题解 | #最长回文子串#

a = list(input())
b = list(reversed(a))

dp = [[0 for i in range(len(a)+1)] for j in range(len(b)+1)]

ml = 0
for i in range(len(a)):
    for j in range(len(b)):
        if a[i] == b[j]:
            dp[i+1][j+1] = dp[i][j] + 1
			%我的评价是神之一笔，判定正反序相同子串是同一序列就可以了
            if dp[i+1][j+1] > ml and abs(j - (len(a)-1-i))+1 == dp[i+1][j+1]:
                ml = dp[i+1][j+1]
print(ml)