1 public class ValidWordAbbr { 2     private Map
     
      > dict; 3     public ValidWordAbbr(String[] dictionary) { 4         dict = new HashMap<>(); 5         for (String word : dictionary) { 6             String str = processStr(word); 7             if (!dict.containsKey(str)) { 8                 dict.put(str, new HashSet<>()); 9             }10             dict.get(str).add(word);11         }12     }13 14     public boolean isUnique(String word) {15         String str = processStr(word);16         if (!dict.containsKey(str) || dict.get(str).contains(word) && dict.get(str).size() == 1) {17             return true;18         }19         return false;20     }21     22     private String processStr(String word) {23         if (word.length() <= 2) {24             return word;25         }26         StringBuilder result = new StringBuilder();27         result.append(word.charAt(0));28         result.append(word.length() - 2);29         result.append(word.charAt(word.length() - 1));30         return result.toString();31         32     }33 }34 35 36 // Your ValidWordAbbr object will be instantiated and called as such:37 // ValidWordAbbr vwa = new ValidWordAbbr(dictionary);38 // vwa.isUnique("Word");39 // vwa.isUnique("anotherWord");
     

 

Remember: need to check whether has the word in hashset and garantee size is one.