Analysis of xx-top500-246-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 1...7..4.....385.............8...6.2...9...1..3........2....3..9..1.............8 initial

Autosolve

position: 153279846.9..385218.2.1.937.183..6922..98..13.39.21.85.218..3.998.1.32.43...921.8 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # D3: 4,6 => CTR => D3: 5
* DIS # B5: 4,6 => CTR => B5: 7
* DIS # D3: 4,6 => CTR => D3: 5
* DIS # D6: 7 => CTR => D6: 4,6
* DIS # F4: 4,5 => CTR => F4: 7
* PRF # F5: 4,5 => SOL
* DIS # A4: 7 => CTR => A4: 4,5
* DIS # C5: 4,7 => CTR => C5: 5,6
* DIS # F5: 4,7 => CTR => F5: 5,6
* PRF # A6: 4,7 => SOL
* DIS # E7: 4 => CTR => E7: 5,6
* CNT  11 HDP CHAINS /  35 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: 4,6 => CTR => D3: 5
* DIS D3: 5 # B5: 4,6 => CTR => B5: 7
* PRF D3: 5 + B5: 7 # C2: 7 => SOL
* STA D3: 5 + B5: 7 + C2: 7
* CNT   3 HDP CHAINS /   6 HYP OPENED

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

Details

Positions

1...7..4.....385.............8...6.2...9...1..3........2....3..9..1.............8 initial
153279846.9..385218.2.1.937.183..6922..98..13.39.21.85.218..3.998.1.32.43...921.8 autosolve
153279846697438521842516937518347692276985413439621785721854369985163274364792158 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (6)
B3: 4,6
D2: 4,6
E4: 4,5
G5: 4,7
G6: 4,7
E8: 5,6

