text: // Given a List of words, return the words that can be typed using letters of alphabet on only one row's of American keyboard
  
  bool isInString(string row, string word)
  {   bool isIn = true;
      for (int i = 0; i<word.size(); i++)
      {
          if (row.find(word[i]) == -1)
          {
              isIn = false;
              break;
          }
      }
      return isIn;
  }
  
  vector<string> findWords(vector<string>& words) {
      string row1 = "qwertyuiopQWERTYUIOP";
      string row2 = "asdfghjklASDFGHJKL";
      string row3 = "zxcvbnmZXCVBNM";
      
      vector<string> res;
      
      for (int i = 0; i<words.size(); i++)
      {   
          if (isInString(row1, words[i]))
              res.push_back(words[i]);
          else if (isInString(row2, words[i]))
              res.push_back(words[i]);
          else if (isInString(row3, words[i]))
              res.push_back(words[i]);
          else if (words[i].size() == 0)
              res.push_back(words[i]);
      }
      return res;
  }