Analysis of xx-top95-091-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: ...658.....4......12............96.7...3..5....2.8...3..19..8..3.6.....4....473.. initial

Autosolve

position: ...658.....4....3.12............96.7...3..5....2.8...3..19..8..3.68.5..4....473.. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # B1: 7,9 => CTR => B1: 3
* DIS # A5: 7,9 => CTR => A5: 4,6,8
* DIS # I3: 5,8 => CTR => I3: 6
* DIS # C4: 5,8 => CTR => C4: 3
* DIS # E3: 7,9 => CTR => E3: 3
* DIS # F5: 4,6 => CTR => F5: 1,2
* DIS # H1: 1,2 => CTR => H1: 4
* DIS # I5: 1,2 => CTR => I5: 8,9
* DIS # I9: 1,2 => CTR => I9: 5,6,9
* DIS # I3: 5,8 => CTR => I3: 6
* DIS # E3: 7,9 => CTR => E3: 3
* DIS # D6: 7 => CTR => D6: 4,5
* DIS # F5: 4,6 => CTR => F5: 1,2
* DIS # H4: 4,8 => CTR => H4: 1,2
* DIS # H4: 1,4 => CTR => H4: 2,8
* PRF # H5: 1,4 => SOL
* DIS # H6: 1,4 => CTR => H6: 9
* PRF # H6: 9 => SOL
* PRF # B6: 1,4 => SOL
* DIS # F6: 1,4 => CTR => F6: 6
* DIS # G1: 1,4 => CTR => G1: 2
* PRF # G1: 2 => SOL
* DIS # B1: 7,9 => CTR => B1: 3
* DIS # H9: 1,2 => CTR => H9: 5,6,9
* DIS # I9: 1,2 => CTR => I9: 5,6,9
* PRF # H7: 2,5 => SOL
* DIS # H7: 7 => CTR => H7: 2,5
* DIS # H9: 2,5 => CTR => H9: 1,6,9
* DIS # I9: 2,5 => CTR => I9: 1,6,9
* DIS # A7: 2,5 => CTR => A7: 4,7
* PRF # A7: 4,7 => SOL
* DIS # H9: 1,2 => CTR => H9: 5,6,9
* DIS # I9: 1,2 => CTR => I9: 5,6,9
* DIS # G1: 4 => CTR => G1: 1,2
* CNT  34 HDP CHAINS /  78 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: 7,9 => CTR => B1: 3
* DIS B1: 3 # A5: 7,9 => CTR => A5: 4,6,8
* DIS B1: 3 + A5: 4,6,8 # I3: 5,8 => CTR => I3: 6
* DIS B1: 3 + A5: 4,6,8 + I3: 6 # C9: 9 => CTR => C9: 5,8
* DIS B1: 3 + A5: 4,6,8 + I3: 6 + C9: 5,8 # E3: 7,9 => CTR => E3: 3
* PRF B1: 3 + A5: 4,6,8 + I3: 6 + C9: 5,8 + E3: 3 => SOL
* STA B1: 3 + A5: 4,6,8 + I3: 6 + C9: 5,8 + E3: 3
* CNT   6 HDP CHAINS /  16 HYP OPENED

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

Details

Positions

...658.....4......12............96.7...3..5....2.8...3..19..8..3.6.....4....473.. initial
...658.....4....3.12............96.7...3..5....2.8...3..19..8..3.68.5..4....473.. autosolve
937658241864291735125734986583419627649372518712586493471963852396825174258147369 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (23)
A1: 7,9
C3: 5,8
D2: 1,2
E2: 7,9
F2: 1,2
D3: 4,7
F3: 3,4
I1: 1,2
G2: 7,9
I2: 5,8
G3: 7,9
D4: 4,5
E4: 1,2
E5: 6,7
G6: 1,4
B8: 7,9
E7: 3,6
F7: 3,6
E8: 1,2
D9: 1,2
I7: 2,5
G8: 1,2
