C#•7d ago

✅ Finding all possibilities of N length in an array

Hey so I have the Following code which basically iterate on all my tiles and create arrays of 3 of them, iterating on all possibilities

List<Tile[]> tiles = [];
for (int i = 0; i < matching.Length - 1; i++)
{
    for (int y = i + 1; y < matching.Length - 1; y++)
    {
        tiles.Add([tile, matching[i], matching[y]]);
    }
}
return tiles;

List<Tile[]> tiles = [];
for (int i = 0; i < matching.Length - 1; i++)
{
    for (int y = i + 1; y < matching.Length - 1; y++)
    {
        tiles.Add([tile, matching[i], matching[y]]);
    }
}
return tiles;

I'm trying to make this code generic so instead of arrays of 3, it can be array of N, but I'm not sure how to approche that Could someone please help me with that?

12 Replies

ero•7d ago

What is matching in this case? You're checking its length, but then access Deck. Seems like a mistake?

ZirkOP•7d ago

Hmm, yeah it's some old code and I think it was indeed a mistake I'll edit the post but it's supposed to be the same list yeah my bad

ero•7d ago

if ((matching.Length % N) != 0)
  throw new ArgumentException();

for (int i = 0; i < matching.Length - N; i += N)
{
  var arr = new Tile[N + 1];
  arr[0] = tile;

  for (int j = 0; j < N; j++)
  {
    arr[1 + j] = matching[i + j];
  }

  tiles.Add(arr);
}

if ((matching.Length % N) != 0)
  throw new ArgumentException();

for (int i = 0; i < matching.Length - N; i += N)
{
  var arr = new Tile[N + 1];
  arr[0] = tile;

  for (int j = 0; j < N; j++)
  {
    arr[1 + j] = matching[i + j];
  }

  tiles.Add(arr);
}

Something like that

ZirkOP•7d ago

I'll need to put that on a paper so my two braincells can understand what is happening but I'll investigate that, thanks a lot

ero•7d ago

There's an easier way actually

ZirkOP•7d ago

Oh, what is it if I may ask?

ero•7d ago

if ((matching.Length % N) != 0)
  throw new ArgumentException();

for (int i = 0; i < matching.Length - N; i += N)
{
  var arr = new Tile[N + 1];
  arr[0] = tile;
  matching.AsSpan(i).CopyTo(arr, 1);

  tiles.Add(arr);
}

if ((matching.Length % N) != 0)
  throw new ArgumentException();

for (int i = 0; i < matching.Length - N; i += N)
{
  var arr = new Tile[N + 1];
  arr[0] = tile;
  matching.AsSpan(i).CopyTo(arr, 1);

  tiles.Add(arr);
}

This should probably also work? Or if you don't like the tospan Mh nah the alternative would suck Ah wait you need to slice matching as well

ZirkOP•7d ago

So from what I understand is final size is 3 and I have [1, 2, 3, 4, 5], 0 given It would give 0, 1, 2, 3 0, 2, 3, 4 0, 3, 4, 5 Right? wait no let me edit

ero•7d ago

Ah, was that the goal? I assumed 1, 2, 3, 4, 5, 6 etc

ZirkOP•7d ago

Maybe im wrong im just trying to understand your code

0 (given)
1 2 3

0 1 2
0 1 3
0 2 3

0 (given)
1 2 3

0 1 2
0 1 3
0 2 3

my goal was this To get all different possibilities So with

But with 4 values instead of 3 it increase a lot the amount of combinaisons

ero•7d ago

for (int i = 0; i < matching.Length - N; i++)
{
  var arr = new Tile[N + 1];
  arr[0] = tile;

  for (int j = 0; j < N; j++)
  {
    arr[1 + j] = matching[i + 1 + j];
  }

  tiles.Add(arr);
}

for (int i = 0; i < matching.Length - N; i++)
{
  var arr = new Tile[N + 1];
  arr[0] = tile;

  for (int j = 0; j < N; j++)
  {
    arr[1 + j] = matching[i + 1 + j];
  }

  tiles.Add(arr);
}

Shouldn't be more complicated than this then

ZirkOP•7d ago

Oh that's simpler than expected I'll try with that, thanks :)

Gaming

Programming

✅ Finding all possibilities of N length in an array

Did you find this page helpful?