View unanswered posts | View active topics It is currently Thu Apr 22, 2021 8:20 pm



← Back to the Calcudoku puzzle page




Reply to topic  [ 3 posts ] 
 Prime Sum Sudoku 
Author Message

Posted on: Wed Jan 06, 2021 7:15 pm




Posts: 33
Joined: Fri Nov 01, 2019 9:33 pm
Post Prime Sum Sudoku
This one's a bit more challenging, but the rules are still simple. The clues hint at both which cells contain primes, and when sums of entries are prime. More info, a solution, and a PDF version at the following link:

https://quadratablog.blogspot.com/2021/ ... udoku.html

Image


Profile
User avatar

Posted on: Thu Jan 07, 2021 5:08 pm




Posts: 300
Joined: Fri Jun 17, 2011 8:15 pm
Post Re: Prime Sum Sudoku
This is pretty clever. I haven't given it a lot of thought but it seems to have its own solving strategies.
If a 2-circle implies that one of the cells must be 2 since its the only even prime.
Similarly, a 0-circle implies that one of the cells must be 9 since its the only odd composite number less than 10.


Profile

Posted on: Thu Feb 25, 2021 7:39 pm




Posts: 33
Joined: Fri Nov 01, 2019 9:33 pm
Post Re: Prime Sum Sudoku
Thanks for the compliment! Yes, there's definitely some new tricks I needed to come up with to make and solve these. One interesting tidbit, is that I couldn't do the same sort of thing for differences at all (without getting tons of extra unwanted solutions.) There's a delicate balance that allows a single solution to sneak out in this sum case.


Profile
Display posts from previous:  Sort by  
Reply to topic   [ 3 posts ] 

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to:  
All forum contents © Patrick Min, and by the post authors.

Forum software phpBB © 2000, 2002, 2005, 2007 phpBB Group.
Designed by STSoftware.