using System;

using System.Collections.Generic;

​

public class Program

{

    public static void Main()

    {

        DoExample();

    }

​

    /// <summary>

    /// Should print a message mentioning the number of primes between 1 and 101

    /// inclusively, [1,101], as well as a list of those prime numbers.

    /// </summary>

    private static void DoExample()

    {

        var primes = new List<int>();

        for (int i = 1; i < 102; i++)

        {

            if (IsPrime(i))

            {

                primes.Add(i);

            }

        }

​

        var primeMessage = string.Empty;

        for (int i = 0; i < primes.Count; i++)

        {

            if (i == primes.Count - 1)

            {

                primeMessage = primeMessage + primes[i];

            }

            else

            {

                primeMessage = primeMessage + primes[i] + ", ";

            }

        }

​

        Console.WriteLine("There are {0} primes in the range [1-101]: {1}", primes.Count, primeMessage);

    }

​

    /// <summary>

    /// Determines if a given number n is prime or not.

    /// A prime number is defined as a number that is only divisible by itself and 1.

    /// </summary>

    /// <param name = "n">The number to evaluate.</param>

    /// <returns>True if n is prime.</returns>

    private static bool IsPrime(int n)

    {

        if (n == 2)

        {

            return true;

        }

        if (n == 1 || n % 2 == 0)

        {

            return false;

        }

        for (int i = 3; i <= Math.Sqrt(n); i += 2)

        {

            if (n % i == 0)

            {

                return false;

            }

        }

​

        return true;

    }

}