Analysis of xx-top500-314-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 2......4....6..3.....1......3.....7.....7..2...1......78..2.........56.....3..1.. initial

Autosolve

position: 21..3.746..76.231.36.1.725..32.16.7.6...73.21.712...63786921.3.143785692.2.364187 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # A4: 4,8 => CTR => A4: 5,9
* PRF # E2: 4 => SOL
* PRF # D4: 5,8 => SOL
* PRF # E2: 4,9 => SOL
* DIS # E2: 5 => CTR => E2: 4,9
* DIS # A4: 4,8 => CTR => A4: 5,9
* DIS # G5: 4,8 => CTR => G5: 5,9
* DIS # A4: 4,8 => CTR => A4: 5,9
* DIS # G5: 4,8 => CTR => G5: 5,9
* PRF # E2: 4 => SOL
* DIS # G4: 4,5 => CTR => G4: 8,9
* PRF # G5: 4,5 => SOL
* PRF # A4: 4,5 => SOL
* DIS # A4: 4,8 => CTR => A4: 5,9
* DIS # G4: 4,5 => CTR => G4: 8,9
* PRF # G5: 4,5 => SOL
* CNT  16 HDP CHAINS /  37 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 # A4: 4,8 => CTR => A4: 5,9
* DIS A4: 5,9 # E2: 5,9 => CTR => E2: 4
* PRF A4: 5,9 + E2: 4 => SOL
* STA A4: 5,9 + E2: 4
* CNT   3 HDP CHAINS /   2 HYP OPENED

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

Details

Positions

2......4....6..3.....1......3.....7.....7..2...1......78..2.........56.....3..1.. initial
21..3.746..76.231.36.1.725..32.16.7.6...73.21.712...63786921.3.143785692.2.364187 autosolve
219538746857642319364197258532816974698473521471259863786921435143785692925364187 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (18)
C1: 5,9
A2: 4,8
B2: 5,9
C3: 4,8
D1: 5,8
F1: 8,9
E3: 4,9
I2: 8,9
I3: 8,9
B5: 5,9
C5: 4,8
E6: 5,9
F6: 8,9
I4: 4,5
A9: 5,9
C9: 5,9
G7: 4,5
I7: 4,5

