Analysis of xx-top500-136-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: ...12....6.....9.....3.......1....3.....8.6...4...9........75.13..4............2. initial

Autosolve

position: .3912.4..6128749534.839.1.2.61.42.3929..83614.436192.598623754132.4.1.9.1.49.832. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # A4: 5,7 => CTR => A4: 8
* PRF # A4: 8 => SOL
* PRF # H1: 7,8 => SOL
* DIS # H1: 6 => CTR => H1: 7,8
* DIS # I8: 7,8 => CTR => I8: 6
* PRF # I8: 6 => SOL
* PRF # H1: 6,7 => SOL
* DIS # H1: 8 => CTR => H1: 6,7
* DIS # A4: 5,7 => CTR => A4: 8
* PRF # A4: 8 => SOL
* PRF # A4: 7,8 => SOL
* DIS # A4: 5 => CTR => A4: 7,8
* DIS # A4: 5,7 => CTR => A4: 8
* PRF # A4: 8 => SOL
* PRF # A4: 7,8 => SOL
* DIS # A4: 5 => CTR => A4: 7,8
* PRF # H1: 7,8 => SOL
* DIS # H1: 6 => CTR => H1: 7,8
* DIS # I8: 7,8 => CTR => I8: 6
* PRF # I8: 6 => SOL
* PRF # I8: 6,7 => SOL
* DIS # I8: 8 => CTR => I8: 6,7
* CNT  22 HDP CHAINS /  22 HYP OPENED

See Appendix: Full HDP Chains for full list of HDP chains.

Pair Reduction

Pair Reduction

The following important HDP chains were detected:

* DIS # A4: 5,7 => CTR => A4: 8
* PRF A4: 8 => SOL
* STA A4: 8
* CNT   2 HDP CHAINS /   1 HYP OPENED

See Appendix: Full HDP Chains for full list of HDP chains.

Details

Positions

...12....6.....9.....3.......1....3.....8.6...4...9........75.13..4............2. initial
.3912.4..6128749534.839.1.2.61.42.3929..83614.436192.598623754132.4.1.9.1.49.832. autosolve
539126478612874953478395162861542739295783614743619285986237541327451896154968327 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (18)
A1: 5,7
B3: 5,7
F1: 5,6
F3: 5,6
I1: 7,8
H3: 6,7
C5: 5,7
A6: 7,8
D4: 5,7
D5: 5,7
G4: 7,8
H6: 7,8
C8: 5,7
B9: 5,7
E8: 5,6
E9: 5,6
G8: 7,8
I9: 6,7

