Analysis of xx-top500-084-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: .5....3.....1...4....2.....4..7.......2...8......5.6..56..3.........4.2.........1 initial

Autosolve

position: 257.4931....17.24.14.2..7..4857261..672391854.1.4586725619324877...14.2..24..7..1 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # A2: 3,9 => CTR => A2: 8
* DIS # C2: 3,9 => CTR => C2: 6,8
* PRF # D9: 6,8 => SOL
* DIS # C3: 6,8 => CTR => C3: 3,9
* DIS # I3: 6,8 => CTR => I3: 5,9
* DIS # I2: 6,8 => CTR => I2: 5,9
* DIS # I3: 6,8 => CTR => I3: 5,9
* DIS # I2: 6,9 => CTR => I2: 5,8
* PRF # I3: 6,9 => SOL
* DIS # C3: 6,9 => CTR => C3: 3,8
* DIS # A2: 3,9 => CTR => A2: 8
* DIS # C2: 3,9 => CTR => C2: 6,8
* DIS # C8: 3,9 => CTR => C8: 8
* DIS # C8: 3,9 => CTR => C8: 8
* PRF # D9: 6,8 => SOL
* CNT  15 HDP CHAINS /  36 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 # A2: 3,9 => CTR => A2: 8
* DIS A2: 8 # C2: 3,9 => CTR => C2: 6
* PRF A2: 8 + C2: 6 # D9: 6,8 => SOL
* STA A2: 8 + C2: 6 + D9: 6,8
* CNT   3 HDP CHAINS /   3 HYP OPENED

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

Details

Positions

.5....3.....1...4....2.....4..7.......2...8......5.6..56..3.........4.2.........1 initial
257.4931....17.24.14.2..7..4857261..672391854.1.4586725619324877...14.2..24..7..1 autosolve
257649318896173245143285769485726193672391854319458672561932487738514926924867531 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (17)
B2: 3,9
D1: 6,8
F2: 3,5
E3: 6,8
F3: 3,5
I1: 6,8
H3: 6,9
A6: 3,9
C6: 3,9
H4: 3,9
I4: 3,9
B8: 3,9
E9: 6,8
G8: 5,9
I8: 3,6
G9: 5,9
H9: 3,6

