Given a roman numeral, convert it to an integer.

RomanNumerals.kt

/*
Given a string, s, that represents a Roman numeral, return its associated integer value.
Ex: s = "DCLII", return 652.
* */
fun romanToInt(s: String): Int {
    val map: MutableMap<Char, Int> = mutableMapOf(
        'I' to 1, 'V' to 5, 'X' to 10, 'L' to 50, 'C' to 100, 'D' to 500, 'M' to 1000
    )
    var number = 0
    var last = 1000
    for (it: Char in s) {
        val value: Int = map.getValue(it)
        if (value > last) {
            number -= last * 2
        }
        number += value
        last = value
    }
    return number
}