interleaving-string

Given s1, s2, s3, find whether s3 is formed by the interleaving of s1 and s2.

For example,
Given:
s1 ="aabcc",
s2 ="dbbca",

When s3 ="aadbbcbcac", return true.
When s3 ="aadbbbaccc", return false.

 1 public class Solution {
 2     public static void main(String[] args)
 3     {
 4         Solution s=new Solution();
 5         String s1="ab";
 6         String s2="";
 7         String s3="ba";
 8         System.out.println(s.isInterleave(s1, s2, s3));
 9     }
10     
11     public boolean isInterleave(String s1, String s2, String s3) {
12        int len1=s1.length();
13        int len2=s2.length();
14        int len3=s3.length();
15         
16         if (s3==null||s3.length()==0)
17             return false;
18         
19         if (len3!=len1+len2)
20             return false;
21         
22         char[] ch1=s1.toCharArray();
23         char[] ch2=s2.toCharArray();
24         char[] ch3=s3.toCharArray();
25         
26         Boolean flag=isInterleave(ch1,len1-1,ch2,len2-1,ch3,len3-1);
27         return flag;
28     }
29     
30     public boolean isInterleave(char[] ch1,int len1,char[] ch2,int len2, char[] ch3,int len3)
31     {
32         Boolean result=false;
33         char c1=' ',c2=' ',c3=' ';
34         if(len1>=0)
35         c1=ch1[len1];
36         
37         if(len2>=0)
38         c2=ch2[len2];
39         
40         if(len3>=0)
41         c3=ch3[len3];
42         
43         if (c3!=c1&&c3!=c2)
44             return false;
45         
46         if(len3==1&&len1==1&&c3==c1)
47         {
48             return true;
49         }
50         
51         if(len3==1&&len2==1&&c3==c2)
52         {
53             return true;
54         }
55         
56         if (c3==c1&&c3!=c2)
57         {
58             result=isInterleave(ch1,len1-1,ch2,len2,ch3,len3-1);
59         }
60         
61         if (c3==c2&&c3!=c1)
62         {
63             result=isInterleave(ch1,len1,ch2,len2-1,ch3,len3-1);
64         }
65         
66         if(c3==c2&&c3==c1)
67         {
68             result=isInterleave(ch1,len1-1,ch2,len2,ch3,len3-1);
69             if(result==false)
70                 result=isInterleave(ch1,len1,ch2,len2-1,ch3,len3-1);
71         }
72         
73         return result;
74         
75         
76     }
77 }

自己写的代码，在本地调没问题，但是提交到牛客网中显示运行错误，不知道怎么回事。（在牛客网提交时注意将main函数注释掉）