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
A1,B3: 5.. / A1 = 5  =>  0 pairs (*) / B3 = 5  =>  0 pairs (X)
F1,F3: 5.. / F1 = 5  =>  0 pairs (X) / F3 = 5  =>  0 pairs (_)
A4,C5: 5.. / A4 = 5  =>  0 pairs (X) / C5 = 5  =>  0 pairs (_)
D4,D5: 5.. / D4 = 5  =>  0 pairs (*) / D5 = 5  =>  0 pairs (X)
C8,B9: 5.. / C8 = 5  =>  0 pairs (X) / B9 = 5  =>  0 pairs (_)
E8,E9: 5.. / E8 = 5  =>  0 pairs (*) / E9 = 5  =>  0 pairs (X)
A1,F1: 5.. / A1 = 5  =>  0 pairs (*) / F1 = 5  =>  0 pairs (X)
B3,F3: 5.. / B3 = 5  =>  0 pairs (X) / F3 = 5  =>  0 pairs (_)
A4,D4: 5.. / A4 = 5  =>  0 pairs (X) / D4 = 5  =>  0 pairs (_)
C5,D5: 5.. / C5 = 5  =>  0 pairs (*) / D5 = 5  =>  0 pairs (X)
C8,E8: 5.. / C8 = 5  =>  0 pairs (X) / E8 = 5  =>  0 pairs (_)
B9,E9: 5.. / B9 = 5  =>  0 pairs (*) / E9 = 5  =>  0 pairs (X)
A1,A4: 5.. / A1 = 5  =>  0 pairs (*) / A4 = 5  =>  0 pairs (X)
B3,B9: 5.. / B3 = 5  =>  0 pairs (X) / B9 = 5  =>  0 pairs (_)
C5,C8: 5.. / C5 = 5  =>  0 pairs (*) / C8 = 5  =>  0 pairs (X)
F1,F3: 6.. / F1 = 6  =>  0 pairs (*) / F3 = 6  =>  0 pairs (X)
H1,H3: 6.. / H1 = 6  =>  0 pairs (X) / H3 = 6  =>  0 pairs (_)
E8,E9: 6.. / E8 = 6  =>  0 pairs (X) / E9 = 6  =>  0 pairs (_)
I8,I9: 6.. / I8 = 6  =>  0 pairs (*) / I9 = 6  =>  0 pairs (X)
F1,H1: 6.. / F1 = 6  =>  0 pairs (*) / H1 = 6  =>  0 pairs (X)
F3,H3: 6.. / F3 = 6  =>  0 pairs (X) / H3 = 6  =>  0 pairs (_)
E8,I8: 6.. / E8 = 6  =>  0 pairs (X) / I8 = 6  =>  0 pairs (_)
E9,I9: 6.. / E9 = 6  =>  0 pairs (*) / I9 = 6  =>  0 pairs (X)
A1,B3: 7.. / A1 = 7  =>  0 pairs (X) / B3 = 7  =>  0 pairs (_)
D4,D5: 7.. / D4 = 7  =>  0 pairs (X) / D5 = 7  =>  0 pairs (_)
G4,H6: 7.. / G4 = 7  =>  0 pairs (*) / H6 = 7  =>  0 pairs (X)
C8,B9: 7.. / C8 = 7  =>  0 pairs (*) / B9 = 7  =>  0 pairs (X)
B3,H3: 7.. / B3 = 7  =>  0 pairs (*) / H3 = 7  =>  0 pairs (X)
C5,D5: 7.. / C5 = 7  =>  0 pairs (X) / D5 = 7  =>  0 pairs (_)
A6,H6: 7.. / A6 = 7  =>  0 pairs (*) / H6 = 7  =>  0 pairs (X)
B9,I9: 7.. / B9 = 7  =>  0 pairs (X) / I9 = 7  =>  0 pairs (_)
B3,B9: 7.. / B3 = 7  =>  0 pairs (*) / B9 = 7  =>  0 pairs (X)
C5,C8: 7.. / C5 = 7  =>  0 pairs (X) / C8 = 7  =>  0 pairs (_)
G4,G8: 7.. / G4 = 7  =>  0 pairs (*) / G8 = 7  =>  0 pairs (X)
H1,I1: 8.. / H1 = 8  =>  0 pairs (X) / I1 = 8  =>  0 pairs (_)
A4,A6: 8.. / A4 = 8  =>  0 pairs (*) / A6 = 8  =>  0 pairs (X)
G4,H6: 8.. / G4 = 8  =>  0 pairs (X) / H6 = 8  =>  0 pairs (_)
G8,I8: 8.. / G8 = 8  =>  0 pairs (*) / I8 = 8  =>  0 pairs (X)
A4,G4: 8.. / A4 = 8  =>  0 pairs (*) / G4 = 8  =>  0 pairs (X)
A6,H6: 8.. / A6 = 8  =>  0 pairs (X) / H6 = 8  =>  0 pairs (_)
G4,G8: 8.. / G4 = 8  =>  0 pairs (X) / G8 = 8  =>  0 pairs (_)
H1,H6: 8.. / H1 = 8  =>  0 pairs (X) / H6 = 8  =>  0 pairs (_)
I1,I8: 8.. / I1 = 8  =>  0 pairs (*) / I8 = 8  =>  0 pairs (X)
* DURATION: 0:01:13.361604  START: 07:23:21.746365  END: 07:24:35.107969 2017-05-04
* CP COUNT: (43)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,A6,B3,B9,C5,C8,D4,D5,E8,E9,F1,F3,G4,G8,H3,H6,I1,I9)
* .3912.4..6128749534.839.1.2.61.42.3929..83614.436192.598623754132.4.1.9.1.49.832.
* PAIR A1: 5,7 COL A
A4: 5,7,8                                # reduction candidate for 5,7
A4: 5,7 => CTR
* .3912.4..6128749534.839.1.2.61.4283929..8361484361927598623754132.4.1798174958326
A4: 8 => SOLVED
* 539126478612874953478395162861542739295783614743619285986237541327451896154968327
* PAIR I1: 7,8 BLK 3
H1: 7,8,6                                # reduction candidate for 7,8
H1: 7,8 => SOLVED
* 539126478612874953478395162861542739295783614743619285986237541327451896154968327
H1: 6 => CTR
* .3912.4686128749534.8396172.61.4273929.7836147436192859862375413274518961549.832.
* PAIR I1: 7,8 COL I
I8: 7,8,6                                # reduction candidate for 7,8
I8: 7,8 => CTR
* .3912.4..612874953458396172561742.3929..83614.436192.598623754132.461.9.1.4958326
I8: 6 => SOLVED
