Analysis of xx-top500-291-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: ...2...6.5.....9......18...6..35............13.........8.7..4.....6...3...1...... initial

Autosolve

position: 1..2..8655.84..91..6.518...61.35..8.8..9..3.13..18.5.6.8673145....6..138.318.56.. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # C1: 4,7 => CTR => C1: 3
* DIS # B5: 4,7 => CTR => B5: 2,5
* DIS # B6: 4,7 => CTR => B6: 2,9
* DIS # A3: 2,7 => CTR => A3: 9
* DIS # I2: 3 => CTR => I2: 2,7
* DIS # B5: 2,7 => CTR => B5: 4,5
* DIS # B8: 2,7 => CTR => B8: 5,9
* DIS # F1: 3 => CTR => F1: 7,9
* DIS # F2: 6,7 => CTR => F2: 3
* DIS # E5: 6,7 => CTR => E5: 2,4
* DIS # H3: 2,7 => CTR => H3: 4
* DIS # I3: 2,7 => CTR => I3: 3,4
* DIS # A3: 2,7 => CTR => A3: 9
* DIS # I4: 2,7 => CTR => I4: 4,9
* DIS # H6: 2,7 => CTR => H6: 4,9
* DIS # C4: 2,7 => CTR => C4: 4,9
* DIS # A8: 2,9 => CTR => A8: 4,7
* DIS # C8: 2,9 => CTR => C8: 5,7
* DIS # A9: 2,9 => CTR => A9: 4
* DIS # A3: 7 => CTR => A3: 2,9
* DIS # I9: 2,9 => CTR => I9: 7
* DIS # I4: 2,9 => CTR => I4: 4,7
* CNT  22 HDP CHAINS /  52 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 # C1: 4,7 => CTR => C1: 3
* PRF C1: 3 # C6: 2,7 => SOL
* STA C1: 3 + C6: 2,7
* CNT   2 HDP CHAINS /   3 HYP OPENED

