TAOCP 7.2.2.1 Exercise 66

Section 7.2.2.1: Dancing Links

Exercise 66. ▶ [30] [30] Arrange the following sets of nine cards in a $3 \times 3$ array so that they define a sudoku problem with a unique solution. (Don't rotate them.)

i)

ii)

Verified: no
Solve time: 1m43s

The figures containing the two sets of nine cards are not available in the prompt. The exercise cannot be solved from the text alone, because the required arrangements depend on the exact markings and orientations of the individual cards.

Please upload figure_66i.png and figure_66ii.png (or provide clear descriptions of the nine cards in each set). Once the card layouts are available, I can give the complete solution with:

1. the $3\times3$ placement of the cards for each set, without rotating any card;
2. the resulting sudoku clues;
3. the unique completed sudoku solution for each arrangement;
4. a verification that no other completion is possible.