Analysis of xx-top500-299-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: .3.6...9.1...8..............2.57.........21........4.87.1.........3...6.4........ initial

Autosolve

position: 23.6...9.1...8....6........824571.3.3968421..5179..4287.1......9.23...6.4.3...... autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # C3: 9 => CTR => C3: 5,8
* DIS # G1: 5,8 => CTR => G1: 7
* PRF # G1: 7 => SOL
* DIS # F2: 4,7 => CTR => F2: 3,5,9
* DIS # H2: 4,7 => CTR => H2: 5
* DIS # I2: 4,7 => CTR => I2: 2,3,5,6
* DIS # C3: 8 => CTR => C3: 5,9
* DIS # F2: 5,9 => CTR => F2: 3,4,7
* DIS # D3: 4,7 => CTR => D3: 1,2
* DIS # F3: 4,7 => CTR => F3: 3,5,9
* PRF # H3: 4,7 => SOL
* PRF # I1: 1,5 => SOL
* DIS # I1: 4,7 => CTR => I1: 1,5
* DIS # H3: 5,7 => CTR => H3: 1,4,8
* DIS # H9: 5,7 => CTR => H9: 1,8
* DIS # I1: 5,7 => CTR => I1: 1,4
* DIS # I2: 5,7 => CTR => I2: 2,3,4,6
* DIS # I8: 5,7 => CTR => I8: 1,4
* DIS # F8: 5,8 => CTR => F8: 4,7
* PRF # G8: 5,8 => SOL
* DIS # G8: 7 => CTR => G8: 5,8
* PRF # I7: 2,4 => SOL
* DIS # D3: 2,4 => CTR => D3: 1,7
* DIS # I8: 1,5 => CTR => I8: 4,7
* PRF # I8: 4,7 => SOL
* CNT  25 HDP CHAINS /  50 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 # C3: 9 => CTR => C3: 5,8
* DIS C3: 5,8 # G1: 5,8 => CTR => G1: 7
* PRF C3: 5,8 + G1: 7 => SOL
* STA C3: 5,8 + G1: 7
* CNT   3 HDP CHAINS /   3 HYP OPENED

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

Details

Positions

.3.6...9.1...8..............2.57.........21........4.87.1.........3...6.4........ initial
23.6...9.1...8....6........824571.3.3968421..5179..4287.1......9.23...6.4.3...... autosolve
238654791149783256675129843824571639396842175517936428761495382982317564453268917 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (14)
C1: 5,8
B2: 4,7
C2: 5,9
B3: 4,7
E1: 1,5
E6: 3,6
F6: 3,6
G4: 6,9
I4: 6,9
H5: 5,7
I5: 5,7
B8: 5,8
D7: 2,4
E8: 1,5

