Analysis of xx-top500-197-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: ..7.4.........1.........2.....3..9...1....4..65.......2..79.......8...5...9.....1 initial

Autosolve

position: 32754.19.4.8..15..1.5...2..8723.491.913...4..6541.98..2317956..7468123595894..721 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # D2: 6,9 => CTR => D2: 2
* PRF # D2: 2 => SOL
* PRF # F5: 6,8 => SOL
* DIS # F5: 7 => CTR => F5: 6,8
* DIS # D2: 6,9 => CTR => D2: 2
* PRF # D2: 2 => SOL
* DIS # I3: 4,8 => CTR => I3: 3,7
* PRF # I3: 3,7 => SOL
* DIS # E5: 5,6 => CTR => E5: 2,7,8
* PRF # E5: 2,7,8 => SOL
* PRF # E5: 2,6 => SOL
* DIS # I5: 2,6 => CTR => I5: 5,7
* PRF # I5: 5,7 => SOL
* DIS # D2: 9 => CTR => D2: 2,6
* PRF # E5: 2,7 => SOL
* DIS # I6: 3 => CTR => I6: 2,7
* PRF # E2: 3,6 => SOL
* PRF # I5: 5,6 => SOL
* DIS # I5: 2,7 => CTR => I5: 5,6
* DIS # I5: 6,7 => CTR => I5: 2,5
* DIS # E5: 6,7 => CTR => E5: 2,5,8
* DIS # F5: 6,7 => CTR => F5: 8
* PRF # F5: 8 => SOL
* DIS # H2: 3 => CTR => H2: 6,7
* DIS # I6: 3,7 => CTR => I6: 2
* PRF # I6: 2 => SOL
* DIS # H2: 3,7 => CTR => H2: 6
* PRF # H2: 6 => SOL
* PRF # E2: 3,6 => SOL
* DIS # I3: 4,8 => CTR => I3: 3,7
* PRF # I3: 3,7 => SOL
* CNT  31 HDP CHAINS /  40 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 # D2: 6,9 => CTR => D2: 2
* PRF D2: 2 => SOL
* STA D2: 2
* CNT   2 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

..7.4.........1.........2.....3..9...1....4..65.......2..79.......8...5...9.....1 initial
32754.19.4.8..15..1.5...2..8723.491.913...4..6541.98..2317956..7468123595894..721 autosolve
327546198498231567165987243872354916913628475654179832231795684746812359589463721 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (16)
B2: 6,9
B3: 6,9
F1: 6,8
D3: 6,9
I1: 6,8
H3: 4,8
E4: 5,6
D5: 2,6
E6: 2,7
I4: 5,6
H5: 6,7
H6: 3,7
E9: 3,6
F9: 3,6
H7: 4,8
I7: 4,8

