...nevermind generating *all* nodes).

[...]

That doesn't solve the problem when graph nodes are generated...

...only be 1 or -1.


Basically, adjacent nodes differ only in a single coordinate, and...

...means your graph is quite sparse, yet nodes are connected ("differ only by a single...

...parallel arrays - you store a bit array in parallel with an array of nodes.

Andrei

...can see, the possible values of the nodes are all the points in N^n...

...duplicate detection, to allow the number of nodes to exceed available RAM.

What we found...

[...]

There are too many nodes to keep in memory, actually. The algorithm also doesn't...

...data structure to keep track of which nodes have
been visited, that (1) allows reasonably...

...But that it would be possible to pass Ast nodes to other functions.

-- 
/Jacob Carlborg

...would be useful but only if some library actually accepted these AST nodes.

-- 
Dmitry Olshansky