Analysis of xx-top500-366-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: ......24.5...3..........6.......5.83.2.6.......1......3.....7.1.6.4........2..... initial

Autosolve

position: 63815.24.542.3681....8426354.6.25183.236..574.513.49623.456.72126.4..3.8...2.34.6 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # B3: 7,9 => CTR => B3: 1
* PRF # F8: 7,9 => SOL
* DIS # F8: 1 => CTR => F8: 7,9
* DIS # B3: 7,9 => CTR => B3: 1
* DIS # B9: 7,9 => CTR => B9: 1,8
* PRF # E5: 8,9 => SOL
* DIS # E5: 1 => CTR => E5: 8,9
* DIS # F5: 8,9 => CTR => F5: 1
* PRF # F5: 1 => SOL
* PRF # E9: 9 => SOL
* PRF # B9: 8,9 => SOL
* DIS # B9: 1,7 => CTR => B9: 8,9
* DIS # E9: 7 => CTR => E9: 8,9
* DIS # F5: 8,9 => CTR => F5: 1
* PRF # F5: 1 => SOL
* DIS # C8: 7 => CTR => C8: 5,9
* CNT  16 HDP CHAINS /  27 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 # B3: 7,9 => CTR => B3: 1
* PRF B3: 1 # F8: 7,9 => SOL
* STA B3: 1 + F8: 7,9
* CNT   2 HDP CHAINS /   5 HYP OPENED

