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Monday 18-Nov-2019

... by: pie314271

The single-digit backdoors D2=4, E3=9, F4=8, G7=3, and each allow the solver to handle the puzzle, albeit using Bowman's. They're fun to click through, though.

Alternatively, E9=2 and J8=2 solve the puzzle normally (with scores 595 and 598, respectively, though with extreme strategies thrown in).

Saturday 16-Nov-2019

... by: hehe

*****************************
The correct answer is :

4 6 3 |1 8 5 |2 7 9
9 5 2 |7 4 6 |1 3 8
7 1 8 |9 3 2 |4 6 5
------ ------ ------
2 4 6 |3 5 9 |8 1 7
8 3 9 |6 7 1 |5 4 2
1 7 5 |8 2 4 |6 9 3
------ ------ ------
6 9 7 |2 1 8 |3 5 4
5 2 1 |4 9 3 |7 8 6
3 8 4 |5 6 7 |9 2 1

*****************************
4
162

81,58

Saturday 16-Nov-2019

... by: Frans Goosens

With trial and error

Combination A1=246 and E5=178

************************************************************
A1=2 E5=1 Wrong, Undo calculation

All reset to initial position

************************************************************
A1=2 E5=7 Wrong, Undo calculation

All reset to initial position

************************************************************
A1=2 E5=8 No solution, Fixed

Combination 2-digits cells

A5=1 Wrong, Undo calculation
A5=6 No solution, Fixed
B3=5 Wrong, Undo calculation
B3=9 Wrong, Undo calculation

All reset to initial position

************************************************************
A1=4 E5=1 Wrong, Undo calculation

All reset to initial position

************************************************************
A1=4 E5=7 ( G2=9 ) Solved,


#374--------------------------Solution
003 005 079-------------463 185 279
000 040 008-------------952 746 138
008 900 060-------------718 932 465

006 009 007-------------246 359 817
030 600 500-------------839 671 542
100 020 000-------------175 824 693

007 008 050-------------697 218 354
020 000 000-------------521 493 786
300 000 000-------------384 567 921

Total solving time is : 131 sec.
Number of logical steps is : 12915

Saturday 16-Nov-2019

... by: Federico

Solved using Ali Assaf code (Algorithm X / Dancing Links)


All test passed

Hints : 22
0 0 3 |0 0 5 |0 7 9
0 0 0 |0 4 0 |0 0 8
0 0 8 |9 0 0 |0 6 0
------+------+------
0 0 6 |0 0 9 |0 0 7
0 3 0 |6 0 0 |5 0 0
1 0 0 |0 2 0 |0 0 0
------+------+------
0 0 7 |0 0 8 |0 5 0
0 2 0 |0 0 0 |0 0 0
3 0 0 |0 0 0 |0 0 0

Solved
4 6 3 |1 8 5 |2 7 9
9 5 2 |7 4 6 |1 3 8
7 1 8 |9 3 2 |4 6 5
------+------+------
2 4 6 |3 5 9 |8 1 7
8 3 9 |6 7 1 |5 4 2
1 7 5 |8 2 4 |6 9 3
------+------+------
6 9 7 |2 1 8 |3 5 4
5 2 1 |4 9 3 |7 8 6
3 8 4 |5 6 7 |9 2 1

(0.70 seconds)

Horiz._Sum : [45 45 45 45 45 45 45 45 45]
Vert.__Sum : [45 45 45 45 45 45 45 45 45]

Hints Position OK

NO Horiz._Duplication
NO Vert.__Duplication

Subgrid : 1 1 NO duplication
Subgrid : 1 2 NO duplication
Subgrid : 1 3 NO duplication
Subgrid : 2 1 NO duplication
Subgrid : 2 2 NO duplication
Subgrid : 2 3 NO duplication
Subgrid : 3 1 NO duplication
Subgrid : 3 2 NO duplication
Subgrid : 3 3 NO duplication

Saturday 16-Nov-2019

... by: numpl_npm

+5C9

MSLS found.

u 1234 / n 56789
. 4 4 _ . _ 3 _ . _ _ _ .
. 2 1 _ . _ 1 _ . u _ _ . (u is one of 1234)

| o o 3 | _ o 5 | _ 7 9 | A 68
| _ _ _ | _ 4 _ | _ _ 8 | B
| o o 8 | 9 o _ | _ 6 5 | C 7

| o o 6 | _ o 9 | o _ 7 | D 58
| _ 3 _ | 6 _ _ | 5 _ _ | E
| 1 _ _ | _ 2 _ | _ _ _ | F

| o o 7 | _ o 8 | o 5 _ | G 69
| _ 2 _ | _ _ _ | _ _ _ | H
| 3 _ _ | _ _ _ | _ _ _ | J

(o 14) - (u 7 + n 7) = 0 ... MSLS

-8A4 So +8A5 and +6B6
-8D4 So +8F4
-5D4 So +5D5
-1E5 So +7E5 and +7F2 +5F3
-7C6 So +7B4 and +7C1

Then

| _ _ 3 | _ 8 5 | _ 7 9 | A
| _ _ _ | 7 4 6 | _ _ 8 | B
| 7 _ 8 | 9 _ _ | _ 6 5 | C

| _ _ 6 | _ 5 9 | _ _ 7 | D
| _ 3 _ | 6 7 _ | 5 _ _ | E
| 1 7 5 | 8 2 _ | _ _ _ | F

| _ _ 7 | _ _ 8 | _ 5 _ | G
| _ 2 _ | _ _ _ | _ _ _ | H
| 3 _ _ | _ _ _ | _ _ _ | J

(SE7.3)

Saturday 16-Nov-2019

... by: SuDokuFan

MSLS Base 1234 in ABCDG1257, -1234ABCDG34689, -56789EFHJ1257, no longer unsolvable

Saturday 16-Nov-2019

... by: BobW

I found a solution involving what I would call two "Almost Exocets" plus 7 inference chains. Too complicated to bother posting.

Couldn't find a single cell backdoor solution.

With the two cell backdoor: A4=1 D7=8 it's solvable with singles.

Saturday 16-Nov-2019

... by: James Havard

247 subs 256 seconds
G7=3 and J8=2 together gives a singles solution.

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