[Swift 알고리즘] 프로그래머스 Lv1 실패율

programmers.co.kr/learn/courses/30/lessons/42889?language=swift

나의 풀이

 

import Foundation

func solution(_ N:Int, _ stages:[Int]) -> [Int] {
 
    var failure: [Int: Float] = [:]
    var player: Int = stages.count
    
    for i in 1...N {
        let n = stages.filter { $0 == i }.count
        failure[i] = Float(n)/Float(player)
        player -= n
    }

    return failure.sorted(by: <).sorted(by: { $0.value > $1.value }).map {$0.key}
}