Using the Zudoku Program

Entering a New Puzzle

You can type a Sudoku puzzle from any other source into Zudoku. Once entered, you can save it and solve it more conveniently than using paper and pencil (and eraser!). To begin, select Menu/File/Empty Grid. You can enter the data with the keyboard or the mouse.

Using the keyboard:

The current cell has a yellow background. Use the cursor (arrow) keys or Tab key to move to different cells. Entering a number from 1 to 9 will place that number in the current cell. Entering the number 0 or a space will clear the cell.

Using the mouse:

Left-click on one of the small numbers in any cell to select that number for the cell. Even if the cell already has a big number, you can select another number by clicking where the small numbers would be if visible. Right-clicking in a cell will clear it.

Test your puzzle

Once you have entered your start data, it is a good idea to let the program solve if for you first to make sure a mistake wasnt made entering the starting numbers. Select Menu/Solve/Loop Through All Strategies. If it runs to completion, then it is a good puzzle. If it runs into an error, then you need to change the starting numbers.

It is also possible that the program runs out of strategies and asks you to pick any number to proceed. This should only happen for the most difficult puzzles. To fully test, you will need to try different numbers until you find a solution or determine that there is no solution. See Picking Trial Numbers under strategies.

Now that you know you have a good puzzle, you might want to do the following optional steps:

Measure its difficulty with Menu/Tools/Measure Difficulty.
Erase the solution and return to start data only with Menu/File/Restart.
Save the puzzle for future use with Menu/File/Save.

Changing between Start Data and Solving Modes

When done entering data, select Menu/Edit/Switch from Entering Start Data to Solving the Puzzle. Everything you entered as Start Data cannot be changed when solving the puzzle.