学习python语法,用py写发尺取
学习了pthon中的map
要注意特判空字符串
class Solution:
def lengthOfLongestSubstring(self, s):
"""
:type s: str
:rtype: int
"""
dict = {}
l = len(s)
if l==0 :
return l
for i in range(l):
dict[s[i]] = -1
a = 0
b = 1
ans = 1
dict[s[a]] = 1
while b<l:
if dict[s[b]]==-1:
ans = max(ans,b-a+1)
dict[s[b]]=1
b+=1
else:
dict[s[a]] = -1
a+=1
return ans