Analysis of xx-top500-448-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 1......28...3.5......6.....82..1..........34...........64...5....3...7.1......... initial

Autosolve

position: 135.4.628486325179972681435827413956651...34.349...81..641..5.3.93..47.1.18.3.2.4 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # D5: 7,9 => CTR => D5: 2,8
* DIS # D9: 7,9 => CTR => D9: 5
* PRF # D9: 5 => SOL
* DIS # F5: 7,9 => CTR => F5: 2,8
* PRF # F9: 7,9 => SOL
* DIS # F9: 6 => CTR => F9: 7,9
* DIS # D5: 7,9 => CTR => D5: 2,8
* DIS # F5: 7,9 => CTR => F5: 2,8
* DIS # D5: 2,7 => CTR => D5: 8,9
* PRF # F5: 2,7 => SOL
* PRF # D6: 2,7 => SOL
* DIS # D6: 5 => CTR => D6: 2,7
* DIS # F6: 2,7 => CTR => F6: 6
* PRF # F6: 6 => SOL
* DIS # D9: 9 => CTR => D9: 5,7
* DIS # D9: 7,9 => CTR => D9: 5
* PRF # D9: 5 => SOL
* PRF # F9: 7,9 => SOL
* DIS # F9: 6 => CTR => F9: 7,9
* DIS # F5: 7,9 => CTR => F5: 2,8
* DIS # D5: 7,9 => CTR => D5: 2,8
* DIS # F9: 7 => CTR => F9: 6,9
* CNT  22 HDP CHAINS /  32 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 # D5: 7,9 => CTR => D5: 2,8
* DIS D5: 2,8 # D9: 7,9 => CTR => D9: 5
* PRF D5: 2,8 + D9: 5 => SOL
* STA D5: 2,8 + D9: 5
* CNT   3 HDP CHAINS /   2 HYP OPENED

