KENDOKU puzzles are built on square grids of typically 5x5 cells (although puzzles having sizes in the range 4x4 up to 9x9 can also be made). To solve them you must place numbers into the puzzle cells in such a way that each row and column contains each of the digits from 1 up to the size of the puzzle. In this respect they are similar to Sudoku puzzles. Unlike Sudoku puzzles, you are not given any starting digits. Instead, the puzzle is divided into Domains which are areas surrounded by a bold outline, and containing from two up to four cells. Each domain contains a hint consisting of a number and one of the mathematical symbols + x — /. The number is the result of applying the mathematical operation represented by the symbol to the digits contained within the domain. This will provide enough information to allow each of the digits to be determined. Each puzzle has a unique solution, and no guessing is required.
The following graphics show a KENDOKU puzzle in the Crossword Express Solve screen and a PNG graphic file produced by the program's print function, showing the complete puzzle solution. See also a full size version of a PDF file showing the solution.
The key features of the Crossword Express Kendoku Construction function are as follows:-