Analysis of xx-top500-069-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: ...6.5...2.....9............76....4....1..2.....83...........57.....4..61...2.... initial

Autosolve

position: ...6.57.225....96.6.....5...76....415..14627.4..837695....6..577....4.2616572.4.9 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # D3: 2,9 => CTR => D3: 3,4
* DIS # I2: 8 => CTR => I2: 3,4
* DIS # A1: 3,8 => CTR => A1: 9
* DIS # D4: 5,9 => CTR => D4: 2
* DIS # E8: 5,9 => CTR => E8: 1,8
* DIS # D4: 5 => CTR => D4: 2,9
* DIS # F3: 1,3,8 => CTR => F3: 2,9
* DIS # F7: 3,9 => CTR => F7: 1,8
* DIS # D8: 3,9 => CTR => D8: 5
* PRF # A7: 8 => SOL
* DIS # F3: 3,8 => CTR => F3: 1,2,9
* 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 # D3: 2,9 => CTR => D3: 3,4
* DIS D3: 3,4 # I2: 8 => CTR => I2: 3,4
* PRF D3: 3,4 + I2: 3,4 # G7: 3,8 => SOL
* STA D3: 3,4 + I2: 3,4 + G7: 3,8
* CNT   3 HDP CHAINS /   7 HYP OPENED

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

Details

Positions

...6.5...2.....9............76....4....1..2.....83...........57.....4..61...2.... initial
...6.57.225....96.6.....5...76....415..14627.4..837695....6..577....4.2616572.4.9 autosolve
948615732251378964637492518376259841589146273412837695824961357793584126165723489 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (13)
D2: 3,4
A4: 3,8
B6: 1,2
C6: 1,2
E4: 5,9
F4: 2,9
G4: 3,8
I5: 3,8
B7: 2,4
C7: 2,4
D7: 3,9
F9: 3,8
H9: 3,8