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

Details

Positions

1......28...3.5......6.....82..1..........34...........64...5....3...7.1......... initial
135.4.628486325179972681435827413956651...34.349...81..641..5.3.93..47.1.18.3.2.4 autosolve
135947628486325179972681435827413956651892347349756812264178593593264781718539264 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (16)
D1: 7,9
F1: 7,9
E5: 7,9
E6: 5,6
I5: 2,7
I6: 2,7
A7: 2,7
A8: 2,5
A9: 5,7
E7: 7,9
F7: 2,8
D8: 2,8
E8: 5,6
H7: 8,9
H8: 6,8
H9: 6,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
I5,I6: 2.. / I5 = 2  => 16 pairs (_) / I6 = 2  =>  0 pairs (*)
A7,A8: 2.. / A7 = 2  =>  0 pairs (*) / A8 = 2  =>  0 pairs (X)
F7,D8: 2.. / F7 = 2  =>  0 pairs (X) / D8 = 2  =>  0 pairs (_)
A7,F7: 2.. / A7 = 2  =>  0 pairs (*) / F7 = 2  =>  0 pairs (X)
A8,D8: 2.. / A8 = 2  =>  0 pairs (X) / D8 = 2  =>  0 pairs (_)
D6,E6: 5.. / D6 = 5  =>  0 pairs (X) / E6 = 5  =>  0 pairs (_)
A8,A9: 5.. / A8 = 5  =>  0 pairs (*) / A9 = 5  =>  0 pairs (X)
E8,D9: 5.. / E8 = 5  =>  0 pairs (X) / D9 = 5  =>  0 pairs (_)
A8,E8: 5.. / A8 = 5  =>  0 pairs (*) / E8 = 5  =>  0 pairs (X)
A9,D9: 5.. / A9 = 5  =>  0 pairs (X) / D9 = 5  =>  0 pairs (_)
D6,D9: 5.. / D6 = 5  =>  0 pairs (X) / D9 = 5  =>  0 pairs (_)
E6,E8: 5.. / E6 = 5  =>  0 pairs (*) / E8 = 5  =>  0 pairs (X)
E6,F6: 6.. / E6 = 6  =>  0 pairs (X) / F6 = 6  =>  0 pairs (_)
E8,F9: 6.. / E8 = 6  =>  0 pairs (*) / F9 = 6  =>  0 pairs (X)
H8,H9: 6.. / H8 = 6  =>  0 pairs (X) / H9 = 6  =>  0 pairs (_)
E8,H8: 6.. / E8 = 6  =>  0 pairs (*) / H8 = 6  =>  0 pairs (X)
F9,H9: 6.. / F9 = 6  =>  0 pairs (X) / H9 = 6  =>  0 pairs (_)
E6,E8: 6.. / E6 = 6  =>  0 pairs (X) / E8 = 6  =>  0 pairs (_)
F6,F9: 6.. / F6 = 6  =>  0 pairs (*) / F9 = 6  =>  0 pairs (X)
D1,F1: 7.. / D1 = 7  => 17 pairs (_) / F1 = 7  => 17 pairs (_)
I5,I6: 7.. / I5 = 7  =>  0 pairs (*) / I6 = 7  =>  0 pairs (X)
A7,A9: 7.. / A7 = 7  =>  0 pairs (X) / A9 = 7  =>  0 pairs (_)
A7,E7: 7.. / A7 = 7  =>  0 pairs (X) / E7 = 7  =>  0 pairs (_)
E5,E7: 7.. / E5 = 7  =>  0 pairs (X) / E7 = 7  =>  0 pairs (_)
D5,F5: 8.. / D5 = 8  =>  0 pairs (*) / F5 = 8  =>  0 pairs (X)
F7,D8: 8.. / F7 = 8  =>  0 pairs (*) / D8 = 8  =>  0 pairs (X)
H7,H8: 8.. / H7 = 8  =>  0 pairs (X) / H8 = 8  =>  0 pairs (_)
F7,H7: 8.. / F7 = 8  =>  0 pairs (*) / H7 = 8  =>  0 pairs (X)
D8,H8: 8.. / D8 = 8  =>  0 pairs (X) / H8 = 8  =>  0 pairs (_)
D5,D8: 8.. / D5 = 8  =>  0 pairs (*) / D8 = 8  =>  0 pairs (X)
F5,F7: 8.. / F5 = 8  =>  0 pairs (X) / F7 = 8  =>  0 pairs (_)
D1,F1: 9.. / D1 = 9  => 17 pairs (_) / F1 = 9  => 17 pairs (_)
H7,H9: 9.. / H7 = 9  =>  0 pairs (*) / H9 = 9  =>  0 pairs (X)
E7,H7: 9.. / E7 = 9  =>  0 pairs (X) / H7 = 9  =>  0 pairs (_)
E5,E7: 9.. / E5 = 9  =>  0 pairs (*) / E7 = 9  =>  0 pairs (X)
* DURATION: 0:01:06.900530  START: 18:03:23.927166  END: 18:04:30.827696 2017-05-04
* CP COUNT: (35)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A7,A8,A9,D1,D8,E5,E6,E7,E8,F1,F7,H7,H8,H9,I5,I6)
* 135.4.628486325179972681435827413956651...34.349...81..641..5.3.93..47.1.18.3.2.4
* PAIR D1: 7,9 COL D
D5: 7,9,2,8                              # reduction candidate for 7,9
D5: 7,9 => CTR
* 135.4.628486325179972681435827413956651..8342349...817.641.2583293854761518.362.4
D5: 2,8                                  # 18 pairs
D9: 7,9,5                                # reduction candidate for 7,9
D9: 7,9 => CTR
* 135.4.628486325179972681435827413956651...34.34956.81.764192583293854761518736294
D9: 5 => SOLVED
* 135947628486325179972681435827413956651892347349756812264178593593264781718539264
* PAIR F1: 7,9 COL F
F5: 7,9,2,8                              # reduction candidate for 7,9
F5: 7,9 => CTR
* 135.4.6284863251799726814358274139566518..342349...817.641.8593.932.4781.18.3.264
F5: 2,8                                  # 18 pairs
F9: 7,9,6                                # reduction candidate for 7,9
F9: 7,9 => SOLVED
* 135947628486325179972681435827413956651892347349756812264178593593264781718539264
F9: 6 => CTR
* 135947628486325179972681435827413956651...34.349.6.81..6419.583.93854761518736294
* PAIR E5: 7,9 BLK 5
D5: 7,9,2,8                              # reduction candidate for 7,9
D5: 7,9 => CTR
* 135.4.628486325179972681435827413956651..8342349...817.641.2583293854761518.362.4
D5: 2,8                                  # 18 pairs
F5: 7,9,2,8                              # reduction candidate for 7,9
F5: 7,9 => CTR
