group shifted strings

fishercoder1534 · fishercoder1534 · commit 1119b9fb9b74 · 2016-11-24T10:04:05.000-08:00
diff --git a/EASY/src/easy/GroupShiftedStrings.java b/EASY/src/easy/GroupShiftedStrings.java
@@ -0,0 +1,36 @@
+package easy;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+public class GroupShiftedStrings {
+
+    public List<List<String>> groupStrings(String[] strings) {
+     
+        List<List<String>> result = new ArrayList<List<String>>();
+        Map<String, List<String>> map = new HashMap<String, List<String>>();
+        
+        for(String word : strings){
+            String key = "";
+            int offset = word.charAt(0) - 'a';
+            for(int i = 1; i < word.length(); i++){
+                key += (word.charAt(i) - offset + 26)%26;
+            }
+            
+            if(!map.containsKey(key)) map.put(key, new ArrayList<String>());
+            map.get(key).add(word);
+        }
+        
+        for(List<String> list : map.values()){
+            Collections.sort(list);  
+            result.add(list);            
+        } 
+        
+        return result;
+       
+    }
+
+}
diff --git a/README.md b/README.md
@@ -60,6 +60,7 @@
 |259|[3Sum Smaller](https://leetcode.com/problems/3sum-smaller/)|[Solution](../../blob/master/MEDIUM/src/medium/_3Sum_Smaller.java)| O(n^2)|O(1) | Medium|
 |257|[Binary Tree Paths](https://leetcode.com/problems/binary-tree-paths/)|[Solution](../../blob/master/EASY/src/easy/BinaryTreePaths.java) | O(n*h) | O(h) | DFS/Recursion
 |252|[Meeting Rooms](https://leetcode.com/problems/meeting-rooms/)|[Solution](../../blob/master/EASY/src/easy/MeetingRooms.java) | O(nlogn) | O(1) | 
+|249|[Group Shifted Strings](https://leetcode.com/problems/group-shifted-strings/)|[Solution](../../blob/master/EASY/src/easy/GroupShiftedStrings.java) | O(nlogn) | O(n) | 
 |246|[Strobogrammatic Number](https://leetcode.com/problems/strobogrammatic-number/)|[Solution](../../blob/master/EASY/src/easy/StrobogrammaticNumber.java) | O(n) | O(1) | 
 |243|[Shortest Word Distance](https://leetcode.com/problems/shortest-word-distance/)|[Solution](../../blob/master/EASY/src/easy/ShortestWordDistance.java) | O(n) | O(1) | 
 |223|[Rectangle Area](https://leetcode.com/problems/rectangle-area/)|[Solution](../../blob/master/EASY/src/easy/RectangleArea.java)| O(1)|O(1) | Easy| 
