[프로그래머스] 베스트 앨범

import java.util.*;

class Solution {
    class song{
        int plays;
        String genres;
        int index;
        
        song(int plays, String genres,int index){
            this.plays=plays;
            this.genres= genres;
            this.index = index;
        }
    }
    
    class Compare{
        String genres;
        int totalPlays;
        
        Compare(String genres, int totalPlays){
            this.genres = genres;
            this.totalPlays = totalPlays;
        }
    }
    
    public int[] solution(String[] genres, int[] plays) {
        int[] answer = {};
        
        List<Integer> answerList = new ArrayList<>();
        Map<String,Integer> countGenres = new HashMap<>();
        List<song> songs = new ArrayList<>();
        List<Compare> compares = new ArrayList<>();
        
        for(int i=0; i<genres.length; i++){
            songs.add(new song(plays[i],genres[i],i));
        }
        
        Collections.sort(songs, new Comparator<song>(){
            public int compare(song s1, song s2){
                if(s1.plays==s2.plays){
                    return 0;
                }else{
                    return s2.plays - s1.plays;
                }
            }    
        });
    
        
        for(int i=0; i<genres.length; i++){
            if(countGenres.containsKey(genres[i])){
                countGenres.put(genres[i],countGenres.get(genres[i])+plays[i]);
            }else{
                countGenres.put(genres[i],plays[i]);
            }
        }
        
        for(String s : countGenres.keySet()){
            compares.add(new Compare(s,countGenres.get(s)));
        }
        
        Collections.sort(compares, new Comparator<Compare>(){
            public int compare(Compare c1, Compare c2){
                return c2.totalPlays - c1.totalPlays;
            }
        });
    
        for(int i=0; i<compares.size(); i++){
            int count=0;
                for(int k=0; k<songs.size(); k++){
                    if(songs.get(k).genres.equals(compares.get(i).genres)){
                        answerList.add(songs.get(k).index);
                        count++;
                    }
                    if(count==2){
                        break;
                    }
                }
        }
   
        answer = new int[answerList.size()];
        
        for(int i=0; i<answer.length; i++){
            answer[i] = answerList.get(i);
        }
        return answer;
    }
}

메소드로 분리해서 푸는 습관을 들여야겠다...