Analysis of xx-top500-386-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: ....2..5.6.....3..8.............1..6..4.5....9.......8.7.6.8.........24....9..... initial

Autosolve

position: ....2..5.6.....3..8.............1..6..4.5...39.......8279648135......249...9.2..7 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # B1: 1,4 => CTR => B1: 3,9
* DIS # H5: 1,7 => CTR => H5: 2,9
* DIS # H5: 7,9 => CTR => H5: 1,2
* DIS # F5: 6 => CTR => F5: 7,9
* DIS # G1: 7,9 => CTR => G1: 6,8
* DIS # A9: 1,3 => CTR => A9: 4,5
* DIS # A1: 1,3 => CTR => A1: 4,7
* DIS # B5: 1,2 => CTR => B5: 6,8
* DIS # A9: 1,3 => CTR => A9: 4,5
* PRF # E3: 1,3 => SOL
* DIS # G1: 7,9 => CTR => G1: 6,8
* CNT  11 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 # B1: 1,4 => CTR => B1: 3,9
* DIS B1: 3,9 # H5: 1,7 => CTR => H5: 2,9
* DIS B1: 3,9 + H5: 2,9 # H4: 2 => CTR => H4: 7,9
* DIS B1: 3,9 + H5: 2,9 + H4: 7,9 # F5: 6 => CTR => F5: 7,9
* PRF B1: 3,9 + H5: 2,9 + H4: 7,9 + F5: 7,9 # F2: 4,5 => SOL
* STA B1: 3,9 + H5: 2,9 + H4: 7,9 + F5: 7,9 + F2: 4,5
* CNT   5 HDP CHAINS /  30 HYP OPENED

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

Details

Positions

....2..5.6.....3..8.............1..6..4.5....9.......8.7.6.8.........24....9..... initial
....2..5.6.....3..8.............1..6..4.5...39.......8279648135......249...9.2..7 autosolve
791326854652784391843519762538291476164857923927463518279648135386175249415932687 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (11)
I1: 1,4
A5: 1,7
G4: 4,5
G5: 7,9
G6: 4,5
A8: 1,3
B8: 6,8
C8: 6,8
E9: 1,3
G9: 6,8
H9: 6,8

