feat: queue data structure

1 files changed, 74 insertions, 0 deletions

diff --git a/I_anno/Programmazione_2/data_structures/queue.cc b/I_anno/Programmazione_2/data_structures/queue.cc
new file mode 100644
index 0000000..476074f
--- /dev/null
+++ b/I_anno/Programmazione_2/data_structures/queue.cc
@@ -0,0 +1,74 @@
+#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;
+    }
+
+    queue<T>* dequeue() {
+        auto iter = _head;
+
+        if(!_head) return this;
+        while(iter->next != _tail) {
+            iter = iter->next;
+        }
+
+        delete iter->next;
+        iter->next = nullptr;
+        _tail = iter;
+
+        return this;
+    }
+
+    void print() {
+        auto iter = _head;
+        while(iter) {
+            cout << iter->value << ' ';
+            iter = iter->next;
+        }
+        cout << endl;
+    }
+private:
+    node<T>* _tail;
+    node<T>* _head;
+};
+
+int main() {
+    queue<int>* q = new queue<int>();
+
+    q->dequeue();
+    q->enqueue(4)->enqueue(2)->enqueue(8);
+    q->dequeue();
+    q->enqueue(1);
+    q->print();
+
+    delete q;
+    return 0;
+}