comefrom: <awangdev>727. Minimum Window Subsequence_1.java
code: private int backtrack(char[] ss, char[] tt, int index) {
  
          for (int i = tt.length - 1; i >= 0; i--) {
              while(ss[index--] != tt[i]);
          }
          return index + 1; 
      }
masked: private int sample_funcname ( char [ ] var_0 , char [ ] var_1 , int var_2 ) {
    for ( int var_5 = var_1 . length - 1 ;
    var_5 >= 0 ;
    var_5 -- ) {
      while ( var_0 [ var_2 -- ] != var_1 [ var_5 ] ) ;
    }
    return var_2 + 1 ;
  }
  