code: public static float trigram(List<Word> words){
          if(words.size() > 2){
              float score=0;
              for(int i=0; i<words.size()-2; i++){
                  score += Trigram.getScore(words.get(i).getText(), words.get(i+1).getText(), words.get(i+2).getText());
              }
              return score;
          }
          return 0;
      }
docs: 计算分词结果的三元模型分值
  @param words 分词结果
  @return 三元模型分值