Analysis of xx-top500-277-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: .3.2...4.1...8..............2.67.........21........5.87.1.........4...3.5........ initial

Autosolve

position: 93.2...4.1...84...4........825671.9.3948521..617.4.5287.1......2.94...3.5.3...... autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # C3: 2 => CTR => C3: 6,8
* DIS # G1: 6,8 => CTR => G1: 7
* PRF # G1: 7 => SOL
* DIS # H2: 5,7 => CTR => H2: 6
* DIS # I2: 5,7 => CTR => I2: 2,3,6,9
* DIS # C3: 8 => CTR => C3: 2,6
* DIS # G2: 2,6 => CTR => G2: 3,7,9
* DIS # I2: 2,6 => CTR => I2: 3,5,7,9
* DIS # D3: 5,7 => CTR => D3: 1,3,9
* DIS # F3: 5,7 => CTR => F3: 3,6,9
* PRF # H3: 5,7 => SOL
* DIS # I3: 5,7 => CTR => I3: 1,2,3,6,9
* PRF # I1: 1,6 => SOL
* DIS # I1: 5,7 => CTR => I1: 1,6
* DIS # D2: 3,9 => CTR => D2: 5,7
* DIS # D3: 3,9 => CTR => D3: 1,5,7
* PRF # F3: 3,9 => SOL
* DIS # G3: 3,9 => CTR => G3: 2,6,7,8
* DIS # I3: 3,9 => CTR => I3: 1,2,5,6,7
* DIS # D2: 3,9 => CTR => D2: 5,7
* DIS # D3: 3,9 => CTR => D3: 1,5,7
* DIS # D7: 3,9 => CTR => D7: 5
* PRF # D7: 5 => SOL
* PRF # F3: 3,9 => SOL
* DIS # F7: 3,9 => CTR => F7: 5,6,8
* DIS # H3: 6,7 => CTR => H3: 1,5,8
* DIS # H9: 6,7 => CTR => H9: 1,8
* DIS # I1: 6,7 => CTR => I1: 1,5
* DIS # I2: 6,7 => CTR => I2: 2,3,5,9
* DIS # I8: 6,7 => CTR => I8: 1,5
* DIS # F8: 6,8 => CTR => F8: 5,7
* PRF # G8: 6,8 => SOL
* DIS # G8: 7 => CTR => G8: 6,8
* DIS # I8: 1,6 => CTR => I8: 5,7
* PRF # I8: 5,7 => SOL
* CNT  35 HDP CHAINS /  72 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: 2 => CTR => C3: 6,8
* DIS C3: 6,8 # H2: 5,7 => CTR => H2: 6
* DIS C3: 6,8 + H2: 6 # I2: 5,7 => CTR => I2: 3,9
* DIS C3: 6,8 + H2: 6 + I2: 3,9 # D2: 3,9 => CTR => D2: 5,7
* DIS C3: 6,8 + H2: 6 + I2: 3,9 + D2: 5,7 # D3: 5,7 => CTR => D3: 1,3,9
* DIS C3: 6,8 + H2: 6 + I2: 3,9 + D2: 5,7 + D3: 1,3,9 # F3: 5,7 => CTR => F3: 3,6,9
* DIS C3: 6,8 + H2: 6 + I2: 3,9 + D2: 5,7 + D3: 1,3,9 + F3: 3,6,9 # I3: 5,7 => CTR => I3: 1,2
* DIS C3: 6,8 + H2: 6 + I2: 3,9 + D2: 5,7 + D3: 1,3,9 + F3: 3,6,9 + I3: 1,2 # D3: 3,9 => CTR => D3: 1
* PRF C3: 6,8 + H2: 6 + I2: 3,9 + D2: 5,7 + D3: 1,3,9 + F3: 3,6,9 + I3: 1,2 + D3: 1 => SOL
* STA C3: 6,8 + H2: 6 + I2: 3,9 + D2: 5,7 + D3: 1,3,9 + F3: 3,6,9 + I3: 1,2 + D3: 1
* CNT   9 HDP CHAINS /  11 HYP OPENED