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
H5,H6: 1.. / H5 = 1  =>  0 pairs (X) / H6 = 1  => 11 pairs (_)
I2,I3: 2.. / I2 = 2  => 12 pairs (_) / I3 = 2  => 12 pairs (_)
G4,G6: 4.. / G4 = 4  =>  9 pairs (_) / G6 = 4  => 14 pairs (_)
A9,B9: 4.. / A9 = 4  =>  9 pairs (_) / B9 = 4  => 14 pairs (_)
D4,G4: 4.. / D4 = 4  => 14 pairs (_) / G4 = 4  =>  9 pairs (_)
A1,A9: 4.. / A1 = 4  => 14 pairs (_) / A9 = 4  =>  9 pairs (_)
G4,G6: 5.. / G4 = 5  => 14 pairs (_) / G6 = 5  =>  9 pairs (_)
D8,F8: 5.. / D8 = 5  => 12 pairs (_) / F8 = 5  => 11 pairs (_)
A4,A9: 5.. / A4 = 5  =>  9 pairs (_) / A9 = 5  => 16 pairs (_)
B8,C8: 6.. / B8 = 6  =>  0 pairs (X) / C8 = 6  => 16 pairs (_)
G9,H9: 6.. / G9 = 6  => 16 pairs (_) / H9 = 6  =>  0 pairs (X)
F1,G1: 6.. / F1 = 6  => 16 pairs (_) / G1 = 6  =>  0 pairs (X)
B5,F5: 6.. / B5 = 6  => 16 pairs (_) / F5 = 6  =>  0 pairs (X)
C6,C8: 6.. / C6 = 6  =>  0 pairs (X) / C8 = 6  => 16 pairs (_)
E3,E6: 6.. / E3 = 6  =>  0 pairs (X) / E6 = 6  => 16 pairs (_)
H3,H9: 6.. / H3 = 6  => 16 pairs (_) / H9 = 6  =>  0 pairs (X)
G1,H2: 8.. / G1 = 8  => 16 pairs (_) / H2 = 8  =>  0 pairs (X)
B8,C8: 8.. / B8 = 8  => 16 pairs (_) / C8 = 8  =>  0 pairs (X)
G9,H9: 8.. / G9 = 8  =>  0 pairs (X) / H9 = 8  => 16 pairs (_)
D1,G1: 8.. / D1 = 8  =>  0 pairs (X) / G1 = 8  => 16 pairs (_)
B5,D5: 8.. / B5 = 8  =>  0 pairs (X) / D5 = 8  => 16 pairs (_)
C4,C8: 8.. / C4 = 8  => 16 pairs (_) / C8 = 8  =>  0 pairs (X)
E2,E4: 8.. / E2 = 8  => 16 pairs (_) / E4 = 8  =>  0 pairs (X)
G1,G9: 8.. / G1 = 8  => 16 pairs (_) / G9 = 8  =>  0 pairs (X)
H2,H9: 8.. / H2 = 8  =>  0 pairs (X) / H9 = 8  => 16 pairs (_)
E4,F5: 9.. / E4 = 9  =>  0 pairs (*) / F5 = 9  =>  0 pairs (X)
E4,H4: 9.. / E4 = 9  =>  0 pairs (*) / H4 = 9  =>  0 pairs (X)
* DURATION: 0:00:50.848643  START: 16:02:02.201552  END: 16:02:53.050195 2017-05-04
* CP COUNT: (27)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A5,A8,B8,C8,E9,G4,G5,G6,G9,H9,I1)
* ....2..5.6.....3..8.............1..6..4.5...39.......8279648135......249...9.2..7
* PAIR I1: 1,4 BLK 3
I2: 1,4,2                                # reduction candidate for 1,4
I2: 1,4                                  # 12 pairs
I3: 1,4,2                                # reduction candidate for 1,4
I3: 1,4                                  # 12 pairs
* PAIR I1: 1,4 ROW 1
A1: 1,4,3,7                              # reduction candidate for 1,4
A1: 1,4                                  # 14 pairs
B1: 1,4,3,9                              # reduction candidate for 1,4
B1: 1,4 => CTR
* ...82..5.6.....38.8............81.96.84.5...39.......8279648135......249...9.2..7
B1: 3,9                                  # 12 pairs
D1: 1,4,3,7,8                            # reduction candidate for 1,4
D1: 1,4                                  # 16 pairs
* PAIR A5: 1,7 BLK 4
C6: 1,7,2,3,5,6                          # reduction candidate for 1,7
C6: 1,7                                  # 16 pairs
C6: 2,3,5,6                              # 11 pairs
* PAIR A5: 1,7 ROW 5
H5: 1,7,2,9                              # reduction candidate for 1,7
H5: 1,7 => CTR
* ....2.65.6...8.3..8...6.79.....91..6..4.569.39.......8279648135......249...9.2..7
H5: 2,9                                  # 12 pairs
* PAIR A5: 1,7 COL A
A1: 1,7,3,4                              # reduction candidate for 1,7
A1: 1,7                                  # 13 pairs
A1: 3,4                                  # 12 pairs
* PAIR G5: 7,9 BLK 6
H4: 7,9,2                                # reduction candidate for 7,9
H4: 7,9                                  # 14 pairs
H5: 7,9,1,2                              # reduction candidate for 7,9
H5: 7,9 => CTR
* ....2685.6...8.3..8......6...8.91.26.64.5...39...6..18279648135..6...249...9.2687
H5: 1,2                                  # 12 pairs
* PAIR G5: 7,9 ROW 5
F5: 7,9,6                                # reduction candidate for 7,9
F5: 6 => CTR
* ....2.65.6...8.3..8...6........91..6..4.56..39.......8279648135......249...9.28.7
F5: 7,9                                  # 16 pairs
* PAIR G5: 7,9 COL G
G1: 7,9,6,8                              # reduction candidate for 7,9
G1: 7,9 => CTR
* ...826.5.6.....38.8............81.96..4.5...39.......8279648135......249...9.2..7
G1: 6,8                                  # 13 pairs
G3: 7,9,6                                # reduction candidate for 7,9
G3: 7,9                                  # 13 pairs
* PAIR A8: 1,3 BLK 7
A9: 1,3,4,5                              # reduction candidate for 1,3
A9: 1,3 => CTR
* 4...2.6516...8.3..8...6.79.5...914.67.4.569.39.....5.8279648135......249.459.2..7
A9: 4,5                                  # 12 pairs
B9: 1,3,4,5                              # reduction candidate for 1,3
B9: 1,3                                  # 11 pairs
C9: 1,3,5                                # reduction candidate for 1,3
C9: 1,3                                  # 14 pairs
* PAIR A8: 1,3 ROW 8
D8: 1,3,5,7                              # reduction candidate for 1,3
