... by: David N. JansenIn the Killer Sudoku of May 25, it seems that the solver does not fully implement this convention. I loaded the Killer Sudoku into the solver and stepped through the solution. At some point, the solver finds out that C3 is 8 and immediately deletes that number from C4, but not from B4.
Andrew Stuart writes:
Interesting point. The puzzles are generated with the convention in mind and the solver is aware of it in terms of the combinations available to that cell, for example in the mouse hover over of that cell its says 7/8/9. (Actually to get 24 you need 9/7/9 as the only possible 'dog leg' cage combo excluded by the convention). But the point you describe is the clear-off of candidates after the placement of a solution. To keep things simple only the candidates in rows, columns and boxes are immediately removed. Those in a cell have to wait for the 'easy combinations' strategy. It's a valid point to assert that cage combinations should also be refreshed but that would require 'easy combinations' to be right at the top of the list. But I suppose if I refreshed the cage combinations just for those cages affected it might make it closer to how a human solves the puzzle.