#### Archived

This topic is now archived and is closed to further replies.

# Astar verification

This topic is 5736 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

## Recommended Posts

Does a* have to have both an open and a closed list to be declared as an a* algorithm? The reason i ask is i have implemented the a* agorithm but instead of using a closed list, i just have a closed state as part of my node object. Any light shed on this would be much appriciated, thanks

##### Share on other sites
I just use an indexed priority queue.

ai-junkie.com

##### Share on other sites
Hi,
Thanks Fup, I''ll explain what i''m upto. I am doing a report for university on the different approaches to pathinding. What i don''t what to do is say "And this is A*" and some moderator say "no it isn''t" and fail me. I have also bought your book to assist me with the genetic approach.

##### Share on other sites
the universtity mathematic people like to define stuff, heh ?

well, all nodes with the member variable for the state set to close build up the close list, the same for open. There are ppl who prefer this flag approach, because they think it''s faster than lists/heaps, because it might be more cache efficient.

I doubt you cannot call that algorithm A* then, it''s the same like with the list, just the underlying data structure is maybe different to their implementations ...

maybe you check http://dynamic.gamespy.com/~botman/yabb/YaBB.pl?board=2&action=display&num=4096

@\$3.1415rin

##### Share on other sites
It''s the algorithm that determines whether it''s A*, not the data structure used to implement it.

A* is simply a combination of best-first search plus a heuristic. The estimated cost at each node is given by:

c(n) = bf(n) + h(n)

nb. The heuristic must always underestimate the distance to the target for A* to work.

Thanks for buying my book, I hope you enjoy it

ai-junkie.com

1. 1
Rutin
45
2. 2
3. 3
4. 4
5. 5
JoeJ
19

• 11
• 13
• 10
• 12
• 10
• ### Forum Statistics

• Total Topics
633001
• Total Posts
3009821
• ### Who's Online (See full list)

There are no registered users currently online

×