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.hasNextLine()) { // 注意 while 处理多个 case
            int max = 0;
            String line = in.nextLine();
            for(int i = 0;i<= line.length();i++){
                for(int j=0;j<i;j++)
                {
                    String sub = line.substring(j, i);
                    if (sub.length() < 2){
                        continue;
                    }
                    StringBuilder sb = new StringBuilder(sub);
                    String sbr = new String( sb.reverse());
                    if (sub.equals(sbr)){
                        int len = sub.length();
                        if (max < len){
                            max = len;
                        }
                    }
                }
            }
            System.out.println(max);
        }
    }
}