1 class Solution {
2 public List<String> topKFrequent(String[] words, int k) {
3 HashMap<String, Integer> map = new HashMap<>();
4 List<String> res = new ArrayList<>();
5 if(words.length == 0) return res;
6 for(String word : words){
7 map.put(word, map.getOrDefault(word, 0) + 1);
8 }
9 List<String>[] arr = new ArrayList[words.length+1];
10 for(String word : map.keySet()){
11 if(arr[map.get(word)] == null){
12 arr[map.get(word)] = new ArrayList<>();
13 }
14 arr[map.get(word)].add(word);
15 }
16 int count = 0;
17 for(int i = arr.length - 1; i >= 0; i--){
18 if(arr[i] != null){
19 Collections.sort(arr[i]);
20 for(int j = 0; j < arr[i].size(); j++){
21 if(count < k){
22 res.add(arr[i].get(j));
23 count++;
24 }
25 }
26 if(count == k){
27 break;
28 }
29 }
30 }
31 return res;
32
33 }
34 }
