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);
        String str = in.nextLine();

        if (str.length() == 1) {
            System.out.println(1);
            return;
        }

        int count = 0;
        for (int i = 0; i < str.length() - 1; i++) {
            for (int j = i+1; j < str.length(); j++) {
                if (isHW(str.substring(i, j+1))) {
                    count = Math.max(count, j - i + 1);
                }
            }
        }
        System.out.println(count);
    }

    public static boolean isHW(String str) {
        int m = str.length() / 2;
        for (int i = 0; i < m; i++) {
            if (str.charAt(i) != str.charAt(str.length() -1 - i)) {
                return false;
            }
        }
        return true;
    }
}