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
F2,F3: 3.. / F2 = 3  =>  0 pairs (*) / F3 = 3  =>  0 pairs (X)
A6,C6: 3.. / A6 = 3  =>  0 pairs (*) / C6 = 3  =>  0 pairs (X)
H4,I4: 3.. / H4 = 3  =>  0 pairs (X) / I4 = 3  =>  0 pairs (_)
I8,H9: 3.. / I8 = 3  =>  0 pairs (X) / H9 = 3  =>  0 pairs (_)
C3,F3: 3.. / C3 = 3  =>  0 pairs (*) / F3 = 3  =>  0 pairs (X)
A9,H9: 3.. / A9 = 3  =>  0 pairs (X) / H9 = 3  =>  0 pairs (_)
B2,B8: 3.. / B2 = 3  => 15 pairs (_) / B8 = 3  =>  0 pairs (*)
H4,H9: 3.. / H4 = 3  =>  0 pairs (X) / H9 = 3  =>  0 pairs (_)
I4,I8: 3.. / I4 = 3  =>  0 pairs (*) / I8 = 3  =>  0 pairs (X)
F2,F3: 5.. / F2 = 5  => 15 pairs (_) / F3 = 5  =>  0 pairs (*)
I2,I3: 5.. / I2 = 5  =>  0 pairs (*) / I3 = 5  =>  0 pairs (X)
D8,D9: 5.. / D8 = 5  =>  0 pairs (*) / D9 = 5  =>  0 pairs (X)
G8,G9: 5.. / G8 = 5  => 17 pairs (_) / G9 = 5  =>  0 pairs (*)
F2,I2: 5.. / F2 = 5  => 15 pairs (_) / I2 = 5  =>  0 pairs (*)
F3,I3: 5.. / F3 = 5  =>  0 pairs (*) / I3 = 5  =>  0 pairs (X)
D8,G8: 5.. / D8 = 5  =>  0 pairs (*) / G8 = 5  =>  0 pairs (X)
D9,G9: 5.. / D9 = 5  => 17 pairs (_) / G9 = 5  =>  0 pairs (*)
C2,C3: 6.. / C2 = 6  => 17 pairs (_) / C3 = 6  =>  0 pairs (X)
D1,E3: 6.. / D1 = 6  =>  0 pairs (*) / E3 = 6  =>  0 pairs (X)
I8,H9: 6.. / I8 = 6  =>  0 pairs (*) / H9 = 6  =>  0 pairs (X)
D1,I1: 6.. / D1 = 6  =>  0 pairs (*) / I1 = 6  =>  0 pairs (X)
C2,I2: 6.. / C2 = 6  => 17 pairs (_) / I2 = 6  =>  0 pairs (X)
D8,I8: 6.. / D8 = 6  =>  0 pairs (X) / I8 = 6  =>  0 pairs (_)
E3,E9: 6.. / E3 = 6  =>  0 pairs (X) / E9 = 6  =>  0 pairs (_)
H3,H9: 6.. / H3 = 6  =>  0 pairs (*) / H9 = 6  =>  0 pairs (X)
D1,E3: 8.. / D1 = 8  =>  0 pairs (X) / E3 = 8  =>  0 pairs (_)
C8,A9: 8.. / C8 = 8  => 19 pairs (_) / A9 = 8  =>  0 pairs (X)
D1,I1: 8.. / D1 = 8  =>  0 pairs (X) / I1 = 8  =>  0 pairs (_)
C8,D8: 8.. / C8 = 8  => 19 pairs (_) / D8 = 8  =>  0 pairs (X)
A2,A9: 8.. / A2 = 8  => 19 pairs (_) / A9 = 8  =>  0 pairs (X)
E3,E9: 8.. / E3 = 8  =>  0 pairs (*) / E9 = 8  =>  0 pairs (X)
A6,C6: 9.. / A6 = 9  => 15 pairs (_) / C6 = 9  =>  0 pairs (*)
H4,I4: 9.. / H4 = 9  =>  0 pairs (*) / I4 = 9  =>  0 pairs (X)
G8,G9: 9.. / G8 = 9  =>  0 pairs (*) / G9 = 9  =>  0 pairs (X)
A9,G9: 9.. / A9 = 9  =>  0 pairs (*) / G9 = 9  =>  0 pairs (X)
B2,B8: 9.. / B2 = 9  =>  0 pairs (*) / B8 = 9  =>  0 pairs (X)
H3,H4: 9.. / H3 = 9  =>  0 pairs (X) / H4 = 9  =>  0 pairs (_)
* DURATION: 0:01:03.643866  START: 05:39:17.008982  END: 05:40:20.652848 2017-05-04
* CP COUNT: (37)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A6,B2,B8,C6,D1,E3,E9,F2,F3,G8,G9,H3,H4,H9,I1,I4,I8)
* 257.4931....17.24.14.2..7..4857261..672391854.1.4586725619324877...14.2..24..7..1
* PAIR B2: 3,9 BLK 1
A2: 3,9,8                                # reduction candidate for 3,9
A2: 3,9 => CTR
* 257649318..817.24614.2..7..4857261..672391854.1.4586725619324877...14.2.824.67931
A2: 8                                    # 19 pairs
C2: 3,9,6,8                              # reduction candidate for 3,9
C2: 3,9 => CTR
* 257.4931....17.246146283795485726139672391854.1.4586725619324877.8614.2..24..7..1
C2: 6,8                                  # 18 pairs
C3: 3,9,6,8                              # reduction candidate for 3,9
C3: 3,9                                  # 21 pairs
* PAIR D1: 6,8 COL D
D8: 6,8,5                                # reduction candidate for 6,8
D8: 6,8                                  # 17 pairs
D9: 6,8,5                                # reduction candidate for 6,8
D9: 6,8 => SOLVED
* 257649318896173245143285769485726193672391854319458672561932487738514926924867531
D9: 5                                    # 17 pairs
* PAIR E3: 6,8 ROW 3
C3: 6,8,3,9                              # reduction candidate for 6,8
C3: 6,8 => CTR
* 257.4931.8391752461462.3795485726139672391854.1.4586725619324877...14.23324..7961
C3: 3,9                                  # 21 pairs
I3: 6,8,5,9                              # reduction candidate for 6,8
I3: 6,8 => CTR
* 257.4931.83.17.24514.2.579.485726139672391854.1.4586725619324877...14.23324..7961
I3: 5,9                                  # 18 pairs
* PAIR I1: 6,8 BLK 3
I2: 6,8,5,9                              # reduction candidate for 6,8
I2: 6,8 => CTR
* 257.4931.8391752461462.37.54857261.9672391854.1.4586725619324877...14.23324..7961
