code: public int getLongestSuffixLength(String word)
      {
          word = reverse(word);
          LinkedList<Map.Entry<String, Integer>> suffixList = trie.commonPrefixSearchWithValue(word);
          if (suffixList.size() == 0) return 0;
          return suffixList.getLast().getValue();
      }
docs: 获取最长的后缀
  @param word
  @return