'i': {
+            Coda<int>* queue = new Coda<int>{};
+            in >> n;
+            int e;
+            for(int i = 0; i < n; ++i) {
+                in >> e;
+                queue->enqueue(e);
+            }
+            while(!queue->is_empty())
+                out << queue->pop()->key() << ' ';
+            out << endl;
+            break;
+        }
+        }
+    }
+    in.close();
+    out.close();
+    return 0;
+}
diff --git a/Year_1/Programming_2/exercises/inserimento-pila.cc b/Year_1/Programming_2/exercises/inserimento-pila.cc
new file mode 100644
index 0000000..0dbe99b
--- /dev/null
+++ b/Year_1/Programming_2/exercises/inserimento-pila.cc
@@ -0,0 +1,116 @@
+#include<iostream>
+#include<fstream>
+
+using namespace std;
+
+template<class T>
+class node {
+public:
+    node(T key, node<T>* next) : _key{key}, _next{next} {}
+    node(T key) : _key{key}, _next{nullptr} {}
+    const T& key() const { return _key; }
+    T& key() { return _key; }
+    const node<T>*& next() const { return _next; }
+    node<T>*& next() { return _next; }
+private:
+    T _key;
+    node<T>* _next;
+};
+
+template<class T>
+class Pila {
+public:
+    Pila() : _head{nullptr}{}
+    ~Pila() {
+
+    }
+    Pila<T>* push(T val) {
+        if(!_head) {
+            _head = new node<T>{val, nullptr};
+        } else {
+            _head = new node<T>{val, _head};
+        }
+
+        return this;
+    }
+    node<T>* pop() {
+        if(!_head) return nullptr;
+        node<T>* elem = _head;
+        delete _head;
+        _head = elem->next();
+
+        return elem;
+    }
+
+    bool is_empty() { return _head == nullptr; }
+private:
+    node<T>* _head;
+};
+
+int main() {
+    ifstream in("input.txt");
+    ofstream out("output.txt");
+
+    for(int ts = 0; ts < 100; ++ts) {
+        string t;
+        int n;
+        in >> t;
+        switch(t.at(0)) {
+        case 'b': {
+            Pila<bool>* stack = new Pila<bool>{};
+            in >> n;
+            bool e;
+            for(int i = 0; i < n; ++i) {
+                in >> e;
+                stack->push(e);
+            }
+            while(!stack->is_empty())
+                out << stack->pop()->key() << ' ';
+            out << endl;
+            break;
+        }
+        case 'd': {
+            Pila<double>* stack = new Pila<double>{};
+            in >> n;
+            double e;
+            for(int i = 0; i < n; ++i) {
+                in >> e;
+                stack->push(e);
+            }
+            while(!stack->is_empty())
+                out << stack->pop()->key() << ' ';
+            out << endl;
+            break;
+        }
+        case 'c': {
+            Pila<char>* stack = new Pila<char>{};
+            in >> n;
+            char e;
+            for(int i = 0; i < n; ++i) {
+                in >> e;
+                stack->push(e);
+            }
+            while(!stack->is_empty())
+                out << stack->pop()->key() << ' ';
+            out << endl;
+            break;
+        }
+        case 'i': {
+            Pila<int>* stack = new Pila<int>{};
+            in >> n;
+            int e;
+            for(int i = 0; i < n; ++i) {
+                in >> e;
+                stack->push(e);
+            }
+            while(!stack->is_empty())
+                out << stack->pop()->key() << ' ';
+            out << endl;
+            break;
+        }
+        }
+    }
+    in.close();
+    out.close();
+    return 0;
+}
diff --git a/Year_1/Programming_2/exercises/matrice-adj.cc b/Year_1/Programming_2/exercises/matrice-adj.cc
new file mode 100644
index 0000000..7830f97
--- /dev/null
+++ b/Year_1/Programming_2/exercises/matrice-adj.cc
@@ -0,0 +1,151 @@
+#include<iostream>
+#include<vector>
+#include<fstream>
+#include<sstream>
+
+using namespace std;
+
+template<class H>