I2: 5,9                                  # 21 pairs
I3: 6,8,5,9                              # reduction candidate for 6,8
I3: 6,8 => CTR
* 257.4931.83.17.24514.2.579.485726139672391854.1.4586725619324877...14.23324..7961
I3: 5,9                                  # 18 pairs
* PAIR H3: 6,9 BLK 3
I2: 6,9,5,8                              # reduction candidate for 6,9
I2: 6,9 => CTR
* 257649318..61752491492837654857261936723918549134586725619324877...14.26.24.67.31
I2: 5,8                                  # 19 pairs
I3: 6,9,5,8                              # reduction candidate for 6,9
I3: 6,9 => SOLVED
* 257649318896173245143285769485726193672391854319458672561932487738514926924867531
I3: 5,8                                  # 18 pairs
* PAIR H3: 6,9 ROW 3
C3: 6,9,3,8                              # reduction candidate for 6,9
C3: 6,9 => CTR
* 257649318..61752491492837654857261936723918549134586725619324877...14.26.24.67.31
C3: 3,8                                  # 19 pairs
* PAIR A6: 3,9 COL A
A2: 3,9,8                                # reduction candidate for 3,9
A2: 3,9 => CTR
* 257649318..817.24614.2..7..4857261..672391854.1.4586725619324877...14.2.824.67931
A2: 8                                    # 19 pairs
A9: 3,9,8                                # reduction candidate for 3,9
A9: 3,9                                  # 19 pairs
* PAIR C6: 3,9 COL C
C2: 3,9,6,8                              # reduction candidate for 3,9
C2: 3,9 => CTR
* 257.4931....17.246146283795485726139672391854.1.4586725619324877.8614.2..24..7..1
C2: 6,8                                  # 18 pairs
C3: 3,9,6,8                              # reduction candidate for 3,9
C3: 3,9                                  # 21 pairs
C8: 3,9,8                                # reduction candidate for 3,9
C8: 3,9 => CTR
* 257649318...17.24.14.2..7..4857261..672391854.1.4586725619324877..814526824567931
C8: 8                                    # 19 pairs
* PAIR B8: 3,9 BLK 7
C8: 3,9,8                                # reduction candidate for 3,9
C8: 3,9 => CTR
* 257649318...17.24.14.2..7..4857261..672391854.1.4586725619324877..814526824567931
C8: 8                                    # 19 pairs
A9: 3,9,8                                # reduction candidate for 3,9
A9: 3,9                                  # 19 pairs
* PAIR E9: 6,8 BLK 8
D8: 6,8,5                                # reduction candidate for 6,8
D8: 6,8                                  # 17 pairs
D9: 6,8,5                                # reduction candidate for 6,8
D9: 6,8 => SOLVED
* 257649318896173245143285769485726193672391854319458672561932487738514926924867531
D9: 5                                    # 17 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-084-base-pr-000.dot
* REASONING
* DIS # A2: 3,9 => CTR => A2: 8
* DIS # C2: 3,9 => CTR => C2: 6,8
* PRF # D9: 6,8 => SOL
* DIS # C3: 6,8 => CTR => C3: 3,9
* DIS # I3: 6,8 => CTR => I3: 5,9
* DIS # I2: 6,8 => CTR => I2: 5,9
* DIS # I3: 6,8 => CTR => I3: 5,9
* DIS # I2: 6,9 => CTR => I2: 5,8
* PRF # I3: 6,9 => SOL
* DIS # C3: 6,9 => CTR => C3: 3,8
* DIS # A2: 3,9 => CTR => A2: 8
* DIS # C2: 3,9 => CTR => C2: 6,8
* DIS # C8: 3,9 => CTR => C8: 8
* DIS # C8: 3,9 => CTR => C8: 8
* PRF # D9: 6,8 => SOL
* CNT  15 HDP CHAINS /  36 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A6,B2,B8,C6,D1,E3,E9,F2,F3,G8,G9,H3,H4,H9,I1,I4,I8)
* 257.4931....17.24.14.2..7..4857261..672391854.1.4586725619324877...14.2..24..7..1
* PAIR B2: 3,9 BLK 1
A2: 3,9,8                                # reduction candidate for 3,9
A2: 3,9 => CTR
* 257649318..817.24614.2..7..4857261..672391854.1.4586725619324877...14.2.824.67931
C2: 3,9,6                                # reduction candidate for 3,9
C2: 3,9 => CTR
* 257.4931.8..17.246146283795485726139672391854.1.4586725619324877.8614.2..24..7..1
* RESTART
* PAIR D1: 6,8 COL D
D9: 6,8,5                                # reduction candidate for 6,8
D9: 6,8 => SOLVED
* 257649318896173245143285769485726193672391854319458672561932487738514926924867531
* DURATION: 0:00:04.203229  START: 05:40:56.525418  END: 05:41:00.728647 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-084-base-pr-001.dot
* REASONING
* DIS # A2: 3,9 => CTR => A2: 8
* DIS A2: 8 # C2: 3,9 => CTR => C2: 6
* PRF A2: 8 + C2: 6 # D9: 6,8 => SOL
* STA A2: 8 + C2: 6 + D9: 6,8
* CNT   3 HDP CHAINS /   3 HYP OPENED

