PolydivisibleGenerator.swift

//Note : this is just an experimental, only works with "1", working for works with any number
//In mathematics a polydivisible number is a number with digits abcde... that has the following properties :
//Its first digit a is not 0.
//The number formed by its first two digits ab is a multiple of 2.
//The number formed by its first three digits abc is a multiple of 3.
//The number formed by its first four digits abcd is a multiple of 4..etc

extension Int {
    func numberOfDigits () -> Int {
        var cont = 0, num = self
        while (num != 0) {
            num = num / 10
            cont++
        }
        return cont
    }
}

struct PolydivisibleGenerator : GeneratorType {
    typealias Element = Int
    var num : Int
    init(num : Int){
        self.num = num
    }
    
    mutating func next() -> Element? {
        while (true) {
            if(num % num.numberOfDigits() == 0) {
                num*=10
                return num
            } else { num++ }
            
        }
    }
}

struct Polydivisible : SequenceType {
    let n : Int
    
    init(n : Int){
        self.n = n
        assert(n != 0, "n != 0")
    }
    
    func generate() -> PolydivisibleGenerator {
        return PolydivisibleGenerator(num: n)
    }
}
var pol = Polydivisible(n: 1).generate()
for _ in 1..<15 {
    println(pol.next())
} 
//OUTPUT ->
//Optional(10)
//Optional(100)
//Optional(1020)
//Optional(10200)
//Optional(102000)
//Optional(1020000)
//Optional(10200050)
//Optional(102000560)
//Optional(1020005640)
//Optional(10200056400)
//Optional(102000564050)
//Optional(1020005640600)
//Optional(10200056406020)
//Optional(102000564060220)