+class matrix_graph {
+public:
+    ~matrix_graph() {
+        delete[] _m;
+        delete[] _k;
+    }
+    matrix_graph(int len) : _len{len}, _nodes{0}, _edges{0} {
+        _m = new int*[len];
+        _k = new H*[len];
+        for(int i = 0; i < len; ++i) {
+            _m[i] = new int[len];
+            _k[i] = nullptr;
+            for(int j = 0; j < len; ++j)
+                _m[i][j] = 0;
+        }
+    }
+
+    matrix_graph<H>* add_node(H k) {
+        if(_len == _nodes) return this; // no more space for new nodes
+        if(_index(k) > -1) return this; // nodes already exists
+
+        _k[_nodes++] = new H(k);
+
+        return this;
+    }
+
+    matrix_graph<H>* add_edge(H x, H y) {
+        int i = _index(x);
+        int j = _index(y);
+        if(i < 0 || j < 0) return this;
+        if(!_m[i][j]) {
+            _m[i][j] = 1;
+            _edges++;
+        }
+        return this;
+    }
+    vector<vector<H>> print() {
+        vector<vector<H>> v;
+        for(int i = 0; i < _len; ++i) {
+            v.push_back(vector<H>{*_k[i]});
+            vector<H> temp;
+            for(int j = 0; j < _len; ++j) {
+                if(_m[i][j]) {
+                    temp.push_back(*_k[j]);
+                }
+            }
+            sort(begin(temp), end(temp));
+            for(auto const& j : temp)
+                v[i].push_back(j);
+        }
+
+        sort(begin(v), end(v));
+        return v;
+    }
+private:
+    int _len, _nodes, _edges;
+    int** _m;
+    H** _k;
+    int _index(H x) {
+        for(int i = 0; i < _nodes; ++i)
+            if(*_k[i] == x) return i;
+        return -1;
+    }
+};
+
+template<class H>
+string result(vector<vector<H>> v) {
+    string s{""};
+    ostringstream ss;
+    for(auto const& i : v) {
+        s += "(";
+        for(auto const& j : i) {
+            ss << j;
+            s+= ss.str();
+            s+= ' ';
+            ss.str(""); ss.clear();
+        }
+        s.pop_back();
+        s += ") ";
+    }
+    return s;
+}
+
+int main() {
+    ifstream in("input.txt");
+    ofstream out("output.txt");
+    for(int ts = 0; ts < 100; ++ts) {
+        int n, m;
+        in >> n >> m;
+        string t;
+        in >> t;
+        if(t == "int") {
+            matrix_graph<int>* g = new matrix_graph<int>(n);
+            int x,y;
+            for(int i = 0; i < n; ++i) {
+               in >> x;
+               g->add_node(x);
+            }
+            char ex;
+            for(int i = 0; i < m; ++i) {
+                in >> ex >> x >> y >> ex;
+                g->add_edge(x, y);
+            }
+            auto v = g->print();
+            out << result(v) << endl;
+            delete g;
+        } else if(t == "double") {
+            matrix_graph<double>* g = new matrix_graph<double>(n);
+            double x,y;
+            for(int i = 0; i < n; ++i) {
+               in >> x;
+               g->add_node(x);
+            }
+            char ex;
+            for(int i = 0; i < m; ++i) {
+                in >> ex >> x >> y >> ex;
+                g->add_edge(x, y);
+            }
+            auto v = g->print();
+            out << result(v) << endl;
+            delete g;
+        } else {
+            matrix_graph<char>* g = new matrix_graph<char>(n);
+            char x,y;
+            for(int i = 0; i < n; ++i) {
+               in >> x;
+               g->add_node(x);
+            }
+            char ex;
+            for(int i = 0; i < m; ++i) {
+                in >> ex >> x >> y >> ex;
+                g->add_edge(x, y);
+            }
+
+            auto v = g->print();
+            out << result(v) << endl;
+            delete g;
+        }
+    }
+    in.close();
+    out.close();
+    return 0;
+}
diff --git a/Year_1/Programming_2/exercises/minore.cc b/Year_1/Programming_2/exercises/minore.cc
new file mode 100644
