题目描述
定义栈的数据结构，请在该类型中实现一个能够得到栈中所含最小元素的min函数（时间复杂度应为O（1））。
# -*- coding:utf-8 -*-
class Solution:
def __init__(self):
self.stack = []
self.min_stack = []
def push(self, node):
# write code here
if not self.min_stack or node < self.min_stack[-1]:
self.min_stack.append(node)
self.stack.append(node)
def pop(self):
# write code here
if self.stack[-1]==self.min_stack[-1]:
self.min_stack.pop()
return self.stack.pop()
def top(self):
# write code here
return self.stack[-1]
def min(self):
# write code here
return self.min_stack[-1]