romanNumerals.swift

func romanNumerals(input: Int) -> String {
    var number = input
    let numerals = ["M", "M", "D", "CD", "C", "XC", "L", "XL", "X", "IX", "V", "IV", "I"]
    let values = [1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1]

    var numeralString = ""
    for (i, numeral) in numerals.enumerate() {
        while number >= values[i] {
            number -= values[i]
            numeralString += numeral
        }
    }

    return numeralString
}