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

Details

Positions

...2...6.5.....9......18...6..35............13.........8.7..4.....6...3...1...... initial
1..2..8655.84..91..6.518...61.35..8.8..9..3.13..18.5.6.8673145....6..138.318.56.. autosolve
143279865578463912962518743619357284854926371327184596286731459795642138431895627 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (8)
B1: 4,7
B2: 2,7
E1: 7,9
E2: 6,7
G3: 2,7
G4: 2,7
A7: 2,9
I7: 2,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
B2,I2: 2.. / B2 = 2  =>  9 pairs (_) / I2 = 2  =>  0 pairs (*)
A7,I7: 2.. / A7 = 2  => 13 pairs (_) / I7 = 2  =>  0 pairs (X)
G3,G4: 2.. / G3 = 2  => 10 pairs (_) / G4 = 2  => 12 pairs (_)
C1,C3: 3.. / C1 = 3  => 13 pairs (_) / C3 = 3  =>  0 pairs (X)
F1,F2: 3.. / F1 = 3  =>  0 pairs (X) / F2 = 3  => 13 pairs (_)
I2,I3: 3.. / I2 = 3  =>  0 pairs (X) / I3 = 3  => 13 pairs (_)
C1,F1: 3.. / C1 = 3  => 13 pairs (_) / F1 = 3  =>  0 pairs (X)
F2,I2: 3.. / F2 = 3  => 13 pairs (_) / I2 = 3  =>  0 pairs (X)
C3,I3: 3.. / C3 = 3  =>  0 pairs (X) / I3 = 3  => 13 pairs (_)
B1,C1: 4.. / B1 = 4  =>  8 pairs (_) / C1 = 4  =>  0 pairs (X)
H3,I3: 4.. / H3 = 4  => 13 pairs (_) / I3 = 4  =>  0 pairs (X)
A8,A9: 4.. / A8 = 4  =>  0 pairs (X) / A9 = 4  =>  9 pairs (_)
A9,E9: 4.. / A9 = 4  =>  9 pairs (_) / E9 = 4  =>  0 pairs (X)
I3,I4: 4.. / I3 = 4  =>  0 pairs (X) / I4 = 4  => 13 pairs (_)
B5,C5: 5.. / B5 = 5  =>  8 pairs (_) / C5 = 5  =>  0 pairs (X)
B8,C8: 5.. / B8 = 5  =>  0 pairs (X) / C8 = 5  =>  8 pairs (_)
B5,B8: 5.. / B5 = 5  =>  8 pairs (_) / B8 = 5  =>  0 pairs (X)
C5,C8: 5.. / C5 = 5  =>  0 pairs (X) / C8 = 5  =>  8 pairs (_)
E2,F2: 6.. / E2 = 6  =>  8 pairs (_) / F2 = 6  =>  0 pairs (X)
E5,F5: 6.. / E5 = 6  =>  0 pairs (X) / F5 = 6  =>  8 pairs (_)
E2,E5: 6.. / E2 = 6  =>  8 pairs (_) / E5 = 6  =>  0 pairs (X)
F2,F5: 6.. / F2 = 6  =>  0 pairs (X) / F5 = 6  =>  8 pairs (_)
H9,I9: 7.. / H9 = 7  =>  0 pairs (X) / I9 = 7  => 12 pairs (_)
A3,A8: 7.. / A3 = 7  =>  0 pairs (X) / A8 = 7  => 10 pairs (_)
G3,G4: 7.. / G3 = 7  => 12 pairs (_) / G4 = 7  => 10 pairs (_)
A3,C3: 9.. / A3 = 9  => 13 pairs (_) / C3 = 9  =>  0 pairs (X)
E1,F1: 9.. / E1 = 9  =>  0 pairs (X) / F1 = 9  => 13 pairs (_)
I4,H6: 9.. / I4 = 9  =>  0 pairs (X) / H6 = 9  => 13 pairs (_)
C4,I4: 9.. / C4 = 9  => 13 pairs (_) / I4 = 9  =>  0 pairs (X)
A7,I7: 9.. / A7 = 9  =>  0 pairs (X) / I7 = 9  => 13 pairs (_)
B6,B8: 9.. / B6 = 9  =>  0 pairs (X) / B8 = 9  => 13 pairs (_)
F1,F8: 9.. / F1 = 9  => 13 pairs (_) / F8 = 9  =>  0 pairs (X)
H6,H9: 9.. / H6 = 9  => 13 pairs (_) / H9 = 9  =>  0 pairs (X)
* DURATION: 0:01:04.786945  START: 12:53:38.491693  END: 12:54:43.278638 2017-05-04
* CP COUNT: (33)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A7,B1,B2,E1,E2,G3,G4,I7)
* 1..2..8655.84..91..6.518...61.35..8.8..9..3.13..18.5.6.8673145....6..138.318.56..
* PAIR B1: 4,7 BLK 1
C1: 4,7,3                                # reduction candidate for 4,7
C1: 4,7 => CTR
* 1..2938655284..913963518...61.35..8.8..9..3.139.18.5.628673145975.6.9138.318.56..
C1: 3                                    # 13 pairs
* PAIR B1: 4,7 COL B
B5: 4,7,2,5                              # reduction candidate for 4,7
B5: 4,7 => CTR
* 1..2..8655284..913.63518...61.35..898.59..3.139.18.5.6986731452.5.6..138.318.5697
B5: 2,5                                  #  9 pairs
B6: 4,7,2,9                              # reduction candidate for 4,7
