using System;

​

class Point 

{

    public int x {get; private set;}

    public int y {get; private set;}

​

    public Point(int x, int y) 

    {

        this.x = x;

        this.y = y;

    }

​

    public override bool Equals(object obj) 

    {

        return obj is Point p && x == p.x && y == p.y;

    }

​

    public override int GetHashCode() 

    {

        return x + y; 

    }

​

    public override String ToString() 

    {

        return $"({x}, {y})";

    }

​

    public Point Copy() 

    {

        return this.MemberwiseClone() as Point;

    }

}

​

public static class App {

    public static void Main() 

    {

        var p1 = new Point(1,2);

        var p2 = p1.Copy();

        var p3 = new Point(2,4);

        Console.WriteLine("p1 : " + p1);

        Console.WriteLine("p2 : " + p2);

        Console.WriteLine("p3 : " + p3);

        Console.WriteLine();

​

        Console.WriteLine("p1 same as p2 : " + Object.ReferenceEquals(p1, p2));

        Console.WriteLine("p1 égal p2    : " + Object.Equals(p1, p2));

        Console.WriteLine("p1 égal p2    : " + p1.Equals(p2));

        Console.WriteLine("p1 égal p3    : " + p1.Equals(p3));

        Console.WriteLine("p1 égal null  : " + p1.Equals(null));

        Console.WriteLine("p1 == p2      : " + (p1 == p2) );

        Console.WriteLine();

        Console.WriteLine("p1 hashcode : " + p1.GetHashCode());

        Console.WriteLine("p3 hashcode : " + p3.GetHashCode());

    }

}

​