Leetcode 225 Implement Stack using Queues Solution in java | Hindi Coding Community

 

Implement a last-in-first-out (LIFO) stack using only two queues. The implemented stack should support all the functions of a normal stack (push, top, pop, and empty).

Implement the MyStack class:

void push(int x) Pushes element x to the top of the stack.

int pop() Removes the element on the top of the stack and returns it.

int top() Returns the element on the top of the stack.

boolean empty() Returns true if the stack is empty, false otherwise.

class MyStack {

    private Queue<Integer> queue = new LinkedList<>();

    public void push(int x) {

        queue.add(x);

        for (int i=1; i<queue.size(); i++)

            queue.add(queue.remove());

    }

    public void pop() {

        queue.remove();

    }

    public int top() {

        return queue.peek();

    }

    public boolean empty() {

        return queue.isEmpty();

    }

}