My own try at A*

[Torahteen]

hm, you do have a point there, i didn't use opened / closed squares, mainly because i don't think i get something....
if you have a map like this:

Code:

0,0,0,0,0
0,1,1,1,0
0,2,0,1,3
0,1,1,1,0
0,0,0,0,0

what's to keep it from going right? :/

Nothing, and in fact, it probably will check that square. But if you are using Closed lists, it should look at that square, put it on the closed list, then never check it again. You don't look at closed squares. Make sense?

[dumbledore]

ok, but once i put it on the closed list, how do i know which squares to check next? the next one on the open list? :???:

[Torahteen]

Well, sort of. You go through the Open list, and choose the square that has the lowest F score. But make sure it isn't on the closed list.

[rpgfan3233]

Also note that no squares/nodes are on the open or closed lists in the beginning.

[Torahteen]

Yeah, look at my code, you'll see I have 2 arrays called OpenList and ClosedList. You add to them as you go, which is why I have a AddToOpen and AddToClosed sub. I don't bother with removing squares from them, I just double check. Like first I'll make sure it isn't on the closed list then I'll see if it is on the open list.

[Neo]

i read the normal a* shouldn't be able to find its way through what i gave it without modification like i did...

For one, A* always finds a way, for complex mazes it will take up almost as much space as a huge deep brute force tree though.
For two, there is no normal A*. Every A* has its own weighting functions and determination of the f = g + h function.

I don't know where you read it, but a good A* always finds a way, and if it doesn't, you either are just short on system memory, or there is no way to the end position.

[Torahteen]

TY neo :wink: .

Edit: So you really shouldn't need that "timevisited" function. But it still finds a way, and that's good.

[Torahteen]

Oh, and I forgot to thank TheBlueKeyboard for the compliment. Ty.

[dumbledore]

ok, thanks, i guess i'll try and implement open / closed lists, doesn't sound too hard...

[Torahteen]

Nope, sure isn't.