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
H1,H3: 1.. / H1 = 1  => 15 pairs (_) / H3 = 1  => 15 pairs (_)
B6,C6: 1.. / B6 = 1  =>  9 pairs (_) / C6 = 1  => 10 pairs (_)
F7,E8: 1.. / F7 = 1  => 18 pairs (_) / E8 = 1  => 17 pairs (_)
G7,G8: 1.. / G7 = 1  => 17 pairs (_) / G8 = 1  => 18 pairs (_)
F7,G7: 1.. / F7 = 1  => 18 pairs (_) / G7 = 1  => 17 pairs (_)
E8,G8: 1.. / E8 = 1  => 17 pairs (_) / G8 = 1  => 18 pairs (_)
D3,F3: 2.. / D3 = 2  =>  0 pairs (X) / F3 = 2  => 11 pairs (_)
B6,C6: 2.. / B6 = 2  => 10 pairs (_) / C6 = 2  =>  9 pairs (_)
D4,F4: 2.. / D4 = 2  => 11 pairs (_) / F4 = 2  =>  0 pairs (X)
B7,C7: 2.. / B7 = 2  =>  9 pairs (_) / C7 = 2  => 10 pairs (_)
B6,B7: 2.. / B6 = 2  => 10 pairs (_) / B7 = 2  =>  9 pairs (_)
C6,C7: 2.. / C6 = 2  =>  9 pairs (_) / C7 = 2  => 10 pairs (_)
D3,D4: 2.. / D3 = 2  =>  0 pairs (X) / D4 = 2  => 11 pairs (_)
F3,F4: 2.. / F3 = 2  => 11 pairs (_) / F4 = 2  =>  0 pairs (X)
G4,I5: 3.. / G4 = 3  =>  0 pairs (X) / I5 = 3  =>  0 pairs (_)
A4,G4: 3.. / A4 = 3  =>  0 pairs (*) / G4 = 3  =>  0 pairs (X)
F9,H9: 3.. / F9 = 3  =>  0 pairs (*) / H9 = 3  =>  0 pairs (X)
B1,C1: 4.. / B1 = 4  =>  9 pairs (_) / C1 = 4  => 10 pairs (_)
D2,D3: 4.. / D2 = 4  => 13 pairs (_) / D3 = 4  => 15 pairs (_)
I2,I3: 4.. / I2 = 4  => 15 pairs (_) / I3 = 4  => 13 pairs (_)
B7,C7: 4.. / B7 = 4  => 10 pairs (_) / C7 = 4  =>  9 pairs (_)
D2,I2: 4.. / D2 = 4  => 13 pairs (_) / I2 = 4  => 15 pairs (_)
D3,I3: 4.. / D3 = 4  => 15 pairs (_) / I3 = 4  => 13 pairs (_)
B1,B7: 4.. / B1 = 4  =>  9 pairs (_) / B7 = 4  => 10 pairs (_)
C1,C7: 4.. / C1 = 4  => 10 pairs (_) / C7 = 4  =>  9 pairs (_)
D4,E4: 5.. / D4 = 5  =>  0 pairs (X) / E4 = 5  => 13 pairs (_)
D8,E8: 5.. / D8 = 5  => 13 pairs (_) / E8 = 5  =>  0 pairs (X)
D4,D8: 5.. / D4 = 5  =>  0 pairs (X) / D8 = 5  => 13 pairs (_)
E4,E8: 5.. / E4 = 5  => 13 pairs (_) / E8 = 5  =>  0 pairs (X)
C2,C3: 7.. / C2 = 7  => 15 pairs (_) / C3 = 7  => 13 pairs (_)
E2,E3: 7.. / E2 = 7  => 13 pairs (_) / E3 = 7  => 15 pairs (_)
C2,E2: 7.. / C2 = 7  => 15 pairs (_) / E2 = 7  => 13 pairs (_)
C3,E3: 7.. / C3 = 7  => 13 pairs (_) / E3 = 7  => 15 pairs (_)
G4,I5: 8.. / G4 = 8  =>  0 pairs (*) / I5 = 8  =>  0 pairs (X)
A4,G4: 8.. / A4 = 8  =>  0 pairs (X) / G4 = 8  =>  0 pairs (_)
F9,H9: 8.. / F9 = 8  =>  0 pairs (X) / H9 = 8  =>  0 pairs (_)
B5,C5: 9.. / B5 = 9  => 15 pairs (_) / C5 = 9  => 15 pairs (_)
A1,A7: 9.. / A1 = 9  => 16 pairs (_) / A7 = 9  =>  0 pairs (X)
* DURATION: 0:01:11.384271  START: 05:02:05.095481  END: 05:03:16.479752 2017-05-04
* CP COUNT: (38)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A4,B6,B7,C6,C7,D2,D7,E4,F4,F9,G4,H9,I5)
* ...6.57.225....96.6.....5...76....415..14627.4..837695....6..577....4.2616572.4.9
* PAIR D2: 3,4 BLK 2
D3: 3,4,2,9                              # reduction candidate for 3,4
D3: 2,9 => CTR
* 9..685712258471963617293584876..23415..1462784..837695....691577...14826165728439
D3: 3,4                                  # 15 pairs
* PAIR D2: 3,4 ROW 2
I2: 3,4,8                                # reduction candidate for 3,4
I2: 8 => CTR
* ...6.57.22534719686.73.25143762598415..1462734..837695...96..577....4.26165723489
I2: 3,4                                  # 20 pairs
* PAIR A4: 3,8 BLK 4
B5: 3,8,9                                # reduction candidate for 3,8
B5: 3,8                                  # 15 pairs
C5: 3,8,9                                # reduction candidate for 3,8
C5: 3,8                                  # 15 pairs
* PAIR A4: 3,8 COL A
A1: 3,8,9                                # reduction candidate for 3,8
A1: 3,8 => CTR
* ...6.57.225.4..96.6.....5.4.76...3415..1462784..8376959..3618577....4126165728439
A1: 9                                    # 16 pairs
A7: 3,8,9                                # reduction candidate for 3,8
A7: 3,8                                  # 16 pairs
* PAIR E4: 5,9 BLK 5
D4: 5,9,2                                # reduction candidate for 5,9
D4: 5,9 => CTR
* 9..685712258471963617293584876..23415..1462784..837695....691577...14826165728439
D4: 2                                    # 11 pairs
* PAIR E4: 5,9 COL E
E8: 5,9,1,8                              # reduction candidate for 5,9
E8: 5,9 => CTR
* ...6.57.225...396.6.....5.3.76...3415..1462784..837695....618577....4126165728439
E8: 1,8                                  # 16 pairs
* PAIR F4: 2,9 BLK 5
D4: 2,9,5                                # reduction candidate for 2,9
D4: 5 => CTR
* ...6.57.225.4.39686..2.9514.76592.415..14627.4..837695....61.577...54126165728439
D4: 2,9                                  # 13 pairs
* PAIR F4: 2,9 COL F
F3: 2,9,1,3,8                            # reduction candidate for 2,9
F3: 1,3,8 => CTR
* 9..68571225.47.9636.7293584.769523415..1462784..837695....691577...14.26165728439
