Kat's Sudoku is a simple helper program for
solving Sudoku puzzles. It starts with an empty
board and prints all possible numbers in each
field. After setting a certain field to a number,
it deletes all occurrences of this number in the
corresponding row/column/block so that scanning of
rows/columns/blocks for possible entries is
unnecessary. Otherwise, there is no logic, which
means that finding the solution is still the
player's task.
