Implement Stack Using Queues - Leetcode Solution

Implement Stack using Queues Link

Companies: Microsoft

Implement the following operations of a stack using queues.

push(x) — Push element x onto stack.
pop() — Removes the element on top of the stack.
top() — Get the top element.
empty() — Return whether the stack is empty.

Example:

MyStack stack = new MyStack();

stack.push(6);

stack.push(3);

stack.top(); // returns 3

stack.pop(); // returns 3

stack.top(); // returns 6

stack.empty(); // returns false

Notes:

• You must use only standard operations of a queue — which means only push to back, peek/pop from front, size, and is empty operations are valid.
• Depending on your language, queue may not be supported natively. You may simulate a queue by using a list or deque (double-ended queue), as long as you use only standard operations of a queue.
• You may assume that all operations are valid (for example, no pop or top operations will be called on an empty stack).

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