[LeetCode] Interleaving String

Problem:

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.

Solution:O(n)

public class Solution {
    public boolean isInterleave(String s1, String s2, String s3) {
       if(s3.length()!=s1.length()+s2.length()) 
          return false;    
        
       boolean [][] match = new boolean [s1.length()+1][s2.length()+1];
       match[0][0]=true;
       
       int i=1;
       while(i<=s1.length() && s1.charAt(i-1)==s3.charAt(i-1)){
           match[i][0]=true;
           i++;
       }
       
       i=1;
       while(i<=s2.length() && s2.charAt(i-1)==s3.charAt(i-1)){
           match[0][i]=true;
           i++;
       }
       
       for(i=1;i<=s1.length();i++){
           for(int j=1;j<=s2.length();j++){
               char c = s3.charAt(i+j-1);
               if(c==s1.charAt(i-1))
                match[i][j]=match[i-1][j] || match[i][j];
               if(c==s2.charAt(j-1))
                match[i][j]=match[i][j-1] || match[i][j];
           }
       }
      return match[s1.length()][s2.length()];
    }
}