Ian Kelly <ian.g.ke...@gmail.com>: > On Mon, Mar 30, 2015 at 1:13 AM, Christian Gollwitzer <aurio...@gmx.de> > wrote: >> Am 30.03.15 um 08:50 schrieb Ian Kelly: >>> >>> On Sun, Mar 29, 2015 at 12:03 PM, Marko Rauhamaa <ma...@pacujo.net> >>> wrote: >>>> >>>> Be careful with the benchmark comparisons. Ian's example can be >>>> solved with the identical algorithm in eight different ways (four >>>> corners, left or right). I ran the example with my recent Python >>>> solver and got these times in the eight cases: >>>> >>>> 884 s >>>> 2.5 s >>>> 13 s >>>> 499 s >>>> 5.9 s >>>> 128 s >>>> 1360 s >>>> 36 s >>> >>> >>> That sounds to me like either a transcription error was made to the >>> puzzle at some point, or there's something wrong with your solver. >>> The whole point of that example was that it was a puzzle with the >>> minimum number of clues to specify a unique solution. >> >> I think Marko meant, that if he creates symmetrically equivalent >> puzzles by rotating / mirroring the grid, he gets vastly different >> execution times, but ends up with the same solution. > > That makes sense, but it is true for all puzzles that there are eight > possible orientations (since it's impossible for a puzzle solution to > be symmetric), and the wording made it sound like he was describing a > property specific to the puzzle that I posted.
Thing is, if you are not careful in your comparisons, you might easily get a good-looking time from one implementation and a lousy time from another implementation because of a different traversal order. That is why brute-force sudoku might not be as good for benchmark testing as BertC was hoping. Marko -- https://mail.python.org/mailman/listinfo/python-list
