Only a brief introduction to SuDoku puzzle solving is given here. A very simplistic approach is presented.
Let's learn by playing an easy level puzzle. Generate one by selecting New->Easy from the menu.
The following shows a Palm generated puzzle.
There are many ways to solve the puzzle but start by noticing that several 3x3 boxes already contain the number 4.
Look at the highlighted box. It must contain a 4, but it is already present in the highlighted rows and columns. The only square it can possibly go is circled. If the 4 were placed in any of the other blank squares it would contradict the rule that each number only appears once in each row and column.
Another 4.
There is nothing special about the number 4. The same logic applies with any number. For instance 3.
Another 3.
Another 3.
A 7.
A 1.
Another 3.
The last 3.
We have now finished the 3's. There is one and only one in each 3x3 box, each row, and each column.
A 4.
The last 4.
Another way to locate numbers is when all others are already present in the same row or column.
Or same row, column, and 3x3 box.
The circled squares now have only one possibility.
Let's fill them in.
This has updated the situation so that now the circled squares have only one possibility.
Let's fill them in.
Using the same techniques it's now trivial to complete the puzzle.
