by kifotv » Sat May 07, 2011 7:02 am
Since most books have puzzles that are relatively easy, I think including the answers is pretty much useless, but only if the puzzles are relatively easy. I have a few books which I am glad contain the answers, and I always print the answers with puzzles I generate on my own. I think once I get to the point where I'm spending a few hours on a puzzle, or using chain/loop/ALS techniques, it's kind of easy to make a mistake with just pencil marks to go on, so I usually check any cell I solve against the answer, just to make sure that I'm not making a stupid mistake (not guessing, just when getting into longer chains, its easy to forget the premise it started with), and to make sure that after spending 3 more hours on the puzzle, I don't suddenly realize that I have a 0 candidate cell.
Oh, and in one of my favorite sudoku books (sudoku addicts workbook), under each puzzle is a short paragraph talking about the path(s) and technique(s) you can plan on finding, and in the solutions, a vague-ish hint is given for 1-2 techniques, usually in the form of highlighting the cells the pattern occurs in, and (sometimes) naming the technique. It's pretty much useless about halfway through, when you have a lot more choice in your approach and solution path, but its better than nothing...