692. Top K Frequent Words 

 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 }

 

posted @ 2018-10-28 10:27  jasoncool1  阅读(150)  评论(0)    收藏  举报