# @File: stack
# 列表实现栈
class MyStack(object):
def __init__(self):
self.data = []
def push(self, item):
self.data.append(item)
def pop(self):
return self.data.pop()
def top(self):
return self.data[-1]
def is_empty(self):
return self.data == []
def size(self):
return len(self.data)
stack = MyStack()
stack.push(9)
stack.push(9)
print(stack)
print(stack.top())
print(stack.pop())
print(stack)
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import queue
stack = queue.LifoQueue() # 可看LifoQueue的源码，就是以上原理
stack.put(1)
stack.put(2)
print(stack.get())
print(stack.queue)
print(stack.qsize())
# stack.empty() # 栈空
# stack.full() # 栈满
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# 例子（括号匹配）
def bracket_match(s):
stack = []
d = {"}": "{", ']': '[', ')': ')'}
for ch in s:
if ch in {'{', '[', '('}:
stack.append(ch)
elif len(stack) == 0:
print('缺少左括号')
elif d[ch] == stack[-1]:
stack.pop()
else:
print('左右括号不匹配')
return False
if len(stack) > 0:
print('缺少右括号')
return False
else:
return True
# print(bracket_match("[(])"))
