func digit(character:Character) -> Int? {
    let digitValue: Int?
    switch character{
    case "0":
        digitValue = 0
    case "1":
        digitValue = 1
    case "2":
        digitValue = 2
    case "3":
        digitValue = 3
    case "4":
        digitValue = 4
    case "5":
        digitValue = 5
    case "6":
        digitValue = 6
    case "7":
        digitValue = 7
    case "8":
        digitValue = 8
    case "9":
        digitValue = 9
    default:
        digitValue = nil
    }                                                         return digitValue
}
func number(string:String) -> Int {
    var n = 0

    for character in string {
        let digitValue = digit(character:character)
        if digitValue != nil {
            n *= 10
            n += digitValue!
        }
    }
    return n
}
// Prints the specific bill used (if it can be apliied to the current situation)
// Returns the number of bills issued
func printBill (dollars:Int, billValue:Int) -> Int{
    var billCount = 0
    var remainingDollars = dollars

    while (remainingDollars >= billValue) {
        billCount += 1
        remainingDollars -= billValue
    }

    var printString = "\(billCount) x $\(billValue) bill"
    if billCount > 1 {
        printString += "s"
    }
    if billCount > 0 {
        print(printString)
    }
    return billCount
}

func currencyString(dollars:Int, cents:Int) -> String {
    let dollarString = "$\(dollars)"
    var cents = "\(cents)"
    if cents.count < 2 {
        cents = "0" + cents
    }

    let completeString = dollarString + "." + cents
    return completeString
}
func printCent (Cent:Int, centValue:Int) -> Int{
    var centCount = 0
    var remainingCents = Cent

    while (remainingCents >= centValue) {
        centCount += 1
        remainingCents -= centValue
    }
    var printString = ""
    switch centValue {
    case 50:
        printString = "\(centCount) x half-dollar coin"
    case 25:
        printString = "\(centCount) x quarter"
    case 10:
        printString = "\(centCount) x dime"
    case 5:
        printString = "\(centCount) x nickel"
    case 1:
        printString = "\(centCount) x penny"
    default:
        break
    }
    if centValue == 1 && centCount > 1{
        printString = "\(centCount) x pennies"
        print(printString)
    }
    else if centCount > 1  {
        printString += "s"
        print(printString)
    }
    else if centCount > 0 {
        print(printString)
    }
    return centCount
}
//This prints the bills used added to the sum of dollars
// This returns the number of bills which were used
func printBills(dollars:Int) -> Int {
    var remainingDollars = dollars
    var totalBillsIssued = 0

    let hundredsValue = 100
    let hundredsIssued = printBill(dollars:remainingDollars, billValue:hundredsValue)
    totalBillsIssued += hundredsIssued
    remainingDollars -= hundredsIssued * hundredsValue

    let fiftiesValue = 50
    let fiftiesIssued = printBill(dollars:remainingDollars, billValue:fiftiesValue)
    totalBillsIssued += fiftiesIssued
    remainingDollars -= fiftiesIssued * fiftiesValue

    let twentiesValue = 20
    let twentiesIssued = printBill(dollars:remainingDollars, billValue:twentiesValue)
    totalBillsIssued += twentiesIssued
        remainingDollars -= twentiesIssued * twentiesValue

        let tensValue = 10
        let tensIssued = printBill(dollars:remainingDollars, billValue:tensValue)
        totalBillsIssued += tensIssued
        remainingDollars -= tensIssued * tensValue

        let fivesValue = 5
        let fivesIssued = printBill(dollars:remainingDollars, billValue:fivesValue)
        totalBillsIssued += fivesIssued
        remainingDollars -= fivesIssued * fivesValue

        let twosValue = 2
        let twosIssued = printBill(dollars:remainingDollars, billValue:twosValue)
        totalBillsIssued += twosIssued
        remainingDollars -= twosIssued * twosValue

        let onesValue = 1
        let onesIssued = printBill(dollars:remainingDollars, billValue:onesValue)
        totalBillsIssued += onesIssued
        remainingDollars -= onesIssued * onesValue

        return totalBillsIssued
}
func printCents(cents:Int) -> Int {
    var remainingCents = cents
    var totalCoinsIssued = 0

    let halfDollarValue = 50
    let halfDollarsIssued = printCent(Cent:remainingCents, centValue:halfDollarValue)
    totalCoinsIssued += halfDollarsIssued
    remainingCents -= halfDollarsIssued * halfDollarValue

    let quarterValue = 25
    let quarterIssued = printCent(Cent:remainingCents, centValue:quarterValue)
    totalCoinsIssued += quarterIssued
    remainingCents -= quarterIssued * quarterValue

    let dimeValue = 10
    let dimeIssued = printCent(Cent:remainingCents, centValue:dimeValue)
    totalCoinsIssued += dimeIssued
    remainingCents -= dimeIssued * dimeValue

    let nickelValue = 5
    let nickelIssued = printCent(Cent:remainingCents, centValue:nickelValue)
    totalCoinsIssued += nickelIssued
    remainingCents -= nickelIssued * nickelValue

    let penniesValue = 1
    let penniesIssued = printCent(Cent:remainingCents, centValue:penniesValue)
    totalCoinsIssued += penniesIssued
    remainingCents -= penniesIssued * penniesValue

    return totalCoinsIssued
}
func printDenominations(forSum:String){
    let totalcents = number(string:forSum)
    let dollars = totalcents / 100
    let cents = totalcents % dollars

    let originalSum =  "Original sum: \(currencyString(dollars:dollars, cents:cents))"
    print(originalSum)

    let billsIssued = printBills(dollars:dollars)
    let coinsIssued = printCents(cents:cents)

    print("")
    print("Bills: \(billsIssued)")
    print("Coins: \(coinsIssued)")
}                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
    switch character{