cardPackets.swift

import Foundation

/*
 * Complete the 'cardPackets' function below.
 *
 * The function is expected to return an INTEGER.
 * The function accepts INTEGER_ARRAY cardTypes as parameter.
 */

func cardPackets(cardTypes: [Int]) -> Int {
    // Write your code here
    
    // 2 packets
    
    var cardMinimums: [Int: Int] = [:]
    
    for i in 2...5 {
        let minimum = cardsNeeded(packets: i, cardTypes: cardTypes)
        
//        print("@\(i) packets. total = \(minimum)")
        
        cardMinimums[i] = minimum
    }
    
    let cardMinimum = cardMinimums.min { a, b in a.value < b.value }
    
    return cardMinimum?.value ?? 0
}

func nextMod(_ a: Int, _ b: Int) -> Int {
    let nextQuotient: Int = (a / b) + 1
    
    let nextMod = (b * nextQuotient) - a
    
//    print("\(a) %^ \(b) = \(nextMod)")
    
    return nextMod
}

func cardsNeeded(packets: Int, cardTypes: [Int]) -> Int {
    
    var cardCount = 0
    
    for type in cardTypes {
        if type % packets != 0 {
            let remainder = nextMod(type, packets)
            
            cardCount += remainder
        }
    }
    
    return cardCount
}

func generateRandomArray() -> [Int] {
    
    var arr: [Int] = []
    
    for _ in 0...9 {
        arr.append(Int.random(in: 1...9))
    }
    
//    print("random array =", arr)
    return arr
}

//let stdout = ProcessInfo.processInfo.environment["OUTPUT_PATH"]!

let cards = [3,8,7,6,4]
cardPackets(cardTypes: cards) // 2

let cards2 = generateRandomArray()
cardPackets(cardTypes: cards2)