Uniqueness of solutions edit
How can one ensure that a su doku puzzle has a unique solution? Lupin 02:01, 11 Mar 2005 (UTC)
- As far as I have seen the only known methods involve brute force, that is, exhaustive checking. Since Su Doku is essentially a graph coloring problem, and such problems are known, or suspected, to be computationally difficult, it would be surprising if there were some efficient way of checking whether a puzzle can be completed in a unique way. Dillon256 13:04, 8 Apr 2005 (UTC)
Deleted sentence edit
I have removed the sentence "Despite it being called a mathematical puzzle there is no arithmetic actually involved, solving the puzzles requires just simple logic." It is often stated that solving Su Doku involves no mathematics, which is clearly wrong; solving the puzzle is an application of mathematics. Also, I can't see any reason why mathematical puzzles should be expected to contain arithmetic (witness, Soma cube, Tangram). Dillon256 13:04, 8 Apr 2005 (UTC)