D8: 1,3                                  # 13 pairs
E8: 1,3,7                                # reduction candidate for 1,3
E8: 1,3                                  # 15 pairs
* PAIR A8: 1,3 COL A
A1: 1,3,4,7                              # reduction candidate for 1,3
A1: 1,3 => CTR
* ....2.65.6...8.3..8...6.79.5...914.67.4.569.39.....5.8279648135......2494..9.2..7
A1: 4,7                                  # 12 pairs
* PAIR B8: 6,8 COL B
B5: 6,8,1,2                              # reduction candidate for 6,8
B5: 1,2 => CTR
* ....2..5.6.....3..8.............1..6..4856..39.......8279648135......249...9.2..7
B5: 6,8                                  # 12 pairs
* PAIR E9: 1,3 BLK 8
D8: 1,3,5,7                              # reduction candidate for 1,3
D8: 1,3                                  # 13 pairs
E8: 1,3,7                                # reduction candidate for 1,3
E8: 1,3                                  # 15 pairs
* PAIR E9: 1,3 ROW 9
A9: 1,3,4,5                              # reduction candidate for 1,3
A9: 1,3 => CTR
* 4...2.6516...8.3..8...6.79.5...914.67.4.569.39.....5.8279648135......249.459.2..7
A9: 4,5                                  # 12 pairs
B9: 1,3,4,5                              # reduction candidate for 1,3
B9: 1,3                                  # 11 pairs
C9: 1,3,5                                # reduction candidate for 1,3
C9: 1,3                                  # 14 pairs
* PAIR E9: 1,3 COL E
E3: 1,3,6,7,9                            # reduction candidate for 1,3
E3: 1,3 => SOLVED
* 791326854652784391843519762538291476164857923927463518279648135386175249415932687
E3: 6,7,9                                # 11 pairs
* PAIR G9: 6,8 COL G
G1: 6,8,7,9                              # reduction candidate for 6,8
G1: 7,9 => CTR
* ...826.5.6.....38.8............81.96..4.5...39.......8279648135......249...9.2..7
G1: 6,8                                  # 13 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-386-base-pr-000.dot
* REASONING
* DIS # B1: 1,4 => CTR => B1: 3,9
* DIS # H5: 1,7 => CTR => H5: 2,9
* DIS # H5: 7,9 => CTR => H5: 1,2
* DIS # F5: 6 => CTR => F5: 7,9
* DIS # G1: 7,9 => CTR => G1: 6,8
* DIS # A9: 1,3 => CTR => A9: 4,5
* DIS # A1: 1,3 => CTR => A1: 4,7
* DIS # B5: 1,2 => CTR => B5: 6,8
* DIS # A9: 1,3 => CTR => A9: 4,5
* PRF # E3: 1,3 => SOL
* DIS # G1: 7,9 => CTR => G1: 6,8
* CNT  11 HDP CHAINS /  40 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A5,A8,B8,C8,E9,G4,G5,G6,G9,H9,I1)
* ....2..5.6.....3..8.............1..6..4.5...39.......8279648135......249...9.2..7
* PAIR I1: 1,4 BLK 3
I2: 1,4,2                                # reduction candidate for 1,4
I2: 1,4                                  # 12 pairs
I3: 1,4,2                                # reduction candidate for 1,4
I3: 1,4                                  # 12 pairs
* PAIR I1: 1,4 ROW 1
A1: 1,4,3,7                              # reduction candidate for 1,4
A1: 1,4                                  # 14 pairs
B1: 1,4,3,9                              # reduction candidate for 1,4
B1: 1,4 => CTR
* ...82..5.6.....38.8............81.96.84.5...39.......8279648135......249...9.2..7
D1: 1,4,3,7,8                            # reduction candidate for 1,4
D1: 1,4                                  # 16 pairs
* PAIR RESTART
* PAIR I1: 1,4 BLK 3
I2: 1,4,2                                # reduction candidate for 1,4
I2: 1,4                                  # 13 pairs
I3: 1,4,2                                # reduction candidate for 1,4
I3: 1,4                                  # 13 pairs
* PAIR I1: 1,4 ROW 1
A1: 1,4,3,7                              # reduction candidate for 1,4
A1: 1,4                                  # 14 pairs
D1: 1,4,3,7,8                            # reduction candidate for 1,4
D1: 1,4                                  # 16 pairs
* PAIR A5: 1,7 BLK 4
C6: 1,7,2,3,5,6                          # reduction candidate for 1,7
C6: 1,7                                  # 16 pairs
C6: 2,3,5,6                              # 12 pairs
* PAIR A5: 1,7 ROW 5
H5: 1,7,2,9                              # reduction candidate for 1,7
H5: 1,7 => CTR
* ....2.65.6...8.3..8...6.79.....91..6..4.569.39.......8279648135......249...9.2..7
* PAIR A5: 1,7 COL A
A1: 1,7,3,4                              # reduction candidate for 1,7
A1: 3,4                                  # 16 pairs
A1: 1,7                                  # 15 pairs
* PAIR RESTART
* PAIR A5: 1,7 COL A
A1: 1,7,3,4                              # reduction candidate for 1,7
A1: 3,4                                  # 16 pairs
A1: 1,7                                  # 15 pairs
* PAIR G5: 7,9 BLK 6
H4: 7,9,2                                # reduction candidate for 7,9
H4: 2 => CTR
* ....2..5.6...8.37.8......6.....91.261.4.567939......182796481353.....249...932687
* PAIR G5: 7,9 ROW 5
F5: 7,9,6                                # reduction candidate for 7,9
F5: 6 => CTR
* ....2.65.6...8.39.8............91.76..4.569239......18279648135......249...9.2..7
* PAIR RESTART