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
D2,E2: 2.. / D2 = 2  =>  0 pairs (*) / E2 = 2  =>  0 pairs (X)
I5,I6: 2.. / I5 = 2  =>  0 pairs (X) / I6 = 2  =>  0 pairs (_)
E6,I6: 2.. / E6 = 2  =>  0 pairs (X) / I6 = 2  =>  0 pairs (_)
D2,D5: 2.. / D2 = 2  =>  0 pairs (*) / D5 = 2  =>  0 pairs (X)
H6,I6: 3.. / H6 = 3  => 17 pairs (_) / I6 = 3  =>  0 pairs (X)
E9,F9: 3.. / E9 = 3  =>  0 pairs (X) / F9 = 3  =>  0 pairs (_)
F3,F9: 3.. / F3 = 3  =>  0 pairs (X) / F9 = 3  =>  0 pairs (_)
H2,H6: 3.. / H2 = 3  =>  0 pairs (X) / H6 = 3  => 17 pairs (_)
H3,I3: 4.. / H3 = 4  => 13 pairs (_) / I3 = 4  =>  0 pairs (X)
H7,I7: 4.. / H7 = 4  =>  0 pairs (X) / I7 = 4  => 13 pairs (_)
H3,H7: 4.. / H3 = 4  => 13 pairs (_) / H7 = 4  =>  0 pairs (X)
I3,I7: 4.. / I3 = 4  =>  0 pairs (X) / I7 = 4  => 13 pairs (_)
E4,E5: 5.. / E4 = 5  =>  0 pairs (*) / E5 = 5  =>  0 pairs (X)
I4,I5: 5.. / I4 = 5  =>  0 pairs (X) / I5 = 5  =>  0 pairs (_)
E4,I4: 5.. / E4 = 5  =>  0 pairs (*) / I4 = 5  =>  0 pairs (X)
E5,I5: 5.. / E5 = 5  =>  0 pairs (X) / I5 = 5  =>  0 pairs (_)
B2,B3: 6.. / B2 = 6  =>  0 pairs (X) / B3 = 6  => 14 pairs (_)
E9,F9: 6.. / E9 = 6  =>  0 pairs (*) / F9 = 6  =>  0 pairs (X)
F1,I1: 6.. / F1 = 6  =>  0 pairs (*) / I1 = 6  =>  0 pairs (X)
B3,D3: 6.. / B3 = 6  => 14 pairs (_) / D3 = 6  =>  0 pairs (X)
E4,I4: 6.. / E4 = 6  =>  0 pairs (X) / I4 = 6  =>  0 pairs (_)
H2,H5: 6.. / H2 = 6  =>  0 pairs (*) / H5 = 6  =>  0 pairs (X)
F3,F5: 7.. / F3 = 7  =>  0 pairs (*) / F5 = 7  =>  0 pairs (X)
E5,F5: 8.. / E5 = 8  =>  0 pairs (X) / F5 = 8  =>  0 pairs (_)
H7,I7: 8.. / H7 = 8  => 13 pairs (_) / I7 = 8  =>  0 pairs (X)
F1,I1: 8.. / F1 = 8  =>  0 pairs (X) / I1 = 8  =>  0 pairs (_)
E3,E5: 8.. / E3 = 8  =>  0 pairs (*) / E5 = 8  =>  0 pairs (X)
H3,H7: 8.. / H3 = 8  =>  0 pairs (X) / H7 = 8  => 13 pairs (_)
B2,B3: 9.. / B2 = 9  => 14 pairs (_) / B3 = 9  =>  0 pairs (X)
D2,D3: 9.. / D2 = 9  =>  0 pairs (X) / D3 = 9  => 14 pairs (_)
B2,D2: 9.. / B2 = 9  => 14 pairs (_) / D2 = 9  =>  0 pairs (X)
B3,D3: 9.. / B3 = 9  =>  0 pairs (X) / D3 = 9  => 14 pairs (_)
* DURATION: 0:00:54.922588  START: 09:28:02.156834  END: 09:28:57.079422 2017-05-04
* CP COUNT: (32)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B2,B3,D3,D5,E4,E6,E9,F1,F9,H3,H5,H6,H7,I1,I4,I7)
* 32754.19.4.8..15..1.5...2..8723.491.913...4..6541.98..2317956..7468123595894..721
* PAIR B2: 6,9 ROW 2
D2: 6,9,2                                # reduction candidate for 6,9
D2: 6,9 => CTR
* 32754.19.4.8.215731.5.372..8723.49159132..4.76541798322317956..7468123595894.3721
D2: 2 => SOLVED
* 327546198498231567165987243872354916913628475654179832231795684746812359589463721
* PAIR F1: 6,8 COL F
F5: 6,8,7                                # reduction candidate for 6,8
F5: 6,8 => SOLVED
* 327546198498231567165987243872354916913628475654179832231795684746812359589463721
F5: 7 => CTR
* 32754.19.4.8..15..1.5...2..8723.491.913.874656541.98..2317956..7468123595894..721
* PAIR D3: 6,9 BLK 2
D2: 6,9,2                                # reduction candidate for 6,9
D2: 6,9 => CTR
* 32754.19.4.8.215731.5.372..8723.49159132..4.76541798322317956..7468123595894.3721
D2: 2 => SOLVED
* 327546198498231567165987243872354916913628475654179832231795684746812359589463721
* PAIR H3: 4,8 BLK 3
I3: 4,8,3,7                              # reduction candidate for 4,8
I3: 4,8 => CTR
* 3275481964.8..15..1.5...2..8723649159132..4..6541.98..2317956..7468123595894..721
I3: 3,7 => SOLVED
* 327546198498231567165987243872354916913628475654179832231795684746812359589463721
* PAIR E4: 5,6 BLK 5
E5: 5,6,2,7,8                            # reduction candidate for 5,6
E5: 5,6 => CTR
* 3275461984.8.215.31.598.24.8723.491.913..84..6541798322317956847468123595894..721
E5: 2,7,8 => SOLVED
* 327546198498231567165987243872354916913628475654179832231795684746812359589463721
* PAIR D5: 2,6 BLK 5
E5: 2,6,5,7,8                            # reduction candidate for 2,6
E5: 2,6 => SOLVED
* 327546198498231567165987243872354916913628475654179832231795684746812359589463721
E5: 5,7,8                                # 16 pairs
* PAIR D5: 2,6 ROW 5
I5: 2,6,5,7                              # reduction candidate for 2,6
I5: 2,6 => CTR
* 3275461984.8.2156.1.5...2..8723.4915913.584766541798322317956..7468123595894..721
I5: 5,7 => SOLVED
* 327546198498231567165987243872354916913628475654179832231795684746812359589463721
* PAIR D5: 2,6 COL D
D2: 2,6,9                                # reduction candidate for 2,6
D2: 9 => CTR
* 3275481964689215731956372..87236491.9132..4..6541798322317956..7468123595894..721
D2: 2,6                                  # 14 pairs
* PAIR E6: 2,7 BLK 5
E5: 2,7,5,6,8                            # reduction candidate for 2,7
E5: 2,7 => SOLVED
