Analysis of xx-top500-121-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: .3.....2.....4.5..6..7......8.3.2.........4.1.........4.5.6.......5...3.1........ initial

Autosolve

position: 539681724817249563642735819.84312.5.326.5.4.1.514.63824.51632.82.85.413.1.3.2..45 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # B8: 7,9 => CTR => B8: 6
* PRF # B8: 6 => SOL
* PRF # B9: 7,9 => SOL
* DIS # B9: 6 => CTR => B9: 7,9
* DIS # B8: 7,9 => CTR => B8: 6
* PRF # B8: 6 => SOL
* PRF # B8: 6,7 => SOL
* DIS # B8: 9 => CTR => B8: 6,7
* PRF # B9: 6,9 => SOL
* DIS # B9: 7 => CTR => B9: 6,9
* CNT  10 HDP CHAINS /  10 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 # B8: 7,9 => CTR => B8: 6
* PRF B8: 6 => SOL
* STA B8: 6
* CNT   2 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

.3.....2.....4.5..6..7......8.3.2.........4.1.........4.5.6.......5...3.1........ initial
539681724817249563642735819.84312.5.326.5.4.1.514.63824.51632.82.85.413.1.3.2..45 autosolve
539681724817249563642735819784312956326958471951476382475163298268594137193827645 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (15)
A4: 7,9
A6: 7,9
D5: 8,9
F5: 7,8
E6: 7,9
G4: 6,9
I4: 6,7
H5: 7,9
B7: 7,9
E8: 7,9
D9: 8,9
F9: 7,8
H7: 7,9
I8: 6,7
G9: 6,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
G4,I4: 6.. / G4 = 6  =>  0 pairs (X) / I4 = 6  =>  0 pairs (_)
B8,B9: 6.. / B8 = 6  =>  0 pairs (*) / B9 = 6  =>  0 pairs (X)
I8,G9: 6.. / I8 = 6  =>  0 pairs (X) / G9 = 6  =>  0 pairs (_)
B8,I8: 6.. / B8 = 6  =>  0 pairs (*) / I8 = 6  =>  0 pairs (X)
B9,G9: 6.. / B9 = 6  =>  0 pairs (X) / G9 = 6  =>  0 pairs (_)
G4,G9: 6.. / G4 = 6  =>  0 pairs (X) / G9 = 6  =>  0 pairs (_)
I4,I8: 6.. / I4 = 6  =>  0 pairs (*) / I8 = 6  =>  0 pairs (X)
A4,A6: 7.. / A4 = 7  =>  0 pairs (*) / A6 = 7  =>  0 pairs (X)
F5,E6: 7.. / F5 = 7  =>  0 pairs (X) / E6 = 7  =>  0 pairs (_)
I4,H5: 7.. / I4 = 7  =>  0 pairs (X) / H5 = 7  =>  0 pairs (_)
E8,F9: 7.. / E8 = 7  =>  0 pairs (X) / F9 = 7  =>  0 pairs (_)
H7,I8: 7.. / H7 = 7  =>  0 pairs (X) / I8 = 7  =>  0 pairs (_)
A4,I4: 7.. / A4 = 7  =>  0 pairs (*) / I4 = 7  =>  0 pairs (X)
F5,H5: 7.. / F5 = 7  =>  0 pairs (X) / H5 = 7  =>  0 pairs (_)
A6,E6: 7.. / A6 = 7  =>  0 pairs (X) / E6 = 7  =>  0 pairs (_)
B7,H7: 7.. / B7 = 7  =>  0 pairs (*) / H7 = 7  =>  0 pairs (X)
B9,F9: 7.. / B9 = 7  =>  0 pairs (X) / F9 = 7  =>  0 pairs (_)
E6,E8: 7.. / E6 = 7  =>  0 pairs (*) / E8 = 7  =>  0 pairs (X)
F5,F9: 7.. / F5 = 7  =>  0 pairs (X) / F9 = 7  =>  0 pairs (_)
H5,H7: 7.. / H5 = 7  =>  0 pairs (*) / H7 = 7  =>  0 pairs (X)
I4,I8: 7.. / I4 = 7  =>  0 pairs (X) / I8 = 7  =>  0 pairs (_)
D5,F5: 8.. / D5 = 8  =>  0 pairs (X) / F5 = 8  =>  0 pairs (_)
D9,F9: 8.. / D9 = 8  =>  0 pairs (*) / F9 = 8  =>  0 pairs (X)
D5,D9: 8.. / D5 = 8  =>  0 pairs (X) / D9 = 8  =>  0 pairs (_)
F5,F9: 8.. / F5 = 8  =>  0 pairs (*) / F9 = 8  =>  0 pairs (X)
A4,A6: 9.. / A4 = 9  =>  0 pairs (X) / A6 = 9  =>  0 pairs (_)
D5,E6: 9.. / D5 = 9  =>  0 pairs (*) / E6 = 9  =>  0 pairs (X)
G4,H5: 9.. / G4 = 9  =>  0 pairs (*) / H5 = 9  =>  0 pairs (X)
E8,D9: 9.. / E8 = 9  =>  0 pairs (*) / D9 = 9  =>  0 pairs (X)
H7,G9: 9.. / H7 = 9  =>  0 pairs (*) / G9 = 9  =>  0 pairs (X)
A4,G4: 9.. / A4 = 9  =>  0 pairs (X) / G4 = 9  =>  0 pairs (_)
D5,H5: 9.. / D5 = 9  =>  0 pairs (*) / H5 = 9  =>  0 pairs (X)
A6,E6: 9.. / A6 = 9  =>  0 pairs (*) / E6 = 9  =>  0 pairs (X)
B7,H7: 9.. / B7 = 9  =>  0 pairs (X) / H7 = 9  =>  0 pairs (_)
B8,E8: 9.. / B8 = 9  =>  0 pairs (X) / E8 = 9  =>  0 pairs (_)
D5,D9: 9.. / D5 = 9  =>  0 pairs (*) / D9 = 9  =>  0 pairs (X)
E6,E8: 9.. / E6 = 9  =>  0 pairs (X) / E8 = 9  =>  0 pairs (_)
G4,G9: 9.. / G4 = 9  =>  0 pairs (*) / G9 = 9  =>  0 pairs (X)
