Sudoku Puzzles

Was the old one torn down, Sue?

9:11 the old one could still be in use.

Fast time for me today, shame I didn't time myself.

1. Unique possibility: g7=8. (UP 24)
2. If c1=9,pair 48 at a23;if a2=9=g1,triple 247 at bgi4 creates another pair 48 at a34.Hence c9=4,a6=67.UP 25
3. If b4=4,i4=7;if b4=2,b8=1,b7=6=a6,pair 47 at i46.So 7s are locked at i46,i8=3,i7=5.UP 27.
4. This chain is very long ,but it does knock the More...

Silos are having a sale, at least in the USA.

~1 hour

Hi, Alfred.
My step 2 was --
i8=3 or 7. If i8=7, 14=4, i6=6, b5=6, b4=2, h6=2, leaving only 1 as a possibility for b78, so i8=3.
Then I did the 9s in your step 2, but took c1=9 to a contradiction: If c1=9, (48 pair at a23)a4=7, a6=6, a9=3, g5=6, h5=3, i4=4, i6=7, i7=5, b4=2, b8=1, c8=2, More...

Did check. The i8=3 isn't necessary to get the a2=9 to UP 81, so my step 2 isn't necessary.

Hi, all. I think Alfred has found a flaw in my solution. So ignore, please.

Hi, Alfred. Yikes, I think you're right. Somehow 7 escaped getting entered as a candidate in c8 in the first place. Looking to see if anything can be rescued.

Thanks,
Brenda

47:50

SE=7.3

long path:SST to UP=24
1.{(9)a7=a2-c1=g1-g4=(34')gh5-(6)g5=b5-b7=(36')a79}
>> -7a79 -4a9 -9g25 -6g1 -7gh5 -4h5 >> UP27
2.{(278=4)c6ab4-(4=7)i4}-a4=(67')ai6
>> -7g4 -8a6 -4i6|f4 >> UP29
3.(7=2)h7-g9=(2-9)g4=(9-3)h5=h3 >> -7h3 (SF7dfg359)
4.(9=3)g1-e1=e9-a9=(3-9)a7=c78 >> -9c1 >> UP81