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
A2,C3: 4.. / A2 = 4  => 15 pairs (_) / C3 = 4  =>  0 pairs (*)
E2,E3: 4.. / E2 = 4  =>  0 pairs (*) / E3 = 4  =>  0 pairs (X)
D4,D5: 4.. / D4 = 4  => 19 pairs (_) / D5 = 4  =>  0 pairs (*)
G7,I7: 4.. / G7 = 4  =>  0 pairs (*) / I7 = 4  =>  0 pairs (X)
A2,E2: 4.. / A2 = 4  => 15 pairs (_) / E2 = 4  =>  0 pairs (*)
C3,E3: 4.. / C3 = 4  =>  0 pairs (*) / E3 = 4  =>  0 pairs (X)
A6,G6: 4.. / A6 = 4  =>  0 pairs (*) / G6 = 4  =>  0 pairs (X)
C3,C5: 4.. / C3 = 4  =>  0 pairs (*) / C5 = 4  =>  0 pairs (X)
I4,I7: 4.. / I4 = 4  =>  0 pairs (*) / I7 = 4  =>  0 pairs (X)
C1,B2: 5.. / C1 = 5  =>  0 pairs (X) / B2 = 5  =>  0 pairs (_)
D1,E2: 5.. / D1 = 5  =>  0 pairs (*) / E2 = 5  =>  0 pairs (X)
A9,C9: 5.. / A9 = 5  =>  0 pairs (X) / C9 = 5  =>  0 pairs (_)
G7,I7: 5.. / G7 = 5  => 17 pairs (_) / I7 = 5  =>  0 pairs (*)
C1,D1: 5.. / C1 = 5  =>  0 pairs (X) / D1 = 5  =>  0 pairs (_)
B2,E2: 5.. / B2 = 5  =>  0 pairs (*) / E2 = 5  =>  0 pairs (X)
B2,B5: 5.. / B2 = 5  =>  0 pairs (*) / B5 = 5  =>  0 pairs (X)
C1,C9: 5.. / C1 = 5  =>  0 pairs (X) / C9 = 5  =>  0 pairs (_)
E2,E6: 5.. / E2 = 5  =>  0 pairs (X) / E6 = 5  =>  0 pairs (_)
I4,I7: 5.. / I4 = 5  => 17 pairs (_) / I7 = 5  =>  0 pairs (*)
A2,C3: 8.. / A2 = 8  =>  0 pairs (*) / C3 = 8  =>  0 pairs (X)
D1,F1: 8.. / D1 = 8  =>  0 pairs (X) / F1 = 8  =>  0 pairs (_)
I2,I3: 8.. / I2 = 8  => 15 pairs (_) / I3 = 8  =>  0 pairs (*)
A2,I2: 8.. / A2 = 8  =>  0 pairs (*) / I2 = 8  =>  0 pairs (X)
C3,I3: 8.. / C3 = 8  => 15 pairs (_) / I3 = 8  =>  0 pairs (*)
C3,C5: 8.. / C3 = 8  => 15 pairs (_) / C5 = 8  =>  0 pairs (*)
F1,F6: 8.. / F1 = 8  =>  0 pairs (*) / F6 = 8  =>  0 pairs (X)
C1,B2: 9.. / C1 = 9  =>  0 pairs (*) / B2 = 9  =>  0 pairs (X)
I2,I3: 9.. / I2 = 9  =>  0 pairs (*) / I3 = 9  =>  0 pairs (X)
A4,B5: 9.. / A4 = 9  =>  0 pairs (X) / B5 = 9  =>  0 pairs (_)
E6,F6: 9.. / E6 = 9  =>  0 pairs (X) / F6 = 9  =>  0 pairs (_)
G4,G5: 9.. / G4 = 9  =>  0 pairs (*) / G5 = 9  =>  0 pairs (X)
A9,C9: 9.. / A9 = 9  =>  0 pairs (*) / C9 = 9  =>  0 pairs (X)
C1,F1: 9.. / C1 = 9  =>  0 pairs (*) / F1 = 9  =>  0 pairs (X)
E3,I3: 9.. / E3 = 9  =>  0 pairs (*) / I3 = 9  =>  0 pairs (X)
A4,G4: 9.. / A4 = 9  =>  0 pairs (X) / G4 = 9  =>  0 pairs (_)
B5,G5: 9.. / B5 = 9  =>  0 pairs (*) / G5 = 9  =>  0 pairs (X)
A4,A9: 9.. / A4 = 9  =>  0 pairs (X) / A9 = 9  =>  0 pairs (_)
B2,B5: 9.. / B2 = 9  =>  0 pairs (X) / B5 = 9  =>  0 pairs (_)
C1,C9: 9.. / C1 = 9  =>  0 pairs (*) / C9 = 9  =>  0 pairs (X)
F1,F6: 9.. / F1 = 9  =>  0 pairs (X) / F6 = 9  =>  0 pairs (_)
* DURATION: 0:01:19.328732  START: 13:43:07.701551  END: 13:44:27.030283 2017-05-04
* CP COUNT: (40)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A2,A9,B2,B5,C1,C3,C5,C9,D1,E3,E6,F1,F6,G7,I2,I3,I4,I7)
* 21..3.746..76.231.36.1.725..32.16.7.6...73.21.712...63786921.3.143785692.2.364187
* PAIR A2: 4,8 COL A
A4: 4,8,5,9                              # reduction candidate for 4,8
A4: 4,8 => CTR
* 21..3.746..76.231.36.1.725..32.1697.69..73.21571298463786921534143785692925364187
A4: 5,9                                  # 20 pairs
A6: 4,8,5                                # reduction candidate for 4,8
A6: 4,8                                  # 20 pairs
* PAIR B2: 5,9 ROW 2
E2: 5,9,4                                # reduction candidate for 5,9
E2: 4 => SOLVED
* 219538746857642319364197258532816974698473521471259863786921435143785692925364187
E2: 5,9                                  # 15 pairs
* PAIR D1: 5,8 COL D
D4: 5,8,4                                # reduction candidate for 5,8
D4: 5,8 => SOLVED
* 219538746857642319364197258532816974698473521471259863786921435143785692925364187
D4: 4                                    # 19 pairs
D5: 5,8,4                                # reduction candidate for 5,8
D5: 5,8                                  # 19 pairs
* PAIR E3: 4,9 BLK 2
E2: 4,9,5                                # reduction candidate for 4,9
E2: 4,9 => SOLVED
* 219538746857642319364197258532816974698473521471259863786921435143785692925364187
E2: 5 => CTR
* 21..3.7464.7652318368147259.32.16.7.654873.21.712...63786921.3.143785692.2.364187
* PAIR B5: 5,9 BLK 4
A4: 5,9,4,8                              # reduction candidate for 5,9
A4: 4,8 => CTR
* 21..3.746..76.231.36.1.725..32.1697.69..73.21571298463786921534143785692925364187
A4: 5,9                                  # 20 pairs
* PAIR B5: 5,9 ROW 5
G5: 5,9,4,8                              # reduction candidate for 5,9
G5: 4,8 => CTR
