题解 | #最长回文子串#

import java.util.Scanner;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    /**
     * 判断是否是回文串
     */
    public static boolean isPalindrome(String text) {
        return text.equals(new StringBuilder(text).reverse().toString());
    }

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String text = sc.next();
        int ans = 1;
        int n = text.length();
        for (int i = 0; i < n; i++) {
            for (int j = i + 1; j <= n; j++) {
                if (j - i < ans) {
                    continue;
                }
                String s = text.substring(i, j);
                if (isPalindrome(s)) {
                    ans = Math.max(ans, s.length());
                }
            }
        }
        System.out.println(ans);
    }
}