Analysis of xx-top500-173-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 2.....7.3...5.1...............83...2.71.............6.3...2.4...6....15.......... initial

Autosolve

position: 215.4.7.373.5.16246.43725.154683791287126934592341586735.12.47.4627.315.1.7.5423. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # I7: 8,9 => SOL
* DIS # I7: 6 => CTR => I7: 8,9
* DIS # I9: 8,9 => CTR => I9: 6
* PRF # I9: 6 => SOL
* PRF # I7: 6,8 => SOL
* DIS # I7: 9 => CTR => I7: 6,8
* PRF # I9: 6,9 => SOL
* DIS # I9: 8 => CTR => I9: 6,9
* PRF # I7: 8,9 => SOL
* DIS # I7: 6 => CTR => I7: 8,9
* DIS # I9: 8,9 => CTR => I9: 6
* PRF # I9: 6 => SOL
* CNT  12 HDP CHAINS /  12 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 # I7: 8,9 => SOL
* STA I7: 8,9
* CNT   1 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

2.....7.3...5.1...............83...2.71.............6.3...2.4...6....15.......... initial
215.4.7.373.5.16246.43725.154683791287126934592341586735.12.47.4627.315.1.7.5423. autosolve
215648793738591624694372581546837912871269345923415867359126478462783159187954236 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (13)
C2: 8,9
B3: 8,9
D1: 6,9
F1: 6,8
E2: 8,9
H1: 8,9
H3: 8,9
C7: 8,9
B9: 8,9
F7: 6,8
E8: 8,9
D9: 6,9
I8: 8,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
D1,F1: 6.. / D1 = 6  =>  0 pairs (*) / F1 = 6  =>  0 pairs (X)
F7,D9: 6.. / F7 = 6  =>  0 pairs (*) / D9 = 6  =>  0 pairs (X)
I7,I9: 6.. / I7 = 6  =>  0 pairs (X) / I9 = 6  =>  0 pairs (_)
F7,I7: 6.. / F7 = 6  =>  0 pairs (*) / I7 = 6  =>  0 pairs (X)
D9,I9: 6.. / D9 = 6  =>  0 pairs (X) / I9 = 6  =>  0 pairs (_)
D1,D9: 6.. / D1 = 6  =>  0 pairs (*) / D9 = 6  =>  0 pairs (X)
F1,F7: 6.. / F1 = 6  =>  0 pairs (X) / F7 = 6  =>  0 pairs (_)
C2,B3: 8.. / C2 = 8  =>  0 pairs (*) / B3 = 8  =>  0 pairs (X)
F1,E2: 8.. / F1 = 8  =>  0 pairs (*) / E2 = 8  =>  0 pairs (X)
H1,H3: 8.. / H1 = 8  =>  0 pairs (X) / H3 = 8  =>  0 pairs (_)
C7,B9: 8.. / C7 = 8  =>  0 pairs (X) / B9 = 8  =>  0 pairs (_)
F7,E8: 8.. / F7 = 8  =>  0 pairs (X) / E8 = 8  =>  0 pairs (_)
F1,H1: 8.. / F1 = 8  =>  0 pairs (*) / H1 = 8  =>  0 pairs (X)
C2,E2: 8.. / C2 = 8  =>  0 pairs (*) / E2 = 8  =>  0 pairs (X)
B3,H3: 8.. / B3 = 8  =>  0 pairs (X) / H3 = 8  =>  0 pairs (_)
E8,I8: 8.. / E8 = 8  =>  0 pairs (*) / I8 = 8  =>  0 pairs (X)
B9,I9: 8.. / B9 = 8  =>  0 pairs (*) / I9 = 8  =>  0 pairs (X)
B3,B9: 8.. / B3 = 8  =>  0 pairs (X) / B9 = 8  =>  0 pairs (_)
C2,C7: 8.. / C2 = 8  =>  0 pairs (*) / C7 = 8  =>  0 pairs (X)
E2,E8: 8.. / E2 = 8  =>  0 pairs (X) / E8 = 8  =>  0 pairs (_)
F1,F7: 8.. / F1 = 8  =>  0 pairs (*) / F7 = 8  =>  0 pairs (X)
C2,B3: 9.. / C2 = 9  =>  0 pairs (X) / B3 = 9  =>  0 pairs (_)
D1,E2: 9.. / D1 = 9  =>  0 pairs (X) / E2 = 9  =>  0 pairs (_)
H1,H3: 9.. / H1 = 9  =>  0 pairs (*) / H3 = 9  =>  0 pairs (X)
C7,B9: 9.. / C7 = 9  =>  0 pairs (*) / B9 = 9  =>  0 pairs (X)
E8,D9: 9.. / E8 = 9  =>  0 pairs (X) / D9 = 9  =>  0 pairs (_)
D1,H1: 9.. / D1 = 9  =>  0 pairs (X) / H1 = 9  =>  0 pairs (_)
C2,E2: 9.. / C2 = 9  =>  0 pairs (X) / E2 = 9  =>  0 pairs (_)
B3,H3: 9.. / B3 = 9  =>  0 pairs (*) / H3 = 9  =>  0 pairs (X)
C7,I7: 9.. / C7 = 9  =>  0 pairs (*) / I7 = 9  =>  0 pairs (X)
E8,I8: 9.. / E8 = 9  =>  0 pairs (X) / I8 = 9  =>  0 pairs (_)
B3,B9: 9.. / B3 = 9  =>  0 pairs (*) / B9 = 9  =>  0 pairs (X)
C2,C7: 9.. / C2 = 9  =>  0 pairs (X) / C7 = 9  =>  0 pairs (_)
D1,D9: 9.. / D1 = 9  =>  0 pairs (X) / D9 = 9  =>  0 pairs (_)
E2,E8: 9.. / E2 = 9  =>  0 pairs (*) / E8 = 9  =>  0 pairs (X)
* DURATION: 0:01:02.168676  START: 08:38:02.939484  END: 08:39:05.108160 2017-05-04
* CP COUNT: (35)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B3,B9,C2,C7,D1,D9,E2,E8,F1,F7,H1,H3,I8)
