CPF Generator

fun main() {
    var generator = GeneratorAlgorithm()

    for (i in 0..100){
        println(generator.generateCPF())
    }
}

class GeneratorAlgorithm() {
    fun generateCPF() : String {
        var buildCPF = ArrayList<Int>()

        for (i in 0..8) {
            buildCPF.add((0..9).random())
        }

        for (i in 0..1) {
            buildCPF.add(digit(buildCPF))
        }

        return buildString(buildCPF)
    }

    private fun digit(buildCPF : ArrayList<Int>) : Int {
        var sum: Int = 0
        var index: Int = buildCPF.size + 1

        for (i in buildCPF) {
            sum += i * index
            index--
        }

        return verifySum(sum)
    }

    private fun verifySum(sum: Int) : Int {
        if ((sum % 11) < 2) return 0 else return 11 - (sum % 11)
    }

    private fun buildString(buildCPF : ArrayList<Int>) : String {
        var getNumbers = ArrayList<String>()

        for (i in buildCPF) {
            getNumbers.add(i.toString())
        }

        var CPF: String = ""

        getNumbers.add(3, ".")
        getNumbers.add(7, ".")
        getNumbers.add(11, "-")

        for (i in getNumbers) {
            CPF += i.toString()
        }

        return CPF
    }
}