CppDSA/35_stack_Implement.cpp at main · Rishav07-05/CppDSA · GitHub

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// stack implementaion
// Two type of stack implementaion => 1. Linked List , 2. Array

#include <iostream>
#include <stack>
using namespace std;

class Stack
{
    // properties
public:
    int *arr;
    int top;
    int size;

    // behaviour
    Stack(int size)
    {
        this->size = size;
        arr = new int[size];
        top = -1;
    }

    void push(int element)
    {
        if (size - top > 1)
        {
            top++;
            arr[top] = element;
        }
        else
        {
            cout << "Stack Overflow" << endl;
        }
    }

    void pop()
    {
        if (top >= 0)
        {
            top--;
        }
        else
        {
            cout << "Stack underflow";
        }
    }

    int peek()
    {
        if (top >= 0)
        {
            return arr[top];
        }
        else
        {
            cout << "Stack is Empty" << endl;
            return -1;
        }
    }

    bool isEmpty()
    {
        if (top == -1)
            return true;
        else
        {
            return false;
        }
    }
};

int main()
{
    Stack st(5);

    st.push(22);
    st.push(43);
    st.push(20);

    cout << st.peek() << endl;

    st.pop();

    cout << st.peek() << endl;

    st.pop();

    cout << st.peek() << endl;

    st.pop();

    cout << st.peek() << endl;
}