H5,H7: 9.. / H5 = 9  =>  0 pairs (X) / H7 = 9  =>  0 pairs (_)
* DURATION: 0:01:04.977217  START: 06:55:00.550701  END: 06:56:05.527918 2017-05-04
* CP COUNT: (39)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A4,A6,B7,D5,D9,E6,E8,F5,F9,G4,G9,H5,H7,I4,I8)
* 539681724817249563642735819.84312.5.326.5.4.1.514.63824.51632.82.85.413.1.3.2..45
* PAIR B7: 7,9 BLK 7
B8: 7,9,6                                # reduction candidate for 7,9
B8: 7,9 => CTR
* 539681724817249563642735819.84312.5.326.5.4.1.514.63824.51632.82.85.4136163.27945
B8: 6 => SOLVED
* 539681724817249563642735819784312956326958471951476382475163298268594137193827645
B9: 7,9,6                                # reduction candidate for 7,9
B9: 7,9 => SOLVED
* 539681724817249563642735819784312956326958471951476382475163298268594137193827645
B9: 6 => CTR
* 539681724817249563642735819.84312.5.326.5.4.1.514.63824.51632.82.85.413.163.27945
* PAIR E8: 7,9 ROW 8
B8: 7,9,6                                # reduction candidate for 7,9
B8: 7,9 => CTR
* 539681724817249563642735819.84312.5.326.5.4.1.514.63824.51632.82.85.4136163.27945
B8: 6 => SOLVED
* 539681724817249563642735819784312956326958471951476382475163298268594137193827645
* PAIR I8: 6,7 ROW 8
B8: 6,7,9                                # reduction candidate for 6,7
B8: 6,7 => SOLVED
* 539681724817249563642735819784312956326958471951476382475163298268594137193827645
B8: 9 => CTR
* 539681724817249563642735819.84312.5.326.5.4.1.514.63824.51632.82985741361.3.2..45
* PAIR G9: 6,9 ROW 9
B9: 6,9,7                                # reduction candidate for 6,9
B9: 6,9 => SOLVED
* 539681724817249563642735819784312956326958471951476382475163298268594137193827645
B9: 7 => CTR
* 539681724817249563642735819.84312.5.326.5.4.1.514.63824.51632.82685941371.3.2..45
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-121-base-pr-000.dot
* REASONING
* DIS # B8: 7,9 => CTR => B8: 6
* PRF # B8: 6 => SOL
* PRF # B9: 7,9 => SOL
* DIS # B9: 6 => CTR => B9: 7,9
* DIS # B8: 7,9 => CTR => B8: 6
* PRF # B8: 6 => SOL
* PRF # B8: 6,7 => SOL
* DIS # B8: 9 => CTR => B8: 6,7
* PRF # B9: 6,9 => SOL
* DIS # B9: 7 => CTR => B9: 6,9
* CNT  10 HDP CHAINS /  10 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A4,A6,B7,D5,D9,E6,E8,F5,F9,G4,G9,H5,H7,I4,I8)
* 539681724817249563642735819.84312.5.326.5.4.1.514.63824.51632.82.85.413.1.3.2..45
* PAIR B7: 7,9 BLK 7
B8: 7,9,6                                # reduction candidate for 7,9
B8: 7,9 => CTR
* 539681724817249563642735819.84312.5.326.5.4.1.514.63824.51632.82.85.4136163.27945
B8: 6 => SOLVED
* 539681724817249563642735819784312956326958471951476382475163298268594137193827645
* DURATION: 0:00:01.797356  START: 06:56:17.516486  END: 06:56:19.313842 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-121-base-pr-001.dot
* REASONING
* DIS # B8: 7,9 => CTR => B8: 6
* PRF B8: 6 => SOL
* STA B8: 6
* CNT   2 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 121

solution: 539681724817249563642735819784312956326958471951476382475163298268594137193827645
info: 1803     FNWX     S8.f     17390

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

Solution

position: 539681724817249563642735819784312956326958471951476382475163298268594137193827645 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 # B8: 7,9 => CTR => B8: 6
* PRF # B8: 6 => SOL
* PRF # B9: 7,9 => SOL
* DIS # B9: 6 => CTR => B9: 7,9
* DIS # B8: 7,9 => CTR => B8: 6
* PRF # B8: 6 => SOL
* PRF # B8: 6,7 => SOL
* DIS # B8: 9 => CTR => B8: 6,7
* PRF # B9: 6,9 => SOL
* DIS # B9: 7 => CTR => B9: 6,9
* CNT  10 HDP CHAINS /  10 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # B8: 7,9 => CTR => B8: 6
* PRF B8: 6 => SOL
* STA B8: 6
* CNT   2 HDP CHAINS /   1 HYP OPENED