index 0000000..677da76
--- /dev/null
+++ b/Year_1/Programming_2/exercises/minore.cc
@@ -0,0 +1,27 @@
+#include<iostream>
+#include<string>
+#include<fstream>
+
+using namespace std;
+
+int main() {
+    ifstream in("input.txt");
+    ofstream out("output.txt");
+
+    for(int ts = 0; ts < 100; ++ts) {
+        string s;
+        in >> s;
+        int minor = stoi(s);
+        for(in >> s; s != "STOP"; in >> s) {
+            int si = stoi(s);
+            if(si < minor)
+                minor = si;
+        }
+
+        out << minor << '\n';
+    }
+
+    in.close();
+    out.close();
+    return 0;
+}
diff --git a/Year_1/Programming_2/exercises/pop-stack.cc b/Year_1/Programming_2/exercises/pop-stack.cc
new file mode 100644
index 0000000..3739450
--- /dev/null
+++ b/Year_1/Programming_2/exercises/pop-stack.cc
@@ -0,0 +1,132 @@
+#include<iostream>
+#include<fstream>
+
+using namespace std;
+
+template<class T>
+class node {
+public:
+    node(T key, node<T>* next) : _key{key}, _next{next} {}
+    node(T key) : _key{key}, _next{nullptr} {}
+    const T& key() const { return _key; }
+    T& key() { return _key; }
+    const node<T>*& next() const { return _next; }
+    node<T>*& next() { return _next; }
+private:
+    T _key;
+    node<T>* _next;
+};
+
+template<class T>
+class Pila {
+public:
+    Pila() : _head{nullptr}{}
+    ~Pila() {
+
+    }
+    Pila<T>* push(T val) {
+        if(!_head) {
+            _head = new node<T>{val, nullptr};
+        } else {
+            _head = new node<T>{val, _head};
+        }
+
+        return this;
+    }
+    node<T>* pop() {
+        if(!_head) return nullptr;
+        node<T>* elem = _head;
+        delete _head;
+        _head = elem->next();
+
+        return elem;
+    }
+
+    bool is_empty() { return _head == nullptr; }
+private:
+    node<T>* _head;
+};
+
+int main() {
+    ifstream in("input.txt");
+    ofstream out("output.txt");
+
+    for(int ts = 0; ts < 100; ++ts) {
+        string t;
+        int n;
+        in >> t;
+        switch(t.at(0)) {
+        case 'b': {
+            Pila<bool>* stack = new Pila<bool>{};
+            in >> n;
+            string s;
+            for(int i = 0; i < n; ++i) {
+                in >> s;
+                if(s.at(0) == 'i') {
+                    stack->push(s.at(1) - '0');
+                } else {
+                    stack->pop();
+                }
+            }
+            while(!stack->is_empty())
+                out << stack->pop()->key() << ' ';
+            out << endl;
+            break;
+        }
+        case 'd': {
+            Pila<double>* stack = new Pila<double>{};
+            in >> n;
+            string s;
+            for(int i = 0; i < n; ++i) {
+                in >> s;
+                if(s.at(0) == 'i') {
+                    stack->push(stod(s.substr(1, s.length()-1)));
+                } else {
+                    stack->pop();
+                }
+            }
+            while(!stack->is_empty())
+                out << stack->pop()->key() << ' ';
+            out << endl;
+            break;
+        }
+        case 'c': {
+            Pila<char>* stack = new Pila<char>{};
+            in >> n;
+            string s;
+            for(int i = 0; i < n; ++i) {
+                in >> s;
+                if(s.at(0) == 'i') {
+                    stack->push(s.at(1));
+                } else {
+                    stack->pop();
+                }
+            }
+            while(!stack->is_empty())
+                out << stack->pop()->key() << ' ';
+            out << endl;
+            break;
+        }
+        case 'i': {
+            Pila<int>* stack = new Pila<int>{};
+            in >> n;
+            string s;
+            for(int i = 0; i < n; ++i) {
+                in >> s;
+                if(s.at(0) == 'i') {
