text: int lengthOfLastWord(char* s) {
      if(NULL == s){
          return 0;
      }
      
      int len = strlen(s);
      if(len <= 0){
          return 0;
      }
      
      char* prev = NULL;
      char* current = NULL;
      char* delim = " ";
      
      current = strtok(s, delim);
      if(NULL == current){
          return 0;
      }
      
      do{
          prev = current;
          current = strtok(NULL, delim);
      }while(NULL != current);
      
      return strlen(prev);
      
  }