* 539126478612874953478395162861542739295783614743619285986237541327451896154968327
* PAIR H3: 6,7 BLK 3
H1: 6,7,8                                # reduction candidate for 6,7
H1: 6,7 => SOLVED
* 539126478612874953478395162861542739295783614743619285986237541327451896154968327
H1: 8 => CTR
* .39126487612874953478395162.61.4283929..836148436192759862375413274.1.9.1.49.832.
* PAIR C5: 5,7 BLK 4
A4: 5,7,8                                # reduction candidate for 5,7
A4: 5,7 => CTR
* .3912.4..6128749534.839.1.2.61.4283929..8361484361927598623754132.4.1798174958326
A4: 8 => SOLVED
* 539126478612874953478395162861542739295783614743619285986237541327451896154968327
* PAIR A6: 7,8 BLK 4
A4: 7,8,5                                # reduction candidate for 7,8
A4: 7,8 => SOLVED
* 539126478612874953478395162861542739295783614743619285986237541327451896154968327
A4: 5 => CTR
* .3912.4..6128749534.839.1.25617428392975836148436192759862375413254617981749.832.
* PAIR D4: 5,7 ROW 4
A4: 5,7,8                                # reduction candidate for 5,7
A4: 5,7 => CTR
* .3912.4..6128749534.839.1.2.61.4283929..8361484361927598623754132.4.1798174958326
A4: 8 => SOLVED
* 539126478612874953478395162861542739295783614743619285986237541327451896154968327
* PAIR G4: 7,8 ROW 4
A4: 7,8,5                                # reduction candidate for 7,8
A4: 7,8 => SOLVED
* 539126478612874953478395162861542739295783614743619285986237541327451896154968327
A4: 5 => CTR
* .3912.4..6128749534.839.1.25617428392975836148436192759862375413254617981749.832.
* PAIR H6: 7,8 COL H
H1: 7,8,6                                # reduction candidate for 7,8
H1: 7,8 => SOLVED
* 539126478612874953478395162861542739295783614743619285986237541327451896154968327
H1: 6 => CTR
* .3912.4686128749534.8396172.61.4273929.7836147436192859862375413274518961549.832.
* PAIR G8: 7,8 BLK 9
I8: 7,8,6                                # reduction candidate for 7,8
I8: 7,8 => CTR
* .3912.4..612874953458396172561742.3929..83614.436192.598623754132.461.9.1.4958326
I8: 6 => SOLVED
* 539126478612874953478395162861542739295783614743619285986237541327451896154968327
* PAIR I9: 6,7 BLK 9
I8: 6,7,8                                # reduction candidate for 6,7
I8: 6,7 => SOLVED
* 539126478612874953478395162861542739295783614743619285986237541327451896154968327
I8: 8 => CTR
* .3912.4876128749534.839.1.2.61.42.3929..83614.436192.598623754132.461.981.4958326
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-136-base-pr-000.dot
* REASONING
* DIS # A4: 5,7 => CTR => A4: 8
* PRF # A4: 8 => SOL
* PRF # H1: 7,8 => SOL
* DIS # H1: 6 => CTR => H1: 7,8
* DIS # I8: 7,8 => CTR => I8: 6
* PRF # I8: 6 => SOL
* PRF # H1: 6,7 => SOL
* DIS # H1: 8 => CTR => H1: 6,7
* DIS # A4: 5,7 => CTR => A4: 8
* PRF # A4: 8 => SOL
* PRF # A4: 7,8 => SOL
* DIS # A4: 5 => CTR => A4: 7,8
* DIS # A4: 5,7 => CTR => A4: 8
* PRF # A4: 8 => SOL
* PRF # A4: 7,8 => SOL
* DIS # A4: 5 => CTR => A4: 7,8
* PRF # H1: 7,8 => SOL
* DIS # H1: 6 => CTR => H1: 7,8
* DIS # I8: 7,8 => CTR => I8: 6
* PRF # I8: 6 => SOL
* PRF # I8: 6,7 => SOL
* DIS # I8: 8 => CTR => I8: 6,7
* CNT  22 HDP CHAINS /  22 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,A6,B3,B9,C5,C8,D4,D5,E8,E9,F1,F3,G4,G8,H3,H6,I1,I9)
* .3912.4..6128749534.839.1.2.61.42.3929..83614.436192.598623754132.4.1.9.1.49.832.
* PAIR A1: 5,7 COL A
A4: 5,7,8                                # reduction candidate for 5,7
A4: 5,7 => CTR
* .3912.4..6128749534.839.1.2.61.4283929..8361484361927598623754132.4.1798174958326
A4: 8 => SOLVED
* 539126478612874953478395162861542739295783614743619285986237541327451896154968327
* DURATION: 0:00:02.916924  START: 07:25:01.697243  END: 07:25:04.614167 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-136-base-pr-001.dot
* REASONING
* DIS # A4: 5,7 => CTR => A4: 8
* PRF A4: 8 => SOL
* STA A4: 8
* CNT   2 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 136

