Probably using a sudoku solver and copying the answer.
But I have a more general question : trying to improve my skill, I have tried different tricks, with more or less succes. Some are obviously cheating, and I have decided not to use them anymore. But I still use minor tricks that I don't consider as cheating (like a lot of the players I think, for small puzzles, I use the loading time and the transparency of the loading frame to solve mentaly the puzzle). Some are more on the edge. When I see the scores of
@Alex54, I understand it is possible to compute programs that solve the puzzle and send the reponse instead of you. So, whre cheating starts, and where cheating ends ? It is a serious question, I don't have the answer.