Watching this guy solve a sudoku is deeply satisfying

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Incredible. I’m surprised he doesn’t even mention the other repeating pattern in the solution. The numbers in the horizontal rows are always in the same order, just starting from a different point.
ie 483726159, then 726159483, 159483726, 837261594…


That promised a lot and absolutely delivered. Wow.


There are a lot of extra constraints, so it’s not too surprising to me that it’s solvable. I’m surprised that the puzzle is definable.


I’ve been watching CTC for the past several months. It’s always a delight. I feel like I’m getting much better at Sudoku too! They have 3 sudoku apps for Android/IOS/Steam. All 3 are great in different ways. All the puzzles included in the apps are hand-crafted, and 5 new puzzles are added every month to Sandwich and Classic until they hit 100 puzzles.

Sandwich sudoku was the first one. Clues outside the grid give the sum of all the digits that appear between the 1 and 9.

Classic sudoku was second. It’s classic sudoku. They get progressively more difficult.

Chess Sudoku is the latest. This one has 2 types of puzzles, with a 3rd being added for free at a later date. Knight Sudoku is like classic, but you you cannot put the same digit a knights move away from itself. King sudoku, similarly you can’t put a digit a kings move away. Coming later is Queen sudoku, where all 9’s have a restriction that they can’t be a queens move away.

I bought all 3 on android for $4.99 each. I think they are higher on steam.


I liked the reveal. Having just two clue numbers pop up made for a great, “are you … kidding” moment. And then having the whole thing build from there. Also, I have no idea how the puzzle creator made this. Which just makes it more wonderful.

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That made my heart sing.

I absolutely love his enthusiasm. That was well worth the time to watch, and makes me want to solve some sodoku puzzles.

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I agree that the constraints are so restrictive that it’s not actually that surprising that it’s solvable.
I think that once you see the pattern at the end, mentioned by @dropcap above, you can see how it was built. Looking at the patterns that the numbers make, and turning them into rules, and then the minimum initial conditions from which it can all flow.
Still really cool watch it come together.

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