comefrom: <awangdev>Interleaving String_4.java
code: public boolean isInterleave(String s1, String s2, String s3) {
          if (s3 == null || (s1 == null && s2 == null) || s1.length() + s2.length() != s3.length()) {
          	return false;
          }
  
          int i = 0; 
          int j = 0;
          String base = "";
          for (int k = 0; k < s1.length()*s2.length() - 1; k++) {
          	if (i < s1.length() || j < s2.length()) {
  	        	if (i < s1.length() && s3.indexOf(base + s1.charAt(i)) == 0) {
  	        		base += s1.charAt(i);
  	        		i++;
  	        	} else if (j < s2.length() && s3.indexOf(base + s2.charAt(j)) == 0) {
  	        		base += s2.charAt(j);
  	        		j++;
  	        	} else {
  	        		return false;
  	        	}
          	}
          }
          return true;
      }
masked: public boolean var_0 ( String var_1 , String var_2 , String var_3 ) {
    if ( var_3 == null || ( var_1 == null && var_2 == null ) || var_1 . length ( ) + var_2 . length ( ) != var_3 . length ( ) ) {
      return false ;
    }
    int var_4 = 0 ;
    int var_5 = 0 ;
    String var_6 = "" ;
    for ( int var_7 = 0 ;
    var_7 < var_1 . length ( ) * var_2 . length ( ) - 1 ;
    var_7 ++ ) {
      if ( var_4 < var_1 . length ( ) || var_5 < var_2 . length ( ) ) {
        if ( var_4 < var_1 . length ( ) && var_3 . indexOf ( var_6 + var_1 . charAt ( var_4 ) ) == 0 ) {
          var_6 += var_1 . charAt ( var_4 ) ;
          var_4 ++ ;
        }
        else if ( var_5 < var_2 . length ( ) && var_3 . indexOf ( var_6 + var_2 . charAt ( var_5 ) ) == 0 ) {
          var_6 += var_2 . charAt ( var_5 ) ;
          var_5 ++ ;
        }
        else {
          return false ;
        }
      }
    }
    return true ;
  }
  