B6: 4,7 => CTR
* 14327986552846391796751824361.35..8485.9.63.13..18.5962867314597956..1384318956..
B6: 2,9                                  #  9 pairs
* PAIR B2: 2,7 BLK 1
A3: 2,7,9                                # reduction candidate for 2,7
A3: 2,7 => CTR
* 1..2..8655.84..91..69518..361.35..8.8..9..3.13..18.5.6.8673145....6..138.318.56..
A3: 9                                    # 13 pairs
C3: 2,7,3,9                              # reduction candidate for 2,7
C3: 2,7                                  # 13 pairs
* PAIR B2: 2,7 ROW 2
I2: 2,7,3                                # reduction candidate for 2,7
I2: 3 => CTR
* 1..2.38655284..913963518...61.35..8.8..9..3.13..18.5.62867314597..6.91384318256..
I2: 2,7                                  # 13 pairs
* PAIR B2: 2,7 COL B
B5: 2,7,4,5                              # reduction candidate for 2,7
B5: 2,7 => CTR
* 14.2..8655284..91376.518...61.35..898.59..3.139.18.5.6986731452.5.6..138.318.5697
B5: 4,5                                  #  9 pairs
B6: 2,7,4,9                              # reduction candidate for 2,7
B6: 2,7                                  # 13 pairs
B8: 2,7,5,9                              # reduction candidate for 2,7
B8: 2,7 => CTR
* 14.2..8655.84..91..69518..361.35..8.85.9..3.139.18.5.6.8673145...56..138.318.5697
B8: 5,9                                  #  9 pairs
* PAIR E1: 7,9 BLK 2
F1: 7,9,3                                # reduction candidate for 7,9
F1: 3 => CTR
* 1..2938655284..913963518...61.35..8.8..9..3.139.18.5.628673145975.6.9138.318.56..
F1: 7,9                                  # 13 pairs
* PAIR E2: 6,7 BLK 2
F2: 6,7,3                                # reduction candidate for 6,7
F2: 6,7 => CTR
* 1..2938655284..913963518...61.35..8.8..9..3.139.18.5.628673145975.6.9138.318.56..
F2: 3                                    # 13 pairs
* PAIR E2: 6,7 COL E
E5: 6,7,2,4                              # reduction candidate for 6,7
E5: 6,7 => CTR
* 1..29.8655.84..91..69518..361.35..8.8..9..3.139.18.5.6.8673145....6.9138.318.5697
E5: 2,4                                  # 13 pairs
* PAIR G3: 2,7 BLK 3
I2: 2,7,3                                # reduction candidate for 2,7
I2: 2,7                                  # 13 pairs
H3: 2,7,4                                # reduction candidate for 2,7
H3: 2,7 => CTR
* 1..2.38655284..913963518..461.35..8.8..9..3.13..18.5.62867314597..6.91384318256..
H3: 4                                    # 13 pairs
I3: 2,7,3,4                              # reduction candidate for 2,7
I3: 2,7 => CTR
* 1..2..8655.84..913.63518.4.61.35..848..9..3.13..18.596.8673145..956..138.318956..
I3: 3,4                                  #  9 pairs
* PAIR G3: 2,7 ROW 3
A3: 2,7,9                                # reduction candidate for 2,7
A3: 2,7 => CTR
* 1..2..8655.84..91..69518..361.35..8.8..9..3.13..18.5.6.8673145....6..138.318.56..
A3: 9                                    # 13 pairs
C3: 2,7,3,9                              # reduction candidate for 2,7
C3: 2,7                                  # 13 pairs
* PAIR G4: 2,7 BLK 6
I4: 2,7,4,9                              # reduction candidate for 2,7
I4: 2,7 => CTR
* 1..2798655.846391.963518..4619354.8.85.9..3.13..18.596.8673145..956.2138.318956..
I4: 4,9                                  #  9 pairs
H5: 2,7,4                                # reduction candidate for 2,7
H5: 2,7                                  # 11 pairs