* 21..3.746..76.231.36.1.725..32.1697.69.573.21.71298.63786921.3.143785692925364187
G5: 5,9                                  # 20 pairs
* PAIR C5: 4,8 BLK 4
A4: 4,8,5,9                              # reduction candidate for 4,8
A4: 4,8 => CTR
* 21..3.746..76.231.36.1.725..32.1697.69..73.21571298463786921534143785692925364187
A4: 5,9                                  # 20 pairs
A6: 4,8,5                                # reduction candidate for 4,8
A6: 4,8                                  # 20 pairs
* PAIR C5: 4,8 ROW 5
D5: 4,8,5                                # reduction candidate for 4,8
D5: 4,8                                  # 20 pairs
G5: 4,8,5,9                              # reduction candidate for 4,8
G5: 4,8 => CTR
* 21..3.746..76.231.36.1.725..32.1697.69.573.21.71298.63786921.3.143785692925364187
G5: 5,9                                  # 20 pairs
* PAIR E6: 5,9 COL E
E2: 5,9,4                                # reduction candidate for 5,9
E2: 4 => SOLVED
* 219538746857642319364197258532816974698473521471259863786921435143785692925364187
E2: 5,9                                  # 15 pairs
* PAIR I4: 4,5 BLK 6
G4: 4,5,8,9                              # reduction candidate for 4,5
G4: 4,5 => CTR
* 21..3.746..76.231.36.1.725.932816.7.65.47392147125..63786921.3.143785692.2.364187
G4: 8,9                                  # 19 pairs
G5: 4,5,8,9                              # reduction candidate for 4,5
G5: 4,5 => SOLVED
* 219538746857642319364197258532816974698473521471259863786921435143785692925364187
G5: 8,9                                  # 19 pairs
G6: 4,5,8                                # reduction candidate for 4,5
G6: 4,5                                  # 21 pairs
* PAIR I4: 4,5 ROW 4
A4: 4,5,8,9                              # reduction candidate for 4,5
A4: 4,5 => SOLVED
* 219538746857642319364197258532816974698473521471259863786921435143785692925364187
A4: 8,9                                  # 19 pairs
D4: 4,5,8                                # reduction candidate for 4,5
D4: 4,5                                  # 21 pairs
* PAIR A9: 5,9 COL A
A4: 5,9,4,8                              # reduction candidate for 5,9
A4: 4,8 => CTR
* 21..3.746..76.231.36.1.725..32.1697.69..73.21571298463786921534143785692925364187
A4: 5,9                                  # 20 pairs
* PAIR G7: 4,5 COL G
G4: 4,5,8,9                              # reduction candidate for 4,5
G4: 4,5 => CTR
* 21..3.746..76.231.36.1.725.932816.7.65.47392147125..63786921.3.143785692.2.364187
G4: 8,9                                  # 19 pairs
G5: 4,5,8,9                              # reduction candidate for 4,5
G5: 4,5 => SOLVED
* 219538746857642319364197258532816974698473521471259863786921435143785692925364187
G5: 8,9                                  # 19 pairs
G6: 4,5,8                                # reduction candidate for 4,5
G6: 4,5                                  # 21 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-314-base-pr-000.dot
* REASONING
* DIS # A4: 4,8 => CTR => A4: 5,9
* PRF # E2: 4 => SOL
* PRF # D4: 5,8 => SOL
* PRF # E2: 4,9 => SOL
* DIS # E2: 5 => CTR => E2: 4,9
* DIS # A4: 4,8 => CTR => A4: 5,9
* DIS # G5: 4,8 => CTR => G5: 5,9
* DIS # A4: 4,8 => CTR => A4: 5,9
* DIS # G5: 4,8 => CTR => G5: 5,9
* PRF # E2: 4 => SOL
* DIS # G4: 4,5 => CTR => G4: 8,9
* PRF # G5: 4,5 => SOL
* PRF # A4: 4,5 => SOL
* DIS # A4: 4,8 => CTR => A4: 5,9
* DIS # G4: 4,5 => CTR => G4: 8,9
* PRF # G5: 4,5 => SOL
* CNT  16 HDP CHAINS /  37 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A2,A9,B2,B5,C1,C3,C5,C9,D1,E3,E6,F1,F6,G7,I2,I3,I4,I7)
* 21..3.746..76.231.36.1.725..32.16.7.6...73.21.712...63786921.3.143785692.2.364187
* PAIR A2: 4,8 COL A
A4: 4,8,5,9                              # reduction candidate for 4,8
A4: 4,8 => CTR
* 21..3.746..76.231.36.1.725..32.1697.69..73.21571298463786921534143785692925364187
* RESTART
* PAIR RESTART
* PAIR B2: 5,9 ROW 2
E2: 5,9,4                                # reduction candidate for 5,9
E2: 5,9 => CTR
* 2195387464576.2318368147259.32.16.7.6.4.73.218712.9463786921534143785692.2.364187
E2: 4 => SOLVED
* 219538746857642319364197258532816974698473521471259863786921435143785692925364187
* DURATION: 0:00:04.808610  START: 13:45:11.069625  END: 13:45:15.878235 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-314-base-pr-001.dot
* REASONING
* DIS # A4: 4,8 => CTR => A4: 5,9
* DIS A4: 5,9 # E2: 5,9 => CTR => E2: 4
* PRF A4: 5,9 + E2: 4 => SOL
* STA A4: 5,9 + E2: 4
* CNT   3 HDP CHAINS /   2 HYP OPENED

