leetcode1328

 1 class Solution:
 2     def breakPalindrome(self, palindrome: str) -> str:
 3         n = len(palindrome)
 4         if n <= 1:
 5             return ‘‘
 6         half = n // 2
 7         sub = palindrome[0:half]#不包含index==half的字符
 8         
 9         for i in range(len(sub)):
10             c = palindrome[i]
11             if ord(c) > ord(‘a‘):
12                 palindrome = palindrome[0:i] + ‘a‘ + palindrome[i+1:]
13                 return palindrome
14         begin = half if n % 2 == 0 else (half + 1)
15         for j in range(n-1,begin-1,-1):
16             c = palindrome[j]
17             if ord(c) < ord(‘z‘):
18                 palindrome = palindrome[0:j] + chr(ord(c) + 1) + palindrome[j+1:]
19                 return palindrome
20         return ‘‘