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

Details

Positions

.3.2...4.1...8..............2.67.........21........5.87.1.........4...3.5........ initial
93.2...4.1...84...4........825671.9.3948521..617.4.5287.1......2.94...3.5.3...... autosolve
938265741152784963476193852825671394394852176617349528741536289289417635563928417 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (15)
C1: 6,8
B2: 5,7
C2: 2,6
B3: 5,7
E1: 1,6
E3: 3,9
D6: 3,9
F6: 3,9
G4: 3,4
I4: 3,4
H5: 6,7
I5: 6,7
B8: 6,8
E8: 1,6
E9: 2,9

--------------------------------------------------
* 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 (_)
C2,C3: 2.. / C2 = 2  => 16 pairs (_) / C3 = 2  =>  0 pairs (X)
E7,E9: 2.. / E7 = 2  => 15 pairs (_) / E9 = 2  => 15 pairs (_)
D6,F6: 3.. / D6 = 3  => 14 pairs (_) / F6 = 3  => 15 pairs (_)
G4,I4: 3.. / G4 = 3  => 13 pairs (_) / I4 = 3  => 13 pairs (_)
E3,E7: 3.. / E3 = 3  => 17 pairs (_) / E7 = 3  => 14 pairs (_)
G4,I4: 4.. / G4 = 4  => 13 pairs (_) / I4 = 4  => 13 pairs (_)
B7,B9: 4.. / B7 = 4  => 16 pairs (_) / B9 = 4  => 16 pairs (_)
B2,B3: 5.. / B2 = 5  => 16 pairs (_) / B3 = 5  => 16 pairs (_)
F1,I1: 5.. / F1 = 5  =>  0 pairs (*) / I1 = 5  =>  0 pairs (X)
F8,I8: 5.. / F8 = 5  =>  0 pairs (X) / I8 = 5  =>  0 pairs (_)
H5,I5: 6.. / H5 = 6  =>  0 pairs (X) / I5 = 6  => 14 pairs (_)
E1,E8: 6.. / E1 = 6  =>  0 pairs (*) / E8 = 6  =>  0 pairs (X)
B2,B3: 7.. / B2 = 7  => 16 pairs (_) / B3 = 7  => 16 pairs (_)
H5,I5: 7.. / H5 = 7  => 14 pairs (_) / I5 = 7  =>  0 pairs (X)
C1,C3: 8.. / C1 = 8  => 16 pairs (_) / C3 = 8  =>  0 pairs (X)
C1,G1: 8.. / C1 = 8  => 16 pairs (_) / G1 = 8  =>  0 pairs (X)
D6,F6: 9.. / D6 = 9  => 15 pairs (_) / F6 = 9  => 14 pairs (_)
* DURATION: 0:00:35.866295  START: 12:24:19.823688  END: 12:24:55.689983 2017-05-04
* CP COUNT: (24)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B2,B3,B8,C1,C2,D6,E1,E3,E8,E9,F6,G4,H5,I4,I5)
* 93.2...4.1...84...4........825671.9.3948521..617.4.5287.1......2.94...3.5.3......
* PAIR C1: 6,8 BLK 1
C3: 6,8,2                                # reduction candidate for 6,8
C3: 2 => CTR
* 938265741176.84.5.4521.7...825671.9.394852176617.4.5287.15.....2.941..355.37...1.
C3: 6,8                                  # 16 pairs
* PAIR C1: 6,8 ROW 1
G1: 6,8,7                                # reduction candidate for 6,8
G1: 6,8 => CTR
* 93.21..4.1...84...4....6.1.825671.9.3948521..617.4.5287.1......2894657315.31.7...
G1: 7 => SOLVED
* 938265741152784963476193852825671394394852176617349528741536289289417635563928417
* PAIR B2: 5,7 ROW 2
D2: 5,7,3,9                              # reduction candidate for 5,7
D2: 5,7                                  # 19 pairs
H2: 5,7,6                                # reduction candidate for 5,7
H2: 5,7 => CTR
* 93.265.411...84...4..1.7...825671.9.3948521.7617.4.5287.15.....2.941.7355.37...1.
H2: 6                                    # 16 pairs
I2: 5,7,2,3,6,9                          # reduction candidate for 5,7
