In article <87iodoakft....@elektro.pacujo.net>, Marko Rauhamaa <ma...@pacujo.net> wrote: >Ian Kelly <ian.g.ke...@gmail.com>: > >> The test puzzle that you posted has 23 values already filled in. How >> does it perform on harder puzzles with only 17 clues (the proven >> minimum)? One would expect it to be around a million times slower. > >Just try it. The example had a minimum of clues (drop one clue and >you'll get multiple solutions). > ><URL: http://www.telegraph.co.uk/news/science/science-news/9359579/W >orlds-hardest-sudoku-can-you-crack-it.html> mentions this puzzle: > >======================================================================== >8 . . . . . . . . >. . 3 6 . . . . . >. 7 . . 9 . 2 . . >. 5 . . . 7 . . . >. . . . 4 5 7 . . >. . . 1 . . . 3 . >. . 1 . . . . 6 8 >. . 8 5 . . . 1 . >. 9 . . . . 4 . . >======================================================================== > >It takes about 2 seconds for my Python program to find the answer but it >spends a total of 110 seconds to exhaust the problem space. > >The analogous C program finished the whole thing in 200 milliseconds.
That is a more reasonable time for a realistic algorithm. This puzzle takes 255 ms in a program that I wrote in 2008 in Forth. > > >Marko Groetjes Albert -- Albert van der Horst, UTRECHT,THE NETHERLANDS Economic growth -- being exponential -- ultimately falters. albert@spe&ar&c.xs4all.nl &=n http://home.hccnet.nl/a.w.m.van.der.horst -- https://mail.python.org/mailman/listinfo/python-list
