Puzzles solvable by Algorithm X / Dancing Links

Puzzles
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I have added Kids Blocks to my playground.

In even BIGGER NEWS, the provided AlgorithmXSolver has now been translated to Ruby (thanks to @Rafarafa) and Kotlin (thanks to @VizGhar). Please let me know if you have translated the solver to any other languages. If your preferred language is Ruby or Kotlin, make sure to visit my playground’s translations page.

Update March 25, 2025: I have added Depot Organization and Haunted Manor to my playground.

2 Likes
23

Thanks @Timinator for that playground. I am just 12 out of 110 pages in, but already I could solve two puzzles with (your solver for) Algorithm X.

Edit; solved six puzzles (Ms Knut, the four sudoku puzzles, and the latin square). This is cool!
Edit 29-mar – 14 puzzles, at page 36 of the playground. My goodness, this Algorithm X with a carefully crafted route across specially selected puzzles feels almost like cheating - eating away medium up to very hard puzzles as if they are nothing. Thank you for rekindling my Codingame addiction :sweat_smile:.

2 Likes
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This is music to Mrs. Knuth’s ears! Keep going on Winamax. Enumerating the possible actions is very challenging, but seeing Algorithm X easily find the solution is wonderfully satisfying!

This seems like a great opportunity to share my promises from page 1 for anybody that hasn’t yet given in to the the temptation to see what Algorithm X is all about:

My Promise to You

I wholeheartedly believe that working through this playground and the accompanying puzzles will be a great experience on multiple levels. How can I say this? All these things happened for me as I studied Algorithm X and applied it to as many puzzles as possible. I promise…

  • You will become proficient with a powerful and repeatable problem-solving technique known as Algorithm X.
  • You will experience the compelling nature of reusable software architectures.
  • You will find every puzzle listed above significantly easier than it would have been otherwise. I’m not saying they’ll all be easy, but they will indeed be easier.
  • You will have a lot of fun.
  • You will earn up to 2650 CodinGame XP!
1 Like
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The playground focuses mostly on how to apply the solver, but not on how the algorithm itself works. While it is not necessary to understand it in order to use it (you can just copy-paste the solver code), it will feel less cheating if also spending some time on understanding the dancing links and the algorithm x, or even re-implement the solver yourself.

1 Like
27

AlgorithmXSolver has now been translated to PHP (thanks to @TBali). A few new puzzles have also been added to the playground since I last provided an update:

Fix the Spaces
Completed Mahjong Hands
Crossword

Make sure to check out Crossword as it brings a unique example of exact cover, somewhat different than anything covered so far.

3 Likes
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I have added Pips by @VizGhar to my playground. @VizGhar has 2 more exact cover solo games built with the CodinGame SDK on the Contribution page. Be sure to check these new puzzles out!