I2: 5,7 => CTR
* 93.2.584.1.2.84.6.4........825671.9.394852176617.4.5287.15...8.2.94...355.3....1.
I2: 2,3,6,9                              # 15 pairs
* PAIR C2: 2,6 BLK 1
C3: 2,6,8                                # reduction candidate for 2,6
C3: 8 => CTR
* 9362158471.2.84...4.8..6.1.825671.9.394852176617.4.5287.15.....28946.7315.31.7...
C3: 2,6                                  # 16 pairs
* PAIR C2: 2,6 ROW 2
G2: 2,6,3,7,9                            # reduction candidate for 2,6
G2: 2,6 => CTR
* 93.265.411...84...4..1.7...825671.9.3948521.7617.4.5287.15.....2.941.7355.37...1.
G2: 3,7,9                                # 15 pairs
I2: 2,6,3,5,7,9                          # reduction candidate for 2,6
I2: 2,6 => CTR
* 93.265.411...84...4..1.7...825671.9.3948521.7617.4.5287.15.....2.941.7355.37...1.
I2: 3,5,7,9                              # 15 pairs
* PAIR B3: 5,7 ROW 3
D3: 5,7,1,3,9                            # reduction candidate for 5,7
D3: 5,7 => CTR
* 93.21..4.1...84...4......1.825671.9.3948521..617.4.5287.1......2894657315.31.7...
D3: 1,3,9                                # 15 pairs
F3: 5,7,3,6,9                            # reduction candidate for 5,7
F3: 5,7 => CTR
* 9382..74.1...84...4........825671.9.3948521..617.4.5287.1......2.94...3.5.3......
F3: 3,6,9                                # 15 pairs
H3: 5,7,1,6,8                            # reduction candidate for 5,7
H3: 5,7 => SOLVED
* 938265741152784963476193852825671394394852176617349528741536289289417635563928417
H3: 1,6,8                                # 15 pairs
I3: 5,7,1,2,3,6,9                        # reduction candidate for 5,7
I3: 5,7 => CTR
* 93.2.7845172584.6.458..6217825671.9.394852176617.4.5287.1....5.289465.3.5.3......
I3: 1,2,3,6,9                            # 15 pairs
* PAIR E1: 1,6 ROW 1
I1: 1,6,5,7                              # reduction candidate for 1,6
I1: 1,6 => SOLVED
* 938265741152784963476193852825671394394852176617349528741536289289417635563928417
I1: 5,7 => CTR
* 93.21..4.1...84...4......1.825671.9.3948521..617.4.5287.1......2894657315.31.7...
* PAIR E3: 3,9 BLK 2
D2: 3,9,5,7                              # reduction candidate for 3,9
D2: 3,9 => CTR
* 93.265.411...84...4..1.7...825671.9.3948521..617.4.5287.15.....2.941.7355.37...1.
D2: 5,7                                  # 19 pairs
D3: 3,9,1,5,7                            # reduction candidate for 3,9
D3: 3,9 => CTR
* 93.21..4.1..784...47.....1.825671.9.3948521..617.4.5287.15.....289467.315.31.....
D3: 1,5,7                                # 15 pairs
F3: 3,9,5,6,7                            # reduction candidate for 3,9
F3: 3,9 => SOLVED
* 938265741152784963476193852825671394394852176617349528741536289289417635563928417
F3: 5,6,7                                # 15 pairs
* PAIR E3: 3,9 ROW 3
G3: 3,9,2,6,7,8                          # reduction candidate for 3,9
G3: 3,9 => CTR
* 93.265.411...84...4..1.7...825671.9.3948521..617.4.5287.15.....2.941.7355.37...1.
