算法提高 最长字符序列

 1 import java.math.BigInteger;
 2 import java.util.Arrays;
 3 import java.util.Scanner;
 4 
 5 
 6 public class Main {
 7     static String a;
 8     static String b;
 9     static int max;
10     static StringBuffer s;
11     static StringBuffer s1;
12     public static void main(String[] args) {
13         Scanner input = new Scanner(System.in);
14         a = input.next();
15         b = input.next();
16         s = new StringBuffer();
17         s1 = new StringBuffer();
18         f(0);
19         System.out.println(max);
20         
21     }
22     public static void f(int i){
23         int h;
24         for(h=i;h<a.length();h++){
25             s.append(a.charAt(h));
26             if(f1(s.toString())){
27                 if(max<s.length()){
28                     max = s.length();
29                 }
30             }
31             f(h+1);
32             s.deleteCharAt(s.length()-1);
33         }
34     }
35     public static boolean f1(String temp){
36         int j = 0;
37         for(int i=0;i<b.length();i++){
38             if(b.charAt(i)==temp.charAt(j)){
39                 j++;
40                 if(j==temp.length()){
41                     break;
42                 }
43             }
44         }
45         if(j==temp.length()) return true;
46         else return false;
47     }
48 }