CODEWITHSUNDEEP
algorithmrecursionfillflood-fill
Colter Therrell
Colter Therrell

Reputation: 31

Recursion - Flood Fill Algorithm

I need to write a flood fill algorithm to be used in a larger code that fills specific cells of a cave with different colors of water based on which room they are in.

For some reason my recursive algorithm isn't working and keeps telling me I'm exceeding the maximum recursion depth, and I have no clue why.

I'm trying to go cell by cell, checking if it is AIR, STONE, or WATER, and if it is STONE or WATER I want it to do nothing. If it is AIR, I want it to fill that cell.

Can anyone give me some tips or advice?

#flood fill algorithm
def fill(cave, row, col, color):

    caveWidth = len(cave)
    caveHeigth = len(cave[0])


    if row > 0:
        fill(cave, row-1, col, color) #left
    if col > 0:
        fill(cave, row, col-1, color) #up
    if row < caveWidth-1:
        fill(cave, row+1, col, color) #right
    if col < caveHeigth-1:
        fill(cave, row, col+1, color) #down

    if cave[row][col] == STONE or cave[row][col] == WATER:
        return

    if cave[row][col] == AIR : 
        cave[row][col] = WATER
        grid.fill_cell(row, col, color)

Upvotes: 3

Views: 1860

Answers (2)

Tyler Durden
Tyler Durden

Reputation: 11532

Don't use recursive algorithms, they are the devil's playthings.

The wikipedia lists various practical algorithms like scanline fill.

Upvotes: 1

krlmlr
krlmlr

Reputation: 25454

Print row and col at the start of the fill routine to see what's wrong here. A little code reordering and you're fine :-)

Upvotes: 5

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