귤 고르기 - Level 2

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
class Solution {
   public int solution(int k, int[] tangerine) {
        int answer = 0;
        HashMap<Integer, Integer> hashMap1 = new HashMap<>();
        for (Integer integer : tangerine) {
            // 값에 따라 몇개를 들고 있는지 확인.
            hashMap1.put(integer, hashMap1.getOrDefault(integer,0)+1);
        }

        List<Integer> keySet = new ArrayList<>(hashMap1.keySet());
        // value값순으로 내림차순
        keySet.sort(((o1, o2) -> hashMap1.get(o2).compareTo(hashMap1.get(o1))));
       
        int count = 0;
        while(true){
            k -= hashMap1.get(keySet.get(count));
            if(k <= 0) {
                answer++;
                break;
            }

            answer++;
            count++;
        }


        return answer;
    }
}