Blackjack Sudoku-It's all 21
(Published on 21. January 2021, 21:21 by bigger)
I'm so sorry for this sudden puzzle. But it's the 21st day of the 21st year of the 21st century, of course it should be posted at 21:21:21. It's even 21 days to the Chinese New Year.
Standard sudoku rules applies. Fill the grid with numbers from 1 to 9 so each digit occurs exactly once in every row, column and 3x3 box.
The number outside the grid is the breaking point of 21. The sum of the first n digits in that direction has to be bigger than 21 while the sum of the first n-1 digits no bigger than 21, with n as the number outside the grid. No pun intended.
For example, If the number outside the grid is 9, then the first 8 digits in that direction has a sum at most 21, and the first 9 digits has a sum at least 22.
The puzzle was called bust sudoku, you can check Richard's puzzle, if you are interesting in solving more of these.
This puzzle is made by Old Miles from China today.It has a lot of 21, the sum of the number outside should be 21 per side, but with limit time, I give this one a pass. It's a remake of the same rule Old Miles made in 2017. If you think this one is too hard, I can post another one in 4 days with less 21. But you have to ask in the comment. I'm not going to post two puzzle with the same rule with no reason.
Solution code: Row 2 and column 1 and the first 3 Digits in row 1 (it's all 21 all right)
Comments
on 25. January 2021, 07:09 by bigger
Add more link
on 23. January 2021, 15:41 by Realshaggy
I've seen this variant a few times, usually under the name "Bust" (as in Blackjack you are bust, if you go higher than 21)
See puzzle ID 2PK for an example from Richards Sudoku Variant Series. There he mentions Sudoku GP 2014 as inspiration. I'm sure, I've seen it at WSC too.
***bigger: Old Miles said he knew and it's an old concept(I don't) He changed the exposition and the name to fit Chinese's understanding. That was a time when we know a concept but don't know where it's from. Thanks for letting me know there is a source. I'll add a link for those who are interested.
on 22. January 2021, 21:09 by marcmees
nice.
on 22. January 2021, 11:06 by bigger
Add link
on 22. January 2021, 09:38 by OmeWappie
Here's the link for solving online! I'm gonna give it a try now. https://f-puzzles.com/?id=y3sayypw
on 21. January 2021, 22:12 by marcmees
Seems interesting. I'll keep it warm until 22 nd.
on 21. January 2021, 15:13 by bigger
I kind of suddenly realise how big the time lag is. So some back story. Old Miles had the idea of this at 7pm, But with no idea which rule should he use. But he managed to posted the easy one on his WeChat official account on time if not for the bad internet. And I even have enough time to check those before 9. Let's hope this one can be on time.
I promise this is just an accident I post this fast, it won't happen again for a long time.
