Solving Sudoku – elimination method

Solving sudokuInstructables.com has an illustrated article for solving Sudoku. Essentially, the technique involves penciling every possible number in empty spaces, then erasing numbers in rows, columns, and regions eliminated by givens and solved numbers. The key to this technique is a notation used on givens and solved numbers to allow you to know if you’ve eliminated everything you can.

The selling point is that you can walk away from a Sudoku puzzle and come back to it without having to backtrack over any work.

I personally haven’t had any trouble coming back to a half-solved Sudoku grid. Also, this technique doesn’t really add anything new, just a different way of making notes of it. It also involves a lot of erasing which, to me, seems unnecessary, and if your grid isn’t that large or it’s on cheap paper or, worse, you use software which doesn’t allow customized notation, it won’t be worth the trouble. And, of course, this technique still doesn’t help much when you can’t reliably put a number in a grid. (In other words, you know 6 belongs in one of two spaces in a region. If they’re in a row or column together you can eliminate 6 in spaces in other regions.)

For someone just getting into Sudoku it might be helpful.

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Wrathchild

Geek. Gamer. Dad. Husband. Beer drinker. Football fan. Blogger.

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