* 215.4.7.373.5.16246.43725.154683791287126934592341586735.12.47.4627.315.1.7.5423.
* PAIR C7: 8,9 ROW 7
I7: 8,9,6                                # reduction candidate for 8,9
I7: 8,9 => SOLVED
* 215648793738591624694372581546837912871269345923415867359126478462783159187954236
I7: 6 => CTR
* 215.4.7.373.5.16246.43725.154683791287126934592341586735912847646279315.1.7.5423.
* PAIR B9: 8,9 ROW 9
I9: 8,9,6                                # reduction candidate for 8,9
I9: 8,9 => CTR
* 21594678373958162468437259154683791287126934592341586735812.4764627.315.1.765423.
I9: 6 => SOLVED
* 215648793738591624694372581546837912871269345923415867359126478462783159187954236
* PAIR F7: 6,8 ROW 7
I7: 6,8,9                                # reduction candidate for 6,8
I7: 6,8 => SOLVED
* 215648793738591624694372581546837912871269345923415867359126478462783159187954236
I7: 9 => CTR
* 215.4.7.373.5.16246.43725.154683791287126934592341586735.1264794627.315.1.7.5423.
* PAIR D9: 6,9 ROW 9
I9: 6,9,8                                # reduction candidate for 6,9
I9: 6,9 => SOLVED
* 215648793738591624694372581546837912871269345923415867359126478462783159187954236
I9: 8 => CTR
* 215.4.7.373.5.16246.43725.154683791287126934592341586735.12.4764627.31591.7.5423.
* PAIR I8: 8,9 BLK 9
I7: 8,9,6                                # reduction candidate for 8,9
I7: 8,9 => SOLVED
* 215648793738591624694372581546837912871269345923415867359126478462783159187954236
I7: 6 => CTR
* 215.4.7.373.5.16246.43725.154683791287126934592341586735912847646279315.1.7.5423.
I9: 8,9,6                                # reduction candidate for 8,9
I9: 8,9 => CTR
* 21594678373958162468437259154683791287126934592341586735812.4764627.315.1.765423.
I9: 6 => SOLVED
* 215648793738591624694372581546837912871269345923415867359126478462783159187954236
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-173-base-pr-000.dot
* REASONING
* PRF # I7: 8,9 => SOL
* DIS # I7: 6 => CTR => I7: 8,9
* DIS # I9: 8,9 => CTR => I9: 6
* PRF # I9: 6 => SOL
* PRF # I7: 6,8 => SOL
* DIS # I7: 9 => CTR => I7: 6,8
* PRF # I9: 6,9 => SOL
* DIS # I9: 8 => CTR => I9: 6,9
* PRF # I7: 8,9 => SOL
* DIS # I7: 6 => CTR => I7: 8,9
* DIS # I9: 8,9 => CTR => I9: 6
* PRF # I9: 6 => SOL
* CNT  12 HDP CHAINS /  12 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B3,B9,C2,C7,D1,D9,E2,E8,F1,F7,H1,H3,I8)
* 215.4.7.373.5.16246.43725.154683791287126934592341586735.12.47.4627.315.1.7.5423.
* PAIR C7: 8,9 ROW 7
I7: 8,9,6                                # reduction candidate for 8,9
I7: 8,9 => SOLVED
* 215648793738591624694372581546837912871269345923415867359126478462783159187954236
* DURATION: 0:00:02.085978  START: 08:39:20.789294  END: 08:39:22.875272 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-173-base-pr-001.dot
* REASONING
* PRF # I7: 8,9 => SOL
* STA I7: 8,9
* CNT   1 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 173

solution: 215648793738591624694372581546837912871269345923415867359126478462783159187954236
info: 1826     FNTWX    S8.f     27124

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

Solution

position: 215648793738591624694372581546837912871269345923415867359126478462783159187954236 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 # I7: 8,9 => SOL
* DIS # I7: 6 => CTR => I7: 8,9
* DIS # I9: 8,9 => CTR => I9: 6
* PRF # I9: 6 => SOL
* PRF # I7: 6,8 => SOL
* DIS # I7: 9 => CTR => I7: 6,8
* PRF # I9: 6,9 => SOL
* DIS # I9: 8 => CTR => I9: 6,9
* PRF # I7: 8,9 => SOL
* DIS # I7: 6 => CTR => I7: 8,9
* DIS # I9: 8,9 => CTR => I9: 6
* PRF # I9: 6 => SOL
* CNT  12 HDP CHAINS /  12 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* PRF # I7: 8,9 => SOL
* STA I7: 8,9
* CNT   1 HDP CHAINS /   1 HYP OPENED