LeetCode 0232  Implement Queue using Stacks
Implement Queue using Stacks
Desicription
Implement the following operations of a queue using stacks.
 push(x) – Push element x to the back of queue.
 pop() – Removes the element from in front of queue.
 peek() – Get the front element.
 empty() – Return whether the queue is empty.
Example:


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

