Difficulty: Medium
Given an array of strings, group anagrams together.
Example:
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| 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.
Solution
Language: Java
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| class Solution {
public List<List<String>> groupAnagrams(String[] strs) {
List<List<String>> result = new ArrayList<>();
if (strs == null || strs.length == 0) {
return result;
}
Map<String, Integer> indexMap = new HashMap<>();
for (String s : strs) {
String key = genKey(s);
if (!indexMap.containsKey(key)) {
indexMap.put(key, result.size());
result.add(new ArrayList<>());
}
result.get(indexMap.get(key)).add(s);
}
return result;
}
private String genKey(String s) {
char[] a = s.toCharArray();
Arrays.sort(a);
return new String(a);
}
}
|