题解 | 最长回文子串

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        while (in.hasNextLine()) {
            String str = in.nextLine();
            int max = 1;
            for (int i = 0; i < str.length(); i++) {
                int l = i;
                int r = i;
                // 奇数回文
                while (l >= 0 && r < str.length()) {
                    if (str.charAt(l) != str.charAt(r)) {
                        break;
                    }
                    max = Math.max(r - l + 1, max);
                    l--;
                    r++;
                }
                // 偶数回文
                l = i;
                r = i + 1;
                while (l >= 0 && r < str.length()) {
                    if (str.charAt(l) != str.charAt(r)) {
                        break;
                    }
                    max = Math.max(r - l + 1, max);
                    l--;
                    r++;
                }
            }
            System.out.println(max);
        }
    }
}