你的算法有问题,试试这个:
s = input("请输入字符串: ")
m = 0
for i in range(0, len(s)):
for j in range(i+1,len(s)+1):
tmp = s[i:j]
s1 = set(tmp)
if len(s1) == len(tmp):
mm = len(tmp)
if mm > m:
m = mm
x = tmp
else:
break
print('最长子串长度为: ', m)
print('最长子串为: ', x)