random Numbergenerator with different numbers

August 11, 2022

I am currently working on one of my first projects in C#.
Right now i want to create something like a lottomachine.
It should output 6 numbers all differnet from eachother in the range of 1-49.

private void random()
{
    Random rnd = new Random();
    z1 = rnd.Next(1, 49);
    z2 = rnd.Next(1, 49);
    if (z1 == z2)
    {
        z2 = rnd.Next(1, 49);
    }
    z3 = rnd.Next(1, 49);
    if ((z1 == z3) || (z2 == z3))
    {
        z3 = rnd.Next(1, 49);
    }
    z4 = rnd.Next(1, 49);
    if ((z1 == z4) || (z2 == z4) || (z3 == z4))
    {
        z4 = rnd.Next(1, 49);
    }
    z5 = rnd.Next(1, 49);
    if ((z1 == z5) || (z2 == z5) || (z3 == z5) || (z4 == z5))
    {
        z5 = rnd.Next(1, 49);
    }
    z6 = rnd.Next(1, 49);
    if ((z1 == z6) || (z2 == z6) || (z3 == z6) || (z4 == z6) || (z5 == z6))
    {
        z6 = rnd.Next(1, 49);
    }
}

The code is working for me currently, but i think there is a better, much shorter way what my code does. Thats why i am asking for advice or for an idea, how to do it better than me.

Thanks in advance.

>Solution :

One way to solve it would be to simulate what a real lotto machine does.

First, put the 49 balls in the bucket:

var bucket = Enumerable.Range(1, 49).ToList();

Then in a loop, determine a random index in the current bucket, get the number at this index and remove it so that it cannot be drawn again

var random = new Random();
for (var i = 0; i < 6; i++)
{
    var index = random.Next(bucket.Count);
    var number = bucket[index];
    Console.WriteLine(number);
    bucket.RemoveAt(index);
}