49. Group Anagrams

Added solution for 49. Group Anagrams

Author: IshanAryendu

java/49_Group_Anagrams.java

@@ -0,0 +1,20 @@
+class Solution {
+    public List<List<String>> groupAnagrams(String[] strs) {
+        List<List<String>> res = new ArrayList<>();
+        if(strs.length==0) return res;
+        HashMap<String, List<String>> map = new HashMap();
+        for(String s: strs){
+            char[] hash = new char[26];
+            for(char c: s.toCharArray()){
+                hash[c-'a']++;
+            }
+            String str=new String(hash);
+            if(map.get(str)==null){
+                map.put(str, new ArrayList<>());
+            }
+            map.get(str).add(s);
+        }
+        res.addAll(map.values());
+        return res;
+    }
+}