Sudoku, sometimes written Su Doku, is a logic-based placement puzzle, also known as Number Place in the United States. The aim of the puzzle is to enter a numerical digit from 1 to 9 in each cell of a 9x9 grid, starting with various digits given in some cells (the "givens"). The grid is made up of 3x3 subgrids (called "regions"). Each row, column, and region must contain only one instance of each numeral. Completing the puzzle requires patience and logical ability. Although first published in 1979, Sudoku initially caught on in Japan in 1986 and attained international popularity in 2005. Fig Labs Zudoku is a free version of this popular puzzle for your computer.
The Fig Labs management team has over 35 years of portable computing experience; between us we've 'done time' at Psion, Symbian, Motorola, Gemplus and Intuwave, building systems software, applications and middleware. So we now feel that we are uniquely placed to tackle the big issue in constrained appliances - complexity - and subsequently make portable technology usable.
You can use Fig Labs Zudoku to:
When you first start Zudoku, it will generate a new 'medium' level puzzle for you. Thereafter, it will always start up from wherever you left it last time.
The bold digits are part of the puzzle, the "givens" - you can't change those unless you are designing the puzzle yourself. Digits you enter yourself are italic.
You can fill in the blank squares in two ways:
If you fill a square with a digit which breaks the rules of Sudoku, then that digit and those that it clashes with will be highlighted in red.
To delete a digit, just use the cursor keys to move to the square and press Spacebar, or click on it and select the blank entry from the pop-up list.
To help you solve more difficult puzzles, you can make 'pencil' marks on the board. Choose 'Make pencil marks' from the Game menu. After that, any moves you make will appear as small numbers in a gold colour. You can pencil in several numbers in as many squares as you like. To erase a pencil mark, enter the same number again. To erase all marks in a square, press Spacebar or choose the blank entry from the pop up menu.
If you want to start the current puzzle afresh, go to the Game menu and choose Start again.
If you want to print the puzzle out, choose Print from the File menu.
To start a new puzzle from scratch, go to the Game menu and choose New puzzle. While Zudoku is working, the grid will fill with question marks. When it is ready you will be presented with a brand new puzzle - probably one that has never been seen before!
When you start Zudoku, it is set to generate 'medium' level puzzles. To change the level of puzzle generated, go to the Game menu, choose New puzzle level, then pick a new level. If you set the level to Fiendish, sometimes Zudoku can only make a Difficult puzzle. If that happens, just generate again. If you choose 'Unlimited' Zudoku will try and make the hardest puzzle it can.
If you have a printed puzzle, for example in a newspaper, magazine or book, you can enter that into Zudoku. You can then play it or solve it on your computer. To do this, just follow these steps:
Have a go at making your own puzzles - it's harder than it looks! Just go to Design mode as above, and place some digits.
If you try and put a digit in an invalid position while in Design mode, Zudoku won't let you do it. Try putting it somewhere else, or changing one of the other digits in the puzzle first.
Leave Design mode and see what Zudoku makes of your puzzle. It may tell you that there are Many solutions to the puzzle. In this case, you need to enter some more digits to make sure there is only a single solution. Sometimes Zudoku will think for a while and tell you there is no solution - you probably need to remove some digits to make your puzzle solvable.
You can ask Zudoku to show you what numbers can possibly go in the empty squares. From the Game menu, choose Show possible moves. Zudoku will fill in small green digits to show the possibilities for each space. If there are 7 or more possible digits, Zudoku just puts an asterisk. If there are no possible digits, Zudoku puts a red exclamation mark.
If it all gets too much, or you are just interested to watch, you can ask Zudoku to solve the puzzle for you. Just choose Solve from the Game menu. You will see Zudoku rapidly filling in squares until the grid is full. Where a puzzle has more than one solution, it will simply display the first solution it comes across. If the puzzle is not solvable, Zudoku will try for a while before giving up and telling you.