Implement-Stack-Using-Queues.py

class MyStack:

    def __init__(self):
        """
        Initialize your data structure here.
        """
        self.q = []

    def push(self, x: int) -> None:
        """
        Push element x onto stack.
        """
        self.q.append(x)
        for i in range(len(self.q)-1):
            self.q.append(self.q.pop(0))

    def pop(self) -> int:
        """
        Removes the element on top of the stack and returns that element.
        """
        return self.q.pop(0)

    def top(self) -> int:
        """
        Get the top element.
        """
        return self.q[0]


    def empty(self) -> bool:
        """
        Returns whether the stack is empty.
        """
        n = len(self.q)
        return n==0