A program to estimate number of users that a network could support with packet switching by entering the required parameters.

Main.kt

//Author Name : Muhammad Ehsan ul Haq
fun main(args : Array<String>) {
                                    //active probability  totalRate/UserNeededRate   Required probability
    var Users =  UsersNumberPrediction(0.25,                    8000/500,                       0.9)
    println("Number of Users that can be connected simultaneously using Packet Switching = " + Users)
    println("SMG = " + Users.toDouble()/(8000.0/500.0))
}

fun factorial(A: Int) : Double{
    if(A <= 1)
        return 1.0
    return A * factorial(A - 1)
}

fun UsersNumberPrediction(p : Double, X : Int, expProb : Double) : Int{
    var i = 1
    while(CumulativeBinomialDistribution(p, i, X) >= expProb ){
        i++
    }
    return --i
}

fun CumulativeBinomialDistribution(p: Double, N : Int, X :Int) : Double{
    if(X == 0)
        return BinomialDistribution(p, N, 0)
    return BinomialDistribution(p, N, X) + CumulativeBinomialDistribution(p, N, X - 1)
}

fun BinomialDistribution(p: Double, N : Int, X : Int) : Double{
    val NFac = factorial(N)
    val XFac = factorial(X)
    val DiffNX = factorial(N - X)
    val PPowerX = Math.pow(p, X.toDouble())
    val OneMinusProb = Math.pow((1-p), (N - X).toDouble())

    return (NFac / (XFac * DiffNX)) * PPowerX * OneMinusProb
}