실패율

https://programmers.co.kr/learn/courses/30/lessons/42889

코딩테스트 연습 - 실패율

 

 

---

내 풀이

func solution(_ N:Int, _ stages:[Int]) -> [Int] {

    var failureRateDictionary: [Int: Double] = [Int: Double]()

    let numberOfUser: Int = stages.count
    var numberOfFailedUser: Int = 0

    for round in (1...N) {
        let numberOfReached: Int = numberOfUser - numberOfFailedUser

        if numberOfReached == 0 {
            failureRateDictionary[round] = 0
        }else {
            let failRoundUser: Int = stages.filter({$0 == round}).count
            failureRateDictionary[round] = Double(failRoundUser) / Double(numberOfReached)
            numberOfFailedUser += failRoundUser
        }
    }
    
    let result: [Int] = failureRateDictionary.sorted(by: {
        if $0.value != $1.value {
            return $0.value > $1.value
        }
        return $0 < $1
    }).map({$0.key})
    
    return result
}

테스트 9, 22번 시간초과,..