Leetcode 225. Implement Stack using Queues

https://leetcode.com/problems/implement-stack-using-queues/

Solution:

# T:push: O(n), pop: O(1), top: O(1) S:O(n)
class Queue:
    def __init__(self):
        self.data = collections.deque()
        
    def push(self, x):
        self.data.append(x)
    
    def peek(self):
        return self.data[0]
    
    def pop(self):
        return self.data.popleft()
    
    def size(self):
        return len(self.data)
    
    def empty(self):
        return len(self.data) == 0


class Stack:
    # initialize your data structure here.
    def __init__(self):
        self.q_ = Queue()

    # @param x, an integer
    # @return nothing
    def push(self, x):
        self.q_.push(x)
        for _ in xrange(self.q_.size() - 1):
            self.q_.push(self.q_.pop())

    # @return nothing
    def pop(self):
        self.q_.pop()

    # @return an integer
    def top(self):
        return self.q_.peek()

    # @return an boolean
    def empty(self):
        return self.q_.empty()

Run Time: 40 ms