베스트 앨범

programmers.co.kr/learn/courses/30/lessons/42579?language=javascript

코딩테스트 연습 - 베스트앨범

function solution(genres, plays) {
    const summaryGenres = genres.reduce((acc, cur, index) => {
        if (!acc[cur]) {
            acc[cur] = {
                totalPlay: 0,
                playList: []
            };
        }
        acc[cur].totalPlay += plays[index];
        acc[cur].playList.push([index, plays[index]]);
        return acc;
    }, {});
    
    const summaryGenresList = Object.values(summaryGenres).sort((a, b) => b.totalPlay - a.totalPlay);
    const answer = summaryGenresList.reduce((acc, cur) => {
        cur.playList.sort((a,b) => b[1] - a[1]);
        acc.push(cur.playList[0][0]);
        if (cur.playList.length > 1) acc.push(cur.playList[1][0]);
        return acc;
    }, []);
    return answer;
}