C#

class Program
{
    static void Main(string[] args)
    {
        var client = new SmtpClient("smtp.gmail.com", 465)
        {
            UseDefaultCredentials = false,
            Credentials = new NetworkCredential("me@gmail.com", "mypass"),
            EnableSsl = true,
        };
        client.Send("me@gmail.com", "me@gmail.com", "Test", "This is a test");

        Console.WriteLine("Sent");
        Console.ReadLine();
    }
}

private static readonly Random rand = new Random();

private double IntensityFunc(Edge edge)
{
    var hour = DateTime.Now.Hour;

    if (hour > 3 && hour < 12) return edge.IntensityMin;

    if (hour > 22) return edge.IntensityMax;

    return rand.NextDouble() * (edge.IntensityMax - edge.IntensityMin) + edge.IntensityMin;
}

// node or vertex
public class Node: INode // interface not shown 
{
        public Node(string name, int id)
        {
            Name = name;
            Id = id;
        }

	public string Name { set; get; }
	
	public string Id { set; get; }
}

// an edge describes a connection between two nodes
public class Edge: IEdge // interface not shown 
{
    public Edge(Node node1, Node node2, double intensity, double intensityMin = 0.0, double intensityMax = 0.0,
        Func<Edge, double> intensityFunc = null)
    {
        Node1 = node1;
        Node2 = node2;
        Intensity = intensity;
        IntensityMin = intensityMin;
        IntensityMax = intensityMax;
        IntensityFunc = intensityFunc;
    }

    public Node Node1 { set; get; }

    public Node Node2 { set; get; }

    public double Intensity { set; get; }

    public double IntensityMin { set; get; }

    public double IntensityMax { set; get; }

    public Func<Edge, double> IntensityFunc { set; get; }

    public double GetIntensity()
    {
        return IntensityFunc?.Invoke(this) ?? Intensity;
    }
}

// usage example
private void Form1_Load(object sender, EventArgs e)
{
    var Jack = new Node("Jack", 1);

    var Jill = new Node("Jill", 2);

    var JackToJill = new Edge(Jack, Jill, 50.0, 20.0, 80.0);

    var jintensity = JackToJill.Intensity;

    JackToJill.IntensityFunc = IntensityFunc;

    // test intensity func
    for (var i = 0; i < 20; i++)
    {
        var jintensity2 = JackToJill.GetIntensity();
        Console.WriteLine(jintensity2);
    }
}

private double IntensityFunc(Edge edge)
{
    var hour = DateTime.Now.Hour;

    if (hour > 3 && hour < 12) return edge.IntensityMin;

    if (hour > 22) return edge.IntensityMax;

    return rand.NextDouble() * (edge.IntensityMax - edge.IntensityMin) + edge.IntensityMin;
}

class Program
    {
        static void Main(string[] args)
        {
            double b;
            double h;

            Console.WriteLine("Basis: ");
            b= Convert.ToDouble(Console.ReadLine());

            Console.WriteLine("Height: ");
            h= Convert.ToDouble(Console.ReadLine());

            double area1 = Program.calcArea(b, h);
            Console.WriteLine("The area of triangle 1 is: ");
            Console.WriteLine(area1);
            Console.ReadLine();
        }

    public static double calcArea(double b, double h)
        {
            return b * h / 2;
        }
    }
}

private void panel1_MouseDown(object sender, MouseEventArgs e)
        {
            LastX = e.X;
            LastY = e.Y;
        }

        private void panel1_Paint(object sender, PaintEventArgs e)
        {
            Graphics G = panel1.CreateGraphics();
            G.DrawLine(Pens.Black, PointX, PointY, LastX, LastY);
            LastX = PointX;
            LastY = PointY;
        }

        private void panel1_MouseMove(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Left)
            {
                PointX = e.X;
                PointY = e.Y;
                panel1_Paint(this, null);