Sudoku puzzles have only one rule, but they can be fiendishly difficult to solve. The rule is simply this:
Fill in the grid so that every row, every column, and every 3 x 3 box contains the digits 1 through 9.
SadMan Software Sudoku is a fantastic tool to help you solve these puzzles. It can act as an assistant, removing the tedium and error-prone updating of candidate pencil marks, whilst leaving you the fun of spotting the logic and patterns. Or, it can solve the puzzle completely automatically and provides a log of the logic behind each and every number placement and candidate elimination. If you get stuck, it can provide you with a series of increasingly detailed hints to get you going again - this is great for learning the more advanced techniques.
- It can create an effectively unlimited number of Sudoku puzzles with various degrees of difficulty, or requiring particular techniques to solve. Every puzzle has a unique solution.
- It solves Sudokus using exactly the same techniques that a human would, so you can follow the logical steps taken to reach the solution.
- When solving automatically, it creates a log that shows the reason for entering each number in each cell, and the logic that allows for each elimination of candidates. This is great for learning the advanced techniques.
- It can provide increasingly detailed hints. It first gives a fairly vague hint, then adds more detail. Great for learning!
- It can open images of Sudoku puzzles, and extract the puzzle using optical character recognition (OCR.) This means you can drag'n'drop an image of a puzzle from a website, and the puzzle is automatically imported.
- If you enter a puzzle with multiple solutions, it can determine how many there are, and then show them to you. (If only Sky One had used this to avoid the fiasco of their giant prize puzzle with 1905 solutions!)
- It can show the possible candidates ("pencil-marks") for each cell and optionally keep them updated as you solve the puzzle. This removes the tedium and lets you focus on the logic.
- It can highlight and/or prevent invalid entries.
- When pasting from the clipboard, it will accept a wide variety of text styles, and even images. This is extremely useful if you want to copy from discussion forums, websites etc.
- It can print the Sudoku puzzle enabling you to solve away from your computer if you prefer.
- Small and simple to use.
- Currently available in English, Czech, Danish, Dutch, Finnish, French, German, Italian, Polish, Brazilian Portuguese, Russian, Spanish and Turkish. These additional language packs can be downloaded from the translations page. If you'd like to translate Sudoku into your own language please contact me for details — I can provide a machine translation as a starting point, so it should take around two to three hours to verify and correct this. I'd be happy to provide a free registration or two in return as a small thank you.
Sudoku will solve all puzzles - including those in the "fiendish" category published in The Times, as well as those that are even harder.
Want to know what's changed recently, or what's coming up in the next version? Take a look at the change history.
Sudoku is a program for Windows 95, 98, ME, NT4, XP, 2000, 2003, Vista, and Windows 7 and 8. Sorry, but it won't work on a mac or native Linux. (Although the good news for Linux users, is that I've been informed it will run fine under WINE.)