Analysis of xx-top500-486-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: ..35...........2.6.81......56..2...........1.7...........1...8....3.6...4.....7.. initial

Autosolve

position: ..35..1.89..8132.6.81...35.56..218.383.....1.71..38.6.3..1..68.1.83.6.2.4.6.8.731 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # H1: 4,7 => CTR => H1: 9
* DIS # H1: 4,7 => CTR => H1: 9
* DIS # H4: 9 => CTR => H4: 4,7
* DIS # C5: 4,9 => CTR => C5: 2
* DIS # D4: 4,9 => CTR => D4: 7
* DIS # D4: 4,9 => CTR => D4: 7
* PRF # D5: 4,9 => SOL
* DIS # E5: 4,9 => CTR => E5: 5,6,7
* DIS # G6: 4,9 => CTR => G6: 5
* DIS # I6: 4,9 => CTR => I6: 2,5
* DIS # I5: 4,9 => CTR => I5: 2,7
* DIS # G6: 4,9 => CTR => G6: 5
* DIS # I6: 4,9 => CTR => I6: 2,5
* DIS # C5: 4,9 => CTR => C5: 2
* PRF # D5: 4,9 => SOL
* DIS # E5: 4,9 => CTR => E5: 5,6,7
* DIS # G8: 5 => CTR => G8: 4,9
* DIS # B7: 5,7 => CTR => B7: 2,9
* DIS # D3: 2,9 => CTR => D3: 4,6,7
* CNT  19 HDP CHAINS /  64 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 # H1: 4,7 => CTR => H1: 9
* DIS H1: 9 # B2: 5 => CTR => B2: 4,7
* PRF H1: 9 + B2: 4,7 # F1: 2 => SOL
* STA H1: 9 + B2: 4,7 + F1: 2
* CNT   3 HDP CHAINS /   9 HYP OPENED

