```#
#
# @param s string字符串
# @return bool布尔型
#
import collections
class Solution:
def isValid(self , s ):
# write code here
brackets = [i for i in s]
n = len(brackets)
if n==0 or n%2 == 1:
return False
stack = []
match = {"(":")", "[":"]", "{":"}"}
left = match.keys()
right = match.values()
for n in s:
if n in left:
stack.append(n)
elif n in right:
if not stack:
return False
curr = stack.pop()
if curr in left:
if match[curr]!=n:
return False
else:
return False
if stack:
return False
else:
return True