solution: 539126478612874953478395162861542739295783614743619285986237541327451896154968327
info: 1812     FNBWX    S8.f     40956

http://www.sfsudoku.com/su17ExtremeDiff500.txt from http://www.minimumsudoku.com/

Solution

position: 539126478612874953478395162861542739295783614743619285986237541327451896154968327 solved
Solution

See section Pair Reduction for the HDP chains leading to this result.

Appendix: Full HDP Chains

A1. Pair Reduction Analysis

Full list of HDP chains traversed:

* DIS # A4: 5,7 => CTR => A4: 8
* PRF # A4: 8 => SOL
* PRF # H1: 7,8 => SOL
* DIS # H1: 6 => CTR => H1: 7,8
* DIS # I8: 7,8 => CTR => I8: 6
* PRF # I8: 6 => SOL
* PRF # H1: 6,7 => SOL
* DIS # H1: 8 => CTR => H1: 6,7
* DIS # A4: 5,7 => CTR => A4: 8
* PRF # A4: 8 => SOL
* PRF # A4: 7,8 => SOL
* DIS # A4: 5 => CTR => A4: 7,8
* DIS # A4: 5,7 => CTR => A4: 8
* PRF # A4: 8 => SOL
* PRF # A4: 7,8 => SOL
* DIS # A4: 5 => CTR => A4: 7,8
* PRF # H1: 7,8 => SOL
* DIS # H1: 6 => CTR => H1: 7,8
* DIS # I8: 7,8 => CTR => I8: 6
* PRF # I8: 6 => SOL
* PRF # I8: 6,7 => SOL
* DIS # I8: 8 => CTR => I8: 6,7
* CNT  22 HDP CHAINS /  22 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # A4: 5,7 => CTR => A4: 8
* PRF A4: 8 => SOL
* STA A4: 8
* CNT   2 HDP CHAINS /   1 HYP OPENED