12. Integer to Roman

    let romanLUT = [(1000, "M"),
                    (900, "CM"),
                    (500, "D"),
                    (400, "CD"),
                    (100, "C"),
                    (90, "XC"),
                    (50, "L"),
                    (40, "XL"),
                    (10, "X"),
                    (9, "IX"),
                    (5,"V"),
                    (4, "IV"),
                    (1, "I")]

    func intToRoman(_ num: Int) -> String
    {
        var remainder = num
        var result = ""
        for (denom, symbol) in romanLUT
        {
            let symCount = remainder / denom
            remainder = remainder % denom
            for _ in 0..<symCount
            {
                result += symbol
            }
        }
        return result
    }