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 {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        // 注意 hasNext 和 hasNextLine 的区别
        // while (in.hasNextInt()) { // 注意 while 处理多个 case
        //     int a = in.nextInt();
        //     int b = in.nextInt();
        //     System.out.println(a + b);
        // }
        String line = in.nextLine();
        int len = line.length();
        int count = 1;
        for (int i = 0; i < len; i++) {
            char c = line.charAt(i);
            int j = i;
            int k = i;
            int temp = 1;
            while (k < len - 1) {
                k++;
                char ck = line.charAt(k);
                if (c == ck) {
                    temp++;
                } else {
                    k--;
                    break;
                }
            }
            while (j > 0 && k < len - 1) {
                k++;
                j--;
                char cj = line.charAt(j);
                char ck = line.charAt(k);
                if (cj == ck) {
                    temp += 2;
                } else {
                    break;
                }
            }
            count = Math.max(count, temp);
        }
        System.out.print(count);
    }
}