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]