H8: 7,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
D2,F2: 1.. / D2 = 1  =>  0 pairs (X) / F2 = 1  =>  0 pairs (_)
E8,D9: 1.. / E8 = 1  =>  0 pairs (X) / D9 = 1  =>  0 pairs (_)
E8,G8: 1.. / E8 = 1  =>  0 pairs (X) / G8 = 1  =>  0 pairs (_)
D2,D9: 1.. / D2 = 1  =>  0 pairs (X) / D9 = 1  =>  0 pairs (_)
E4,E8: 1.. / E4 = 1  =>  0 pairs (*) / E8 = 1  =>  0 pairs (X)
D2,F2: 2.. / D2 = 2  =>  0 pairs (*) / F2 = 2  =>  0 pairs (X)
E4,F5: 2.. / E4 = 2  =>  0 pairs (X) / F5 = 2  =>  0 pairs (_)
A7,A9: 2.. / A7 = 2  =>  0 pairs (X) / A9 = 2  =>  0 pairs (_)
E8,D9: 2.. / E8 = 2  =>  0 pairs (*) / D9 = 2  =>  0 pairs (X)
E4,H4: 2.. / E4 = 2  =>  0 pairs (X) / H4 = 2  =>  0 pairs (_)
E8,G8: 2.. / E8 = 2  =>  0 pairs (*) / G8 = 2  =>  0 pairs (X)
D2,D9: 2.. / D2 = 2  =>  0 pairs (*) / D9 = 2  =>  0 pairs (X)
E4,E8: 2.. / E4 = 2  =>  0 pairs (X) / E8 = 2  =>  0 pairs (_)
F2,F5: 2.. / F2 = 2  =>  0 pairs (X) / F5 = 2  =>  0 pairs (_)
G1,G8: 2.. / G1 = 2  =>  0 pairs (*) / G8 = 2  =>  0 pairs (X)
B1,C1: 3.. / B1 = 3  => 24 pairs (_) / C1 = 3  =>  0 pairs (X)
E3,F3: 3.. / E3 = 3  => 17 pairs (_) / F3 = 3  =>  0 pairs (X)
B4,C4: 3.. / B4 = 3  =>  0 pairs (X) / C4 = 3  => 24 pairs (_)
E7,F7: 3.. / E7 = 3  =>  0 pairs (X) / F7 = 3  => 17 pairs (_)
B1,B4: 3.. / B1 = 3  => 24 pairs (_) / B4 = 3  =>  0 pairs (X)
C1,C4: 3.. / C1 = 3  =>  0 pairs (X) / C4 = 3  => 24 pairs (_)
E3,E7: 3.. / E3 = 3  => 17 pairs (_) / E7 = 3  =>  0 pairs (X)
F3,F7: 3.. / F3 = 3  =>  0 pairs (X) / F7 = 3  => 17 pairs (_)
D3,F3: 4.. / D3 = 4  =>  0 pairs (X) / F3 = 4  => 17 pairs (_)
G1,H1: 4.. / G1 = 4  =>  0 pairs (X) / H1 = 4  => 26 pairs (_)
A7,B7: 4.. / A7 = 4  =>  0 pairs (*) / B7 = 4  =>  0 pairs (X)
G1,G6: 4.. / G1 = 4  =>  0 pairs (X) / G6 = 4  => 26 pairs (_)
D4,D6: 5.. / D4 = 5  => 25 pairs (_) / D6 = 5  => 16 pairs (_)
A2,B2: 6.. / A2 = 6  => 24 pairs (_) / B2 = 6  => 24 pairs (_)
H3,I3: 6.. / H3 = 6  =>  0 pairs (X) / I3 = 6  => 24 pairs (_)
E7,F7: 6.. / E7 = 6  => 17 pairs (_) / F7 = 6  =>  0 pairs (X)
H9,I9: 6.. / H9 = 6  => 24 pairs (_) / I9 = 6  =>  0 pairs (X)
E5,E7: 6.. / E5 = 6  =>  0 pairs (X) / E7 = 6  => 17 pairs (_)
H3,H9: 6.. / H3 = 6  =>  0 pairs (X) / H9 = 6  => 24 pairs (_)
I3,I9: 6.. / I3 = 6  => 24 pairs (_) / I9 = 6  =>  0 pairs (X)
G2,G3: 7.. / G2 = 7  => 21 pairs (_) / G3 = 7  =>  0 pairs (X)
E5,D6: 7.. / E5 = 7  => 17 pairs (_) / D6 = 7  =>  0 pairs (X)
H7,H8: 7.. / H7 = 7  =>  0 pairs (X) / H8 = 7  =>  0 pairs (_)
E2,G2: 7.. / E2 = 7  =>  0 pairs (X) / G2 = 7  => 21 pairs (_)
