Years back, one of my students got me hooked. On Sudoku. During study hall he pulled out a puzzle book and I wandered over, and that's all it took. The pic above shows a puzzle, and for those not aware of Sudoku requirements, you enter the numbers 1-9 in each box of 9 spaces, in each row and column, without any duplicates. You begin with some numbers filled in and you do the rest. Every possible number candidate gets placed in a box, then you ...