Keep Track of the Best N Nodes in a Graph Traversal Algorithm
I have graph traversal algorithm that needs to keep track of the N best node visit. Every time a visit a new node I get its goodness along with a ref to it. I then want to compare it to every currently best node in this list and replace it with the worst one if its better than the worst. How do I most easily do this with regards to minimizing GC-usage. For N = 3 I mean something like this: (A,1) = [(A,1)] (B,2) = [(A,1), (B,2)] (C,3) = [(A,1), (B,2), (C,3)] (X,0) = [(X,0), (A,1), (B,2)] (Y,1) = [(X,0), (Y,1), (A,1)] ... (A,1) means we just visited node with goodness (distance) 1
Re: Keep Track of the Best N Nodes in a Graph Traversal Algorithm
Nordlöw: I have graph traversal algorithm that needs to keep track of the N best node visit. std.algorithm.topNCopy? Bye, bearophile
Re: Keep Track of the Best N Nodes in a Graph Traversal Algorithm
On Wednesday, 25 March 2015 at 13:55:29 UTC, bearophile wrote: Nordlöw: I have graph traversal algorithm that needs to keep track of the N best node visit. std.algorithm.topNCopy? Bye, bearophile Could you please elaborate a bit how you mean this should be used. Notice that the number of visited nodes are in the millions or perhaps even tens of millions. And N is typically 100-1000.
Re: Keep Track of the Best N Nodes in a Graph Traversal Algorithm
On Wednesday, 25 March 2015 at 13:55:29 UTC, bearophile wrote: Nordlöw: I have graph traversal algorithm that needs to keep track of the N best node visit. std.algorithm.topNCopy? Bye, bearophile Notice that, ideally, I would like my list of top-nodes to have a fixed size during the whole algorithm (99.9 % of time) as soon it has reached the length of N.
Re: Keep Track of the Best N Nodes in a Graph Traversal Algorithm
On Wednesday, 25 March 2015 at 14:40:28 UTC, Per Nordlöw wrote: On Wednesday, 25 March 2015 at 13:55:29 UTC, bearophile wrote: Nordlöw: I have graph traversal algorithm that needs to keep track of the N best node visit. std.algorithm.topNCopy? Bye, bearophile Notice that, ideally, I would like my list of top-nodes to have a fixed size during the whole algorithm (99.9 % of time) as soon it has reached the length of N. What's wrong with binary heaps?
Re: Keep Track of the Best N Nodes in a Graph Traversal Algorithm
On Wednesday, 25 March 2015 at 17:49:49 UTC, Tobias Pankrath wrote: What's wrong with binary heaps? Ahh, a Binary Heap perfectly matches my needs. https://en.wikipedia.org/wiki/Binary_heap http://dlang.org/phobos/std_container_binaryheap.html Thx
Re: Keep Track of the Best N Nodes in a Graph Traversal Algorithm
Nordlöw: Ahh, a Binary Heap perfectly matches my needs. https://en.wikipedia.org/wiki/Binary_heap http://dlang.org/phobos/std_container_binaryheap.html But isn't topNCopy using a heap? Bye, bearophile