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
E1,D3: 1.. / E1 = 1  =>  0 pairs (X) / D3 = 1  =>  0 pairs (_)
E8,D9: 1.. / E8 = 1  =>  0 pairs (*) / D9 = 1  =>  0 pairs (X)
E1,I1: 1.. / E1 = 1  =>  0 pairs (X) / I1 = 1  =>  0 pairs (_)
E8,I8: 1.. / E8 = 1  =>  0 pairs (*) / I8 = 1  =>  0 pairs (X)
D3,D9: 1.. / D3 = 1  =>  0 pairs (*) / D9 = 1  =>  0 pairs (X)
E1,E8: 1.. / E1 = 1  =>  0 pairs (X) / E8 = 1  =>  0 pairs (_)
H3,H9: 1.. / H3 = 1  =>  0 pairs (X) / H9 = 1  =>  0 pairs (_)
E6,F6: 3.. / E6 = 3  => 13 pairs (_) / F6 = 3  =>  0 pairs (X)
G7,I7: 3.. / G7 = 3  => 14 pairs (_) / I7 = 3  => 14 pairs (_)
E3,E6: 3.. / E3 = 3  =>  0 pairs (X) / E6 = 3  => 13 pairs (_)
B2,B3: 4.. / B2 = 4  => 16 pairs (_) / B3 = 4  => 16 pairs (_)
F1,I1: 4.. / F1 = 4  =>  0 pairs (*) / I1 = 4  =>  0 pairs (X)
F8,I8: 4.. / F8 = 4  =>  0 pairs (X) / I8 = 4  =>  0 pairs (_)
H5,I5: 5.. / H5 = 5  =>  0 pairs (X) / I5 = 5  => 13 pairs (_)
E1,E8: 5.. / E1 = 5  =>  0 pairs (*) / E8 = 5  =>  0 pairs (X)
G2,I2: 6.. / G2 = 6  => 12 pairs (_) / I2 = 6  => 12 pairs (_)
E6,F6: 6.. / E6 = 6  =>  0 pairs (X) / F6 = 6  => 13 pairs (_)
G4,I4: 6.. / G4 = 6  => 12 pairs (_) / I4 = 6  => 12 pairs (_)
B7,B9: 6.. / B7 = 6  => 16 pairs (_) / B9 = 6  => 16 pairs (_)
G2,G4: 6.. / G2 = 6  => 12 pairs (_) / G4 = 6  => 12 pairs (_)
I2,I4: 6.. / I2 = 6  => 12 pairs (_) / I4 = 6  => 12 pairs (_)
B2,B3: 7.. / B2 = 7  => 16 pairs (_) / B3 = 7  => 16 pairs (_)
H5,I5: 7.. / H5 = 7  => 13 pairs (_) / I5 = 7  =>  0 pairs (X)
C1,C3: 8.. / C1 = 8  => 15 pairs (_) / C3 = 8  =>  0 pairs (X)
C1,G1: 8.. / C1 = 8  => 15 pairs (_) / G1 = 8  =>  0 pairs (X)
C2,C3: 9.. / C2 = 9  => 14 pairs (_) / C3 = 9  =>  0 pairs (X)
G4,I4: 9.. / G4 = 9  => 12 pairs (_) / I4 = 9  => 12 pairs (_)
C2,F2: 9.. / C2 = 9  => 14 pairs (_) / F2 = 9  =>  0 pairs (X)
* DURATION: 0:00:40.773241  START: 13:10:43.270682  END: 13:11:24.043923 2017-05-04
* CP COUNT: (28)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B2,B3,B8,C1,C2,D7,E1,E6,E8,F6,G4,H5,I4,I5)
* 23.6...9.1...8....6........824571.3.3968421..5179..4287.1......9.23...6.4.3......
* PAIR C1: 5,8 BLK 1
C3: 5,8,9                                # reduction candidate for 5,8
C3: 9 => CTR
* 238654791175289.4.649137...824571.3.3968421755179634287.14.....9.231..644.37...1.
C3: 5,8                                  # 14 pairs
* PAIR C1: 5,8 ROW 1
G1: 5,8,7                                # reduction candidate for 5,8
G1: 5,8 => CTR
* 23.61..9.1...8....6......1.824571.3.3968421..5179..4287.1......9823547614.31.7...
G1: 7 => SOLVED
* 238654791149783256675129843824571639396842175517936428761495382982317564453268917
* PAIR B2: 4,7 ROW 2
D2: 4,7,2                                # reduction candidate for 4,7
D2: 4,7                                  # 17 pairs
F2: 4,7,3,5,9                            # reduction candidate for 4,7
F2: 4,7 => CTR
* 2386.4791149287.5.6751..842824571.3.3968421755179..4287.14...8.9.231.5644.37...19
F2: 3,5,9                                # 14 pairs
H2: 4,7,5                                # reduction candidate for 4,7
H2: 4,7 => CTR
* 23.654.911..28....6..1.7...824571.3.3968421.75179..4287.14.....9.231.7644.37...1.
H2: 5                                    # 15 pairs
I2: 4,7,2,3,5,6                          # reduction candidate for 4,7
I2: 4,7 => CTR
* 23.6.4.9.1.928365767.195...8245719363968421..5179364287.14.....9.23...644.3......