+                    stack->push(stoi(s.substr(1, s.length()-1)));
+                } else {
+                    stack->pop();
+                }
+            }
+            while(!stack->is_empty())
+                out << stack->pop()->key() << ' ';
+            out << endl;
+            break;
+        }
+        }
+    }
+    in.close();
+    out.close();
+    return 0;
+}
diff --git a/Year_1/Programming_2/exercises/prima-maiuscola.cc b/Year_1/Programming_2/exercises/prima-maiuscola.cc
new file mode 100644
index 0000000..6273219
--- /dev/null
+++ b/Year_1/Programming_2/exercises/prima-maiuscola.cc
@@ -0,0 +1,30 @@
+#include<iostream>
+#include<string>
+#include<fstream>
+
+using namespace std;
+
+string result(string s) {
+    s.at(0) = toupper(s.at(0));
+
+    return s;
+}
+
+int main() {
+    ifstream in("input.txt");
+    ofstream out("output.txt");
+
+    for(int ts = 0; ts < 100; ++ts) {
+        int _;
+        string s;
+        for(int i = 0; i < 3; ++i) {
+            in >> _ >> s;
+            out << result(s) << ' ';
+        }
+        out << '\n';
+    }
+
+    in.close();
+    out.close();
+    return 0;
+}
diff --git a/Year_1/Programming_2/exercises/ripetute.cc b/Year_1/Programming_2/exercises/ripetute.cc
new file mode 100644
index 0000000..23d151a
--- /dev/null
+++ b/Year_1/Programming_2/exercises/ripetute.cc
@@ -0,0 +1,20 @@
+#include<iostream>
+#include<string>
+#include<fstream>
+
+using namespace std;
+
+int main() {
+    ifstream in("input.txt");
+    ofstream out("output.txt");
+
+    for(int ts = 0; ts < 100; ++ts) {
+        string s;
+        in >> s;
+        out << s+s << '\n';
+    }
+
+    in.close();
+    out.close();
+    return 0;
+}
diff --git a/Year_1/Programming_2/exercises/sol-ripetute.cc b/Year_1/Programming_2/exercises/sol-ripetute.cc
new file mode 100644
index 0000000..1518d76
--- /dev/null
+++ b/Year_1/Programming_2/exercises/sol-ripetute.cc
@@ -0,0 +1,25 @@
+#include<iostream>
+#include<string>
+#include<fstream>
+
+using namespace std;
+
+string result(string s) {
+    int half = s.length()/2;
+    return s.substr(0, half);
+}
+
+int main() {
+    ifstream in("input.txt");
+    ofstream out("output.txt");
+
+    for(int ts = 0; ts < 100; ++ts) {
+        string s;
+        in >> s;
+        out << result(s) << '\n';
+    }
+
+    in.close();
+    out.close();
+    return 0;
+}
diff --git a/Year_1/Programming_2/exercises/sottosequenza.cc b/Year_1/Programming_2/exercises/sottosequenza.cc
new file mode 100644
index 0000000..1d7c481
--- /dev/null
+++ b/Year_1/Programming_2/exercises/sottosequenza.cc
@@ -0,0 +1,26 @@
+#include<iostream>
+#include<fstream>
+
+using namespace std;
+
+int main() {
+    ifstream in("input.txt");
+    ofstream out("output.txt");
+
+    for(int ts = 0; ts < 100; ++ts) {
+        int n; string s;
+        in >> n >> s;
+        string tm;
+        for(int i = 0; i < n; ++i) {
+            in >> tm;
+            if(tm.find(s) != string::npos)
+                out << tm << ' ';
+        }
+        out << '\n';
+    }
+
+    in.close();
+    out.close();
+
+    return 0;
+}
diff --git a/Year_1/Programming_2/exercises/stringa-inversa.cc b/Year_1/Programming_2/exercises/stringa-inversa.cc
new file mode 100644
index 0000000..5c37718
--- /dev/null
+++ b/Year_1/Programming_2/exercises/stringa-inversa.cc
@@ -0,0 +1,26 @@
+#include<iostream>
+#include<fstream>
+
+using namespace std;
+
+int main() {
+    ifstream in("input.txt");
+    ofstream out("output.txt");
+
+    for(int ts = 0; ts < 100; ++ts) {
+        int n;
+        in >> n;
+        for(int i = 0; i < 3; ++i) {
+            string s;
+            in >> s;
+            for(int j = s.length()-1; j > -1; --j) {
+                out << s.at(j);
+            }
+            out << ' ';
+        }
+        out << endl;
+    }
+
+    out.close();
+    in.close();
+}