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
G5,G6: 4.. / G5 = 4  => 14 pairs (_) / G6 = 4  =>  0 pairs (X)
E4,E7: 4.. / E4 = 4  => 12 pairs (_) / E7 = 4  =>  0 pairs (X)
D3,F3: 5.. / D3 = 5  =>  8 pairs (_) / F3 = 5  =>  0 pairs (X)
A4,C5: 5.. / A4 = 5  =>  0 pairs (*) / C5 = 5  =>  0 pairs (X)
C5,F5: 5.. / C5 = 5  => 12 pairs (_) / F5 = 5  =>  0 pairs (*)
A4,A7: 5.. / A4 = 5  =>  0 pairs (*) / A7 = 5  =>  0 pairs (X)
D3,D9: 5.. / D3 = 5  =>  8 pairs (_) / D9 = 5  =>  0 pairs (X)
F5,D6: 6.. / F5 = 6  => 16 pairs (_) / D6 = 6  =>  0 pairs (*)
E7,E8: 6.. / E7 = 6  => 13 pairs (_) / E8 = 6  =>  8 pairs (_)
A6,D6: 6.. / A6 = 6  => 16 pairs (_) / D6 = 6  =>  0 pairs (*)
F3,F5: 6.. / F3 = 6  =>  0 pairs (*) / F5 = 6  =>  0 pairs (X)
A2,C2: 7.. / A2 = 7  => 16 pairs (_) / C2 = 7  => 10 pairs (_)
G5,G6: 7.. / G5 = 7  =>  0 pairs (X) / G6 = 7  => 14 pairs (_)
F7,D9: 7.. / F7 = 7  =>  0 pairs (X) / D9 = 7  => 14 pairs (_)
A4,F4: 7.. / A4 = 7  =>  0 pairs (X) / F4 = 7  => 14 pairs (_)
C8,H8: 7.. / C8 = 7  => 16 pairs (_) / H8 = 7  =>  9 pairs (_)
B5,B9: 7.. / B5 = 7  => 14 pairs (_) / B9 = 7  =>  0 pairs (X)
D6,D9: 7.. / D6 = 7  =>  0 pairs (X) / D9 = 7  => 14 pairs (_)
* DURATION: 0:00:31.172884  START: 11:12:07.963884  END: 11:12:39.136768 2017-05-04
* CP COUNT: (18)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B3,D2,E4,E8,G5,G6)
* 153279846.9..385218.2.1.937.183..6922..98..13.39.21.85.218..3.998.1.32.43...921.8
* PAIR B3: 4,6 BLK 1
A2: 4,6,7                                # reduction candidate for 4,6
A2: 4,6                                  # 10 pairs
C2: 4,6,7                                # reduction candidate for 4,6
C2: 4,6                                  # 16 pairs
* PAIR B3: 4,6 ROW 3
D3: 4,6,5                                # reduction candidate for 4,6
D3: 4,6 => CTR
* 153279846.9..385218.2.1593771835469224598671363972148552184736998716325436.592178
D3: 5                                    #  8 pairs
F3: 4,6,5                                # reduction candidate for 4,6
F3: 4,6                                  #  8 pairs
* PAIR B3: 4,6 COL B
B5: 4,6,7                                # reduction candidate for 4,6
B5: 4,6 => CTR
* 153279846.9..385218.2.1.9377183..6922.59867136397214855218473699861.327437..921.8
B5: 7                                    # 14 pairs
B9: 4,6,7                                # reduction candidate for 4,6
B9: 4,6                                  # 14 pairs
* PAIR D2: 4,6 BLK 2
D3: 4,6,5                                # reduction candidate for 4,6
D3: 4,6 => CTR
* 153279846.9..385218.2.1593771835469224598671363972148552184736998716325436.592178
D3: 5                                    #  8 pairs
F3: 4,6,5                                # reduction candidate for 4,6
F3: 4,6                                  #  8 pairs
* PAIR D2: 4,6 ROW 2
A2: 4,6,7                                # reduction candidate for 4,6
A2: 4,6                                  # 10 pairs
C2: 4,6,7                                # reduction candidate for 4,6
C2: 4,6                                  # 16 pairs
* PAIR D2: 4,6 COL D
D6: 4,6,7                                # reduction candidate for 4,6
D6: 7 => CTR
* 153279846.9..385218.2.1.9377183..69224598671363972148552184736998.16325437..921.8
D6: 4,6                                  # 14 pairs
* PAIR E4: 4,5 BLK 5
F4: 4,5,7                                # reduction candidate for 4,5
F4: 4,5 => CTR
* 153279846.9..385218.2.1.9377183..6922.598..13.39.21.855218..3.998.1.32.4374592168
F4: 7                                    # 14 pairs
F5: 4,5,6,7                              # reduction candidate for 4,5
F5: 4,5 => SOLVED
* 153279846697438521842516937518347692276985413439621785721854369985163274364792158
F5: 6,7                                  # 13 pairs
* PAIR E4: 4,5 ROW 4
A4: 4,5,7                                # reduction candidate for 4,5
A4: 7 => CTR
* 153279846.9..385218.2.1.9377183..6922.598..13.39.21.855218..3.998.1.32.4374592168
A4: 4,5                                  # 14 pairs
* PAIR E4: 4,5 COL E
E7: 4,5,6                                # reduction candidate for 4,5
E7: 6                                    # 13 pairs
E7: 4,5                                  #  8 pairs
* PAIR G5: 4,7 ROW 5
B5: 4,7,6                                # reduction candidate for 4,7
B5: 4,7                                  #  9 pairs
C5: 4,7,5,6                              # reduction candidate for 4,7
C5: 4,7 => CTR
* 153279846.9..385218.2.1.9375183476922..985.13.39621.85.218.43.998.1.32.43..7921.8
C5: 5,6                                  #  7 pairs
F5: 4,7,5,6                              # reduction candidate for 4,7
F5: 4,7 => CTR
* 153279846.9..385218.2.16937.183..6922.598..13.39621.855218..3.998.1.32.43..792158
F5: 5,6                                  #  7 pairs
* PAIR G6: 4,7 ROW 6
A6: 4,7,6                                # reduction candidate for 4,7
A6: 4,7 => SOLVED
* 153279846697438521842516937518347692276985413439621785721854369985163274364792158
A6: 6                                    # 16 pairs
D6: 4,7,6                                # reduction candidate for 4,7
D6: 4,7                                  # 16 pairs
* PAIR E8: 5,6 BLK 8
E7: 5,6,4                                # reduction candidate for 5,6
E7: 4 => CTR
* 15327984679..385218.2.1593741835.6922.598..13.39.21.855218473699871632543..592178
E7: 5,6                                  # 12 pairs
* PAIR E8: 5,6 ROW 8
C8: 5,6,7                                # reduction candidate for 5,6
C8: 5,6                                  #  9 pairs
H8: 5,6,7                                # reduction candidate for 5,6
H8: 5,6                                  # 16 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-246-base-pr-000.dot
* REASONING
* DIS # D3: 4,6 => CTR => D3: 5
* DIS # B5: 4,6 => CTR => B5: 7
* DIS # D3: 4,6 => CTR => D3: 5
* DIS # D6: 7 => CTR => D6: 4,6
* DIS # F4: 4,5 => CTR => F4: 7
* PRF # F5: 4,5 => SOL
* DIS # A4: 7 => CTR => A4: 4,5
* DIS # C5: 4,7 => CTR => C5: 5,6
* DIS # F5: 4,7 => CTR => F5: 5,6
* PRF # A6: 4,7 => SOL
* DIS # E7: 4 => CTR => E7: 5,6
* CNT  11 HDP CHAINS /  35 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B3,D2,E4,E8,G5,G6)
* 153279846.9..385218.2.1.937.183..6922..98..13.39.21.85.218..3.998.1.32.43...921.8
* PAIR B3: 4,6 BLK 1
A2: 4,6,7                                # reduction candidate for 4,6
A2: 4,6                                  # 10 pairs
C2: 4,6,7                                # reduction candidate for 4,6
C2: 4,6                                  # 16 pairs
* PAIR B3: 4,6 ROW 3
D3: 4,6,5                                # reduction candidate for 4,6
D3: 4,6 => CTR
* 153279846.9..385218.2.1593771835469224598671363972148552184736998716325436.592178
* RESTART
* PAIR B3: 4,6 COL B
B5: 4,6,7                                # reduction candidate for 4,6
B5: 4,6 => CTR
* 153279846.9.638521862514937.1834.69224.9867136397214854218.73.998.1.327437.4921.8
* RESTART
* PAIR RESTART
* PAIR B3: 4,6 BLK 1
C2: 4,6,7                                # reduction candidate for 4,6
C2: 7 => SOLVED
* 153279846697438521842516937518347692276985413439621785721854369985163274364792158
* DURATION: 0:00:07.140607  START: 11:13:12.307314  END: 11:13:19.447921 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-246-base-pr-001.dot
* REASONING
* DIS # D3: 4,6 => CTR => D3: 5
* DIS D3: 5 # B5: 4,6 => CTR => B5: 7
* PRF D3: 5 + B5: 7 # C2: 7 => SOL
* STA D3: 5 + B5: 7 + C2: 7
* CNT   3 HDP CHAINS /   6 HYP OPENED

