题解 | #最长回文子串#

#
# 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
#
# 
# @param A string字符串 
# @return int整型
#
class Solution:
    def getLongestPalindrome(self , A: str) -> int:
        ans = 1
        if len(A) > 1 and A[0] == A[1]:
            ans =2
        def f1(i,j):
            if i-j < 0 or i+j > len(A)-1:
                return j*2-1
            elif A[i-j] == A[i+j]:
                return f1(i,j+1)
            else:
                return j*2-1
        def f2(i,j):
            if i-j < 0 or i+j+1 > len(A)-1:
                return j*2
            elif A[i-j] == A[i+j+1]:
                return f2(i,j+1)
            else:
                return j*2
        for i in range(1,len(A)-1):
            if A[i-1] == A[i+1]:
                ans = max(ans,f1(i,2))
            if A[i] == A[i+1]:
                ans = max(ans,f2(i,1))
                print(ans)
        return ans