Analysis of xx-top500-189-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: .....1.8..6....7......4.......7..2.94.86.....1............3..4...79......2....... initial

Autosolve

position: 2.9.71.8.8642..7.171.84692....784219498612.7.172....6.98.137.42.4792.1...2146..97 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # C4: 3,5 => SOL
* DIS # C4: 6 => CTR => C4: 3,5
* DIS # C4: 5,6 => CTR => C4: 3
* PRF # C4: 3 => SOL
* PRF # A8: 5,6 => SOL
* DIS # A8: 3 => CTR => A8: 5,6
* PRF # C4: 3,5 => SOL
* DIS # C4: 6 => CTR => C4: 3,5
* DIS # G9: 3,5 => CTR => G9: 8
* PRF # G9: 8 => SOL
* PRF # A8: 5,6 => SOL
* DIS # A8: 3 => CTR => A8: 5,6
* DIS # C4: 5,6 => CTR => C4: 3
* PRF # C4: 3 => SOL
* PRF # A8: 3,5 => SOL
* DIS # A8: 6 => CTR => A8: 3,5
* DIS # G9: 3,5 => CTR => G9: 8
* PRF # G9: 8 => SOL
* PRF # G9: 5,8 => SOL
* DIS # G9: 3 => CTR => G9: 5,8
* DIS # G9: 3,5 => CTR => G9: 8
* PRF # G9: 8 => SOL
* PRF # A8: 3,5 => SOL
* DIS # A8: 6 => CTR => A8: 3,5
* CNT  24 HDP CHAINS /  24 HYP OPENED

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

Pair Reduction

Pair Reduction

The following important HDP chains were detected:

* PRF # C4: 3,5 => SOL
* STA C4: 3,5
* CNT   1 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

.....1.8..6....7......4.......7..2.94.86.....1............3..4...79......2....... initial
2.9.71.8.8642..7.171.84692....784219498612.7.172....6.98.137.42.4792.1...2146..97 autosolve
239571684864293751715846923653784219498612375172359468986137542547928136321465897 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (25)
B1: 3,5
C3: 3,5
D1: 3,5
E2: 5,9
F2: 3,9
G1: 4,6
I1: 4,6
H2: 3,5
I3: 3,5
A4: 5,6
B4: 3,5
D6: 3,5
E6: 5,9
F6: 3,9
G5: 3,5
I5: 3,5
G6: 4,8
I6: 4,8
C7: 5,6
A9: 3,5
F8: 5,8
F9: 5,8
G7: 5,6
H8: 3,5
I8: 6,8

