Implement Stack using Queues
Easy
Topics
Implement a last-in-first-out (LIFO) stack using only queues. Implement MyStack with push(x), pop() (removes and returns the top element), top() (returns the top element), and empty().
Example 1
Input: operations = ["MyStack","push","push","top","pop","empty"], values = [[],[1],[2],[],[],[]] Output: [null,null,null,2,2,false]
Constraints
- 1 <= x <= 9
- At most 100 calls to push, pop, top, and empty.
- pop and top are only called on a non-empty stack.
Run ⌘' · Submit ⌘⏎