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.hasNext()) { // 注意 while 处理多个 case String a = in.next(); String b = in.next(); if(a.length() > b.length()){ zichuan(b,a); }else{ zichuan(a,b); } } } public static void zichuan(String s1, String s2) { //i代表子串长度 for (int i = s1.length(); i > 0; i--) { //遍历每个子串长度 //遍历s1 for (int j = 0; j < s1.length() + 1 - i; j++) { if (s2.contains(s1.substring(j, j + i))) { System.out.print(s1.substring(j, j + i)); return; } } } } }