H6: 2,7,4,9                              # reduction candidate for 2,7
H6: 2,7 => CTR
* 1..2..8655284..91376.518...61.35..898..9..3413..18.5.6986731452...6..138.318.5697
H6: 4,9                                  #  9 pairs
* PAIR G4: 2,7 ROW 4
C4: 2,7,4,9                              # reduction candidate for 2,7
C4: 2,7 => CTR
* 1..2..8655284..91376.518...61.35..898..9..3.13..18.5.6986731452...6..138.318.5697
C4: 4,9                                  #  9 pairs
F4: 2,7,4                                # reduction candidate for 2,7
F4: 2,7                                  # 11 pairs
* PAIR A7: 2,9 BLK 7
A8: 2,9,4,7                              # reduction candidate for 2,9
A8: 2,9 => CTR
* 1..2..8655.84..91.76951824361.35..8.8..9..3.13..18.5.6.8673145....6..138.318.56..
A8: 4,7                                  #  9 pairs
B8: 2,9,5,7                              # reduction candidate for 2,9
B8: 2,9                                  # 11 pairs
C8: 2,9,5,7                              # reduction candidate for 2,9
C8: 2,9 => CTR
* 1..2..8655284..91..6.518...61.35..898.59..3.139.18.5.69867314527526..138431825697
C8: 5,7                                  #  9 pairs
A9: 2,9,4                                # reduction candidate for 2,9
A9: 2,9 => CTR
* 1..2..8655.84..91.76951824361.35..8.8..9..3.13..18.5.6.8673145.4..6..138.318456..
A9: 4                                    #  9 pairs
* PAIR A7: 2,9 COL A
A3: 2,9,7                                # reduction candidate for 2,9
A3: 7 => CTR
* 1..2..8655.84..91.76951824361.35..8.8..9..3.13..18.5.6.8673145....6..138.318.56..
A3: 2,9                                  # 10 pairs
* PAIR I7: 2,9 BLK 9
H9: 2,9,7                                # reduction candidate for 2,9
H9: 2,9                                  # 12 pairs
I9: 2,9,7                                # reduction candidate for 2,9
I9: 2,9 => CTR
* 1..27986552846391796751824361935278485.94.3.13..18.596.8673145..956..138.31895672
I9: 7                                    # 12 pairs
* PAIR I7: 2,9 COL I
I4: 2,9,4,7                              # reduction candidate for 2,9
I4: 2,9 => CTR
* 1..2.38655284..913963518..461.35..8.8..9..3.13..18.5.62867314597..6.91384318256.7
I4: 4,7                                  # 13 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-291-base-pr-000.dot
* REASONING
* DIS # C1: 4,7 => CTR => C1: 3
* DIS # B5: 4,7 => CTR => B5: 2,5
* DIS # B6: 4,7 => CTR => B6: 2,9
* DIS # A3: 2,7 => CTR => A3: 9
* DIS # I2: 3 => CTR => I2: 2,7
* DIS # B5: 2,7 => CTR => B5: 4,5
* DIS # B8: 2,7 => CTR => B8: 5,9
* DIS # F1: 3 => CTR => F1: 7,9
* DIS # F2: 6,7 => CTR => F2: 3
* DIS # E5: 6,7 => CTR => E5: 2,4
* DIS # H3: 2,7 => CTR => H3: 4
* DIS # I3: 2,7 => CTR => I3: 3,4
* DIS # A3: 2,7 => CTR => A3: 9
* DIS # I4: 2,7 => CTR => I4: 4,9
* DIS # H6: 2,7 => CTR => H6: 4,9
* DIS # C4: 2,7 => CTR => C4: 4,9
* DIS # A8: 2,9 => CTR => A8: 4,7
* DIS # C8: 2,9 => CTR => C8: 5,7
* DIS # A9: 2,9 => CTR => A9: 4
* DIS # A3: 7 => CTR => A3: 2,9
* DIS # I9: 2,9 => CTR => I9: 7
* DIS # I4: 2,9 => CTR => I4: 4,7
* CNT  22 HDP CHAINS /  52 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A7,B1,B2,E1,E2,G3,G4,I7)
* 1..2..8655.84..91..6.518...61.35..8.8..9..3.13..18.5.6.8673145....6..138.318.56..
* PAIR B1: 4,7 BLK 1
C1: 4,7,3                                # reduction candidate for 4,7
C1: 4,7 => CTR
* 1..2938655284..913963518...61.35..8.8..9..3.139.18.5.628673145975.6.9138.318.56..

