两个栈实现堆

class CQueue:
    def __init__(self):
        self.inner = []
        self.outer = []
    def appendTail(self, value: int) -> None:
        self.inner.append(value)
    def deleteHead(self) -> int:
        if len(self.inner) ==0 and len(self.outer)== 0:  # 啥都没就别瞅了
            return -1 
        if len(self.outer) != 0: 
            return self.outer.pop()
        while len(self.inner) != 0:
            self.outer.append(self.inner.pop())
        return self.outer.pop()

https://leetcode-cn.com/problems/yong-liang-ge-zhan-shi-xian-dui-lie-lcof/