I2: 2,3,5,6                              # 14 pairs
* PAIR C2: 5,9 BLK 1
C3: 5,9,8                                # reduction candidate for 5,9
C3: 8 => CTR
* 2356148971.9.8....6.8....1.824571.3.3968421755179..4287.14.....98235.7614.31.7...
C3: 5,9                                  # 15 pairs
* PAIR C2: 5,9 ROW 2
F2: 5,9,3,4,7                            # reduction candidate for 5,9
F2: 5,9 => CTR
* 23.654.911.5289...6.9137...824571.3.3968421.75179634287.14.....9.231.7644.37...1.
F2: 3,4,7                                # 15 pairs
* PAIR B3: 4,7 ROW 3
D3: 4,7,1,2                              # reduction candidate for 4,7
D3: 4,7 => CTR
* 23.61..9.1...8....6......1.824571.3.3968421..5179..4287.1......9823547614.31.7...
D3: 1,2                                  # 15 pairs
F3: 4,7,3,5,9                            # reduction candidate for 4,7
F3: 4,7 => CTR
* 2386.47911...8..4.64.1.7...824571.3.3968421..5179..4287.14.....9.231..644.37...1.
F3: 3,5,9                                # 14 pairs
H3: 4,7,1,5,8                            # reduction candidate for 4,7
H3: 4,7 => SOLVED
* 238654791149783256675129843824571639396842175517936428761495382982317564453268917
H3: 1,5,8                                # 14 pairs
I3: 4,7,1,2,3,5                          # reduction candidate for 4,7
I3: 4,7                                  # 18 pairs
* PAIR E1: 1,5 ROW 1
I1: 1,5,4,7                              # reduction candidate for 1,5
I1: 1,5 => SOLVED
* 238654791149783256675129843824571639396842175517936428761495382982317564453268917
I1: 4,7 => CTR
* 23.61..9.1...8....6......1.824571.3.3968421..5179..4287.1......9823547614.31.7...
* PAIR H5: 5,7 COL H
H2: 5,7,4                                # reduction candidate for 5,7
H2: 5,7                                  # 17 pairs
H3: 5,7,1,4,8                            # reduction candidate for 5,7
H3: 5,7 => CTR
* 23865479117.28..4.64.1.7852824571.3.3968421755179..4287.14...8.9.231.5644.37...19
H3: 1,4,8                                # 14 pairs
H9: 5,7,1,8                              # reduction candidate for 5,7
H9: 5,7 => CTR
* 23.61..9.1...8..4.64.....1.824571.3.3968421..5179..4287.14...8.9.235..6.4.31.....
H9: 1,8                                  # 15 pairs
* PAIR I5: 5,7 COL I
I1: 5,7,1,4                              # reduction candidate for 5,7
I1: 5,7 => CTR
* 23.614.9.1...8....6........824571.3.3968421..5179..4287.14.....9.235..6.4.3......
I1: 1,4                                  # 15 pairs
I2: 5,7,2,3,4,6                          # reduction candidate for 5,7
I2: 5,7 => CTR
* 23.654.911.92836..6.5197...8245719363968421..5179364287.14.....9.231.7644.37...1.
I2: 2,3,4,6                              # 14 pairs
I3: 5,7,1,2,3,4                          # reduction candidate for 5,7
I3: 5,7                                  # 19 pairs
I8: 5,7,1,4                              # reduction candidate for 5,7
I8: 5,7 => CTR
* 23.6...9.1...8....6........824571.3.3968421..5179..4287.1......9.2314.6.4.3......
I8: 1,4                                  # 15 pairs
I9: 5,7,1,2,9                            # reduction candidate for 5,7
I9: 5,7                                  # 19 pairs
* PAIR B8: 5,8 BLK 7
B7: 5,8,6                                # reduction candidate for 5,8
B7: 5,8                                  # 16 pairs
B9: 5,8,6                                # reduction candidate for 5,8