* 327546198498231567165987243872354916913628475654179832231795684746812359589463721
E5: 5,6,8                                # 16 pairs
* PAIR E6: 2,7 ROW 6
I6: 2,7,3                                # reduction candidate for 2,7
I6: 3 => CTR
* 32754.19.4.8..15..1.5...2..8723.491.913...4.26541298732317956..7468123595894..721
I6: 2,7                                  # 17 pairs
* PAIR E6: 2,7 COL E
E2: 2,7,3,6                              # reduction candidate for 2,7
E2: 3,6 => SOLVED
* 327546198498231567165987243872354916913628475654179832231795684746812359589463721
E2: 2,7                                  # 18 pairs
* PAIR I4: 5,6 BLK 6
I5: 5,6,2,7                              # reduction candidate for 5,6
I5: 5,6 => SOLVED
* 327546198498231567165987243872354916913628475654179832231795684746812359589463721
I5: 2,7 => CTR
* 3275461984.8.2157.1.5...2..8723.4915913.584676541798322317956..7468123595894..721
* PAIR H5: 6,7 BLK 6
I5: 6,7,2,5                              # reduction candidate for 6,7
I5: 6,7 => CTR
* 3275461984.8.215.31659..2..8723.4915913.584..6541798322317956..7468123595894..721
I5: 2,5                                  # 17 pairs
* PAIR H5: 6,7 ROW 5
E5: 6,7,2,5,8                            # reduction candidate for 6,7
E5: 6,7 => CTR
* 3275461984.8.2156.1.5.8.24.872354916913..84756541798322317956847468123595894..721
E5: 2,5,8                                # 16 pairs
F5: 6,7,8                                # reduction candidate for 6,7
F5: 6,7 => CTR
* 32754.19.4.8.215..1.5...2..8723549169132864756541798322317956..746812359589463721
F5: 8 => SOLVED
* 327546198498231567165987243872354916913628475654179832231795684746812359589463721
* PAIR H5: 6,7 COL H
H2: 6,7,3                                # reduction candidate for 6,7
H2: 3 => CTR
* 32754.19.4.8..153.1.5...2..8723.491.913...46.6541.98732317956..7468123595894..721
H2: 6,7                                  # 17 pairs
* PAIR H6: 3,7 BLK 6
I6: 3,7,2                                # reduction candidate for 3,7
I6: 3,7 => CTR
* 32754.19.4.82.15..1.59..2..8723.49159136..4.26541298..2317956..7468123595894..721
I6: 2 => SOLVED
* 327546198498231567165987243872354916913628475654179832231795684746812359589463721
* PAIR H6: 3,7 COL H
H2: 3,7,6                                # reduction candidate for 3,7
H2: 3,7 => CTR
* 32754.19.4.8..15..1.5...2..8723649159132584676541798322317956..746812359589436721
H2: 6 => SOLVED
* 327546198498231567165987243872354916913628475654179832231795684746812359589463721
* PAIR E9: 3,6 COL E
E2: 3,6,2,7                              # reduction candidate for 3,6
E2: 3,6 => SOLVED
* 327546198498231567165987243872354916913628475654179832231795684746812359589463721
E2: 2,7                                  # 18 pairs
* PAIR I7: 4,8 COL I
I3: 4,8,3,7                              # reduction candidate for 4,8
I3: 4,8 => CTR
* 3275481964.8..15..1.5...2..8723649159132..4..6541.98..2317956..7468123595894..721
I3: 3,7 => SOLVED
* 327546198498231567165987243872354916913628475654179832231795684746812359589463721
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-197-base-pr-000.dot
* REASONING
* DIS # D2: 6,9 => CTR => D2: 2
* PRF # D2: 2 => SOL
* PRF # F5: 6,8 => SOL
* DIS # F5: 7 => CTR => F5: 6,8
* DIS # D2: 6,9 => CTR => D2: 2
* PRF # D2: 2 => SOL
* DIS # I3: 4,8 => CTR => I3: 3,7
* PRF # I3: 3,7 => SOL
* DIS # E5: 5,6 => CTR => E5: 2,7,8
* PRF # E5: 2,7,8 => SOL
* PRF # E5: 2,6 => SOL
* DIS # I5: 2,6 => CTR => I5: 5,7
* PRF # I5: 5,7 => SOL
* DIS # D2: 9 => CTR => D2: 2,6
* PRF # E5: 2,7 => SOL
* DIS # I6: 3 => CTR => I6: 2,7
* PRF # E2: 3,6 => SOL
* PRF # I5: 5,6 => SOL
* DIS # I5: 2,7 => CTR => I5: 5,6
* DIS # I5: 6,7 => CTR => I5: 2,5
* DIS # E5: 6,7 => CTR => E5: 2,5,8
* DIS # F5: 6,7 => CTR => F5: 8
* PRF # F5: 8 => SOL
* DIS # H2: 3 => CTR => H2: 6,7
* DIS # I6: 3,7 => CTR => I6: 2
* PRF # I6: 2 => SOL
* DIS # H2: 3,7 => CTR => H2: 6
* PRF # H2: 6 => SOL
* PRF # E2: 3,6 => SOL
* DIS # I3: 4,8 => CTR => I3: 3,7
* PRF # I3: 3,7 => SOL
* CNT  31 HDP CHAINS /  40 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B2,B3,D3,D5,E4,E6,E9,F1,F9,H3,H5,H6,H7,I1,I4,I7)
* 32754.19.4.8..15..1.5...2..8723.491.913...4..6541.98..2317956..7468123595894..721
* PAIR B2: 6,9 ROW 2
D2: 6,9,2                                # reduction candidate for 6,9
D2: 6,9 => CTR
* 32754.19.4.8.215731.5.372..8723.49159132..4.76541798322317956..7468123595894.3721
D2: 2 => SOLVED
* 327546198498231567165987243872354916913628475654179832231795684746812359589463721
* DURATION: 0:00:02.982495  START: 09:29:41.656044  END: 09:29:44.638539 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-197-base-pr-001.dot
* REASONING
* DIS # D2: 6,9 => CTR => D2: 2
* PRF D2: 2 => SOL
* STA D2: 2
* CNT   2 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 197

