by qqwref » Sun Jun 11, 2006 4:22 am
Well, if you're only doing easy/medium puzzles, you'll probably only be finding naked and hidden singles. I can provide one or two tips for finding these faster:
- First look for hidden singles, because those are easier to find. Hidden singles are when a number can only be in one place in a row, column, or box. Look at a row or column of boxes (for example, boxes 4-6); if a number is in the first row in the first box, and the third row in the second box (or whatever), then it must be somewhere in the second row in the third box. This is easy to see and it's faster than looking for each number in each box, because you just have to consider the clues (what you already have). It's most common to use this whenever you already have two of a number in a row or column of boxes. This won't give you all of the hidden singles, but it will help with a lot of them.
- For naked singles (where only one number can fit in a place), look for a specific column, row, or box with four or more numbers already in it. Then make a mental list of the numbers that aren't there; let's say it's 4679. Look at each cell in that row, column, or box, and check what numbers (out of 4679) it can't be. So if a cell can't be 4, 7, or 9, you know immediately it's 6, and now you can look at that column, row, or box again with the list 479 (because the 6 is there now).
I hope that helps... and I hope someone else can explain it better.
