feat: singular list

1 files changed, 105 insertions, 0 deletions

diff --git a/I_anno/Programmazione_2/data_structures/list.cc b/I_anno/Programmazione_2/data_structures/list.cc
new file mode 100644
index 0000000..c0915e7
--- /dev/null
+++ b/I_anno/Programmazione_2/data_structures/list.cc
@@ -0,0 +1,105 @@
+#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 != nullptr) {
+            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) {
+        node<T>* iter = _head;
+        if(_head == nullptr) {
+            _head = new node<T>{val, nullptr};
+        } else {
+            while(iter->next != nullptr) {
+                iter = iter->next;
+            }
+            iter->next = new node<T>{val, nullptr};
+        }
+
+        return this;
+    }
+
+    list* push_after_value(T val, T newval) {
+        node<T>* iter = _head;
+        while(iter && iter->value != val)
+            iter = iter->next;
+
+        if(iter == nullptr)
+            return this->push_front(newval);
+
+        iter->next = new node<T>{newval, iter->next};
+
+        return this;
+    }
+
+    list* push_before_value(T val, T newval) {
+        node<T>* iter = _head;
+
+        while(iter && iter->next && iter->next->value != val)
+            iter = iter->next;
+
+        if(iter == nullptr)
+            return this->push_front(newval);
+
+        iter->next = new node<T>{newval, iter->next};
+
+        return this;
+    }
+
+    void print() {
+        node<T>* iter = _head;
+        while(iter != nullptr) {
+            cout << iter->value << ' ';
+            iter = iter->next;
+        }
+    }
+private:
+    node<T>* _head;
+};
+
+int main() {
+    list<double>* l = new list<double>{};
+    l->push_front(2)->push_front(1.7);
+    // 1.7 2
+
+    l->push_back(5.2);
+    // 2 1.7 5.2
+
+    l->push_back(10.1)->push_back(15);
+    // 2 1.7 5.2 10.1 15
+
+    l->push_after_value(5.2, 6.4);
+    // 2 1.7 5.2 6.4 10.1 15
+
+    l->push_before_value(5.2, 4.1);
+    // 2 1.7 4.1 5.2 6.4 10.1 15
+
+    l->push_before_value(4.1, 3.0);
+    // 2 1.7 3.0 4.1 5.2 6.4 10.1 15
+    l->print();
+
+    return 0;
+}