"A Sudoku a day keeps the doctor away" is a series of Sudoku book written by Arch Koch.
https://www.amazon.com/Arch-Koch/e/B06VXTLKW3
If you are a familiar with Sudoku, try to challenge Vol.3, the hard difficulty level Sudoku puzzles.
djshad wrote:Why it is such expensive?
enxio27 wrote:... the sudoku craze is long past, and that those of us who are still interested have access to literally millions of free puzzles, either through a solver/generator or on various Web sites still in existence.
Mathimagics wrote:The peak is long past, it's true ... but there are still many Sudoku puzzle books and magazines in print. I even buy one myself from time to time.
There is still some attraction in literally P&P solving, obviously ....
Mathimagics wrote:... but there are still many Sudoku puzzle books and magazines in print. I even buy one myself from time to time.
Mathimagics wrote:Oh dear, I seem to have disappointed you
Well, it's a simple matter of expedience. Firstly, I usually have so many computational challenges on the go, that I rarely have time for actually doing puzzles. When I do a puzzle, I prefer Kakuro, and these I do generate/print myself.
Sometimes, once in a while, I like to do a standard Sudoku, just to keep those neural synapses duly exercised. The magazines that I buy (at most 3 per year) are a cheap (15c per puzzle, pre-printed) and convenient source. And they are reliable, I've never come across an invalid puzzle, and their notion of "hard to super-hard" more or less corresponds to my personal "medium to hard" scale.