题目：

题解：

class MinStack:def __init__(self):self.stack = []self.min_stack = [math.inf]def push(self, x: int) -> None:self.stack.append(x)self.min_stack.append(min(x, self.min_stack[-1]))def pop(self) -> None:self.stack.pop()self.min_stack.pop()def top(self) -> int:return self.stack[-1]def getMin(self) -> int:return self.min_stack[-1]