프로그래머스 - 해시 - 베스트앨범 문제

best_albums.py

class Song:
    def __init__(self, number, play):
        self.number = number
        self.play = play


class Genre:
    def __init__(self, name):
        self.name = name
        self.song_list = []  # (song_index, its_played_count)
        self.total_played = 0

        
def solution(genres, plays):
    SONGS_PER_GENRE = 2
    genre_used = {}
    ans = []
    
    for i, g, p in zip(range(len(plays)), genres, plays):
        genre_used[g] = genre_used.get(g) or Genre(g)
        
        genre = genre_used[g]
        genre.total_played += p
        song = Song(i, p)
        genre.song_list.append(song)
        
    genre_list = list(v for k, v in genre_used.items())
    # 1. 정렬 기준: 장르 총 재생 횟수 기준 내림차순
    genre_list.sort(key=lambda x: x.total_played, reverse=True)
    
    # 2. 정렬 기준: 장르 내 재생 횟수 내림차순 및 노래 번호 오름차순
    for genre in genre_list:
        genre.song_list.sort(key=lambda x: (-x.play, x.number))
        ans.extend(
            song.number for song in genre.song_list[:SONGS_PER_GENRE]
        )

    return ans