B9: 5,8                                  # 16 pairs
* PAIR B8: 5,8 ROW 8
F8: 5,8,4,7                              # reduction candidate for 5,8
F8: 5,8 => CTR
* 23.6.4.9.1...8....6........824571.3.3968421..5179..4287.14.....9.231.7644.3......
F8: 4,7                                  # 15 pairs
G8: 5,8,7                                # reduction candidate for 5,8
G8: 5,8 => SOLVED
* 238654791149783256675129843824571639396842175517936428761495382982317564453268917
G8: 7 => CTR
* 23.614.971...8....6......1.824571.3.3968421755179..4287.14.....98235.7614.31.7...
* PAIR D7: 2,4 ROW 7
I7: 2,4,3,5,9                            # reduction candidate for 2,4
I7: 2,4 => SOLVED
* 238654791149783256675129843824571639396842175517936428761495382982317564453268917
I7: 3,5,9                                # 14 pairs
* PAIR D7: 2,4 COL D
D2: 2,4,7                                # reduction candidate for 2,4
D2: 2,4                                  # 17 pairs
D3: 2,4,1,7                              # reduction candidate for 2,4
D3: 2,4 => CTR
* 23.61..9.1..78....67.....1.824571.3.3968421..5179..4287.1......9823547614.31.7...
D3: 1,7                                  # 15 pairs
* PAIR E8: 1,5 ROW 8
I8: 1,5,4,7                              # reduction candidate for 1,5
I8: 1,5 => CTR
* 23.617.941..48....6........824571.3.3968421..5179..4287.12...4.9823.476.4.3......
I8: 4,7 => SOLVED
* 238654791149783256675129843824571639396842175517936428761495382982317564453268917
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-299-base-pr-000.dot
* REASONING
* DIS # C3: 9 => CTR => C3: 5,8
* DIS # G1: 5,8 => CTR => G1: 7
* PRF # G1: 7 => SOL
* DIS # F2: 4,7 => CTR => F2: 3,5,9
* DIS # H2: 4,7 => CTR => H2: 5
* DIS # I2: 4,7 => CTR => I2: 2,3,5,6
* DIS # C3: 8 => CTR => C3: 5,9
* DIS # F2: 5,9 => CTR => F2: 3,4,7
* DIS # D3: 4,7 => CTR => D3: 1,2
* DIS # F3: 4,7 => CTR => F3: 3,5,9
* PRF # H3: 4,7 => SOL
* PRF # I1: 1,5 => SOL
* DIS # I1: 4,7 => CTR => I1: 1,5
* DIS # H3: 5,7 => CTR => H3: 1,4,8
* DIS # H9: 5,7 => CTR => H9: 1,8
* DIS # I1: 5,7 => CTR => I1: 1,4
* DIS # I2: 5,7 => CTR => I2: 2,3,4,6
* DIS # I8: 5,7 => CTR => I8: 1,4
* DIS # F8: 5,8 => CTR => F8: 4,7
* PRF # G8: 5,8 => SOL
* DIS # G8: 7 => CTR => G8: 5,8
* PRF # I7: 2,4 => SOL
* DIS # D3: 2,4 => CTR => D3: 1,7
* DIS # I8: 1,5 => CTR => I8: 4,7
* PRF # I8: 4,7 => SOL
* CNT  25 HDP CHAINS /  50 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B2,B3,B8,C1,C2,D7,E1,E6,E8,F6,G4,H5,I4,I5)
* 23.6...9.1...8....6........824571.3.3968421..5179..4287.1......9.23...6.4.3......
* PAIR C1: 5,8 BLK 1
C3: 5,8,9                                # reduction candidate for 5,8
C3: 9 => CTR
* 238654791175289.4.649137...824571.3.3968421755179634287.14.....9.231..644.37...1.
* PAIR C1: 5,8 ROW 1
G1: 5,8,7                                # reduction candidate for 5,8
G1: 5,8 => CTR
* 23.61..9.1.9.8....6......1.824571.3.3968421..5179..4287.1......9823547614.31.7...
G1: 7 => SOLVED
* 238654791149783256675129843824571639396842175517936428761495382982317564453268917
* DURATION: 0:00:04.784052  START: 13:12:05.557847  END: 13:12:10.341899 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-299-base-pr-001.dot
* REASONING
* DIS # C3: 9 => CTR => C3: 5,8
* DIS C3: 5,8 # G1: 5,8 => CTR => G1: 7
* PRF C3: 5,8 + G1: 7 => SOL
* STA C3: 5,8 + G1: 7
* CNT   3 HDP CHAINS /   3 HYP OPENED

