Number+random.swift

extension Int {
    static func randomNumber(min:Int , max:Int)->Int {
        var minimum = min
        var maximum = max
        if minimum < 0 { minimum = 0 }
        if maximum < 0 { maximum = 0 }
        if minimum == maximum { return minimum }
        else if minimum > maximum { return randomNumber(min:maximum , max:minimum) }
        return minimum + Int(arc4random())%(maximum - minimum)
    }
}