Header Info

Top 500 Minimum 17 314

solution: 219538746857642319364197258532816974698473521471259863786921435143785692925364187
info: 2869     FNBTWX   S8.f     26752

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

Solution

position: 219538746857642319364197258532816974698473521471259863786921435143785692925364187 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 # A4: 4,8 => CTR => A4: 5,9
* INC # A4: 5,9 => UNS
* INC # A6: 4,8 => UNS
* INC # E2: 5,9 => UNS
* PRF # E2: 4 => SOL
* PRF # D4: 5,8 => SOL
* INC # D4: 4 => UNS
* INC # D5: 5,8 => UNS
* PRF # E2: 4,9 => SOL
* DIS # E2: 5 => CTR => E2: 4,9
* INC # A4: 5,9 => UNS
* DIS # A4: 4,8 => CTR => A4: 5,9
* INC # G5: 5,9 => UNS
* DIS # G5: 4,8 => CTR => G5: 5,9
* DIS # A4: 4,8 => CTR => A4: 5,9
* INC # A4: 5,9 => UNS
* INC # A6: 4,8 => UNS
* INC # D5: 4,8 => UNS
* DIS # G5: 4,8 => CTR => G5: 5,9
* INC # G5: 5,9 => UNS
* INC # E2: 5,9 => UNS
* PRF # E2: 4 => SOL
* DIS # G4: 4,5 => CTR => G4: 8,9
* INC # G4: 8,9 => UNS
* PRF # G5: 4,5 => SOL
* INC # G5: 8,9 => UNS
* INC # G6: 4,5 => UNS
* PRF # A4: 4,5 => SOL
* INC # A4: 8,9 => UNS
* INC # D4: 4,5 => UNS
* INC # A4: 5,9 => UNS
* DIS # A4: 4,8 => CTR => A4: 5,9
* DIS # G4: 4,5 => CTR => G4: 8,9
* INC # G4: 8,9 => UNS
* PRF # G5: 4,5 => SOL
* INC # G5: 8,9 => UNS
* INC # G6: 4,5 => UNS
* CNT  37 HDP CHAINS /  37 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # A4: 4,8 => CTR => A4: 5,9
* DIS A4: 5,9 # E2: 5,9 => CTR => E2: 4
* PRF A4: 5,9 + E2: 4 => SOL
* STA A4: 5,9 + E2: 4
* CNT   3 HDP CHAINS /   2 HYP OPENED