Stack - C++

CPP/data-structures/stack.cpp

@@ -0,0 +1,69 @@
+#include <iostream>
+
+using namespace std;
+
+template <typename T>
+class stack {
+public:
+	T *arr;
+	int top;
+	size_t capacity;
+	size_t size;
+
+	stack (size_t capacity) {
+	    this->capacity = capacity;
+	    arr = new T[capacity];
+	    top = -1;
+	    size = 0;
+	}
+
+    void push(T data) {
+        if (size < capacity) {
+            arr[++top] = data;
+            ++size;
+        } else {
+            T *arr2 = new T[capacity * 2];
+            for (int i = 0; i < capacity; ++i) {
+                arr2[i] = arr[i];
+            }
+            arr2[++top] = data;
+            ++size;
+            capacity *= 2;
+
+            delete []arr;
+            arr = arr2;
+        }
+    }
+
+	void pop() {
+	    if (is_empty()) {
+	        cout << "Stack is empty" << endl;
+	        return;
+	    }
+	    --top;
+	    --size;
+	}
+
+	T peek() {
+	    if (is_empty()) {
+	        exit(-1);
+	    }
+	    return arr[top];
+	}
+
+	bool is_empty() {
+	    if (size != 0) {
+	        return false;
+	    }
+	    return true;
+	}
+
+	~stack() {
+	    delete []arr;
+	}
+};
+
+int main()
+{
+	return 0;
+}