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
B1,C3: 3.. / B1 = 3  =>  0 pairs (*) / C3 = 3  =>  0 pairs (X)
D1,F2: 3.. / D1 = 3  =>  0 pairs (X) / F2 = 3  =>  0 pairs (_)
H2,I3: 3.. / H2 = 3  =>  0 pairs (X) / I3 = 3  =>  0 pairs (_)
B4,C4: 3.. / B4 = 3  =>  0 pairs (X) / C4 = 3  =>  0 pairs (_)
D6,F6: 3.. / D6 = 3  =>  0 pairs (*) / F6 = 3  =>  0 pairs (X)
G5,I5: 3.. / G5 = 3  =>  0 pairs (*) / I5 = 3  =>  0 pairs (X)
A8,A9: 3.. / A8 = 3  =>  0 pairs (X) / A9 = 3  =>  0 pairs (_)
H8,G9: 3.. / H8 = 3  =>  0 pairs (*) / G9 = 3  =>  0 pairs (X)
B1,D1: 3.. / B1 = 3  =>  0 pairs (*) / D1 = 3  =>  0 pairs (X)
F2,H2: 3.. / F2 = 3  =>  0 pairs (*) / H2 = 3  =>  0 pairs (X)
C3,I3: 3.. / C3 = 3  =>  0 pairs (X) / I3 = 3  =>  0 pairs (_)
A8,H8: 3.. / A8 = 3  =>  0 pairs (X) / H8 = 3  =>  0 pairs (_)
A9,G9: 3.. / A9 = 3  =>  0 pairs (*) / G9 = 3  =>  0 pairs (X)
B1,B4: 3.. / B1 = 3  =>  0 pairs (*) / B4 = 3  =>  0 pairs (X)
C3,C4: 3.. / C3 = 3  =>  0 pairs (X) / C4 = 3  =>  0 pairs (_)
D1,D6: 3.. / D1 = 3  =>  0 pairs (X) / D6 = 3  =>  0 pairs (_)
F2,F6: 3.. / F2 = 3  =>  0 pairs (*) / F6 = 3  =>  0 pairs (X)
G5,G9: 3.. / G5 = 3  =>  0 pairs (*) / G9 = 3  =>  0 pairs (X)
H2,H8: 3.. / H2 = 3  =>  0 pairs (X) / H8 = 3  =>  0 pairs (_)
I3,I5: 3.. / I3 = 3  =>  0 pairs (*) / I5 = 3  =>  0 pairs (X)
G1,I1: 4.. / G1 = 4  =>  0 pairs (X) / I1 = 4  =>  0 pairs (_)
G6,I6: 4.. / G6 = 4  =>  0 pairs (*) / I6 = 4  =>  0 pairs (X)
G1,G6: 4.. / G1 = 4  =>  0 pairs (X) / G6 = 4  =>  0 pairs (_)
I1,I6: 4.. / I1 = 4  =>  0 pairs (*) / I6 = 4  =>  0 pairs (X)
B1,C3: 5.. / B1 = 5  =>  0 pairs (X) / C3 = 5  =>  0 pairs (_)
D1,E2: 5.. / D1 = 5  =>  0 pairs (*) / E2 = 5  =>  0 pairs (X)
H2,I3: 5.. / H2 = 5  =>  0 pairs (*) / I3 = 5  =>  0 pairs (X)
D6,E6: 5.. / D6 = 5  =>  0 pairs (X) / E6 = 5  =>  0 pairs (_)
G5,I5: 5.. / G5 = 5  =>  0 pairs (X) / I5 = 5  =>  0 pairs (_)
F8,F9: 5.. / F8 = 5  =>  0 pairs (X) / F9 = 5  =>  0 pairs (_)
B1,D1: 5.. / B1 = 5  =>  0 pairs (X) / D1 = 5  =>  0 pairs (_)
E2,H2: 5.. / E2 = 5  =>  0 pairs (X) / H2 = 5  =>  0 pairs (_)
C3,I3: 5.. / C3 = 5  =>  0 pairs (*) / I3 = 5  =>  0 pairs (X)
C7,G7: 5.. / C7 = 5  =>  0 pairs (X) / G7 = 5  =>  0 pairs (_)
B1,B4: 5.. / B1 = 5  =>  0 pairs (X) / B4 = 5  =>  0 pairs (_)
D1,D6: 5.. / D1 = 5  =>  0 pairs (*) / D6 = 5  =>  0 pairs (X)
E2,E6: 5.. / E2 = 5  =>  0 pairs (X) / E6 = 5  =>  0 pairs (_)
H2,H8: 5.. / H2 = 5  =>  0 pairs (*) / H8 = 5  =>  0 pairs (X)
I3,I5: 5.. / I3 = 5  =>  0 pairs (X) / I5 = 5  =>  0 pairs (_)
G1,I1: 6.. / G1 = 6  =>  0 pairs (*) / I1 = 6  =>  0 pairs (X)
A4,C4: 6.. / A4 = 6  =>  0 pairs (*) / C4 = 6  =>  0 pairs (X)
C7,A8: 6.. / C7 = 6  =>  0 pairs (*) / A8 = 6  =>  0 pairs (X)
G7,I8: 6.. / G7 = 6  =>  0 pairs (X) / I8 = 6  =>  0 pairs (_)
C7,G7: 6.. / C7 = 6  =>  0 pairs (*) / G7 = 6  =>  0 pairs (X)
A8,I8: 6.. / A8 = 6  =>  0 pairs (X) / I8 = 6  =>  0 pairs (_)
A4,A8: 6.. / A4 = 6  =>  0 pairs (*) / A8 = 6  =>  0 pairs (X)
C4,C7: 6.. / C4 = 6  =>  0 pairs (X) / C7 = 6  =>  0 pairs (_)
G1,G7: 6.. / G1 = 6  =>  0 pairs (*) / G7 = 6  =>  0 pairs (X)
I1,I8: 6.. / I1 = 6  =>  0 pairs (X) / I8 = 6  =>  0 pairs (_)
G6,I6: 8.. / G6 = 8  =>  0 pairs (X) / I6 = 8  =>  0 pairs (_)
F8,F9: 8.. / F8 = 8  =>  0 pairs (*) / F9 = 8  =>  0 pairs (X)
I8,G9: 8.. / I8 = 8  =>  0 pairs (X) / G9 = 8  =>  0 pairs (_)
F8,I8: 8.. / F8 = 8  =>  0 pairs (*) / I8 = 8  =>  0 pairs (X)
F9,G9: 8.. / F9 = 8  =>  0 pairs (X) / G9 = 8  =>  0 pairs (_)
G6,G9: 8.. / G6 = 8  =>  0 pairs (X) / G9 = 8  =>  0 pairs (_)
I6,I8: 8.. / I6 = 8  =>  0 pairs (*) / I8 = 8  =>  0 pairs (X)
E2,F2: 9.. / E2 = 9  =>  0 pairs (*) / F2 = 9  =>  0 pairs (X)
E6,F6: 9.. / E6 = 9  =>  0 pairs (X) / F6 = 9  =>  0 pairs (_)
E2,E6: 9.. / E2 = 9  =>  0 pairs (*) / E6 = 9  =>  0 pairs (X)
F2,F6: 9.. / F2 = 9  =>  0 pairs (X) / F6 = 9  =>  0 pairs (_)
* DURATION: 0:02:05.592195  START: 09:09:10.095460  END: 09:11:15.687655 2017-05-04
* CP COUNT: (60)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A4,A9,B1,B4,C3,C7,D1,D6,E2,E6,F2,F6,F8,F9,G1,G5,G6,G7,H2,H8,I1,I3,I5,I6,I8)
* 2.9.71.8.8642..7.171.84692....784219498612.7.172....6.98.137.42.4792.1...2146..97
* PAIR C3: 3,5 COL C
C4: 3,5,6                                # reduction candidate for 3,5
C4: 3,5 => SOLVED
* 239571684864293751715846923653784219498612375172359468986137542547928136321465897
C4: 6 => CTR
* 2.9.71.8.8642..7.1713846925.36784219498612573172....6.98513764264792.1...2146..97
* PAIR A4: 5,6 BLK 4
C4: 5,6,3                                # reduction candidate for 5,6
