What are some examples of C++ stack implementations?

Can you give me some examples of stack implementations in C++?

Sure! A stack in C++ can be implemented using arrays or linked lists. Would you like to see code examples for both?

Yes, please show me the array implementation first.

Here's a simple array-based stack implementation:

class Stack {
private:
    int top;
    int capacity;
    int* stack;

public:
    Stack(int size) {
        capacity = size;
        top = -1;
        stack = new int[capacity];
    }

    ~Stack() {
        delete[] stack;
    }

    void push(int x) {
        if (top == capacity - 1) {
            std::cout << "Stack Overflow";
            return;
        }
        stack[++top] = x;
    }

    int pop() {
        if (top == -1) {
            std::cout << "Stack Underflow";
            return -1;
        }
        return stack[top--];
    }
};

Would you like to see the linked list implementation next?

Yes, that would be great!

Here's a simple linked list-based stack implementation:

class Node {
public:
    int data;
    Node* next;
};

class Stack {
private:
    Node* top;

public:
    Stack() {
        top = nullptr;
    }

    void push(int x) {
        Node* newNode = new Node();
        newNode->data = x;
        newNode->next = top;
        top = newNode;
    }

    int pop() {
        if (top == nullptr) {
            std::cout << "Stack Underflow";
            return -1;
        }
        int popped = top->data;
        Node* temp = top;
        top = top->next;
        delete temp;
        return popped;
    }
};

Let me know if you need further explanations!