July 2026: ‘Pent-Up’ Frustration 3 / Knight Moves 7

It’s a little sad to me that this kind of puzzle, which was once a fun challenge, can now be one-shotted by AI. Of course, one doesn’t have to use AI just because it’s available, but I can’t help but feel that we, as humans, are being robbed of something genuinely valuable just by the fact that this is now possible. Going forward, I hope Jane Street will take care to write more of the kinds of puzzles that we’re still better at solving than AI.

I worked on this month’s puzzle with Kelly Su.

Stats:

Difficulty: 2/10

Enjoyability: 2/10

Leaderboard Placing: 37/1139

The approach:

That AI could solve this puzzle more or less instantaneously seemed fairly clear from the beginning. Wishing to derive at least some satisfaction from the solve, Kelly and I instead endeavoured to solve as much of the puzzle as possible “semi-manually”, via a combination of deduction and writing small amounts of our own code. This was enough to uniquely determine most of the first 18 moves, and also to deduce that scores were being recorded every 7 moves after that. Our hand-written code was also enough to determine in which order additive, multiplicative, and divisional moves had to be made throughout the entire tour, though we didn’t know exactly which squares were being visited. This could have been determined by writing some additional code, but it was getting late in our time zone, so we ultimately did turn to AI assistance. Unsurprisingly, Codex had no trouble writing code to close out the solution, leading to the answer of 33609. An underwhelming write-up for an underwhelming puzzle!