G3: 2,6,7,8                              # 15 pairs
I3: 3,9,1,2,5,6,7                        # reduction candidate for 3,9
I3: 3,9 => CTR
* 93.265.411...84...4..1.7...825671.9.3948521..617.4.5287.15.....2.941.7355.37...1.
I3: 1,2,5,6,7                            # 15 pairs
* PAIR E3: 3,9 COL E
E7: 3,9,2                                # reduction candidate for 3,9
E7: 3,9                                  # 15 pairs
E7: 2                                    # 15 pairs
* PAIR D6: 3,9 COL D
D2: 3,9,5,7                              # reduction candidate for 3,9
D2: 3,9 => CTR
* 93.265.411...84...4..1.7...825671.9.3948521..617.4.5287.15.....2.941.7355.37...1.
D2: 5,7                                  # 19 pairs
D3: 3,9,1,5,7                            # reduction candidate for 3,9
D3: 3,9 => CTR
* 93.21..4.1..784...47.....1.825671.9.3948521..617.4.5287.15.....289467.315.31.....
D3: 1,5,7                                # 15 pairs
D7: 3,9,5                                # reduction candidate for 3,9
D7: 3,9 => CTR
* 93.2167451...84.6.4.6....1.825671.9.39485217.617.4.5287.1....5.2.9465.315.31.7...
D7: 5 => SOLVED
* 938265741152784963476193852825671394394852176617349528741536289289417635563928417
* PAIR F6: 3,9 COL F
F3: 3,9,5,6,7                            # reduction candidate for 3,9
F3: 3,9 => SOLVED
* 938265741152784963476193852825671394394852176617349528741536289289417635563928417
F3: 5,6,7                                # 15 pairs
F7: 3,9,5,6,8                            # reduction candidate for 3,9
F7: 3,9 => CTR
* 93.265.411...84...4..1.7...825671.9.3948521..617.4.5287.15.....2.941.7355.37...1.
F7: 5,6,8                                # 15 pairs
* PAIR H5: 6,7 COL H
H2: 6,7,5                                # reduction candidate for 6,7
H2: 6,7                                  # 18 pairs
H3: 6,7,1,5,8                            # reduction candidate for 6,7
H3: 6,7 => CTR
* 93826574117..84.5.45.1.786.825671.9.394852176617.4.5287.15...8.2.941.6355.37...1.
H3: 1,5,8                                # 15 pairs
H9: 6,7,1,8                              # reduction candidate for 6,7
H9: 6,7 => CTR
* 93.21..4.1...84.5.45.....1.825671.9.3948521..617.4.5287.15...8.2.946..3.5.31.....
H9: 1,8                                  # 16 pairs
* PAIR I5: 6,7 COL I
I1: 6,7,1,5                              # reduction candidate for 6,7
I1: 6,7 => CTR
* 93.215.4.1...84...4....6...825671.9.3948521..617.4.5287.15.....2.946..3.5.3......
I1: 1,5                                  # 16 pairs
I2: 6,7,2,3,5,9                          # reduction candidate for 6,7
I2: 6,7 => CTR
* 93.2.5741172.84.5645.1.7.8.825671.9.3948521..617.4.5287.15.....2.94...355.3....1.
I2: 2,3,5,9                              # 15 pairs
I3: 6,7,1,2,3,5,9                        # reduction candidate for 6,7
I3: 6,7                                  # 18 pairs
I8: 6,7,1,5                              # reduction candidate for 6,7