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

Details

Positions

......24.5...3..........6.......5.83.2.6.......1......3.....7.1.6.4........2..... initial
63815.24.542.3681....8426354.6.25183.236..574.513.49623.456.72126.4..3.8...2.34.6 autosolve
638159247542736819719842635476925183923681574851374962394568721265417398187293456 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (14)
C3: 7,9
F1: 7,9
D2: 7,9
I1: 7,9
I2: 7,9
B4: 7,9
A5: 8,9
A6: 7,8
D4: 7,9
E6: 7,8
B7: 8,9
F7: 8,9
H8: 5,9
H9: 5,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
A3,B3: 1.. / A3 = 1  =>  0 pairs (X) / B3 = 1  => 15 pairs (_)
E5,F5: 1.. / E5 = 1  =>  0 pairs (X) / F5 = 1  =>  0 pairs (_)
A9,B9: 1.. / A9 = 1  => 15 pairs (_) / B9 = 1  =>  0 pairs (X)
E8,F8: 1.. / E8 = 1  =>  0 pairs (*) / F8 = 1  =>  0 pairs (X)
A3,A9: 1.. / A3 = 1  =>  0 pairs (X) / A9 = 1  => 15 pairs (_)
B3,B9: 1.. / B3 = 1  => 15 pairs (_) / B9 = 1  =>  0 pairs (X)
E5,E8: 1.. / E5 = 1  =>  0 pairs (X) / E8 = 1  =>  0 pairs (_)
F5,F8: 1.. / F5 = 1  =>  0 pairs (*) / F8 = 1  =>  0 pairs (X)
C8,C9: 5.. / C8 = 5  => 16 pairs (_) / C9 = 5  => 17 pairs (_)
H8,H9: 5.. / H8 = 5  => 17 pairs (_) / H9 = 5  => 16 pairs (_)
C8,H8: 5.. / C8 = 5  => 16 pairs (_) / H8 = 5  => 17 pairs (_)
C9,H9: 5.. / C9 = 5  => 17 pairs (_) / H9 = 5  => 16 pairs (_)
F1,D2: 7.. / F1 = 7  =>  0 pairs (X) / D2 = 7  =>  0 pairs (_)
I1,I2: 7.. / I1 = 7  =>  0 pairs (*) / I2 = 7  =>  0 pairs (X)
B4,A6: 7.. / B4 = 7  =>  0 pairs (*) / A6 = 7  =>  0 pairs (X)
D4,E6: 7.. / D4 = 7  =>  0 pairs (X) / E6 = 7  =>  0 pairs (_)
F1,I1: 7.. / F1 = 7  =>  0 pairs (X) / I1 = 7  =>  0 pairs (_)
D2,I2: 7.. / D2 = 7  =>  0 pairs (*) / I2 = 7  =>  0 pairs (X)
B4,D4: 7.. / B4 = 7  =>  0 pairs (*) / D4 = 7  =>  0 pairs (X)
A6,E6: 7.. / A6 = 7  =>  0 pairs (X) / E6 = 7  =>  0 pairs (_)
D2,D4: 7.. / D2 = 7  =>  0 pairs (*) / D4 = 7  =>  0 pairs (X)
F1,F8: 7.. / F1 = 7  =>  0 pairs (X) / F8 = 7  =>  0 pairs (_)
A5,A6: 8.. / A5 = 8  =>  0 pairs (X) / A6 = 8  =>  0 pairs (_)
B7,B9: 8.. / B7 = 8  =>  0 pairs (X) / B9 = 8  =>  0 pairs (_)
F7,E9: 8.. / F7 = 8  =>  0 pairs (*) / E9 = 8  =>  0 pairs (X)
A6,E6: 8.. / A6 = 8  =>  0 pairs (*) / E6 = 8  =>  0 pairs (X)
B7,F7: 8.. / B7 = 8  =>  0 pairs (X) / F7 = 8  =>  0 pairs (_)
B9,E9: 8.. / B9 = 8  =>  0 pairs (*) / E9 = 8  =>  0 pairs (X)
F5,F7: 8.. / F5 = 8  =>  0 pairs (X) / F7 = 8  =>  0 pairs (_)
F1,D2: 9.. / F1 = 9  =>  0 pairs (*) / D2 = 9  =>  0 pairs (X)
I1,I2: 9.. / I1 = 9  =>  0 pairs (X) / I2 = 9  =>  0 pairs (_)
B4,A5: 9.. / B4 = 9  =>  0 pairs (X) / A5 = 9  =>  0 pairs (_)
H8,H9: 9.. / H8 = 9  => 16 pairs (_) / H9 = 9  => 17 pairs (_)
F1,I1: 9.. / F1 = 9  =>  0 pairs (*) / I1 = 9  =>  0 pairs (X)
D2,I2: 9.. / D2 = 9  =>  0 pairs (X) / I2 = 9  =>  0 pairs (_)
B4,D4: 9.. / B4 = 9  =>  0 pairs (X) / D4 = 9  =>  0 pairs (_)
B7,F7: 9.. / B7 = 9  =>  0 pairs (*) / F7 = 9  =>  0 pairs (X)
D2,D4: 9.. / D2 = 9  =>  0 pairs (X) / D4 = 9  =>  0 pairs (_)
* DURATION: 0:01:33.037775  START: 15:20:54.963206  END: 15:22:28.000981 2017-05-04
* CP COUNT: (38)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A5,A6,B4,B7,C3,D2,D4,E6,F1,F7,H8,H9,I1,I2)
* 63815.24.542.3681....8426354.6.25183.236..574.513.49623.456.72126.4..3.8...2.34.6
* PAIR C3: 7,9 BLK 1
A3: 7,9,1                                # reduction candidate for 7,9
A3: 7,9                                  # 15 pairs
B3: 7,9,1                                # reduction candidate for 7,9
B3: 7,9 => CTR
* 63815.24.542.3681.1..8426354.6.25183.236.857485137496238456972126.4..3.8.1.2834.6
B3: 1                                    # 15 pairs
* PAIR C3: 7,9 COL C
C8: 7,9,5                                # reduction candidate for 7,9
C8: 7,9                                  # 17 pairs
C9: 7,9,5                                # reduction candidate for 7,9
C9: 7,9                                  # 16 pairs
* PAIR F1: 7,9 COL F
F8: 7,9,1                                # reduction candidate for 7,9
F8: 7,9 => SOLVED
* 638159247542736819719842635476925183923681574851374962394568721265417398187293456
F8: 1 => CTR
* 638157249542936817...8426354967251838236..57475138496238456.72126.4..3.8...2.34.6
* PAIR B4: 7,9 COL B
B3: 7,9,1                                # reduction candidate for 7,9
B3: 7,9 => CTR
* 63815.24.542.3681.1..8426354.6.25183.236.857485137496238456972126.4..3.8.1.2834.6
B3: 1                                    # 15 pairs
B9: 7,9,1,8                              # reduction candidate for 7,9
B9: 7,9 => CTR
* 638157249542936817.1.842635496725183.236..574.513.496238456972126.4..3.81..2834.6
B9: 1,8                                  # 15 pairs
* PAIR A5: 8,9 ROW 5
E5: 8,9,1                                # reduction candidate for 8,9
E5: 8,9 => SOLVED
* 638159247542736819719842635476925183923681574851374962394568721265417398187293456
E5: 1 => CTR
* 638157249542936817...842635496725183823619574.513.49623.456.72126.4.13.8...2.34.6
F5: 8,9,1                                # reduction candidate for 8,9
F5: 8,9 => CTR
* 638157249542936817...842635496725183823619574.513.49623.456.72126.4.13.8...2.34.6
F5: 1 => SOLVED
* 638159247542736819719842635476925183923681574851374962394568721265417398187293456
* PAIR E6: 7,8 COL E
E9: 7,8,9                                # reduction candidate for 7,8
E9: 9 => SOLVED
* 638159247542736819719842635476925183923681574851374962394568721265417398187293456
E9: 7,8                                  # 17 pairs
* PAIR B7: 8,9 BLK 7
B9: 8,9,1,7                              # reduction candidate for 8,9
B9: 8,9 => SOLVED
* 638159247542736819719842635476925183923681574851374962394568721265417398187293456
B9: 1,7 => CTR
* 638157249542936817...842635496725183.236..574.513.496238456972126.4..3.8...2834.6
* PAIR F7: 8,9 BLK 8
E9: 8,9,7                                # reduction candidate for 8,9
E9: 7 => CTR
* 638157249542936817.1.8426354.6.25183.236..574.513.49623.456872126.4..3.8.8.2734.6
E9: 8,9                                  # 18 pairs
* PAIR F7: 8,9 COL F
F5: 8,9,1                                # reduction candidate for 8,9
F5: 8,9 => CTR
* 638157249542936817...842635496725183823619574.513.49623.456.72126.4.13.8...2.34.6
F5: 1 => SOLVED
* 638159247542736819719842635476925183923681574851374962394568721265417398187293456
* PAIR H8: 5,9 ROW 8
C8: 5,9,7                                # reduction candidate for 5,9
C8: 7 => CTR
* 638157249542936817..98426354967251838236..57475138496238456.7212674..358..5273496
C8: 5,9                                  # 18 pairs
* PAIR H9: 5,9 ROW 9
C9: 5,9,7                                # reduction candidate for 5,9
C9: 5,9                                  # 19 pairs
C9: 7                                    # 17 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-366-base-pr-000.dot
* REASONING
* DIS # B3: 7,9 => CTR => B3: 1
* PRF # F8: 7,9 => SOL
* DIS # F8: 1 => CTR => F8: 7,9
* DIS # B3: 7,9 => CTR => B3: 1
* DIS # B9: 7,9 => CTR => B9: 1,8
* PRF # E5: 8,9 => SOL
* DIS # E5: 1 => CTR => E5: 8,9
* DIS # F5: 8,9 => CTR => F5: 1
* PRF # F5: 1 => SOL
* PRF # E9: 9 => SOL
* PRF # B9: 8,9 => SOL
* DIS # B9: 1,7 => CTR => B9: 8,9
* DIS # E9: 7 => CTR => E9: 8,9
* DIS # F5: 8,9 => CTR => F5: 1
* PRF # F5: 1 => SOL
* DIS # C8: 7 => CTR => C8: 5,9
* CNT  16 HDP CHAINS /  27 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A5,A6,B4,B7,C3,D2,D4,E6,F1,F7,H8,H9,I1,I2)
* 63815.24.542.3681....8426354.6.25183.236..574.513.49623.456.72126.4..3.8...2.34.6
* PAIR C3: 7,9 BLK 1
A3: 7,9,1                                # reduction candidate for 7,9
A3: 7,9                                  # 15 pairs
B3: 7,9,1                                # reduction candidate for 7,9
B3: 7,9 => CTR
* 63815.24.542.3681.1..8426354.6.25183.236.857485137496238456972126.4..3.8.1.2834.6
* RESTART
* PAIR C3: 7,9 COL C
C8: 7,9,5                                # reduction candidate for 7,9
C8: 7,9                                  # 18 pairs
C9: 7,9,5                                # reduction candidate for 7,9
C9: 7,9                                  # 17 pairs
* PAIR F1: 7,9 COL F
F8: 7,9,1                                # reduction candidate for 7,9
F8: 7,9 => SOLVED
* 638159247542736819719842635476925183923681574851374962394568721265417398187293456
* DURATION: 0:00:08.227301  START: 15:23:08.700837  END: 15:23:16.928138 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-366-base-pr-001.dot
* REASONING
* DIS # B3: 7,9 => CTR => B3: 1
* PRF B3: 1 # F8: 7,9 => SOL
* STA B3: 1 + F8: 7,9
* CNT   2 HDP CHAINS /   5 HYP OPENED

