题解 | #最长回文子串#

import java.util.*;
public class Main {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        char[] chrs = scan.nextLine().toCharArray();
        int len = chrs.length;
        boolean[][] dp = new boolean[len][len];
        int ans = 1;
        for (int i = len - 1; i > -1; i--) {
            for (int j = i; j < len; j++) {
                if (i == j || (chrs[i] == chrs[j] && (j - i <= 2 || dp[i + 1][j - 1]))) {
                    dp[i][j] = true;
                }
                if (dp[i][j] && j - i + 1 >= ans) {
                    ans = j - i + 1;
                }
            }
        }
        System.out.println(ans);
    }
}