B8,H8: 7.. / B8 = 7  =>  0 pairs (X) / H8 = 7  =>  0 pairs (_)
C1,C5: 7.. / C1 = 7  => 23 pairs (_) / C5 = 7  =>  0 pairs (X)
D3,D6: 7.. / D3 = 7  => 17 pairs (_) / D6 = 7  =>  0 pairs (X)
E2,E3: 9.. / E2 = 9  => 21 pairs (_) / E3 = 9  =>  0 pairs (X)
G2,G3: 9.. / G2 = 9  =>  0 pairs (X) / G3 = 9  => 21 pairs (_)
E2,G2: 9.. / E2 = 9  => 21 pairs (_) / G2 = 9  =>  0 pairs (X)
E3,G3: 9.. / E3 = 9  =>  0 pairs (X) / G3 = 9  => 21 pairs (_)
B8,H8: 9.. / B8 = 9  =>  0 pairs (*) / H8 = 9  =>  0 pairs (X)
I5,I9: 9.. / I5 = 9  =>  0 pairs (X) / I9 = 9  =>  0 pairs (_)
* DURATION: 0:01:53.368045  START: 01:05:21.925855  END: 01:07:15.293900 2017-05-04
* CP COUNT: (48)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,B8,C3,D2,D3,D4,D9,E2,E4,E5,E7,E8,F2,F3,F7,G2,G3,G6,G8,H8,I1,I2,I7)
* ...658.....4....3.12............96.7...3..5....2.8...3..19..8..3.68.5..4....473..
* PAIR A1: 7,9 BLK 1
B1: 7,9,3                                # reduction candidate for 7,9
B1: 7,9 => CTR
* 793658.....4....3.1254.3....385.96.74.736.5.9..278...3..19368..3768.5.94..9.473..
B1: 3                                    # 24 pairs
C1: 7,9,3                                # reduction candidate for 7,9
C1: 7,9                                  # 24 pairs
* PAIR A1: 7,9 COL A
A5: 7,9,4,6,8                            # reduction candidate for 7,9
A5: 7,9 => CTR
* .3.658241..42.1.3.12.4.3..68435196.7...36.5....278..934719368..3968.51742..147369
A5: 4,6,8                                # 23 pairs
A6: 7,9,4,5,6                            # reduction candidate for 7,9
A6: 7,9                                  # 25 pairs
* PAIR C3: 5,8 BLK 1
A2: 5,8,6                                # reduction candidate for 5,8
A2: 5,8                                  # 24 pairs
B2: 5,8,6                                # reduction candidate for 5,8
B2: 5,8                                  # 24 pairs
* PAIR C3: 5,8 ROW 3
H3: 5,8,6                                # reduction candidate for 5,8
H3: 5,8                                  # 24 pairs
I3: 5,8,6                                # reduction candidate for 5,8
I3: 5,8 => CTR
* ...658241..42.1.3.12...4.6....419627.17362589..2.8.413..19..8.23.68251.42..1473.6
I3: 6                                    # 24 pairs
* PAIR C3: 5,8 COL C
C4: 5,8,3                                # reduction candidate for 5,8
C4: 5,8 => CTR
* 793658.....4....3.1254.3....385.96.74.736.5.9..278...3..19368..3768.5.94..9.473..
