By now almost everybody will be familiar with the Sudoku puzzle, but in case you are not, it is a 9x9 grid in which some of the cells have symbols (usually the digits 1 to 9) inserted in them. To solve the puzzle, you must insert a single symbol into each of the blank cells in such a way that each row and each column of cells contains each of the nine symbols once and once only. In addition, each 3x3 sub-square must also contain each symbol exactly once.
You may occasionaly see Sudoku puzzles in 16x16 or 25x25 format. These are really of academic interest only, but Crossword Express will make them for you if you are interested in giving them a try.
All Sudoku puzzles have a unique solution, and no guessing is required.
Of course Sudoku puzzles don't necessarily have to use the digits 1 to 9. They can for example be made using any subset of nine letters of the alphabet. The puzzle shown here is of such a type.
Notice that some of the vacant cells have been highlighted by means of a distinctive colour. When you have completed the solution of this puzzle, the letters in these cells will spell out a message.
You can practice your skill at solving Sudoku puzzles using the Crossword Express Sudoku applet by clicking the graphic at the left. Registered owners of the Pro version of Crossword Express can use this applet to publish interactive SUDOKU puzzles in their own web site.
If you like to "pencil in" candidate symbols into the vacant cells as an aid to solving the puzzles, you will find that the applet does that part of the job for you, leaving you to concentrate on the interesting analytical processes which lead you to a solution.
You can enter your solution by typing the desired symbol directly into the focus cell (coloured red), or you can remove candidate symbols from a cell by pointing to them with the mouse and clicking. When you remove the last such symbol, it will become the solution symbol for that cell.
If you prefer to work without the candidate symbols being displayed, you can do this by clicking the Assist button. Clicking the Undo button will undo changes you have made in the reverse order of them being made.
If you point your mouse cursor to any location within the bounds of the puzzle, then most web browsers will dispaly a set of icons in the top left hand corner of the puzzle area. One of these icons will be a printer, and clicking it will result in the puzzle being sent to your printer.