Method A and one more clue solves

krcgee · Posted: Wed Nov 23, 2005 2:24 am Post subject: Method A and one more clue solves

While developing my own solver
http://www.geocities.com/krcgee/sudoku ,I have
noticed a curious fact. A logically solvable
Sudoku problem with a unique solution can be
solved by method A alone or can be reduced to
one solvable by method A by adding one more
clue. The clue to be added can be found by a
combination of method A, guess and again
method A. I have tested this with many problems
including the the very hard problems given at the
site www.sudokusolver.co.uk/. To quote a few:
#1 add 6 at A3 ,#2 add 7 at A1, #7 add 7 at A1 , #11
add 7 at A9, #12 add 4 at A2, #17 add 4 at A1, #19
add 6 at A1 , #20 add 8 at A2, #30 add 9 at A2
I wonder whether all problems will follow this
pattern.

dukuso · Posted: Wed Nov 23, 2005 5:41 am Post subject:

I would describe this as level-1-lookahead or such.
Reminds me to "magic cells"