I8: 6,7 => CTR
* 93.2...4.1...84...4........825671.9.3948521..617.4.5287.1......2.9415.3.5.3......
I8: 1,5                                  # 16 pairs
I9: 6,7,1,2,4,9                          # reduction candidate for 6,7
I9: 6,7                                  # 18 pairs
* PAIR B8: 6,8 BLK 7
B7: 6,8,4                                # reduction candidate for 6,8
B7: 6,8                                  # 16 pairs
B9: 6,8,4                                # reduction candidate for 6,8
B9: 6,8                                  # 16 pairs
* PAIR B8: 6,8 ROW 8
F8: 6,8,5,7                              # reduction candidate for 6,8
F8: 6,8 => CTR
* 93.2.5.4.1...84...4........825671.9.3948521..617.4.5287.15.....2.941.7355.3......
F8: 5,7                                  # 16 pairs
G8: 6,8,7                                # reduction candidate for 6,8
G8: 6,8 => SOLVED
* 938265741152784963476193852825671394394852176617349528741536289289417635563928417
G8: 7 => CTR
* 93.215.471...84...4....6.1.825671.9.394852176617.4.5287.15.....28946.7315.31.7...
* PAIR E8: 1,6 ROW 8
I8: 1,6,5,7                              # reduction candidate for 1,6
I8: 1,6 => CTR
* 93.217.451...84...4....6...825671.9.3948521..617.4.5287.1....5.28946573.5.3......
I8: 5,7 => SOLVED
* 938265741152784963476193852825671394394852176617349528741536289289417635563928417
* PAIR E9: 2,9 BLK 8
E7: 2,9,3                                # reduction candidate for 2,9
E7: 2,9                                  # 17 pairs
E7: 3                                    # 14 pairs
* PAIR E9: 2,9 ROW 9
G9: 2,9,4,6,7,8                          # reduction candidate for 2,9
G9: 2,9                                  # 17 pairs
I9: 2,9,1,4,6,7                          # reduction candidate for 2,9
I9: 2,9                                  # 17 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-277-base-pr-000.dot
* REASONING
* DIS # C3: 2 => CTR => C3: 6,8
* DIS # G1: 6,8 => CTR => G1: 7
* PRF # G1: 7 => SOL
* DIS # H2: 5,7 => CTR => H2: 6
* DIS # I2: 5,7 => CTR => I2: 2,3,6,9
* DIS # C3: 8 => CTR => C3: 2,6
* DIS # G2: 2,6 => CTR => G2: 3,7,9
* DIS # I2: 2,6 => CTR => I2: 3,5,7,9
* DIS # D3: 5,7 => CTR => D3: 1,3,9
* DIS # F3: 5,7 => CTR => F3: 3,6,9
* PRF # H3: 5,7 => SOL
* DIS # I3: 5,7 => CTR => I3: 1,2,3,6,9
* PRF # I1: 1,6 => SOL
* DIS # I1: 5,7 => CTR => I1: 1,6
* DIS # D2: 3,9 => CTR => D2: 5,7
* DIS # D3: 3,9 => CTR => D3: 1,5,7
* PRF # F3: 3,9 => SOL
* DIS # G3: 3,9 => CTR => G3: 2,6,7,8
* DIS # I3: 3,9 => CTR => I3: 1,2,5,6,7
* DIS # D2: 3,9 => CTR => D2: 5,7
* DIS # D3: 3,9 => CTR => D3: 1,5,7
* DIS # D7: 3,9 => CTR => D7: 5
* PRF # D7: 5 => SOL
* PRF # F3: 3,9 => SOL
* DIS # F7: 3,9 => CTR => F7: 5,6,8
* DIS # H3: 6,7 => CTR => H3: 1,5,8
* DIS # H9: 6,7 => CTR => H9: 1,8
* DIS # I1: 6,7 => CTR => I1: 1,5
* DIS # I2: 6,7 => CTR => I2: 2,3,5,9
* DIS # I8: 6,7 => CTR => I8: 1,5
* DIS # F8: 6,8 => CTR => F8: 5,7
* PRF # G8: 6,8 => SOL