Header Info

Top 500 Minimum 17 246

solution: 153279846697438521842516937518347692276985413439621785721854369985163274364792158
info: 2071     FNBWXY   S8.f     25384

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

Solution

position: 153279846697438521842516937518347692276985413439621785721854369985163274364792158 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 # A2: 4,6 => UNS
* INC # C2: 4,6 => UNS
* DIS # D3: 4,6 => CTR => D3: 5
* INC # D3: 5 => UNS
* INC # F3: 4,6 => UNS
* DIS # B5: 4,6 => CTR => B5: 7
* INC # B5: 7 => UNS
* INC # B9: 4,6 => UNS
* DIS # D3: 4,6 => CTR => D3: 5
* INC # D3: 5 => UNS
* INC # F3: 4,6 => UNS
* INC # A2: 4,6 => UNS
* INC # C2: 4,6 => UNS
* INC # D6: 4,6 => UNS
* DIS # D6: 7 => CTR => D6: 4,6
* DIS # F4: 4,5 => CTR => F4: 7
* INC # F4: 7 => UNS
* PRF # F5: 4,5 => SOL
* INC # F5: 6,7 => UNS
* INC # A4: 4,5 => UNS
* DIS # A4: 7 => CTR => A4: 4,5
* INC # E7: 4,5 => UNS
* INC # E7: 6 => UNS
* INC # B5: 4,7 => UNS
* DIS # C5: 4,7 => CTR => C5: 5,6
* INC # C5: 5,6 => UNS
* DIS # F5: 4,7 => CTR => F5: 5,6
* INC # F5: 5,6 => UNS
* PRF # A6: 4,7 => SOL
* INC # A6: 6 => UNS
* INC # D6: 4,7 => UNS
* INC # E7: 5,6 => UNS
* DIS # E7: 4 => CTR => E7: 5,6
* INC # C8: 5,6 => UNS
* INC # H8: 5,6 => UNS
* CNT  35 HDP CHAINS /  35 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # A2: 4,6 => UNS
* INC # C2: 4,6 => UNS
* DIS # D3: 4,6 => CTR => D3: 5
* DIS D3: 5 # B5: 4,6 => CTR => B5: 7
* INC D3: 5 + B5: 7 # C2: 4,6 => UNS
* PRF D3: 5 + B5: 7 # C2: 7 => SOL
* STA D3: 5 + B5: 7 + C2: 7
* CNT   6 HDP CHAINS /   6 HYP OPENED