C4: 5,6 => CTR
* 2.9.71.8.8642..7.1713846925.3.784219498612573172....6.98513764264792.1...2146..97
C4: 3 => SOLVED
* 239571684864293751715846923653784219498612375172359468986137542547928136321465897
* PAIR A4: 5,6 COL A
A8: 5,6,3                                # reduction candidate for 5,6
A8: 5,6 => SOLVED
* 239571684864293751715846923653784219498612375172359468986137542547928136321465897
A8: 3 => CTR
* 2.9.71.8.8642..7.171.84692.6..784219498612.7.172....6.98613754234792.1...2146..97
* PAIR B4: 3,5 BLK 4
C4: 3,5,6                                # reduction candidate for 3,5
C4: 3,5 => SOLVED
* 239571684864293751715846923653784219498612375172359468986137542547928136321465897
C4: 6 => CTR
* 2.9.71.8.8642..7.1713846925.36784219498612573172....6.98513764264792.1...2146..97
* PAIR G5: 3,5 COL G
G9: 3,5,8                                # reduction candidate for 3,5
G9: 3,5 => CTR
* 2.9.714868642.375171584692....784219498612.7.172...86498.137642647925138321468597
G9: 8 => SOLVED
* 239571684864293751715846923653784219498612375172359468986137542547928136321465897
* PAIR C7: 5,6 BLK 7
A8: 5,6,3                                # reduction candidate for 5,6
A8: 5,6 => SOLVED
* 239571684864293751715846923653784219498612375172359468986137542547928136321465897
A8: 3 => CTR
* 2.9.71.8.8642..7.171.84692.6..784219498612.7.172....6.98613754234792.1...2146..97
* PAIR C7: 5,6 COL C
C4: 5,6,3                                # reduction candidate for 5,6
C4: 5,6 => CTR
* 2.9.71.8.8642..7.1713846925.3.784219498612573172....6.98513764264792.1...2146..97
C4: 3 => SOLVED
* 239571684864293751715846923653784219498612375172359468986137542547928136321465897
* PAIR A9: 3,5 BLK 7
A8: 3,5,6                                # reduction candidate for 3,5
A8: 3,5 => SOLVED
* 239571684864293751715846923653784219498612375172359468986137542547928136321465897
A8: 6 => CTR
* 2.9.71.868642.375171584692....784219498612.7.172....6.98.137.4264792.138321468597
* PAIR A9: 3,5 ROW 9
G9: 3,5,8                                # reduction candidate for 3,5
G9: 3,5 => CTR
* 2.9.714868642.375171584692....784219498612.7.172...86498.137642647925138321468597
G9: 8 => SOLVED
* 239571684864293751715846923653784219498612375172359468986137542547928136321465897
* PAIR F9: 5,8 ROW 9
G9: 5,8,3                                # reduction candidate for 5,8
G9: 5,8 => SOLVED
* 239571684864293751715846923653784219498612375172359468986137542547928136321465897
G9: 3 => CTR
* 2.9.71.8.8642..7.171.84692....784219498612.7.172...86498.137.42.4792.1.8.21468397
* PAIR H8: 3,5 BLK 9
G9: 3,5,8                                # reduction candidate for 3,5
G9: 3,5 => CTR
* 2.9.714868642.375171584692....784219498612.7.172...86498.137642647925138321468597
G9: 8 => SOLVED
* 239571684864293751715846923653784219498612375172359468986137542547928136321465897
* PAIR H8: 3,5 ROW 8
A8: 3,5,6                                # reduction candidate for 3,5
A8: 3,5 => SOLVED
* 239571684864293751715846923653784219498612375172359468986137542547928136321465897
A8: 6 => CTR
* 2.9.71.868642.375171584692....784219498612.7.172....6.98.137.4264792.138321468597
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-189-base-pr-000.dot
* REASONING
* PRF # C4: 3,5 => SOL
* DIS # C4: 6 => CTR => C4: 3,5
* DIS # C4: 5,6 => CTR => C4: 3
* PRF # C4: 3 => SOL
* PRF # A8: 5,6 => SOL
* DIS # A8: 3 => CTR => A8: 5,6
* PRF # C4: 3,5 => SOL
* DIS # C4: 6 => CTR => C4: 3,5
* DIS # G9: 3,5 => CTR => G9: 8
* PRF # G9: 8 => SOL
* PRF # A8: 5,6 => SOL
* DIS # A8: 3 => CTR => A8: 5,6
* DIS # C4: 5,6 => CTR => C4: 3
* PRF # C4: 3 => SOL
* PRF # A8: 3,5 => SOL
* DIS # A8: 6 => CTR => A8: 3,5
* DIS # G9: 3,5 => CTR => G9: 8
* PRF # G9: 8 => SOL
* PRF # G9: 5,8 => SOL
* DIS # G9: 3 => CTR => G9: 5,8
* DIS # G9: 3,5 => CTR => G9: 8
* PRF # G9: 8 => SOL
* PRF # A8: 3,5 => SOL
* DIS # A8: 6 => CTR => A8: 3,5
* CNT  24 HDP CHAINS /  24 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A4,A9,B1,B4,C3,C7,D1,D6,E2,E6,F2,F6,F8,F9,G1,G5,G6,G7,H2,H8,I1,I3,I5,I6,I8)
* 2.9.71.8.8642..7.171.84692....784219498612.7.172....6.98.137.42.4792.1...2146..97
* PAIR C3: 3,5 COL C
C4: 3,5,6                                # reduction candidate for 3,5
C4: 3,5 => SOLVED
* 239571684864293751715846923653784219498612375172359468986137542547928136321465897
* DURATION: 0:00:02.350970  START: 09:11:49.973294  END: 09:11:52.324264 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-189-base-pr-001.dot
* REASONING
* PRF # C4: 3,5 => SOL
* STA C4: 3,5
* CNT   1 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 189