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

Details

Positions

..35...........2.6.81......56..2...........1.7...........1...8....3.6...4.....7.. initial
..35..1.89..8132.6.81...35.56..218.383.....1.71..38.6.3..1..68.1.83.6.2.4.6.8.731 autosolve
673542198945813276281697354569721843832465917714938562327154689198376425456289731 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (10)
A1: 2,6
B1: 4,7
C2: 5,7
A3: 2,6
H2: 4,7
C4: 4,9
D6: 4,9
G5: 4,9
C7: 5,7
D9: 2,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
A1,A3: 2.. / A1 = 2  =>  8 pairs (_) / A3 = 2  =>  9 pairs (_)
C5,C6: 2.. / C5 = 2  => 12 pairs (_) / C6 = 2  =>  0 pairs (X)
I5,I6: 2.. / I5 = 2  =>  0 pairs (X) / I6 = 2  => 12 pairs (_)
B7,B9: 2.. / B7 = 2  => 11 pairs (_) / B9 = 2  =>  0 pairs (X)
A1,F1: 2.. / A1 = 2  =>  8 pairs (_) / F1 = 2  =>  9 pairs (_)
C5,I5: 2.. / C5 = 2  => 12 pairs (_) / I5 = 2  =>  0 pairs (X)
C6,I6: 2.. / C6 = 2  =>  0 pairs (X) / I6 = 2  => 12 pairs (_)
B7,F7: 2.. / B7 = 2  => 11 pairs (_) / F7 = 2  =>  0 pairs (X)
D3,D9: 2.. / D3 = 2  =>  0 pairs (X) / D9 = 2  => 11 pairs (_)
B1,B2: 4.. / B1 = 4  => 12 pairs (_) / B2 = 4  => 13 pairs (_)
B2,H2: 4.. / B2 = 4  => 13 pairs (_) / H2 = 4  => 12 pairs (_)
B2,C2: 5.. / B2 = 5  => 12 pairs (_) / C2 = 5  => 11 pairs (_)
E5,F5: 5.. / E5 = 5  => 10 pairs (_) / F5 = 5  => 16 pairs (_)
G6,I6: 5.. / G6 = 5  => 11 pairs (_) / I6 = 5  =>  0 pairs (X)
B9,F9: 5.. / B9 = 5  => 17 pairs (_) / F9 = 5  => 11 pairs (_)
C2,C7: 5.. / C2 = 5  => 11 pairs (_) / C7 = 5  => 12 pairs (_)
G6,G8: 5.. / G6 = 5  => 11 pairs (_) / G8 = 5  =>  0 pairs (X)
A1,A3: 6.. / A1 = 6  =>  9 pairs (_) / A3 = 6  =>  8 pairs (_)
D5,E5: 6.. / D5 = 6  => 10 pairs (_) / E5 = 6  =>  0 pairs (*)
A1,E1: 6.. / A1 = 6  =>  9 pairs (_) / E1 = 6  =>  8 pairs (_)
D3,D5: 6.. / D3 = 6  =>  0 pairs (*) / D5 = 6  =>  0 pairs (X)
H4,I5: 7.. / H4 = 7  =>  0 pairs (X) / I5 = 7  => 14 pairs (_)
D4,H4: 7.. / D4 = 7  => 14 pairs (_) / H4 = 7  =>  0 pairs (X)
B8,E8: 7.. / B8 = 7  => 13 pairs (_) / E8 = 7  => 12 pairs (_)
C2,C7: 7.. / C2 = 7  => 12 pairs (_) / C7 = 7  => 11 pairs (_)
I3,I5: 7.. / I3 = 7  =>  0 pairs (X) / I5 = 7  => 14 pairs (_)
H1,I3: 9.. / H1 = 9  => 12 pairs (_) / I3 = 9  =>  0 pairs (X)
H1,H4: 9.. / H1 = 9  => 12 pairs (_) / H4 = 9  =>  0 pairs (X)
* DURATION: 0:00:45.225522  START: 19:14:34.300287  END: 19:15:19.525809 2017-05-04
* CP COUNT: (28)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,A3,B1,C2,C4,C7,D6,D9,G5,H2)
* ..35..1.89..8132.6.81...35.56..218.383.....1.71..38.6.3..1..68.1.83.6.2.4.6.8.731
* PAIR B1: 4,7 BLK 1
B2: 4,7,5                                # reduction candidate for 4,7
B2: 5                                    # 12 pairs
B2: 4,7                                  # 11 pairs
* PAIR B1: 4,7 ROW 1
E1: 4,7,6,9                              # reduction candidate for 4,7
E1: 4,7                                  # 12 pairs
F1: 4,7,2,9                              # reduction candidate for 4,7
F1: 4,7                                  # 11 pairs
H1: 4,7,9                                # reduction candidate for 4,7
H1: 4,7 => CTR
* ..35.21.89..8132.62816..3595647218938329654177194385623..1..68.1.83.692.4.6.8.731
H1: 9                                    # 12 pairs
* PAIR C2: 5,7 BLK 1
B2: 5,7,4                                # reduction candidate for 5,7
B2: 4                                    # 13 pairs
B2: 5,7                                  # 12 pairs
* PAIR A3: 2,6 ROW 3
D3: 2,6,4,7,9                            # reduction candidate for 2,6
D3: 2,6                                  # 12 pairs
D3: 4,7,9                                # 11 pairs
* PAIR H2: 4,7 BLK 3
H1: 4,7,9                                # reduction candidate for 4,7
H1: 4,7 => CTR
* ..35.21.89..8132.62816..3595647218938329654177194385623..1..68.1.83.692.4.6.8.731
H1: 9                                    # 12 pairs
I3: 4,7,9                                # reduction candidate for 4,7
I3: 4,7                                  # 12 pairs
* PAIR H2: 4,7 ROW 2
B2: 4,7,5                                # reduction candidate for 4,7
