Other researchers did a similar thing to prove that a sudoku puzzle needs at least 17 clues to make a unique grid. They went from 6.7E21 possible grids to check

Other researchers did a similar thing to prove that a sudoku puzzle needs at least 17 clues to make a unique grid. They went from 6.7E21 possible grids to check, to 5.4E9 possible grids to check. http://www.youtube.com/watch?v=MlyTq-xVkQE http://www.youtube.com/watch?v=MlyTq-xVkQE