* DIS # G8: 7 => CTR => G8: 6,8
* DIS # I8: 1,6 => CTR => I8: 5,7
* PRF # I8: 5,7 => SOL
* CNT  35 HDP CHAINS /  72 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B2,B3,B8,C1,C2,D6,E1,E3,E8,E9,F6,G4,H5,I4,I5)
* 93.2...4.1...84...4........825671.9.3948521..617.4.5287.1......2.94...3.5.3......
* PAIR C1: 6,8 BLK 1
C3: 6,8,2                                # reduction candidate for 6,8
C3: 2 => CTR
* 938265741176.84.5.4521.7...825671.9.394852176617.4.5287.15.....2.941..355.37...1.
* PAIR B2: 5,7 ROW 2
D2: 5,7,3,9                              # reduction candidate for 5,7
D2: 5,7                                  # 19 pairs
H2: 5,7,6                                # reduction candidate for 5,7
H2: 5,7 => CTR
* 93.265.411.2.84...4.61.7.8.825671.9.3948521.7617.4.5287.15...6.2.941..355.37.....
I2: 5,7,3,9                              # reduction candidate for 5,7
I2: 5,7 => CTR
* 93.2.584.1.2.84.6.4........825671.9.394852176617.4.5287.15...8.2.94...355.3....1.
* RESTART
* PAIR B2: 5,7 ROW 2
D2: 5,7,3,9                              # reduction candidate for 5,7
D2: 3,9 => CTR
* 93.2.7845152.8476.4781.....825671.9.394852176617.4.5287.1......2.94...3.5.37.....
* PAIR RESTART
* PAIR B3: 5,7 ROW 3
D3: 5,7,1,3,9                            # reduction candidate for 5,7
D3: 5,7 => CTR
* 93.21..4.1.2.84.6.4......1.825671.9.394852176617.4.5287.1....5.2894657315.31.7.8.
F3: 5,7,3,6,9                            # reduction candidate for 5,7
F3: 5,7 => CTR
* 9382..74.1.2.84.6.4.6......825671.9.394852176617.4.5287.1......2.94...3.5.3......
I3: 5,7,1,2                              # reduction candidate for 5,7
I3: 5,7 => CTR
* 93.2.7845172584.6.458..6217825671.9.394852176617.4.5287.1....5.289465.3.5.3......
* RESTART
* PAIR RESTART
* PAIR E3: 3,9 BLK 2
D3: 3,9,1                                # reduction candidate for 3,9
D3: 3,9 => CTR
* 93621.84.1.2784.6.478..6...825671.9.394852176617.4.5287.1......2.946..315.31...8.
D3: 1 => SOLVED
* 938265741152784963476193852825671394394852176617349528741536289289417635563928417
* DURATION: 0:00:12.232439  START: 12:25:55.380943  END: 12:26:07.613382 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-277-base-pr-001.dot
* REASONING
* DIS # C3: 2 => CTR => C3: 6,8
* DIS C3: 6,8 # H2: 5,7 => CTR => H2: 6
* DIS C3: 6,8 + H2: 6 # I2: 5,7 => CTR => I2: 3,9
* DIS C3: 6,8 + H2: 6 + I2: 3,9 # D2: 3,9 => CTR => D2: 5,7
* DIS C3: 6,8 + H2: 6 + I2: 3,9 + D2: 5,7 # D3: 5,7 => CTR => D3: 1,3,9
* DIS C3: 6,8 + H2: 6 + I2: 3,9 + D2: 5,7 + D3: 1,3,9 # F3: 5,7 => CTR => F3: 3,6,9
* DIS C3: 6,8 + H2: 6 + I2: 3,9 + D2: 5,7 + D3: 1,3,9 + F3: 3,6,9 # I3: 5,7 => CTR => I3: 1,2
* DIS C3: 6,8 + H2: 6 + I2: 3,9 + D2: 5,7 + D3: 1,3,9 + F3: 3,6,9 + I3: 1,2 # D3: 3,9 => CTR => D3: 1
* PRF C3: 6,8 + H2: 6 + I2: 3,9 + D2: 5,7 + D3: 1,3,9 + F3: 3,6,9 + I3: 1,2 + D3: 1 => SOL
* STA C3: 6,8 + H2: 6 + I2: 3,9 + D2: 5,7 + D3: 1,3,9 + F3: 3,6,9 + I3: 1,2 + D3: 1
* CNT   9 HDP CHAINS /  11 HYP OPENED