F3: 2,9                                  # 14 pairs
* PAIR G4: 3,8 COL G
G7: 3,8,1                                # reduction candidate for 3,8
G7: 3,8                                  # 18 pairs
G8: 3,8,1                                # reduction candidate for 3,8
G8: 3,8                                  # 17 pairs
* PAIR I5: 3,8 ROW 5
B5: 3,8,9                                # reduction candidate for 3,8
B5: 3,8                                  # 15 pairs
C5: 3,8,9                                # reduction candidate for 3,8
C5: 3,8                                  # 15 pairs
* PAIR I5: 3,8 COL I
I2: 3,8,4                                # reduction candidate for 3,8
I2: 3,8                                  # 13 pairs
I3: 3,8,4                                # reduction candidate for 3,8
I3: 3,8                                  # 15 pairs
* PAIR D7: 3,9 BLK 8
F7: 3,9,1,8                              # reduction candidate for 3,9
F7: 3,9 => CTR
* ...6.57.225....96.6.....5...76.5.3415..1462784..8376958...6.1577...14.26165728439
F7: 1,8                                  # 15 pairs
D8: 3,9,5                                # reduction candidate for 3,9
D8: 3,9 => CTR
* ...6.57.225.4.39686..2.9514.76592.415..14627.4..837695....61.577...54126165728439
D8: 5                                    # 13 pairs
* PAIR D7: 3,9 ROW 7
A7: 3,9,8                                # reduction candidate for 3,9
A7: 8 => SOLVED
* 948615732251378964637492518376259841589146273412837695824961357793584126165723489
A7: 3,9                                  # 19 pairs
* PAIR D7: 3,9 COL D
D3: 3,9,2,4                              # reduction candidate for 3,9
D3: 2,4                                  # 14 pairs
D3: 3,9                                  # 12 pairs
* PAIR F9: 3,8 BLK 8
F7: 3,8,1,9                              # reduction candidate for 3,8
F7: 3,8                                  # 17 pairs
F7: 1,9                                  # 14 pairs
* PAIR F9: 3,8 COL F
F2: 3,8,1                                # reduction candidate for 3,8
F2: 3,8                                  # 17 pairs
F3: 3,8,1,2,9                            # reduction candidate for 3,8
F3: 3,8 => CTR
* 9..68571225.4719636.7293584.769523415..1462784.1837695....691577...14.26165728439
F3: 1,2,9                                # 13 pairs
* PAIR H9: 3,8 BLK 9
G7: 3,8,1                                # reduction candidate for 3,8
G7: 3,8                                  # 18 pairs
G8: 3,8,1                                # reduction candidate for 3,8
G8: 3,8                                  # 17 pairs
* PAIR H9: 3,8 COL H
H1: 3,8,1                                # reduction candidate for 3,8
H1: 3,8                                  # 15 pairs
H3: 3,8,1                                # reduction candidate for 3,8
H3: 3,8                                  # 15 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-069-base-pr-000.dot
* REASONING
* DIS # D3: 2,9 => CTR => D3: 3,4
* DIS # I2: 8 => CTR => I2: 3,4
* DIS # A1: 3,8 => CTR => A1: 9
* DIS # D4: 5,9 => CTR => D4: 2
* DIS # E8: 5,9 => CTR => E8: 1,8
* DIS # D4: 5 => CTR => D4: 2,9
* DIS # F3: 1,3,8 => CTR => F3: 2,9
* DIS # F7: 3,9 => CTR => F7: 1,8
* DIS # D8: 3,9 => CTR => D8: 5
* PRF # A7: 8 => SOL
* DIS # F3: 3,8 => CTR => F3: 1,2,9
* CNT  11 HDP CHAINS /  40 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A4,B6,B7,C6,C7,D2,D7,E4,F4,F9,G4,H9,I5)
* ...6.57.225....96.6.....5...76....415..14627.4..837695....6..577....4.2616572.4.9
* PAIR D2: 3,4 BLK 2
D3: 3,4,2,9                              # reduction candidate for 3,4
D3: 2,9 => CTR
* 9..685712258471963617293584876..23415..1462784..837695....691577...14826165728439
* PAIR D2: 3,4 ROW 2
I2: 3,4,8                                # reduction candidate for 3,4
I2: 8 => CTR
* 9..6.57.225.47.968687392514.762598415.81462734..8376958..96..577.9584126165723489
* PAIR RESTART
* PAIR A4: 3,8 BLK 4
B5: 3,8,9                                # reduction candidate for 3,8
B5: 3,8                                  # 19 pairs
C5: 3,8,9                                # reduction candidate for 3,8
C5: 3,8                                  # 19 pairs
* PAIR G4: 3,8 COL G
G7: 3,8,1                                # reduction candidate for 3,8
G7: 3,8 => SOLVED
* 948615732251378964637492518376259841589146273412837695824961357793584126165723489
* DURATION: 0:00:09.892202  START: 05:03:57.517545  END: 05:04:07.409747 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-069-base-pr-001.dot
* REASONING
* DIS # D3: 2,9 => CTR => D3: 3,4
* DIS D3: 3,4 # I2: 8 => CTR => I2: 3,4
* PRF D3: 3,4 + I2: 3,4 # G7: 3,8 => SOL
* STA D3: 3,4 + I2: 3,4 + G7: 3,8
* CNT   3 HDP CHAINS /   7 HYP OPENED

