Update 288. Unique Word Abbreviation

Author: futurus

288. Unique Word Abbreviation

@@ -45,3 +45,34 @@ public class ValidWordAbbr {
 // ValidWordAbbr vwa = new ValidWordAbbr(dictionary);
 // vwa.isUnique("Word");
 // vwa.isUnique("anotherWord");
+
+
+// Shorter solution for ref (https://discuss.leetcode.com/topic/30533/java-solution-with-one-hashmap-string-string-beats-90-of-submissions/2)
+public class ValidWordAbbr {
+    HashMap<String, String> map;
+    public ValidWordAbbr(String[] dictionary) {
+        map = new HashMap<String, String>();
+        for(String str:dictionary){
+            String key = getKey(str);
+            // If there is more than one string belong to the same key
+            // then the key will be invalid, we set the value to ""
+            if(map.containsKey(key)){
+                if(!map.get(key).equals(str)){
+                    map.put(key, "");
+                }
+            }
+            else{
+                map.put(key, str);
+            }
+        }
+    }
+
+    public boolean isUnique(String word) {
+        return !map.containsKey(getKey(word))||map.get(getKey(word)).equals(word);
+    }
+    
+    String getKey(String str){
+        if(str.length()<=2) return str;
+        return str.charAt(0)+Integer.toString(str.length()-2)+str.charAt(str.length()-1);
+    }
+}