49 Group Anagrams

Given an array of strings, group anagrams together.

Example:

Input: ["eat", "tea", "tan", "ate", "nat", "bat"],
Output:
[
  ["ate","eat","tea"],
  ["nat","tan"],
  ["bat"]
]


 public List<List<String>> groupAnagrams(String[] strs) {
        
        List<List<String>> result = new ArrayList();
        HashMap<String,List<String>> map = new HashMap();
        //["eat", "tea", "tan", "ate", "nat", "bat"]
        for(int i=0;i<strs.length;i++){
            char[] characters = strs[i].toCharArray(); //e a t
            Arrays.sort(characters); // a e t
            String sorted = new String(characters);//aet -- eat
            
            if(!map.containsKey(sorted)){
                map.put(sorted,new ArrayList());
            }
            
            map.get(sorted).add(strs[i]);  
        }
        
        result.addAll(map.values());
        return result;
    }

    //HasHMap<String,List<String>>
    
    //aet , List<eat,tea,ate>             
    //ant , List<tan,nat>
    //abt , List<bat>