timmc

(defmacro essentially
  "Like letfn, but with the bindings at the end. Connotes that the
bindings are not important for the core logic, just for logging,
metrics, debugging etc. Recommend using footnote-looking bindings such
as *0, *1, *2 or even Unicode daggers if you are super-brave.
This is like Haskell's `where`. Thanks to amalloy for the pointer; no
blame attaches to him, though."
  [& args]
  `(letfn ~(last args)
     ~@(butlast args)))

hwayne

It's time to drag the Island of Knights and Knaves kicking and screaming into the 19th century! We're going to run a train. For these puzzles, you'll have a set of stations with possible connections, and you need to find a route that starts at one station, goes through every other station exactly once, and ends in a station. IE if our map was

A -- B -- C
|    |    |
D -- E -- F

Valid routes might be A B C F E D, or A D E B C F, but A B E D C F is invalid. The ordering matters: A B C is a different route from C B A.