标签：init 插入 val value class tail 声明 object and
用两个栈实现一个队列。队列的声明如下，请实现它的两个函数 appendTail 和 deleteHead ，分别完成在队列尾部插入整数和在队列头部删除整数的功能。(若队列中没有元素，deleteHead 操作返回 -1 )
示例 1：
输入：
["CQueue","appendTail","deleteHead","deleteHead"]
[[],[3],[],[]]
输出：[null,null,3,-1]
示例 2：
输入：
["CQueue","deleteHead","appendTail","appendTail","deleteHead","deleteHead"]
[[],[],[5],[2],[],[]]
输出：[null,-1,null,null,5,2]
class CQueue: def __init__(self): self.s1 = [] self.s2 = [] self.size = 0 def appendTail(self, value: int) -> None: self.s1.append(value) self.size += 1 def deleteHead(self) -> int: if(0 == self.size): return -1 if self.s2 == []: while self.s1 != []: self.s2.append(self.s1.pop()) self.size -= 1 return self.s2.pop() # Your CQueue object will be instantiated and called as such: # obj = CQueue() # obj.appendTail(value) # param_2 = obj.deleteHead()
标签：init 插入 val value class tail 声明 object and
原文地址：https://www.cnblogs.com/boluo007/p/12607437.html
