Group Anagrams

Given an array of strings, group anagrams together.

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Example:

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

Note:

• All inputs will be in lowercase.
• The order of your output does not matter.

class Solution {
    public List<List<String>> groupAnagrams(String[] strs) {
  if (strs.length == 0) return new ArrayList();
        Map<String, List> ans = new HashMap<String, List>();
        for (String s : strs) {
            char[] ca = s.toCharArray();
            Arrays.sort(ca);
            String key = String.valueOf(ca);
            if (!ans.containsKey(key)) ans.put(key, new ArrayList());
            ans.get(key).add(s);
        }
        return new ArrayList(ans.values());
    }
}


Here string is to be stored as a key to check whether the same string is already present or not. For comparison of string , it is to be converted to character array and sort it and compare it with other strings.


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