C4: 3                                    # 24 pairs
C9: 5,8,9                                # reduction candidate for 5,8
C9: 5,8                                  # 26 pairs
* PAIR E2: 7,9 BLK 2
E3: 7,9,3                                # reduction candidate for 7,9
E3: 7,9 => CTR
* ...658241..42.1.3.12.4.3..6...519627.1.36258...278..93..19368..3968.5174...147369
E3: 3                                    # 17 pairs
* PAIR F2: 1,2 COL F
F5: 1,2,4,6                              # reduction candidate for 1,2
F5: 4,6 => CTR
* ...658.....4..2.3.12...........296.7...3..5....2.81493..19..8..396815274...2473.9
F5: 1,2                                  # 25 pairs
* PAIR D3: 4,7 COL D
D6: 4,7,5                                # reduction candidate for 4,7
D6: 4,7                                  # 25 pairs
D6: 5                                    # 16 pairs
* PAIR I1: 1,2 BLK 3
G1: 1,2,4                                # reduction candidate for 1,2
G1: 1,2                                  # 26 pairs
H1: 1,2,4                                # reduction candidate for 1,2
H1: 1,2 => CTR
* .39658412..41.2.38128..4.56.134296874873615.9..2.8.1432419..875376815294..5247361
H1: 4                                    # 26 pairs
* PAIR I1: 1,2 COL I
I5: 1,2,8,9                              # reduction candidate for 1,2
I5: 1,2 => CTR
* ...658.....4....38128....56.....96.7...3..5....2.8...3..19..825396825174285147369
I5: 8,9                                  # 26 pairs
I9: 1,2,5,6,9                            # reduction candidate for 1,2
I9: 1,2 => CTR
* 739658.....4....381284.3.56..35.96.7..736.5.9..278...32419368753768.5.94..5.4736.
I9: 5,6,9                                # 23 pairs
* PAIR I2: 5,8 BLK 3
H3: 5,8,6                                # reduction candidate for 5,8
H3: 5,8                                  # 24 pairs
I3: 5,8,6                                # reduction candidate for 5,8
I3: 5,8 => CTR
* ...658241..42.1.3.12...4.6....419627.17362589..2.8.413..19..8.23.68251.42..1473.6
I3: 6                                    # 24 pairs
* PAIR I2: 5,8 ROW 2
A2: 5,8,6                                # reduction candidate for 5,8
A2: 5,8                                  # 24 pairs
B2: 5,8,6                                # reduction candidate for 5,8
B2: 5,8                                  # 24 pairs
* PAIR G3: 7,9 ROW 3
E3: 7,9,3                                # reduction candidate for 7,9
E3: 7,9 => CTR
* ...658241..42.1.3.12.4.3..6...519627.1.36258...278..93..19368..3968.5174...147369
E3: 3                                    # 17 pairs
* PAIR D4: 4,5 BLK 5
D6: 4,5,7                                # reduction candidate for 4,5
D6: 7 => CTR
* ...658241..42.1.3.12.4.3..6...519627.1.36258...278..93..19368..3968.5174...147369
D6: 4,5                                  # 17 pairs
* PAIR D4: 4,5 ROW 4
A4: 4,5,8                                # reduction candidate for 4,5
A4: 4,5                                  # 25 pairs
B4: 4,5,1,3,8                            # reduction candidate for 4,5
B4: 4,5                                  # 29 pairs
* PAIR E4: 1,2 BLK 5
F5: 1,2,4,6                              # reduction candidate for 1,2
F5: 4,6 => CTR
* ...658.....4..2.3.12...........296.7...3..5....2.81493..19..8..396815274...2473.9
F5: 1,2                                  # 25 pairs
* PAIR E4: 1,2 ROW 4
H4: 1,2,4,8                              # reduction candidate for 1,2
H4: 4,8 => CTR
* 739658..2..41.2.381284.3.56.13529687.87361529..27841.3241936875376815294..5247361
H4: 1,2                                  # 25 pairs
* PAIR E5: 6,7 ROW 5
A5: 6,7,4,8,9                            # reduction candidate for 6,7
A5: 6,7                                  # 24 pairs
B5: 6,7,1,4,8,9                          # reduction candidate for 6,7
B5: 6,7                                  # 25 pairs
* PAIR G6: 1,4 BLK 6
H4: 1,4,2,8                              # reduction candidate for 1,4
H4: 1,4 => CTR
* ...658.....41.2.38128....56....296.7...3..58...2.8...32419..875376815294...2473..
