Today, I am going to break my code of silence and tell you about the 7 steps that can help you solve every Sudoku puzzle including SAPs and regular puzzles, too.
But before I do, try your hand at solving a Simple-As-Possible (SAP) Puzzle.
Click below to access the puzzle:
http://www.howtosolveallsudokupuzzles.com/olacc/o2p7.php
Did you break your head trying to solve the SAP puzzle? I’m afraid, the puzzle has ‘NO Solution’ as it is a wrong one.
Click below to take a peek at the worked sample of the SAP puzzle:
http://www.howtosolveallsudokupuzzles.com/olacc/o2s7.php
You may arrive at different sets of values if you proceed in a different way, and yet, whichever way you go, you can never resolve it. So, it’s an incorrectly composed puzzle.
For example, if you fill up Cell (1,3) with the value 2, which Cell in Row 1 will get the value 1? If you fill up Cell (1,3) with the value 1, Cell (1,4) can’t take the value 2, as the column 4 already has a 2.
Such a puzzle is very rarely given, if at all. And such puzzles could be given by a mistake in transcription, or deliberately to see if you are able to realize the mistake in the puzzle early. I gave it to you so that you are aware that it is possible that some puzzles don’t have a solution!
You can declare such puzzles as unsolvable if conflicts arise (which are not resolvable)!
Now, you are completely equipped to solve a Sudoku puzzle properly, but before you do that, let’s make sure you have learned to solve the Sudoku SAP fully.
In a nutshell, follow the 7 steps to solve Sudoku SAP puzzles — and even regular Sudokus.
You will not go wrong if you:
1. Create the Possibility Matrix.
2. Perform iterative (repeated) reductions of the Possibility Matrix.
3. Perform Group Reductions.
4. Perform Reductions and Group Reductions alternatively.
5. Resolve impasse through Tie Breaker and arrive at one possible solution.
6. Repeat Tie-breakers with other possible values to arrive at all possible solutions, if required.
7. Declare the puzzle as unsolvable if conflicts arise that are not resolvable.
Article source: Expert Articles
