查找两个字符串a,b中的最长公共子串。若有多个，输出在较短串中最先出现的那个。
import java.util.*;
public class Main{
public static void main(String[] args){
Scanner in = new Scanner(System.in);
while(in.hasNext()){
String s1 = in.nextLine();
String s2 = in.nextLine();
String max = s1.length() >= s2.length()?s1:s2;
String min = s1.length() >= s2.length()?s2:s1;
int l = 0;
String s ="";
for(int i=0;i<min.length();i++){
for(int j=i+1;j<=min.length();j++){
if(max.contains(min.substring(i,j)) && j-i>l){
l=j-i;
s=min.substring(i,j);
}
}
}
System.out.println(s);
}
}
}
