<https://gist.github.com/joelpedraza/b43efc1d91053...

# advent-of-code

[joelpedraza]

https://gist.github.com/joelpedraza/b43efc1d91053d9e9ff18872cbb3c1b2

[karelpeeters]

What's going on with the leaves? I think you can simplify that to

val frontier = graph.filterTo(PriorityQueue()) { it.children.isEmpty() }