H4: 2,8                                  # 24 pairs
H5: 1,4,2,8,9                            # reduction candidate for 1,4
H5: 1,4 => SOLVED
* 937658241864291735125734986583419627649372518712586493471963852396825174258147369
H5: 2,8,9                                # 23 pairs
H6: 1,4,9                                # reduction candidate for 1,4
H6: 1,4 => CTR
* 937658..2..41927351257349..513429687..83715.9792586..3..19638..376815294..92473..
H6: 9 => SOLVED
* 937658241864291735125734986583419627649372518712586493471963852396825174258147369
* PAIR G6: 1,4 ROW 6
B6: 1,4,5,6,7,9                          # reduction candidate for 1,4
B6: 1,4 => SOLVED
* 937658241864291735125734986583419627649372518712586493471963852396825174258147369
B6: 5,6,7,9                              # 23 pairs
F6: 1,4,6                                # reduction candidate for 1,4
F6: 1,4 => CTR
* ...658241..42.1.3.12......6....19627.1.3.258...2.8..93..19..8..3968.5174...147369
F6: 6                                    # 17 pairs
* PAIR G6: 1,4 COL G
G1: 1,4,2                                # reduction candidate for 1,4
G1: 1,4 => CTR
* 7.9658..2..41.2.381284.3.564135296878.736.529..278...3241936875376815294..5247361
G1: 2 => SOLVED
* 937658241864291735125734986583419627649372518712586493471963852396825174258147369
* PAIR B8: 7,9 COL B
B1: 7,9,3                                # reduction candidate for 7,9
B1: 7,9 => CTR
* 793658.....4....3.1254.3....385.96.74.736.5.9..278...3..19368..3768.5.94..9.473..
B1: 3                                    # 24 pairs
B5: 7,9,1,4,6,8                          # reduction candidate for 7,9
B5: 7,9                                  # 27 pairs
B6: 7,9,1,4,5,6                          # reduction candidate for 7,9
B6: 7,9                                  # 27 pairs
* PAIR D9: 1,2 ROW 9
H9: 1,2,5,6,9                            # reduction candidate for 1,2
H9: 1,2 => CTR
* ...658.....4....3.12.....6......96.7...3..5....2.8...3..19..8523.68251.4....473..
H9: 5,6,9                                # 23 pairs
I9: 1,2,5,6,9                            # reduction candidate for 1,2
I9: 1,2 => CTR
* 739658.....4....381284.3.56..35.96.7..736.5.9..278...32419368753768.5.94..5.4736.
I9: 5,6,9                                # 23 pairs
* PAIR I7: 2,5 BLK 9
H7: 2,5,7                                # reduction candidate for 2,5
H7: 2,5 => SOLVED
* 937658241864291735125734986583419627649372518712586493471963852396825174258147369
H7: 7 => CTR
* 937658.....4.9273.125734968513429687..8371529792586..3..196387.376815294..9.473..
H9: 2,5,1,6,9                            # reduction candidate for 2,5
H9: 2,5 => CTR
* ...658241..42.1.3.12...4.6....419627.17362589..2.8.413..19..8723768251942..147356
H9: 1,6,9                                # 23 pairs
I9: 2,5,1,6,9                            # reduction candidate for 2,5
I9: 2,5 => CTR
* ...658241..42.1.381284.3.56...519627..7362589..2784..3..19368..3.68.5194...14736.
I9: 1,6,9                                # 23 pairs
* PAIR I7: 2,5 ROW 7
A7: 2,5,4,7                              # reduction candidate for 2,5
A7: 2,5 => CTR
* 937658..26.419273.12.7349.6.13429687468371529792586..324196387537681529485.2473.1
A7: 4,7 => SOLVED
* 937658241864291735125734986583419627649372518712586493471963852396825174258147369
* PAIR G8: 1,2 BLK 9
H9: 1,2,5,6,9                            # reduction candidate for 1,2
H9: 1,2 => CTR
* ...658.....4....3.12.....6......96.7...3..5....2.8...3..19..8523.68251.4....473..
H9: 5,6,9                                # 23 pairs
I9: 1,2,5,6,9                            # reduction candidate for 1,2
I9: 1,2 => CTR
* 739658.....4....381284.3.56..35.96.7..736.5.9..278...32419368753768.5.94..5.4736.
