题解 | #用两个栈实现队列#
用两个栈实现队列
http://www.nowcoder.com/practice/54275ddae22f475981afa2244dd448c6
class Solution: def __init__(self): self.stack1 = [] self.stack2 = [] def push(self, node): # write code here self.stack1.append(node) def pop(self): # return xx if not self.stack1 and not self.stack2: return None if self.stack2: return self.stack2.pop() else: while self.stack1: self.stack2.append(self.stack1.pop()) return self.stack2.pop()
