https://www.stolaf.edu/people/hansonr/sudoku/12rules.htm
With a simple array of unsigned int and bit operations like 20 years ago. It could solve a lot of puzzles within microseconds. Later I realized rules 1, 2, 5, 6 are pretty much the same.
https://www.stolaf.edu/people/hansonr/sudoku/12rules.htm
With a simple array of unsigned int and bit operations like 20 years ago. It could solve a lot of puzzles within microseconds. Later I realized rules 1, 2, 5, 6 are pretty much the same.