프로그래머스 - 실패율 2019 KAKAO BILND RECRUITMENT (카카오)

 

시간초과 문제

import Foundation

func solution(_ N:Int, _ stages:[Int]) -> [Int] {
    let failedList: [Int] = Array(1...N).map { index in
        stages.filter { $0 == index }.count
    }
    let challengedList: [Int] = Array(1...N).map { index in
        stages.filter { $0 >= index }.count
    }
    var list: [(Int,Double)] = Array(1...N).map { index in
        let failed = failedList[index-1]
        let challenged = challengedList[index-1]
        let failedRate = Double(Double(failed) / Double(challenged))
        return (index, failedRate)
    }
    list.sort(by: { $0.1 > $1.1 })
    return list.map { $0.0 }
}

 

 

시간초과 해결문제

import Foundation

func solution(_ N:Int, _ stages:[Int]) -> [Int] {
    var failedList: [Int] = .init(repeating: 0, count: N + 1)
    
    for stage in stages {
        if stage <= N {
            failedList[stage] += 1
        }
    }

    var challengedList: [Int] = .init(repeating: 0, count: N + 1)
    var players = stages.count
    for i in 1...N {
        challengedList[i] = players
        players -= failedList[i]
    }
    
    var list: [(Int,Double)] = Array(1...N).map { index in
        let failed = failedList[index]
        let challenged = challengedList[index]
        let failedRate = Double(Double(failed) / Double(challenged))
        return (index, failedRate)
        
    }
    list.sort(by: { $0.1 > $1.1 })
    return list.map { $0.0 }
}