The initial puzzle is singles only.
- Code: Select all
. . . | . . . | . . .
. 1 . | 2 . 3 | . 4 .
. . . | 4 5 6 | . . .
-------+-------+-------
. 4 7 | . . . | 8 9 .
. . 2 | . 7 . | 6 . .
. 9 8 | . . . | 7 5 .
-------+-------+-------
. . . | 6 8 4 | . . .
. 3 . | 7 . 1 | . 6 .
. . . | . . . | . . .
S.E. gives a rating = 2.3 for Naked Single and 2.0 for Hidden Pair.
Therefore, Hidden Pair will be chosen before Nacked Single.
Here is one path to solve the puzzle with singles only :
1: r1c6=7 r2c5=9 r5c2=5 r5c9=4 r6c5=4 r6c6=2
2: r1c4=8 r1c5=1 r2c7=5 r4c5=6 r4c6=5 r4c9=2 r5c6=8 r6c1=6 r8c5=2
3: r2c3=6 r5c4=9 r9c4=5 r9c5=3 r9c6=9
4: r1c2=2 r1c9=6 r9c2=6
5: r1c8=3 r3c2=8 r7c2=7
6: r1c7=9 r2c1=7 r2c9=8 r3c3=3 r5c1=3 r5c8=1 r6c9=3 r7c7=3 r9c8=8
7: r3c1=9 r3c8=7 r4c1=1 r4c4=3 r6c4=1 r7c8=2 r8c1=8 r8c7=4 r9c9=7
8: r3c7=2 r3c9=1 r7c1=5 r9c1=2 r9c7=1
9: r1c1=4 r1c3=5 r7c3=1 r7c9=9 r8c3=9 r8c9=5 r9c3=4
JPF