Sudoku - DAY 1

Ok, now that we know the 4 "Basic Rules" of Sudoku, let's solve the "gimme" numbers. I think there are four of them, and here is what our board looks like now. Remember, each of these was solved using rule 4 (Each number 1-9) can appear only once in each box section. The box sections are as follows. A1 - C9 ; D1 - F9 ; G1 - J9 (rows) and A1 - J3 ; A4 - J6 ; A7 - J9 (columns).


Here are 2 of the 4 proofs:

Solving: A9 = 9 : Row B and Row C already have a 9 so Row A needs a 9.
Cannot be in A1-A3 (already a 9 in box 1 [B2])
Cannot be in A4 (already a 9 in box 2 [C6])
Cannot be in A8 (already a 9 in column 8 [G8])
G9 = 9

Solving: D6 = 4 : Row E and Row F already have a 4 so Row D needs a 4
Cannot be D2 - D3 (Box 4 already has a 4 [E1])
Cannot be D7 - D8 (Box 6 already has a 4 [F9])
Cannot be D4 (already a 4 in column 4 [J4])
D6 = 4

The other two J1 and H4 were solved using the same logic. Using rules 1 - 4.

Try to do this on the rest of the puzzle after solving those 4 numbers and you will see why this puzzle is classified as diabolical. We'll start on the hard stuff later today solving three numbers per day until the puzzle is complete.

Questions / Comments / or a better way of doing it? Post a comment.

Dr. Sudoku.