I9: 5,6,9                                # 23 pairs
* PAIR G8: 1,2 COL G
G1: 1,2,4                                # reduction candidate for 1,2
G1: 4 => CTR
* .39658412..41.2.38128..4.56.134296874873615.9..2.8.1432419..875376815294..5247361
G1: 1,2                                  # 26 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top95-091-base-pr-000.dot
* REASONING
* DIS # B1: 7,9 => CTR => B1: 3
* DIS # A5: 7,9 => CTR => A5: 4,6,8
* DIS # I3: 5,8 => CTR => I3: 6
* DIS # C4: 5,8 => CTR => C4: 3
* DIS # E3: 7,9 => CTR => E3: 3
* DIS # F5: 4,6 => CTR => F5: 1,2
* DIS # H1: 1,2 => CTR => H1: 4
* DIS # I5: 1,2 => CTR => I5: 8,9
* DIS # I9: 1,2 => CTR => I9: 5,6,9
* DIS # I3: 5,8 => CTR => I3: 6
* DIS # E3: 7,9 => CTR => E3: 3
* DIS # D6: 7 => CTR => D6: 4,5
* DIS # F5: 4,6 => CTR => F5: 1,2
* DIS # H4: 4,8 => CTR => H4: 1,2
* DIS # H4: 1,4 => CTR => H4: 2,8
* PRF # H5: 1,4 => SOL
* DIS # H6: 1,4 => CTR => H6: 9
* PRF # H6: 9 => SOL
* PRF # B6: 1,4 => SOL
* DIS # F6: 1,4 => CTR => F6: 6
* DIS # G1: 1,4 => CTR => G1: 2
* PRF # G1: 2 => SOL
* DIS # B1: 7,9 => CTR => B1: 3
* DIS # H9: 1,2 => CTR => H9: 5,6,9
* DIS # I9: 1,2 => CTR => I9: 5,6,9
* PRF # H7: 2,5 => SOL
* DIS # H7: 7 => CTR => H7: 2,5
* DIS # H9: 2,5 => CTR => H9: 1,6,9
* DIS # I9: 2,5 => CTR => I9: 1,6,9
* DIS # A7: 2,5 => CTR => A7: 4,7
* PRF # A7: 4,7 => SOL
* DIS # H9: 1,2 => CTR => H9: 5,6,9
* DIS # I9: 1,2 => CTR => I9: 5,6,9
* DIS # G1: 4 => CTR => G1: 1,2
* CNT  34 HDP CHAINS /  78 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,B8,C3,D2,D3,D4,D9,E2,E4,E5,E7,E8,F2,F3,F7,G2,G3,G6,G8,H8,I1,I2,I7)
* ...658.....4....3.12............96.7...3..5....2.8...3..19..8..3.68.5..4....473..
* PAIR A1: 7,9 BLK 1
B1: 7,9,3                                # reduction candidate for 7,9
B1: 7,9 => CTR
* 793658.....4....3.1254.3....385.96.74.736.5.9..278...3..19368..3768.5.94..9.473..
* RESTART
* PAIR A1: 7,9 COL A
A5: 7,9,4,6,8                            # reduction candidate for 7,9
A5: 7,9 => CTR
* .3.658241..42.1.3.12.4.3..68435196.7...36.5....278..934719368..3968.51742..147369
A6: 7,9,4,5,6                            # reduction candidate for 7,9
A6: 7,9                                  # 25 pairs
* RESTART
* PAIR A1: 7,9 COL A
A6: 7,9,4,5,6                            # reduction candidate for 7,9
A6: 4,5,6                                # 29 pairs
A6: 7,9                                  # 25 pairs
* PAIR RESTART
* PAIR A1: 7,9 COL A
A6: 7,9,4,5,6                            # reduction candidate for 7,9
A6: 4,5,6                                # 29 pairs
A6: 7,9                                  # 25 pairs
* PAIR C3: 5,8 BLK 1
A2: 5,8,6                                # reduction candidate for 5,8
A2: 5,8                                  # 25 pairs
B2: 5,8,6                                # reduction candidate for 5,8
B2: 5,8                                  # 26 pairs
* PAIR C3: 5,8 ROW 3
H3: 5,8,6                                # reduction candidate for 5,8
H3: 5,8                                  # 25 pairs
I3: 5,8,6                                # reduction candidate for 5,8
I3: 5,8 => CTR
* .3.658241..42.1.3.12...4.6...3419627.17362589..2.8.413..19..8.23.68251.42..1473.6
* RESTART
* PAIR C3: 5,8 COL C
C9: 5,8,9                                # reduction candidate for 5,8
C9: 9 => CTR
* .3.658.....4....3.125....86..3..96.7..83..5....2.8...3..19..8523.68251742...4736.
