comefrom: <awangdev>844. Backspace String Compare_1.java
code: private int backtrack(String s, int index) {
  
          int i = index, count = 0;
          while (i >= 0) {
              if (s.charAt(i) == '#') {
                  count++;
                  i--;
              } else if (count > 0) {
                  count--;
                  i--;
              } else break;
          }
          return i;
      }
masked: private int sample_funcname ( String var_1 , int var_2 ) {
    int var_3 = var_2 , var_5 = 0 ;
    while ( var_3 >= 0 ) {
      if ( var_1 . charAt ( var_3 ) == '#' ) {
        var_5 ++ ;
        var_3 -- ;
      }
      else if ( var_5 > 0 ) {
        var_5 -- ;
        var_3 -- ;
      }
      else break ;
    }
    return var_3 ;
  }
  