[fidotron]

Numbers in arrays can be treated as pointers, into that same array, giving a graph. It's just a question of context. If you were storing RDF triples in K you'd simply have an array for subjects, one for objects, one for predicates, and one of the URIs/text. Simply store the index of the URI/text item in each of the subject, object and predicate columns. An individual triple would be formed by the same index applied to the subject, object and predicate arrays.

DFS is then a variation of the more familiar functional style of tackling the problem where you have your end condition (i.e. something that matches what you're looking for) and failing that do something else (typically recursion).

I can't recall enough of the K syntax these days to actually implement that right now though, or if K has TCO.