DSA Day 44/100

DSA Day 44/100

Topic: Stack

Questions Successfully Completed: 1

1) Implement Stack using Linked List

Easy

Implementing Stack using Linked List

Question
Input: push(2) push(3) pop() push(4) pop() Output: 3 4 Explanation: push(2) the stack will be {2} push(3) the stack will be {2 3} pop() poped element will be 3,   the stack will be {2} push(4) the stack will be {2 4} pop() poped element will be 4
class MyStack 
{
    // class StackNode {
    //     int data;
    //     StackNode next;
    //     StackNode(int a) {
    //         data = a;
    //         next = null;
    //     }
    // }   
    StackNode top;

    //Function to push an integer into the stack.
    void push(int a) 
    {
        StackNode s = new StackNode(a);
        s.next = top;
        top = s;
    }

    //Function to remove an item from top of the stack.
    int pop() 
    {
        if(top==null){return -1;}
        int x = top.data;
        top = top.next;
        return x;
    }
}

Thank you for reading :)