* LEVEL 0 PASS 1 ROUND 2 (AUTO SOLVE) (B2,B6,C3,E5,E8,F4,F8,G3,G4,H5,H9,I2,I9)
* 1432798655.846391.96.518.4361935..8485.9.63.13..18.5962867314597956..1384318956..
* PAIR C3: 2,7 COL C
C5: 2,7,4                                # reduction candidate for 2,7
C5: 2,7                                  # 12 pairs
C6: 2,7,4                                # reduction candidate for 2,7
C6: 2,7 => SOLVED
* 143279865578463912962518743619357284854926371327184596286731459795642138431895627
* DURATION: 0:00:06.330085  START: 12:55:36.928642  END: 12:55:43.258727 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-291-base-pr-001.dot
* REASONING
* DIS # C1: 4,7 => CTR => C1: 3
* PRF C1: 3 # C6: 2,7 => SOL
* STA C1: 3 + C6: 2,7
* CNT   2 HDP CHAINS /   3 HYP OPENED

Header Info

Top 500 Minimum 17 291

solution: 143279865578463912962518743619357284854926371327184596286731459795642138431895627
info: 2404     FNBTHWXY S8.f     47450

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

Solution

position: 143279865578463912962518743619357284854926371327184596286731459795642138431895627 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 # C1: 4,7 => CTR => C1: 3
* INC # C1: 3 => UNS
* DIS # B5: 4,7 => CTR => B5: 2,5
* INC # B5: 2,5 => UNS
* DIS # B6: 4,7 => CTR => B6: 2,9
* INC # B6: 2,9 => UNS
* DIS # A3: 2,7 => CTR => A3: 9
* INC # A3: 9 => UNS
* INC # C3: 2,7 => UNS
* INC # I2: 2,7 => UNS
* DIS # I2: 3 => CTR => I2: 2,7
* DIS # B5: 2,7 => CTR => B5: 4,5
* INC # B5: 4,5 => UNS
* INC # B6: 2,7 => UNS
* DIS # B8: 2,7 => CTR => B8: 5,9
* INC # B8: 5,9 => UNS
* INC # F1: 7,9 => UNS
* DIS # F1: 3 => CTR => F1: 7,9
* DIS # F2: 6,7 => CTR => F2: 3
* INC # F2: 3 => UNS
* DIS # E5: 6,7 => CTR => E5: 2,4
* INC # E5: 2,4 => UNS
* INC # I2: 2,7 => UNS
* DIS # H3: 2,7 => CTR => H3: 4
* INC # H3: 4 => UNS
* DIS # I3: 2,7 => CTR => I3: 3,4
* INC # I3: 3,4 => UNS
* DIS # A3: 2,7 => CTR => A3: 9
* INC # A3: 9 => UNS
* INC # C3: 2,7 => UNS
* DIS # I4: 2,7 => CTR => I4: 4,9
* INC # I4: 4,9 => UNS
* INC # H5: 2,7 => UNS
* DIS # H6: 2,7 => CTR => H6: 4,9
* INC # H6: 4,9 => UNS
* DIS # C4: 2,7 => CTR => C4: 4,9
* INC # C4: 4,9 => UNS
* INC # F4: 2,7 => UNS
* DIS # A8: 2,9 => CTR => A8: 4,7
* INC # A8: 4,7 => UNS
* INC # B8: 2,9 => UNS
* DIS # C8: 2,9 => CTR => C8: 5,7
* INC # C8: 5,7 => UNS
* DIS # A9: 2,9 => CTR => A9: 4
* INC # A9: 4 => UNS
* INC # A3: 2,9 => UNS
* DIS # A3: 7 => CTR => A3: 2,9
* INC # H9: 2,9 => UNS
* DIS # I9: 2,9 => CTR => I9: 7
* INC # I9: 7 => UNS
* DIS # I4: 2,9 => CTR => I4: 4,7
* INC # I4: 4,7 => UNS
* CNT  52 HDP CHAINS /  52 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # C1: 4,7 => CTR => C1: 3
* INC C1: 3 # C5: 2,7 => UNS
* PRF C1: 3 # C6: 2,7 => SOL
* STA C1: 3 + C6: 2,7
* CNT   3 HDP CHAINS /   3 HYP OPENED