* PAIR RESTART
* PAIR C3: 5,8 BLK 1
A2: 5,8,6                                # reduction candidate for 5,8
A2: 5,8                                  # 28 pairs
B2: 5,8,6                                # reduction candidate for 5,8
B2: 5,8                                  # 29 pairs
* PAIR E2: 7,9 BLK 2
E3: 7,9,3                                # reduction candidate for 7,9
E3: 7,9 => CTR
* .3.658.....4....3.12.4.3..6.135296.7...36.5....278..93.419368..3968152.4....4736.
E3: 3 => SOLVED
* 937658241864291735125734986583419627649372518712586493471963852396825174258147369
* DURATION: 0:00:21.510382  START: 01:08:46.010268  END: 01:09:07.520650 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top95-091-base-pr-001.dot
* REASONING
* DIS # B1: 7,9 => CTR => B1: 3
* DIS B1: 3 # A5: 7,9 => CTR => A5: 4,6,8
* DIS B1: 3 + A5: 4,6,8 # I3: 5,8 => CTR => I3: 6
* DIS B1: 3 + A5: 4,6,8 + I3: 6 # C9: 9 => CTR => C9: 5,8
* DIS B1: 3 + A5: 4,6,8 + I3: 6 + C9: 5,8 # E3: 7,9 => CTR => E3: 3
* PRF B1: 3 + A5: 4,6,8 + I3: 6 + C9: 5,8 + E3: 3 => SOL
* STA B1: 3 + A5: 4,6,8 + I3: 6 + C9: 5,8 + E3: 3
* CNT   6 HDP CHAINS /  16 HYP OPENED

Header Info

Top 95 Sudokus 091
[sudoku:top95] “95 Hard Puzzles”, http://magictour.free.fr/top95, or http://norvig.com/top95.txt

Solution

position: 937658241864291735125734986583419627649372518712586493471963852396825174258147369 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 # B1: 7,9 => CTR => B1: 3
* INC # B1: 3 => UNS
* INC # C1: 7,9 => UNS
* DIS # A5: 7,9 => CTR => A5: 4,6,8
* INC # A5: 4,6,8 => UNS
* INC # A6: 7,9 => UNS
* INC # A2: 5,8 => UNS
* INC # B2: 5,8 => UNS
* INC # H3: 5,8 => UNS
* DIS # I3: 5,8 => CTR => I3: 6
* INC # I3: 6 => UNS
* DIS # C4: 5,8 => CTR => C4: 3
* INC # C4: 3 => UNS
* INC # C9: 5,8 => UNS
* DIS # E3: 7,9 => CTR => E3: 3
* INC # E3: 3 => UNS
* INC # F5: 1,2 => UNS
* DIS # F5: 4,6 => CTR => F5: 1,2
* INC # D6: 4,7 => UNS
* INC # D6: 5 => UNS
* INC # G1: 1,2 => UNS
* DIS # H1: 1,2 => CTR => H1: 4
* INC # H1: 4 => UNS
* DIS # I5: 1,2 => CTR => I5: 8,9
* INC # I5: 8,9 => UNS
* DIS # I9: 1,2 => CTR => I9: 5,6,9
* INC # I9: 5,6,9 => UNS
* INC # H3: 5,8 => UNS
* DIS # I3: 5,8 => CTR => I3: 6
* INC # I3: 6 => UNS
* INC # A2: 5,8 => UNS
* INC # B2: 5,8 => UNS
