[JAVA/코딩테스트] 귤 고르기

문제

https://school.programmers.co.kr/learn/courses/30/lessons/138476

프로그래머스

 

import java.util.*;

class Solution {
     public int solution(int k, int[] tangerine) {

        List<Integer> keySet = new ArrayList<>();
        HashMap<Integer,Integer> map = new HashMap<>();

        int answer = Integer.MAX_VALUE;

        Arrays.sort(tangerine);

        for(int i=0; i<tangerine.length; i++){
            if(!map.containsKey(tangerine[i])){
                map.put(tangerine[i], 1);
            }else{
                map.put(tangerine[i], map.get(tangerine[i]).intValue()+1);
            }
        }


        keySet.addAll(map.keySet());

        // Value 값으로 오름차순 정렬
        keySet.sort(new Comparator<Integer>() {
            @Override
            public int compare(Integer o1, Integer o2) {
                return map.get(o2).compareTo(map.get(o1));
            }
        });

        int sum = 0;
        int index = 0;

        for(int i=0; i<keySet.size(); i++){
            
            sum += map.get(keySet.get(i)).intValue();

            if(k<=sum){
                answer = Math.min(answer, (i+1)-index);
                sum = 0;
                index++;
            }
            
        }

        if(answer == Integer.MAX_VALUE){
            answer = 1;
        }

        return answer;
    }
}