* 135.4.6284863251799726814358274139566518..342349...817.641.8593.932.4781.18.3.264
F5: 2,8                                  # 18 pairs
* PAIR I5: 2,7 ROW 5
D5: 2,7,8,9                              # reduction candidate for 2,7
D5: 2,7 => CTR
* 135947628486325179972681435827413956651..834.349...81..641.2583293854761518.36294
D5: 8,9                                  # 17 pairs
F5: 2,7,8,9                              # reduction candidate for 2,7
F5: 2,7 => SOLVED
* 135947628486325179972681435827413956651892347349756812264178593593264781718539264
F5: 8,9                                  # 17 pairs
* PAIR I6: 2,7 ROW 6
D6: 2,7,5                                # reduction candidate for 2,7
D6: 2,7 => SOLVED
* 135947628486325179972681435827413956651892347349756812264178593593264781718539264
D6: 5 => CTR
* 135.4.628486325179972681435827413956651...34.34956.81.764192583293854761518736294
F6: 2,7,6                                # reduction candidate for 2,7
F6: 2,7 => CTR
* 135.4.628486325179972681435827413956651...34.34956.81.764192583293854761518736294
F6: 6 => SOLVED
* 135947628486325179972681435827413956651892347349756812264178593593264781718539264
* PAIR A9: 5,7 ROW 9
D9: 5,7,9                                # reduction candidate for 5,7
D9: 9 => CTR
* 135.4.628486325179972681435827413956651...34.34956.81..641..5.3.93.5476151893.2.4
D9: 5,7                                  # 18 pairs
* PAIR E7: 7,9 BLK 8
D9: 7,9,5                                # reduction candidate for 7,9
D9: 7,9 => CTR
* 135.4.628486325179972681435827413956651...34.34956.81.764192583293854761518736294
D9: 5 => SOLVED
* 135947628486325179972681435827413956651892347349756812264178593593264781718539264
F9: 7,9,6                                # reduction candidate for 7,9
F9: 7,9 => SOLVED
* 135947628486325179972681435827413956651892347349756812264178593593264781718539264
F9: 6 => CTR
* 135947628486325179972681435827413956651...34.349.6.81..6419.583.93854761518736294
* PAIR F7: 2,8 COL F
F5: 2,8,7,9                              # reduction candidate for 2,8
F5: 7,9 => CTR
* 135.4.6284863251799726814358274139566518..342349...817.641.8593.932.4781.18.3.264
F5: 2,8                                  # 18 pairs
* PAIR D8: 2,8 COL D
D5: 2,8,7,9                              # reduction candidate for 2,8
D5: 7,9 => CTR
* 135.4.628486325179972681435827413956651..8342349...817.641.2583293854761518.362.4
D5: 2,8                                  # 18 pairs
* PAIR H9: 6,9 ROW 9
F9: 6,9,7                                # reduction candidate for 6,9
F9: 7 => CTR
* 135.4.628486325179972681435827413956651...34.349..681..641..5.3.93.64781.185372.4
F9: 6,9                                  # 18 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-448-base-pr-000.dot
* REASONING
* DIS # D5: 7,9 => CTR => D5: 2,8
* DIS # D9: 7,9 => CTR => D9: 5
* PRF # D9: 5 => SOL
* DIS # F5: 7,9 => CTR => F5: 2,8
* PRF # F9: 7,9 => SOL
* DIS # F9: 6 => CTR => F9: 7,9
* DIS # D5: 7,9 => CTR => D5: 2,8
* DIS # F5: 7,9 => CTR => F5: 2,8
* DIS # D5: 2,7 => CTR => D5: 8,9
* PRF # F5: 2,7 => SOL
* PRF # D6: 2,7 => SOL
* DIS # D6: 5 => CTR => D6: 2,7
* DIS # F6: 2,7 => CTR => F6: 6
* PRF # F6: 6 => SOL
* DIS # D9: 9 => CTR => D9: 5,7
* DIS # D9: 7,9 => CTR => D9: 5
* PRF # D9: 5 => SOL
* PRF # F9: 7,9 => SOL
* DIS # F9: 6 => CTR => F9: 7,9
* DIS # F5: 7,9 => CTR => F5: 2,8
* DIS # D5: 7,9 => CTR => D5: 2,8
* DIS # F9: 7 => CTR => F9: 6,9
* CNT  22 HDP CHAINS /  32 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A7,A8,A9,D1,D8,E5,E6,E7,E8,F1,F7,H7,H8,H9,I5,I6)
* 135.4.628486325179972681435827413956651...34.349...81..641..5.3.93..47.1.18.3.2.4
* PAIR D1: 7,9 COL D
D5: 7,9,2,8                              # reduction candidate for 7,9
D5: 7,9 => CTR
* 135.4.628486325179972681435827413956651..8342349...817.641.2583293854761518.362.4
D9: 7,9,5                                # reduction candidate for 7,9
D9: 7,9 => CTR
* 135947628486325179972681435827413956651.79342349562817.641..5.3.93.54761518.36294
D9: 5 => SOLVED
* 135947628486325179972681435827413956651892347349756812264178593593264781718539264
* DURATION: 0:00:03.025719  START: 18:05:07.821741  END: 18:05:10.847460 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-448-base-pr-001.dot
* REASONING
* DIS # D5: 7,9 => CTR => D5: 2,8
* DIS D5: 2,8 # D9: 7,9 => CTR => D9: 5
* PRF D5: 2,8 + D9: 5 => SOL
* STA D5: 2,8 + D9: 5
* CNT   3 HDP CHAINS /   2 HYP OPENED

