LeetCode - Group Anagrams

28 Dec 2017 • LeetCode

Question Definition

Given an array of strings, group anagrams together.

For example, given: ["eat", "tea", "tan", "ate", "nat", "bat"], Return:

[
  ["ate", "eat","tea"],
  ["nat","tan"],
  ["bat"]
]

Note: All inputs will be in lower-case.

Java Solution

public List<List<String>> groupAnagrams(String[] strs) {
    Map<String, List<String>> map = new HashMap<>();
    for(String str : strs){
        char[] chars = str.toCharArray();
        Arrays.sort(chars);
        String key = new String(chars);
        map.putIfAbsent(key, new LinkedList<>());
        map.get(key).add(str);
    }
    return new LinkedList<>(map.values());
}

LeetCode Medium Hash Table

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