Install gnudoq by entering the following commands in the terminal:
sudo apt update sudo apt install gnudoq
Description:
An open source, graphical Su Doku generator and solver with printer support
GNUDoQ is an open source, graphical Su Doku generator and solver that features a powerful Su Doku generator, a Su Doku solver a Puzzle printouts or PDF exports. This program is based on the excellent work of the GNUDoku team, which developed the Su Doku engine behind GNUDoQ.
Homepage: https://tracker.debian.org/pkg/gnudoq
Version: 0.94-2.2
Section: universe/games