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Hey Brian, I really enjoyed reading your work on the Pips game! I found myself applying a similar backtracking algorithm to my Pythonic solution (https://github

by ematth 11mo ago

Hey Brian, I really enjoyed reading your work on the Pips game! I found myself applying a similar backtracking algorithm to my Pythonic solution (https://github.com/ematth/pips https://github.com/ematth/pips). I focused on finding a single solution for each puzzle as opposed to all possible solutions. For hard puzzles with longer run times, I found that running multiple processes, each with the domino list shuffled, gets the solve time down to <15 seconds.

brianberns 11mo ago
Thanks! I'm glad to see I'm not the only one who went down this rabbit hole. :) I considered parallelizing my solution as well, but the problem is that it only gives a linear speedup, while the problem space increases exponentially. I decided to focus on pruning the search tree instead, and that seemed to work pretty well (after much thinking).
- prb 11mo ago
  It's getting crowded down here in the rabbithole... One more to peek at: https://github.com/prb/pips-solver/blob/main/README.md https://github.com/prb/pips-solver/blob/main/README.md
  - munchler 11mo ago
    That's great! Your experience with the 2025-09-15 and 2025-10-14 puzzles was very similar to mine, I think. I'm impressed that you were able to get AI models to solve this game effectively. I coded it the old-fashioned way myself, mostly, with occasional help from Gemini Pro.
    - prb 11mo ago
      I did write the spec first — data model, algorithm, etc. That may have helped the agents get traction.
  - tzs 11mo ago
    Last updated 2025-10-27. [...] The puzzles with the most solutions are: • 2025-09-15 hard: 2,764,800 solutions • 2025-10-05 hard: 344 solutions • 2025-09-30 hard: 110 solutions • 2025-09-04 hard: 86 solutions • 2025-08-23 hard: 80 solutions Hah...it's like the NYT was just waiting for you to update so they could immediately release a puzzle that makes your list out of date. 2025-10-28 hard has 166 724 solutions.

by ematth 11mo ago

brianberns 11mo ago

Thanks! I'm glad to see I'm not the only one who went down this rabbit hole. :) I considered parallelizing my solution as well, but the problem is that it only gives a linear speedup, while the problem space increases exponentially. I decided to focus on pruning the search tree instead, and that seemed to work pretty well (after much thinking).

prb 11mo ago
It's getting crowded down here in the rabbithole... One more to peek at: https://github.com/prb/pips-solver/blob/main/README.md https://github.com/prb/pips-solver/blob/main/README.md
- munchler 11mo ago
  That's great! Your experience with the 2025-09-15 and 2025-10-14 puzzles was very similar to mine, I think. I'm impressed that you were able to get AI models to solve this game effectively. I coded it the old-fashioned way myself, mostly, with occasional help from Gemini Pro.
  - prb 11mo ago
    I did write the spec first — data model, algorithm, etc. That may have helped the agents get traction.
- tzs 11mo ago
  Last updated 2025-10-27. [...] The puzzles with the most solutions are: • 2025-09-15 hard: 2,764,800 solutions • 2025-10-05 hard: 344 solutions • 2025-09-30 hard: 110 solutions • 2025-09-04 hard: 86 solutions • 2025-08-23 hard: 80 solutions Hah...it's like the NYT was just waiting for you to update so they could immediately release a puzzle that makes your list out of date. 2025-10-28 hard has 166 724 solutions.