Header Info

Top 500 Minimum 17 069

solution: 948615732251378964637492518376259841589146273412837695824961357793584126165723489
info: 1448     FNBTHWX  S8.f     10910

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

Solution

position: 948615732251378964637492518376259841589146273412837695824961357793584126165723489 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 # D3: 3,4 => UNS
* DIS # D3: 2,9 => CTR => D3: 3,4
* INC # I2: 3,4 => UNS
* DIS # I2: 8 => CTR => I2: 3,4
* INC # B5: 3,8 => UNS
* INC # C5: 3,8 => UNS
* DIS # A1: 3,8 => CTR => A1: 9
* INC # A1: 9 => UNS
* INC # A7: 3,8 => UNS
* DIS # D4: 5,9 => CTR => D4: 2
* INC # D4: 2 => UNS
* DIS # E8: 5,9 => CTR => E8: 1,8
* INC # E8: 1,8 => UNS
* INC # D4: 2,9 => UNS
* DIS # D4: 5 => CTR => D4: 2,9
* INC # F3: 2,9 => UNS
* DIS # F3: 1,3,8 => CTR => F3: 2,9
* INC # G7: 3,8 => UNS
* INC # G8: 3,8 => UNS
* INC # B5: 3,8 => UNS
* INC # C5: 3,8 => UNS
* INC # I2: 3,8 => UNS
* INC # I3: 3,8 => UNS
* DIS # F7: 3,9 => CTR => F7: 1,8
* INC # F7: 1,8 => UNS
* DIS # D8: 3,9 => CTR => D8: 5
* INC # D8: 5 => UNS
* INC # A7: 3,9 => UNS
* PRF # A7: 8 => SOL
* INC # D3: 3,9 => UNS
* INC # D3: 2,4 => UNS
* INC # F7: 3,8 => UNS
* INC # F7: 1,9 => UNS
* INC # F2: 3,8 => UNS
* DIS # F3: 3,8 => CTR => F3: 1,2,9
* INC # F3: 1,2,9 => UNS
* INC # G7: 3,8 => UNS
* INC # G8: 3,8 => UNS
* INC # H1: 3,8 => UNS
* INC # H3: 3,8 => UNS
* CNT  40 HDP CHAINS /  40 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # D3: 3,4 => UNS
* DIS # D3: 2,9 => CTR => D3: 3,4
* INC D3: 3,4 # I2: 3,4 => UNS
* DIS D3: 3,4 # I2: 8 => CTR => I2: 3,4
* INC D3: 3,4 + I2: 3,4 # B5: 3,8 => UNS
* INC D3: 3,4 + I2: 3,4 # C5: 3,8 => UNS
* PRF D3: 3,4 + I2: 3,4 # G7: 3,8 => SOL
* STA D3: 3,4 + I2: 3,4 + G7: 3,8
* CNT   7 HDP CHAINS /   7 HYP OPENED