题解 | #用两个栈实现队列#

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 len(self.stack2) == 0:
            while len(self.stack1) > 0:
                temp = self.stack1.pop()
                self.stack2.append(temp)
        return self.stack2.pop()