solution: 327546198498231567165987243872354916913628475654179832231795684746812359589463721
info: 1880     FNTHWY   S8.f     45534

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

Solution

position: 327546198498231567165987243872354916913628475654179832231795684746812359589463721 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 # D2: 6,9 => CTR => D2: 2
* PRF # D2: 2 => SOL
* PRF # F5: 6,8 => SOL
* DIS # F5: 7 => CTR => F5: 6,8
* DIS # D2: 6,9 => CTR => D2: 2
* PRF # D2: 2 => SOL
* DIS # I3: 4,8 => CTR => I3: 3,7
* PRF # I3: 3,7 => SOL
* DIS # E5: 5,6 => CTR => E5: 2,7,8
* PRF # E5: 2,7,8 => SOL
* PRF # E5: 2,6 => SOL
* INC # E5: 5,7,8 => UNS
* DIS # I5: 2,6 => CTR => I5: 5,7
* PRF # I5: 5,7 => SOL
* INC # D2: 2,6 => UNS
* DIS # D2: 9 => CTR => D2: 2,6
* PRF # E5: 2,7 => SOL
* INC # E5: 5,6,8 => UNS
* INC # I6: 2,7 => UNS
* DIS # I6: 3 => CTR => I6: 2,7
* INC # E2: 2,7 => UNS
* PRF # E2: 3,6 => SOL
* PRF # I5: 5,6 => SOL
* DIS # I5: 2,7 => CTR => I5: 5,6
* DIS # I5: 6,7 => CTR => I5: 2,5
* INC # I5: 2,5 => UNS
* DIS # E5: 6,7 => CTR => E5: 2,5,8
* INC # E5: 2,5,8 => UNS
* DIS # F5: 6,7 => CTR => F5: 8
* PRF # F5: 8 => SOL
* INC # H2: 6,7 => UNS
* DIS # H2: 3 => CTR => H2: 6,7
* DIS # I6: 3,7 => CTR => I6: 2
* PRF # I6: 2 => SOL
* DIS # H2: 3,7 => CTR => H2: 6
* PRF # H2: 6 => SOL
* PRF # E2: 3,6 => SOL
* INC # E2: 2,7 => UNS
* DIS # I3: 4,8 => CTR => I3: 3,7
* PRF # I3: 3,7 => SOL
* CNT  40 HDP CHAINS /  40 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # D2: 6,9 => CTR => D2: 2
* PRF D2: 2 => SOL
* STA D2: 2
* CNT   2 HDP CHAINS /   1 HYP OPENED