Question

Write a  C++program to do the following ADT

stack

que

pop

linked list

Answer 1

#include <bits/stdc++.h>

using namespace std;

#define MAX 1000

class Stack {

    int top;

public:

    int a[MAX];

    Stack() { top = -1; }

    bool push(int x);

    int pop();

    int peek();

    bool isEmpty();

};

bool Stack::push(int x)

{

    if (top >= (MAX - 1)) {

        cout << "Stack Overflow";

        return false;

    }

    else {

        a[++top] = x;

        cout << x << " pushed into stack\n";

        return true;

    }

}

int Stack::pop()

{

    if (top < 0) {

        cout << "Stack Underflow";

        return 0;

    }

    else {

        int x = a[top--];

        return x;

    }

}

int Stack::peek()

{

    if (top < 0) {

        cout << "Stack is Empty";

        return 0;

    }

    else {

        int x = a[top];

        return x;

    }

}

bool Stack::isEmpty()

{

    return (top < 0);

}

int main()

{

    class Stack s;

    s.push(10);

    s.push(20);

    s.push(30);

    cout << s.pop() << " Popped from stack\n";

 

    cout<<"Elements present in stack : ";

    while(!s.isEmpty())

    {

        // print top element in stack

        cout<<s.peek()<<" ";

        

        s.pop();

    }

    return 0;

}

Comments

Your code looks like it works just fine! :)

Here are some improvement ideas:

1. Your stack is limited to a predetermined size. It would be nice if either this size is configurable (e.g. passed to the constructor) or the size dynamically changes based on how many elements you put in it.
2. You implemented a concrete stack for integers. The original description talked about abstract data type, so you should implement a generic (template) class instead.