* LEVEL 0 PASS 1 ROUND 2 (AUTO SOLVE) (B4,B6,B9,C1,C9,D4,E4,E8,F5,F6,F8,G3,G5,H2,H4,I1)
* 79..2685.6...8.3..8......6.5.8..14.616485..239.7.6.518279648135386...2494..932687
* PAIR C1: 1,3 BLK 1
C3: 1,3,2,5                              # reduction candidate for 1,3
C3: 1,3                                  # 18 pairs
C3: 2,5                                  # 17 pairs
* PAIR C1: 1,3 ROW 1
D1: 1,3,4                                # reduction candidate for 1,3
D1: 1,3                                  # 18 pairs
D1: 4                                    # 16 pairs
* PAIR I1: 1,4 BLK 3
I2: 1,4,2                                # reduction candidate for 1,4
I2: 1,4                                  # 17 pairs
I3: 1,4,2                                # reduction candidate for 1,4
I3: 1,4                                  # 18 pairs
* PAIR I1: 1,4 ROW 1
D1: 1,4,3                                # reduction candidate for 1,4
D1: 1,4                                  # 16 pairs
D1: 3                                    # 11 pairs
* PAIR H2: 7,9 ROW 2
F2: 7,9,4,5                              # reduction candidate for 7,9
F2: 4,5 => SOLVED
* 791326854652784391843519762538291476164857923927463518279648135386175249415932687
* DURATION: 0:00:37.824545  START: 16:03:31.337813  END: 16:04:09.162358 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-386-base-pr-001.dot
* REASONING
* DIS # B1: 1,4 => CTR => B1: 3,9
* DIS B1: 3,9 # H5: 1,7 => CTR => H5: 2,9
* DIS B1: 3,9 + H5: 2,9 # H4: 2 => CTR => H4: 7,9
* DIS B1: 3,9 + H5: 2,9 + H4: 7,9 # F5: 6 => CTR => F5: 7,9
* PRF B1: 3,9 + H5: 2,9 + H4: 7,9 + F5: 7,9 # F2: 4,5 => SOL
* STA B1: 3,9 + H5: 2,9 + H4: 7,9 + F5: 7,9 + F2: 4,5
* CNT   5 HDP CHAINS /  30 HYP OPENED