Header Info

Top 500 Minimum 17 277

solution: 938265741152784963476193852825671394394852176617349528741536289289417635563928417
info: 2208     FNBTHWY  S8.f     17898

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

Solution

position: 938265741152784963476193852825671394394852176617349528741536289289417635563928417 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: 6,8 => UNS
* DIS # C3: 2 => CTR => C3: 6,8
* DIS # G1: 6,8 => CTR => G1: 7
* PRF # G1: 7 => SOL
* INC # D2: 5,7 => UNS
* DIS # H2: 5,7 => CTR => H2: 6
* INC # H2: 6 => UNS
* DIS # I2: 5,7 => CTR => I2: 2,3,6,9
* INC # I2: 2,3,6,9 => UNS
* INC # C3: 2,6 => UNS
* DIS # C3: 8 => CTR => C3: 2,6
* DIS # G2: 2,6 => CTR => G2: 3,7,9
* INC # G2: 3,7,9 => UNS
* DIS # I2: 2,6 => CTR => I2: 3,5,7,9
* INC # I2: 3,5,7,9 => UNS
* DIS # D3: 5,7 => CTR => D3: 1,3,9
* INC # D3: 1,3,9 => UNS
* DIS # F3: 5,7 => CTR => F3: 3,6,9
* INC # F3: 3,6,9 => UNS
* PRF # H3: 5,7 => SOL
* INC # H3: 1,6,8 => UNS
* DIS # I3: 5,7 => CTR => I3: 1,2,3,6,9
* INC # I3: 1,2,3,6,9 => UNS
* PRF # I1: 1,6 => SOL
* DIS # I1: 5,7 => CTR => I1: 1,6
* DIS # D2: 3,9 => CTR => D2: 5,7
* INC # D2: 5,7 => UNS
* DIS # D3: 3,9 => CTR => D3: 1,5,7
* INC # D3: 1,5,7 => UNS
* PRF # F3: 3,9 => SOL
* INC # F3: 5,6,7 => UNS
* DIS # G3: 3,9 => CTR => G3: 2,6,7,8
* INC # G3: 2,6,7,8 => UNS
* DIS # I3: 3,9 => CTR => I3: 1,2,5,6,7
* INC # I3: 1,2,5,6,7 => UNS
* INC # E7: 3,9 => UNS
* INC # E7: 2 => UNS
* DIS # D2: 3,9 => CTR => D2: 5,7
* INC # D2: 5,7 => UNS
* DIS # D3: 3,9 => CTR => D3: 1,5,7
* INC # D3: 1,5,7 => UNS
* DIS # D7: 3,9 => CTR => D7: 5
* PRF # D7: 5 => SOL
* PRF # F3: 3,9 => SOL
* INC # F3: 5,6,7 => UNS
* DIS # F7: 3,9 => CTR => F7: 5,6,8
* INC # F7: 5,6,8 => UNS
* INC # H2: 6,7 => UNS
* DIS # H3: 6,7 => CTR => H3: 1,5,8
* INC # H3: 1,5,8 => UNS
* DIS # H9: 6,7 => CTR => H9: 1,8
* INC # H9: 1,8 => UNS
* DIS # I1: 6,7 => CTR => I1: 1,5
* INC # I1: 1,5 => UNS
* DIS # I2: 6,7 => CTR => I2: 2,3,5,9
* INC # I2: 2,3,5,9 => UNS
* INC # I3: 6,7 => UNS
* DIS # I8: 6,7 => CTR => I8: 1,5
* INC # I8: 1,5 => UNS
* INC # I9: 6,7 => UNS
* INC # B7: 6,8 => UNS
* INC # B9: 6,8 => UNS
* DIS # F8: 6,8 => CTR => F8: 5,7
* INC # F8: 5,7 => UNS
* PRF # G8: 6,8 => SOL
* DIS # G8: 7 => CTR => G8: 6,8
* DIS # I8: 1,6 => CTR => I8: 5,7
* PRF # I8: 5,7 => SOL
* INC # E7: 2,9 => UNS
* INC # E7: 3 => UNS
* INC # G9: 2,9 => UNS
* INC # I9: 2,9 => UNS
* CNT  72 HDP CHAINS /  72 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # C3: 6,8 => UNS
* DIS # C3: 2 => CTR => C3: 6,8
* INC C3: 6,8 # D2: 5,7 => UNS
* DIS C3: 6,8 # H2: 5,7 => CTR => H2: 6
* DIS C3: 6,8 + H2: 6 # I2: 5,7 => CTR => I2: 3,9
* INC C3: 6,8 + H2: 6 + I2: 3,9 # D2: 5,7 => UNS
* DIS C3: 6,8 + H2: 6 + I2: 3,9 # D2: 3,9 => CTR => D2: 5,7
* DIS C3: 6,8 + H2: 6 + I2: 3,9 + D2: 5,7 # D3: 5,7 => CTR => D3: 1,3,9
* DIS C3: 6,8 + H2: 6 + I2: 3,9 + D2: 5,7 + D3: 1,3,9 # F3: 5,7 => CTR => F3: 3,6,9
* DIS C3: 6,8 + H2: 6 + I2: 3,9 + D2: 5,7 + D3: 1,3,9 + F3: 3,6,9 # I3: 5,7 => CTR => I3: 1,2
* DIS C3: 6,8 + H2: 6 + I2: 3,9 + D2: 5,7 + D3: 1,3,9 + F3: 3,6,9 + I3: 1,2 # D3: 3,9 => CTR => D3: 1
* PRF C3: 6,8 + H2: 6 + I2: 3,9 + D2: 5,7 + D3: 1,3,9 + F3: 3,6,9 + I3: 1,2 + D3: 1 => SOL
* STA C3: 6,8 + H2: 6 + I2: 3,9 + D2: 5,7 + D3: 1,3,9 + F3: 3,6,9 + I3: 1,2 + D3: 1
* CNT  12 HDP CHAINS /  11 HYP OPENED