How to make Flood fill algorithm return different Lists of separate groups in the grid?

Question

So i have this flood fill method :

 public int groupedCells(int y, int x, int value)
{
    //base state
    if (!gSetup.isValidLocation(y, x) ||
        gSetup.getCell(y, x).value != value ||
        gSetup.getCell(y, x).cMAtch.isInMatchPool)
    {
        return 0;
    }

    // keep track of matched cells
    gSetup.getCell(y, x).cMAtch.isInMatchPool = true;

    // collect
    int up = groupedCells(y + 1, x, value);  //  up
    int left = groupedCells(y, x - 1, value);  //  left 
    int right = groupedCells(y, x + 1, value);  //  right
    int down = groupedCells(y - 1, x, value);  //  down 

    // sum
    int total = up + left + right + down + 1;

    return total;
}

basically i have this grid :

and currently if i click on a yellow triangle, the method above will tell me how many of them are next to each other.

What i want is a solution that will run all over the grid, and check if a group has :

• less than 3-triangles then do (A)

• if it has 3-triangles then do (B)

• if it has 4-triangles then do (C)

etc ...

Am not sure about this, but i thought the best way is to have a list for every group, and then check those conditions over the lists.

I tried it here but the list keep re-initializing itself, so it always either have 0 cells or 1 :

  public List<CellSetup> listedCells(int y, int x, int value)
{
    List<CellSetup> cList = new List<CellSetup>();
    //base state
    if (!gSetup.isValidLocation(y, x) ||
        gSetup.getCell(y, x).value != value ||
        gSetup.getCell(y, x).cMAtch.isInMatchPool)
    {
        return cList;
    }

    // keep track of matched cells
    gSetup.getCell(y, x).cMAtch.isInMatchPool = true;
    cList.Add(gSetup.getCell(y, x));
    // collect
    List<CellSetup> up = listedCells(y + 1, x, value);  //  up
    List<CellSetup> left = listedCells(y, x - 1, value);  //  left 
    List<CellSetup> right = listedCells(y, x + 1, value);  //  right
    List<CellSetup> down = listedCells(y - 1, x, value);  //  down 


    return cList;
}

The result of that method when its called here :

for (int y = 0; y < gSetup.cell2DArray.GetLength(0); y++)
        {
            for (int x = 0; x < gSetup.cell2DArray.GetLength(1); x++)
            {

                print(listedCells(y, x, 1).Count);
            }
        }

is printing "1" three times and "0" 22 times.

Thank you

Answer 1

as written, your listedCells function needs to take cList as a parameter so you don't create a new list for every recursive call.