실패율

package programmers;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;

public class 실패율 {

   public static int[] solution(int N, int[] stages) {
      HashMap<Integer, Double> map = getMap(N, stages);
      List<Integer> list = new ArrayList<>(map.keySet());

      sortByValue(map, list);

      return listToIntArray(list);
   }

   private static int[] listToIntArray(List<Integer> list) {
      int[] answer = new int[list.size()];
      for (int i = 0; i < list.size(); i++) {
         answer[i] = list.get(i);
      }
      return answer;
   }

   private static void sortByValue(HashMap<Integer, Double> map, List<Integer> list) {
      list.sort((o1, o2) -> {
         if (map.get(o2) - map.get(o1) == 0) {
            return o1 - o2;
         }
         if (map.get(o2) - map.get(o1) > 0) {
            return 1;
         } else if (map.get(o2) - map.get(o1) < 0) {
            return -1;
         }
         return 0;
      });
   }

   private static HashMap<Integer, Double> getMap(int N, int[] stages) {
      HashMap<Integer, Double> map = new HashMap<>();

      for (int i = 1; i <= N; i++) {
         int nonClear = 0;
         int player = 0;
         for (int stage : stages) {
            if (stage >= i) {
               player++;
               if (stage == i) {
                  nonClear++;
               }
            }
         }
         if (player == 0) {
            map.put(i, 0.0);
            continue;
         }
         double fail = (double)nonClear / player;

         map.put(i, fail);
      }
      return map;
   }

   public static void main(String[] args) {
      System.out.println(Arrays.toString(solution(5, new int[] {2, 1, 2, 6, 2, 4, 3, 3})));
      System.out.println(Arrays.toString(solution(4, new int[] {4, 4, 4, 4, 4})));
   }
}