* DIS # E3: 7,9 => CTR => E3: 3
* INC # E3: 3 => UNS
* INC # D6: 4,5 => UNS
* DIS # D6: 7 => CTR => D6: 4,5
* INC # A4: 4,5 => UNS
* INC # B4: 4,5 => UNS
* INC # F5: 1,2 => UNS
* DIS # F5: 4,6 => CTR => F5: 1,2
* INC # H4: 1,2 => UNS
* DIS # H4: 4,8 => CTR => H4: 1,2
* INC # A5: 6,7 => UNS
* INC # B5: 6,7 => UNS
* DIS # H4: 1,4 => CTR => H4: 2,8
* INC # H4: 2,8 => UNS
* PRF # H5: 1,4 => SOL
* INC # H5: 2,8,9 => UNS
* DIS # H6: 1,4 => CTR => H6: 9
* PRF # H6: 9 => SOL
* PRF # B6: 1,4 => SOL
* INC # B6: 5,6,7,9 => UNS
* DIS # F6: 1,4 => CTR => F6: 6
* INC # F6: 6 => UNS
* DIS # G1: 1,4 => CTR => G1: 2
* PRF # G1: 2 => SOL
* DIS # B1: 7,9 => CTR => B1: 3
* INC # B1: 3 => UNS
* INC # B5: 7,9 => UNS
* INC # B6: 7,9 => UNS
* DIS # H9: 1,2 => CTR => H9: 5,6,9
* INC # H9: 5,6,9 => UNS
* DIS # I9: 1,2 => CTR => I9: 5,6,9
* INC # I9: 5,6,9 => UNS
* PRF # H7: 2,5 => SOL
* DIS # H7: 7 => CTR => H7: 2,5
* DIS # H9: 2,5 => CTR => H9: 1,6,9
* INC # H9: 1,6,9 => UNS
* DIS # I9: 2,5 => CTR => I9: 1,6,9
* INC # I9: 1,6,9 => UNS
* DIS # A7: 2,5 => CTR => A7: 4,7
* PRF # A7: 4,7 => SOL
* DIS # H9: 1,2 => CTR => H9: 5,6,9
* INC # H9: 5,6,9 => UNS
* DIS # I9: 1,2 => CTR => I9: 5,6,9
* INC # I9: 5,6,9 => UNS
* INC # G1: 1,2 => UNS
* DIS # G1: 4 => CTR => G1: 1,2
* CNT  78 HDP CHAINS /  78 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # B1: 7,9 => CTR => B1: 3
* DIS B1: 3 # A5: 7,9 => CTR => A5: 4,6,8
* INC B1: 3 + A5: 4,6,8 # A6: 7,9 => UNS
* INC B1: 3 + A5: 4,6,8 # A6: 7,9 => UNS
* INC B1: 3 + A5: 4,6,8 # A6: 4,5,6 => UNS
* INC B1: 3 + A5: 4,6,8 # A6: 7,9 => UNS
* INC B1: 3 + A5: 4,6,8 # A6: 4,5,6 => UNS
* INC B1: 3 + A5: 4,6,8 # A2: 5,8 => UNS
* INC B1: 3 + A5: 4,6,8 # B2: 5,8 => UNS
* INC B1: 3 + A5: 4,6,8 # H3: 5,8 => UNS
* DIS B1: 3 + A5: 4,6,8 # I3: 5,8 => CTR => I3: 6
* INC B1: 3 + A5: 4,6,8 + I3: 6 # C9: 5,8 => UNS
* DIS B1: 3 + A5: 4,6,8 + I3: 6 # C9: 9 => CTR => C9: 5,8
* INC B1: 3 + A5: 4,6,8 + I3: 6 + C9: 5,8 # A2: 5,8 => UNS
* INC B1: 3 + A5: 4,6,8 + I3: 6 + C9: 5,8 # B2: 5,8 => UNS
* DIS B1: 3 + A5: 4,6,8 + I3: 6 + C9: 5,8 # E3: 7,9 => CTR => E3: 3
* PRF B1: 3 + A5: 4,6,8 + I3: 6 + C9: 5,8 + E3: 3 => SOL
* STA B1: 3 + A5: 4,6,8 + I3: 6 + C9: 5,8 + E3: 3
* CNT  17 HDP CHAINS /  16 HYP OPENED