Sudoko fever has swept me in. But the problem now takes something like 5-8 minutes at max to solve from 3 hrs of thinking on the first puzzle. This is the timeline of Sudoko introduction to me.
18th Aug Didi Asks me if I solved Sudoko. I told I never tried. Suggests me about writing program for it.
20th Aug I try solving sudoko in the Hitvada paper for a long long duration.
24th Aug Read about sudoko from Paresh's weblog and found one website for solving it online.
28th Aug Completed my program (C++) for Sudoko.
I looked newspapers for input cases and solved them manually too. Its interesting.
One thing I must inform you about Sudoko puzzles in news papers is that they don't require recursion/backtracing. Just pure logic, which could programmatically be put using simple iterations over the blocks of 9 cells.
I will have to extend the program the handle the cases which require recursion. The interesting issue is to discover at what particular situation in the board you will have to try backtracing to get the answer.