comefrom: <awangdev>Longest Substring Without Repeating Characters_1.java
code: public int lengthOfLongestSubstring(String s) {
          if (s == null || s.length() == 0) {
              return 0;
          }
          boolean[] chars = new boolean[256]; 
          int rst = 0;
          int start = 0;
          int end = 0;
          while (start < s.length()) {
              while (end < s.length() && !chars[s.charAt(end)]) {
                  chars[s.charAt(end)] = true;
                  rst = Math.max(rst, end - start + 1);
                  end++;
              }
              chars[s.charAt(start)] = false;
              start++;
          }
          return rst;
      }
masked: public int sample_funcname ( String var_0 ) {
    if ( var_0 == null || var_0 . length ( ) == 0 ) {
      return 0 ;
    }
    boolean [ ] var_1 = new boolean [ 256 ] ;
    int var_2 = 0 ;
    int var_3 = 0 ;
    int var_4 = 0 ;
    while ( var_3 < var_0 . length ( ) ) {
      while ( var_4 < var_0 . length ( ) && ! var_1 [ var_0 . charAt ( var_4 ) ] ) {
        var_1 [ var_0 . charAt ( var_4 ) ] = true ;
        var_2 = Math . max ( var_2 , var_4 - var_3 + 1 ) ;
        var_4 ++ ;
      }
      var_1 [ var_0 . charAt ( var_3 ) ] = false ;
      var_3 ++ ;
    }
    return var_2 ;
  }
  