solution: 239571684864293751715846923653784219498612375172359468986137542547928136321465897
info: 1836     FNBTWY   S8.f     41070

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

Solution

position: 239571684864293751715846923653784219498612375172359468986137542547928136321465897 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:

* PRF # C4: 3,5 => SOL
* DIS # C4: 6 => CTR => C4: 3,5
* DIS # C4: 5,6 => CTR => C4: 3
* PRF # C4: 3 => SOL
* PRF # A8: 5,6 => SOL
* DIS # A8: 3 => CTR => A8: 5,6
* PRF # C4: 3,5 => SOL
* DIS # C4: 6 => CTR => C4: 3,5
* DIS # G9: 3,5 => CTR => G9: 8
* PRF # G9: 8 => SOL
* PRF # A8: 5,6 => SOL
* DIS # A8: 3 => CTR => A8: 5,6
* DIS # C4: 5,6 => CTR => C4: 3
* PRF # C4: 3 => SOL
* PRF # A8: 3,5 => SOL
* DIS # A8: 6 => CTR => A8: 3,5
* DIS # G9: 3,5 => CTR => G9: 8
* PRF # G9: 8 => SOL
* PRF # G9: 5,8 => SOL
* DIS # G9: 3 => CTR => G9: 5,8
* DIS # G9: 3,5 => CTR => G9: 8
* PRF # G9: 8 => SOL
* PRF # A8: 3,5 => SOL
* DIS # A8: 6 => CTR => A8: 3,5
* CNT  24 HDP CHAINS /  24 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* PRF # C4: 3,5 => SOL
* STA C4: 3,5
* CNT   1 HDP CHAINS /   1 HYP OPENED