day10.py

# 56ms
class MinStack:
    def __init__(self):
        self.minHistory = [float('inf')]
        self.stack = []

    def push(self, x: int) -> None:
        self.stack += [x]
        if x <= self.minHistory[-1]:
            self.minHistory.append(x)

    def pop(self) -> None:
        if self.stack:
            if self.stack[-1] == self.minHistory[-1]:
                self.minHistory.pop()
            self.stack.pop()

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

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