Discussion about math, puzzles, games and fun. Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ π -¹ ² ³ °

You are not logged in.

- Topics: Active | Unanswered

Hi,

can someone help me understand how the author arrived at 2222 rows for the exact cover matrix in this article?

Puzzling Over Exact Cover Problems

http://www.ams.org/samplings/feature-co … c-kanoodle

Given an exact cover matrix consisting of:

1. 67 columns: one for each of the 12 Kanoodle pieces and one for each cell in the 5 by 11 grid.

2. 12 Rows per solution corresponding to the 12 Kanoodle pieces.

3. A solution is 12 pieces placed filling the 5 by 11 grid

"We will therefore have one row in our matrix for each possible placement of each of the 12 pieces, which leads to 2222 rows."

I don't understand how the author arrived at 2222 rows

Thanks!

Eschew obfuscation!

Offline