1 files changed, 132 insertions, 0 deletions
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;
+}