Header Info

Top 500 Minimum 17 084

solution: 257649318896173245143285769485726193672391854319458672561932487738514926924867531
info: 1558     FNBWXY   S8.f     19764

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

Solution

position: 257649318896173245143285769485726193672391854319458672561932487738514926924867531 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 # A2: 3,9 => CTR => A2: 8
* INC # A2: 8 => UNS
* DIS # C2: 3,9 => CTR => C2: 6,8
* INC # C2: 6,8 => UNS
* INC # C3: 3,9 => UNS
* INC # D8: 6,8 => UNS
* PRF # D9: 6,8 => SOL
* INC # D9: 5 => UNS
* DIS # C3: 6,8 => CTR => C3: 3,9
* INC # C3: 3,9 => UNS
* DIS # I3: 6,8 => CTR => I3: 5,9
* INC # I3: 5,9 => UNS
* DIS # I2: 6,8 => CTR => I2: 5,9
* INC # I2: 5,9 => UNS
* DIS # I3: 6,8 => CTR => I3: 5,9
* INC # I3: 5,9 => UNS
* DIS # I2: 6,9 => CTR => I2: 5,8
* INC # I2: 5,8 => UNS
* PRF # I3: 6,9 => SOL
* INC # I3: 5,8 => UNS
* DIS # C3: 6,9 => CTR => C3: 3,8
* INC # C3: 3,8 => UNS
* DIS # A2: 3,9 => CTR => A2: 8
* INC # A2: 8 => UNS
* INC # A9: 3,9 => UNS
* DIS # C2: 3,9 => CTR => C2: 6,8
* INC # C2: 6,8 => UNS
* INC # C3: 3,9 => UNS
* DIS # C8: 3,9 => CTR => C8: 8
* INC # C8: 8 => UNS
* DIS # C8: 3,9 => CTR => C8: 8
* INC # C8: 8 => UNS
* INC # A9: 3,9 => UNS
* INC # D8: 6,8 => UNS
* PRF # D9: 6,8 => SOL
* INC # D9: 5 => UNS
* CNT  36 HDP CHAINS /  36 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # A2: 3,9 => CTR => A2: 8
* DIS A2: 8 # C2: 3,9 => CTR => C2: 6
* PRF A2: 8 + C2: 6 # D9: 6,8 => SOL
* STA A2: 8 + C2: 6 + D9: 6,8
* CNT   3 HDP CHAINS /   3 HYP OPENED