Header Info

Top 500 Minimum 17 448

solution: 135947628486325179972681435827413956651892347349756812264178593593264781718539264
info: 95363    FNTHYK   S8.f     42780

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

Solution

position: 135947628486325179972681435827413956651892347349756812264178593593264781718539264 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 # D5: 7,9 => CTR => D5: 2,8
* INC # D5: 2,8 => UNS
* DIS # D9: 7,9 => CTR => D9: 5
* PRF # D9: 5 => SOL
* DIS # F5: 7,9 => CTR => F5: 2,8
* INC # F5: 2,8 => UNS
* PRF # F9: 7,9 => SOL
* DIS # F9: 6 => CTR => F9: 7,9
* DIS # D5: 7,9 => CTR => D5: 2,8
* INC # D5: 2,8 => UNS
* DIS # F5: 7,9 => CTR => F5: 2,8
* INC # F5: 2,8 => UNS
* DIS # D5: 2,7 => CTR => D5: 8,9
* INC # D5: 8,9 => UNS
* PRF # F5: 2,7 => SOL
* INC # F5: 8,9 => UNS
* PRF # D6: 2,7 => SOL
* DIS # D6: 5 => CTR => D6: 2,7
* DIS # F6: 2,7 => CTR => F6: 6
* PRF # F6: 6 => SOL
* INC # D9: 5,7 => UNS
* DIS # D9: 9 => CTR => D9: 5,7
* DIS # D9: 7,9 => CTR => D9: 5
* PRF # D9: 5 => SOL
* PRF # F9: 7,9 => SOL
* DIS # F9: 6 => CTR => F9: 7,9
* INC # F5: 2,8 => UNS
* DIS # F5: 7,9 => CTR => F5: 2,8
* INC # D5: 2,8 => UNS
* DIS # D5: 7,9 => CTR => D5: 2,8
* INC # F9: 6,9 => UNS
* DIS # F9: 7 => CTR => F9: 6,9
* CNT  32 HDP CHAINS /  32 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # D5: 7,9 => CTR => D5: 2,8
* DIS D5: 2,8 # D9: 7,9 => CTR => D9: 5
* PRF D5: 2,8 + D9: 5 => SOL
* STA D5: 2,8 + D9: 5
* CNT   3 HDP CHAINS /   2 HYP OPENED