B2: 5                                    # 12 pairs
B2: 4,7                                  # 11 pairs
* PAIR H2: 4,7 COL H
H4: 4,7,9                                # reduction candidate for 4,7
H4: 9 => CTR
* ..35.21.89..8132.62816..3595647218938329654177194385623..1..68.1.83.692.4.6.8.731
H4: 4,7                                  # 12 pairs
* PAIR C4: 4,9 BLK 4
C5: 4,9,2                                # reduction candidate for 4,9
C5: 4,9 => CTR
* 6.35.21989.58132462816..35756..2187383.765.12712.38.6.3271..68.198376.2.456289731
C5: 2                                    # 12 pairs
C6: 4,9,2                                # reduction candidate for 4,9
C6: 4,9                                  # 12 pairs
* PAIR C4: 4,9 ROW 4
D4: 4,9,7                                # reduction candidate for 4,9
D4: 4,9 => CTR
* 6435721989758132462816..35756..2187383.765.1.71..38.6.3271..68.1983.6.2.456289731
D4: 7                                    # 14 pairs
H4: 4,9,7                                # reduction candidate for 4,9
H4: 4,9                                  # 14 pairs
* PAIR D6: 4,9 BLK 5
D4: 4,9,7                                # reduction candidate for 4,9
D4: 4,9 => CTR
* 6435721989758132462816..35756..2187383.765.1.71..38.6.3271..68.1983.6.2.456289731
D4: 7                                    # 14 pairs
D5: 4,9,6,7                              # reduction candidate for 4,9
D5: 4,9 => SOLVED
* 673542198945813276281697354569721843832465917714938562327154689198376425456289731
D5: 6,7                                  # 11 pairs
E5: 4,9,5,6,7                            # reduction candidate for 4,9
E5: 4,9 => CTR
* ..35..1.89.58132.6.81..735456.72184383264591771493856232715468919837642545628.731
E5: 5,6,7                                # 10 pairs
F5: 4,9,5,7                              # reduction candidate for 4,9
F5: 4,9                                  # 15 pairs
* PAIR D6: 4,9 ROW 6
C6: 4,9,2                                # reduction candidate for 4,9
C6: 4,9                                  # 12 pairs
G6: 4,9,5                                # reduction candidate for 4,9
G6: 4,9 => CTR
* 6.35.21989.58132462816..35756..2187383.765.12712.38.6532715.68.198376524456289731
G6: 5                                    # 11 pairs
I6: 4,9,2,5                              # reduction candidate for 4,9
I6: 4,9 => CTR
* 6.35.21989.58132462816..35756..2187383.765.12712.3856.3271..68.198376425456289731
I6: 2,5                                  # 11 pairs
* PAIR D6: 4,9 COL D
D3: 4,9,2,6,7                            # reduction candidate for 4,9
D3: 4,9                                  # 18 pairs
D3: 2,6,7                                # 10 pairs
* PAIR G5: 4,9 BLK 6
H4: 4,9,7                                # reduction candidate for 4,9
H4: 4,9                                  # 14 pairs
I5: 4,9,2,7                              # reduction candidate for 4,9
I5: 4,9 => CTR
* 6.35.21989.58132462816..35756..21873832765.1.71..385623271..68.198376425456289731
I5: 2,7                                  # 11 pairs
G6: 4,9,5                                # reduction candidate for 4,9
G6: 4,9 => CTR
* 6.35.21989.58132462816..35756..2187383.765.12712.38.6532715.68.198376524456289731
G6: 5                                    # 11 pairs
I6: 4,9,2,5                              # reduction candidate for 4,9
I6: 4,9 => CTR
* 6.35.21989.58132462816..35756..2187383.765.12712.3856.3271..68.198376425456289731
I6: 2,5                                  # 11 pairs
* PAIR G5: 4,9 ROW 5
C5: 4,9,2                                # reduction candidate for 4,9
C5: 4,9 => CTR
* 6.35.21989.58132462816..35756..2187383.765.12712.38.6.3271..68.198376.2.456289731
C5: 2                                    # 12 pairs
D5: 4,9,6,7                              # reduction candidate for 4,9
D5: 4,9 => SOLVED
* 673542198945813276281697354569721843832465917714938562327154689198376425456289731
D5: 6,7                                  # 11 pairs
E5: 4,9,5,6,7                            # reduction candidate for 4,9
E5: 4,9 => CTR
