2019-08-24LeetCode155. 最小栈

5min，一次过，爽啊

class MinStack:

    def __init__(self):
        """
        initialize your data structure here.
        """
        self.store=[]
        self.min_store=[]

    def push(self, x: int) -> None:
        self.store.append(x)
        if not self.min_store:self.min_store.append(x)
        elif x<self.min_store[-1]:self.min_store.append(x)
        elif x>=self.min_store[-1]:self.min_store.append(self.min_store[-1])

    def pop(self) -> None:
        self.store.pop()
        self.min_store.pop()

    def top(self) -> int:
        return self.store[-1]

    def getMin(self) -> int:
        return self.min_store[-1]