Header Info

Top 500 Minimum 17 299

solution: 238654791149783256675129843824571639396842175517936428761495382982317564453268917
info: 2545     FNBTHWY  S8.f     18016

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

Solution

position: 238654791149783256675129843824571639396842175517936428761495382982317564453268917 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 # C3: 5,8 => UNS
* DIS # C3: 9 => CTR => C3: 5,8
* DIS # G1: 5,8 => CTR => G1: 7
* PRF # G1: 7 => SOL
* INC # D2: 4,7 => UNS
* DIS # F2: 4,7 => CTR => F2: 3,5,9
* INC # F2: 3,5,9 => UNS
* DIS # H2: 4,7 => CTR => H2: 5
* INC # H2: 5 => UNS
* DIS # I2: 4,7 => CTR => I2: 2,3,5,6
* INC # I2: 2,3,5,6 => UNS
* INC # C3: 5,9 => UNS
* DIS # C3: 8 => CTR => C3: 5,9
* DIS # F2: 5,9 => CTR => F2: 3,4,7
* INC # F2: 3,4,7 => UNS
* DIS # D3: 4,7 => CTR => D3: 1,2
* INC # D3: 1,2 => UNS
* DIS # F3: 4,7 => CTR => F3: 3,5,9
* INC # F3: 3,5,9 => UNS
* PRF # H3: 4,7 => SOL
* INC # H3: 1,5,8 => UNS
* INC # I3: 4,7 => UNS
* PRF # I1: 1,5 => SOL
* DIS # I1: 4,7 => CTR => I1: 1,5
* INC # H2: 5,7 => UNS
* DIS # H3: 5,7 => CTR => H3: 1,4,8
* INC # H3: 1,4,8 => UNS
* DIS # H9: 5,7 => CTR => H9: 1,8
* INC # H9: 1,8 => UNS
* DIS # I1: 5,7 => CTR => I1: 1,4
* INC # I1: 1,4 => UNS
* DIS # I2: 5,7 => CTR => I2: 2,3,4,6
* INC # I2: 2,3,4,6 => UNS
* INC # I3: 5,7 => UNS
* DIS # I8: 5,7 => CTR => I8: 1,4
* INC # I8: 1,4 => UNS
* INC # I9: 5,7 => UNS
* INC # B7: 5,8 => UNS
* INC # B9: 5,8 => UNS
* DIS # F8: 5,8 => CTR => F8: 4,7
* INC # F8: 4,7 => UNS
* PRF # G8: 5,8 => SOL
* DIS # G8: 7 => CTR => G8: 5,8
* PRF # I7: 2,4 => SOL
* INC # I7: 3,5,9 => UNS
* INC # D2: 2,4 => UNS
* DIS # D3: 2,4 => CTR => D3: 1,7
* INC # D3: 1,7 => UNS
* DIS # I8: 1,5 => CTR => I8: 4,7
* PRF # I8: 4,7 => SOL
* CNT  50 HDP CHAINS /  50 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # C3: 5,8 => UNS
* DIS # C3: 9 => CTR => C3: 5,8
* DIS C3: 5,8 # G1: 5,8 => CTR => G1: 7
* PRF C3: 5,8 + G1: 7 => SOL
* STA C3: 5,8 + G1: 7
* CNT   4 HDP CHAINS /   3 HYP OPENED