* ..35..1.89.58132.6.81..735456.72184383264591771493856232715468919837642545628.731
E5: 5,6,7                                # 10 pairs
F5: 4,9,5,7                              # reduction candidate for 4,9
F5: 4,9                                  # 15 pairs
* PAIR G5: 4,9 COL G
G8: 4,9,5                                # reduction candidate for 4,9
G8: 5 => CTR
* 6.35.21989.58132462816..35756..2187383.765.12712.38.6532715.68.198376524456289731
G8: 4,9                                  # 11 pairs
* PAIR C7: 5,7 BLK 7
B7: 5,7,2,9                              # reduction candidate for 5,7
B7: 5,7 => CTR
* 2.356.1.89..8132.66812..35.56..218.383.65941771.438.623..1.26891983.6.2.426985731
B7: 2,9                                  # 11 pairs
B8: 5,7,9                                # reduction candidate for 5,7
B8: 5,7                                  # 13 pairs
* PAIR C7: 5,7 ROW 7
E7: 5,7,4,9                              # reduction candidate for 5,7
E7: 5,7                                  # 14 pairs
F7: 5,7,2,4,9                            # reduction candidate for 5,7
F7: 5,7                                  # 15 pairs
* PAIR D9: 2,9 BLK 8
F7: 2,9,4,5,7                            # reduction candidate for 2,9
F7: 2,9                                  # 16 pairs
F9: 2,9,5                                # reduction candidate for 2,9
F9: 2,9                                  # 17 pairs
* PAIR D9: 2,9 ROW 9
B9: 2,9,5                                # reduction candidate for 2,9
B9: 5                                    # 17 pairs
B9: 2,9                                  # 11 pairs
* PAIR D9: 2,9 COL D
D3: 2,9,4,6,7                            # reduction candidate for 2,9
D3: 2,9 => CTR
* 2.35691.89..8132.6.812..3595647218938326..41771943856239.1.268.1.83.692.426985731
D3: 4,6,7                                # 11 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-486-base-pr-000.dot
* REASONING
* DIS # H1: 4,7 => CTR => H1: 9
* DIS # H1: 4,7 => CTR => H1: 9
* DIS # H4: 9 => CTR => H4: 4,7
* DIS # C5: 4,9 => CTR => C5: 2
* DIS # D4: 4,9 => CTR => D4: 7
* DIS # D4: 4,9 => CTR => D4: 7
* PRF # D5: 4,9 => SOL
* DIS # E5: 4,9 => CTR => E5: 5,6,7
* DIS # G6: 4,9 => CTR => G6: 5
* DIS # I6: 4,9 => CTR => I6: 2,5
* DIS # I5: 4,9 => CTR => I5: 2,7
* DIS # G6: 4,9 => CTR => G6: 5
* DIS # I6: 4,9 => CTR => I6: 2,5
* DIS # C5: 4,9 => CTR => C5: 2
* PRF # D5: 4,9 => SOL
* DIS # E5: 4,9 => CTR => E5: 5,6,7
* DIS # G8: 5 => CTR => G8: 4,9
* DIS # B7: 5,7 => CTR => B7: 2,9
* DIS # D3: 2,9 => CTR => D3: 4,6,7
* CNT  19 HDP CHAINS /  64 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,A3,B1,C2,C4,C7,D6,D9,G5,H2)
* ..35..1.89..8132.6.81...35.56..218.383.....1.71..38.6.3..1..68.1.83.6.2.4.6.8.731
* PAIR B1: 4,7 BLK 1
B2: 4,7,5                                # reduction candidate for 4,7
B2: 5                                    # 12 pairs
B2: 4,7                                  # 11 pairs
* PAIR B1: 4,7 ROW 1
E1: 4,7,6,9                              # reduction candidate for 4,7
E1: 4,7                                  # 12 pairs
F1: 4,7,2,9                              # reduction candidate for 4,7
F1: 4,7                                  # 11 pairs
H1: 4,7,9                                # reduction candidate for 4,7
H1: 4,7 => CTR
* ..35.21.89..8132.62816..3595647218938329654177194385623..1..68.1.83.692.4.6.8.731
* PAIR RESTART
* PAIR B1: 4,7 BLK 1
B2: 4,7,5                                # reduction candidate for 4,7
B2: 5 => CTR
* .435..198957813246.81...35756..2187383.765.1.71..38.6.3.51..68.1.8356.2.4.6.8.731
* PAIR B1: 4,7 ROW 1
F1: 4,7,2                                # reduction candidate for 4,7
F1: 2 => SOLVED
* 673542198945813276281697354569721843832465917714938562327154689198376425456289731
* DURATION: 0:00:09.343570  START: 19:16:16.113013  END: 19:16:25.456583 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-486-base-pr-001.dot
* REASONING
* DIS # H1: 4,7 => CTR => H1: 9
* DIS H1: 9 # B2: 5 => CTR => B2: 4,7
* PRF H1: 9 + B2: 4,7 # F1: 2 => SOL
* STA H1: 9 + B2: 4,7 + F1: 2
* CNT   3 HDP CHAINS /   9 HYP OPENED