Header Info

Top 500 Minimum 17 366

solution: 638159247542736819719842635476925183923681574851374962394568721265417398187293456
info: 5021     FNBHWY   S8.f     1066

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

Solution

position: 638159247542736819719842635476925183923681574851374962394568721265417398187293456 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:

* INC # A3: 7,9 => UNS
* DIS # B3: 7,9 => CTR => B3: 1
* INC # B3: 1 => UNS
* INC # C8: 7,9 => UNS
* INC # C9: 7,9 => UNS
* PRF # F8: 7,9 => SOL
* DIS # F8: 1 => CTR => F8: 7,9
* DIS # B3: 7,9 => CTR => B3: 1
* INC # B3: 1 => UNS
* DIS # B9: 7,9 => CTR => B9: 1,8
* INC # B9: 1,8 => UNS
* PRF # E5: 8,9 => SOL
* DIS # E5: 1 => CTR => E5: 8,9
* DIS # F5: 8,9 => CTR => F5: 1
* PRF # F5: 1 => SOL
* INC # E9: 7,8 => UNS
* PRF # E9: 9 => SOL
* PRF # B9: 8,9 => SOL
* DIS # B9: 1,7 => CTR => B9: 8,9
* INC # E9: 8,9 => UNS
* DIS # E9: 7 => CTR => E9: 8,9
* DIS # F5: 8,9 => CTR => F5: 1
* PRF # F5: 1 => SOL
* INC # C8: 5,9 => UNS
* DIS # C8: 7 => CTR => C8: 5,9
* INC # C9: 5,9 => UNS
* INC # C9: 7 => UNS
* CNT  27 HDP CHAINS /  27 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # A3: 7,9 => UNS
* DIS # B3: 7,9 => CTR => B3: 1
* INC B3: 1 # C8: 7,9 => UNS
* INC B3: 1 # C9: 7,9 => UNS
* PRF B3: 1 # F8: 7,9 => SOL
* STA B3: 1 + F8: 7,9
* CNT   5 HDP CHAINS /   5 HYP OPENED