Header Info

Top 500 Minimum 17 386

solution: 791326854652784391843519762538291476164857923927463518279648135386175249415932687
info: 34914    FNBTHXYK S8.f     46770

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

Solution

position: 791326854652784391843519762538291476164857923927463518279648135386175249415932687 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 # I2: 1,4 => UNS
* INC # I3: 1,4 => UNS
* INC # A1: 1,4 => UNS
* DIS # B1: 1,4 => CTR => B1: 3,9
* INC # B1: 3,9 => UNS
* INC # D1: 1,4 => UNS
* INC # C6: 1,7 => UNS
* INC # C6: 2,3,5,6 => UNS
* DIS # H5: 1,7 => CTR => H5: 2,9
* INC # H5: 2,9 => UNS
* INC # A1: 1,7 => UNS
* INC # A1: 3,4 => UNS
* INC # H4: 7,9 => UNS
* DIS # H5: 7,9 => CTR => H5: 1,2
* INC # H5: 1,2 => UNS
* INC # F5: 7,9 => UNS
* DIS # F5: 6 => CTR => F5: 7,9
* DIS # G1: 7,9 => CTR => G1: 6,8
* INC # G1: 6,8 => UNS
* INC # G3: 7,9 => UNS
* DIS # A9: 1,3 => CTR => A9: 4,5
* INC # A9: 4,5 => UNS
* INC # B9: 1,3 => UNS
* INC # C9: 1,3 => UNS
* INC # D8: 1,3 => UNS
* INC # E8: 1,3 => UNS
* DIS # A1: 1,3 => CTR => A1: 4,7
* INC # A1: 4,7 => UNS
* INC # B5: 6,8 => UNS
* DIS # B5: 1,2 => CTR => B5: 6,8
* INC # D8: 1,3 => UNS
* INC # E8: 1,3 => UNS
* DIS # A9: 1,3 => CTR => A9: 4,5
* INC # A9: 4,5 => UNS
* INC # B9: 1,3 => UNS
* INC # C9: 1,3 => UNS
* PRF # E3: 1,3 => SOL
* INC # E3: 6,7,9 => UNS
* INC # G1: 6,8 => UNS
* DIS # G1: 7,9 => CTR => G1: 6,8
* CNT  40 HDP CHAINS /  40 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # I2: 1,4 => UNS
* INC # I3: 1,4 => UNS
* INC # A1: 1,4 => UNS
* DIS # B1: 1,4 => CTR => B1: 3,9
* INC B1: 3,9 # D1: 1,4 => UNS
* INC B1: 3,9 # I2: 1,4 => UNS
* INC B1: 3,9 # I3: 1,4 => UNS
* INC B1: 3,9 # A1: 1,4 => UNS
* INC B1: 3,9 # D1: 1,4 => UNS
* INC B1: 3,9 # C6: 1,7 => UNS
* INC B1: 3,9 # C6: 2,3,5,6 => UNS
* DIS B1: 3,9 # H5: 1,7 => CTR => H5: 2,9
* INC B1: 3,9 + H5: 2,9 # A1: 1,7 => UNS
* INC B1: 3,9 + H5: 2,9 # A1: 3,4 => UNS
* INC B1: 3,9 + H5: 2,9 # A1: 1,7 => UNS
* INC B1: 3,9 + H5: 2,9 # A1: 3,4 => UNS
* INC B1: 3,9 + H5: 2,9 # H4: 7,9 => UNS
* DIS B1: 3,9 + H5: 2,9 # H4: 2 => CTR => H4: 7,9
* INC B1: 3,9 + H5: 2,9 + H4: 7,9 # F5: 7,9 => UNS
* DIS B1: 3,9 + H5: 2,9 + H4: 7,9 # F5: 6 => CTR => F5: 7,9
* INC B1: 3,9 + H5: 2,9 + H4: 7,9 + F5: 7,9 # C3: 1,3 => UNS
* INC B1: 3,9 + H5: 2,9 + H4: 7,9 + F5: 7,9 # C3: 2,5 => UNS
* INC B1: 3,9 + H5: 2,9 + H4: 7,9 + F5: 7,9 # D1: 1,3 => UNS
* INC B1: 3,9 + H5: 2,9 + H4: 7,9 + F5: 7,9 # D1: 4 => UNS
* INC B1: 3,9 + H5: 2,9 + H4: 7,9 + F5: 7,9 # I2: 1,4 => UNS
* INC B1: 3,9 + H5: 2,9 + H4: 7,9 + F5: 7,9 # I3: 1,4 => UNS
* INC B1: 3,9 + H5: 2,9 + H4: 7,9 + F5: 7,9 # D1: 1,4 => UNS
* INC B1: 3,9 + H5: 2,9 + H4: 7,9 + F5: 7,9 # D1: 3 => UNS
* INC B1: 3,9 + H5: 2,9 + H4: 7,9 + F5: 7,9 # F2: 7,9 => UNS
* PRF B1: 3,9 + H5: 2,9 + H4: 7,9 + F5: 7,9 # F2: 4,5 => SOL
* STA B1: 3,9 + H5: 2,9 + H4: 7,9 + F5: 7,9 + F2: 4,5
* CNT  30 HDP CHAINS /  30 HYP OPENED