Header Info

Top 500 Minimum 17 486

solution: 673542198945813276281697354569721843832465917714938562327154689198376425456289731
info: 96136    FNBXK    S8.f     13519

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

Solution

position: 673542198945813276281697354569721843832465917714938562327154689198376425456289731 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 # B2: 4,7 => UNS
* INC # B2: 5 => UNS
* INC # E1: 4,7 => UNS
* INC # F1: 4,7 => UNS
* DIS # H1: 4,7 => CTR => H1: 9
* INC # H1: 9 => UNS
* INC # B2: 5,7 => UNS
* INC # B2: 4 => UNS
* INC # D3: 2,6 => UNS
* INC # D3: 4,7,9 => UNS
* DIS # H1: 4,7 => CTR => H1: 9
* INC # H1: 9 => UNS
* INC # I3: 4,7 => UNS
* INC # B2: 4,7 => UNS
* INC # B2: 5 => UNS
* INC # H4: 4,7 => UNS
* DIS # H4: 9 => CTR => H4: 4,7
* DIS # C5: 4,9 => CTR => C5: 2
* INC # C5: 2 => UNS
* INC # C6: 4,9 => UNS
* DIS # D4: 4,9 => CTR => D4: 7
* INC # D4: 7 => UNS
* INC # H4: 4,9 => UNS
* DIS # D4: 4,9 => CTR => D4: 7
* INC # D4: 7 => UNS
* PRF # D5: 4,9 => SOL
* INC # D5: 6,7 => UNS
* DIS # E5: 4,9 => CTR => E5: 5,6,7
* INC # E5: 5,6,7 => UNS
* INC # F5: 4,9 => UNS
* INC # C6: 4,9 => UNS
* DIS # G6: 4,9 => CTR => G6: 5
* INC # G6: 5 => UNS
* DIS # I6: 4,9 => CTR => I6: 2,5
* INC # I6: 2,5 => UNS
* INC # D3: 4,9 => UNS
* INC # D3: 2,6,7 => UNS
* INC # H4: 4,9 => UNS
* DIS # I5: 4,9 => CTR => I5: 2,7
* INC # I5: 2,7 => UNS
* DIS # G6: 4,9 => CTR => G6: 5
* INC # G6: 5 => UNS
* DIS # I6: 4,9 => CTR => I6: 2,5
* INC # I6: 2,5 => UNS
* DIS # C5: 4,9 => CTR => C5: 2
* INC # C5: 2 => UNS
* PRF # D5: 4,9 => SOL
* INC # D5: 6,7 => UNS
* DIS # E5: 4,9 => CTR => E5: 5,6,7
* INC # E5: 5,6,7 => UNS
* INC # F5: 4,9 => UNS
* INC # G8: 4,9 => UNS
* DIS # G8: 5 => CTR => G8: 4,9
* DIS # B7: 5,7 => CTR => B7: 2,9
* INC # B7: 2,9 => UNS
* INC # B8: 5,7 => UNS
* INC # E7: 5,7 => UNS
* INC # F7: 5,7 => UNS
* INC # F7: 2,9 => UNS
* INC # F9: 2,9 => UNS
* INC # B9: 2,9 => UNS
* INC # B9: 5 => UNS
* DIS # D3: 2,9 => CTR => D3: 4,6,7
* INC # D3: 4,6,7 => UNS
* CNT  64 HDP CHAINS /  64 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # B2: 4,7 => UNS
* INC # B2: 5 => UNS
* INC # E1: 4,7 => UNS
* INC # F1: 4,7 => UNS
* DIS # H1: 4,7 => CTR => H1: 9
* INC H1: 9 # B2: 4,7 => UNS
* DIS H1: 9 # B2: 5 => CTR => B2: 4,7
* INC H1: 9 + B2: 4,7 # F1: 4,7 => UNS
* PRF H1: 9 + B2: 4,7 # F1: 2 => SOL
* STA H1: 9 + B2: 4,7 + F1: 2
* CNT   9 HDP CHAINS /   9 HYP OPENED