题解 | #查找两个字符串a,b中的最长公共子串#

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) {
        test65();
    }
    private static void test65() {
        Scanner in = new Scanner(System.in);
        // 注意 hasNext 和 hasNextLine 的区别
        // 注意 while 处理多个 case
        while (in.hasNext()) {
            String a = in.nextLine();
            String b = in.nextLine();
            int n = Math.min(a.length(), b.length());

            String aa = a.length() == n ? a : b;
            String bb = a.length() != n ? a : b;

            int[] db = new int[n];
            for (int i = 0; i <= n - 1; i++) {
                db[i] = 0;
                for (int j = 0; j <= i; j++) {
                    if (bb.contains(aa.substring(j, i + 1))) {
                        db[i] = Math.max(db[i], aa.substring(j, i + 1).length());
                    }
                }
            }

            int v = 0;
            for (int j : db) {
                v = Math.max(v, j);
            }

            for (int i = 0; i < db.length; i++) {
                if (db[i] == v) {
                    System.out.println(aa.substring(i + 1 - v, i + 1));
                    break;
                }
            }
        }

    }
}