Analysis of xx-top500-056-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 1.......2....8..7.....1....4..3..6..5.8...1.....7......7...2......6...3.......4.. initial

Autosolve

position: 1...67..2....8..717...1..644273.168.538.261.7...7.82.3.74832.1....6..73....17.42. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # C2: 2,3 => CTR => C2: 5,6,9
* DIS # C3: 2,3 => CTR => C3: 5,9
* DIS # F2: 3,9 => CTR => F2: 4
* PRF # F2: 4 => SOL
* PRF # G3: 3,9 => SOL
* DIS # G1: 5,9 => CTR => G1: 3,8
* PRF # G3: 5,9 => SOL
* DIS # B1: 5,9 => CTR => B1: 4,8
* DIS # C1: 5,9 => CTR => C1: 3
* PRF # C1: 3 => SOL
* PRF # D1: 5,9 => SOL
* DIS # D1: 4 => CTR => D1: 5,9
* DIS # C6: 6,9 => CTR => C6: 1
* DIS # D2: 4,9 => CTR => D2: 2,5
* DIS # I7: 5,9 => CTR => I7: 6
* PRF # I7: 6 => SOL
* PRF # C9: 6,9 => SOL
* PRF # I7: 6,9 => SOL
* DIS # I7: 5 => CTR => I7: 6,9
* DIS # F8: 4,9 => CTR => F8: 5
* PRF # F8: 5 => SOL
* PRF # F8: 5,9 => SOL
* DIS # F8: 4 => CTR => F8: 5,9
* DIS # C9: 5,9 => CTR => C9: 3,6
* DIS # I7: 5,9 => CTR => I7: 6
* PRF # I7: 6 => SOL
* DIS # G1: 5,9 => CTR => G1: 3,8
* PRF # G3: 5,9 => SOL
* PRF # I9: 8,9 => SOL
* DIS # I9: 6 => CTR => I9: 8,9
* CNT  30 HDP CHAINS /  49 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 # C2: 2,3 => CTR => C2: 5,6,9
* DIS C2: 5,6,9 # C3: 2,3 => CTR => C3: 5,9
* PRF C2: 5,6,9 + C3: 5,9 => SOL
* STA C2: 5,6,9 + C3: 5,9
* CNT   3 HDP CHAINS /   2 HYP OPENED

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

Details

Positions

1.......2....8..7.....1....4..3..6..5.8...1.....7......7...2......6...3.......4.. initial
1...67..2....8..717...1..644273.168.538.261.7...7.82.3.74832.1....6..73....17.42. autosolve
143967852269584371785213964427391685538426197691758243974832516812645739356179428 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (17)
A2: 2,3
F3: 3,9
H1: 5,9
A6: 6,9
E4: 5,9
D5: 4,9
E6: 4,5
I4: 5,9
H5: 4,9
H6: 4,5
A7: 6,9
A8: 2,8
A9: 3,8
E8: 4,9
F9: 5,9
G7: 5,9
I8: 8,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
B6,C6: 1.. / B6 = 1  =>  0 pairs (X) / C6 = 1  => 18 pairs (_)
B8,C8: 1.. / B8 = 1  => 18 pairs (_) / C8 = 1  =>  0 pairs (X)
B6,B8: 1.. / B6 = 1  =>  0 pairs (X) / B8 = 1  => 18 pairs (_)
C6,C8: 1.. / C6 = 1  => 18 pairs (_) / C8 = 1  =>  0 pairs (X)
D2,D3: 2.. / D2 = 2  =>  0 pairs (X) / D3 = 2  => 17 pairs (_)
A8,C8: 2.. / A8 = 2  =>  0 pairs (X) / C8 = 2  =>  0 pairs (_)
C3,D3: 2.. / C3 = 2  =>  0 pairs (X) / D3 = 2  => 17 pairs (_)
A2,A8: 2.. / A2 = 2  =>  0 pairs (*) / A8 = 2  =>  0 pairs (X)
F2,F3: 3.. / F2 = 3  =>  0 pairs (X) / F3 = 3  => 17 pairs (_)
A9,C9: 3.. / A9 = 3  =>  0 pairs (*) / C9 = 3  =>  0 pairs (X)
C1,G1: 3.. / C1 = 3  =>  0 pairs (*) / G1 = 3  =>  0 pairs (X)
A2,A9: 3.. / A2 = 3  =>  0 pairs (X) / A9 = 3  =>  0 pairs (_)
B1,B2: 4.. / B1 = 4  =>  0 pairs (*) / B2 = 4  =>  0 pairs (X)
D5,E6: 4.. / D5 = 4  =>  0 pairs (*) / E6 = 4  =>  0 pairs (X)
H5,H6: 4.. / H5 = 4  =>  0 pairs (X) / H6 = 4  =>  0 pairs (_)
E8,F8: 4.. / E8 = 4  =>  0 pairs (*) / F8 = 4  =>  0 pairs (X)
B1,D1: 4.. / B1 = 4  =>  0 pairs (*) / D1 = 4  =>  0 pairs (X)
D5,H5: 4.. / D5 = 4  =>  0 pairs (*) / H5 = 4  =>  0 pairs (X)
E6,H6: 4.. / E6 = 4  =>  0 pairs (X) / H6 = 4  =>  0 pairs (_)
E6,E8: 4.. / E6 = 4  =>  0 pairs (X) / E8 = 4  =>  0 pairs (_)
F2,F8: 4.. / F2 = 4  =>  0 pairs (*) / F8 = 4  =>  0 pairs (X)
E4,E6: 5.. / E4 = 5  =>  0 pairs (X) / E6 = 5  =>  0 pairs (_)
I4,H6: 5.. / I4 = 5  =>  0 pairs (*) / H6 = 5  =>  0 pairs (X)
F8,F9: 5.. / F8 = 5  =>  0 pairs (*) / F9 = 5  =>  0 pairs (X)
G7,I7: 5.. / G7 = 5  =>  0 pairs (*) / I7 = 5  =>  0 pairs (X)
E4,I4: 5.. / E4 = 5  =>  0 pairs (X) / I4 = 5  =>  0 pairs (_)
E6,H6: 5.. / E6 = 5  =>  0 pairs (*) / H6 = 5  =>  0 pairs (X)
H1,H6: 5.. / H1 = 5  =>  0 pairs (*) / H6 = 5  =>  0 pairs (X)
I4,I7: 5.. / I4 = 5  =>  0 pairs (*) / I7 = 5  =>  0 pairs (X)
B2,C2: 6.. / B2 = 6  =>  0 pairs (*) / C2 = 6  =>  0 pairs (X)
I7,I9: 6.. / I7 = 6  =>  0 pairs (*) / I9 = 6  =>  0 pairs (X)
A7,I7: 6.. / A7 = 6  =>  0 pairs (X) / I7 = 6  =>  0 pairs (_)
A6,A7: 6.. / A6 = 6  =>  0 pairs (*) / A7 = 6  =>  0 pairs (X)
B1,B3: 8.. / B1 = 8  =>  0 pairs (X) / B3 = 8  =>  0 pairs (_)
G1,G3: 8.. / G1 = 8  =>  0 pairs (*) / G3 = 8  =>  0 pairs (X)
A8,A9: 8.. / A8 = 8  =>  0 pairs (*) / A9 = 8  =>  0 pairs (X)
I8,I9: 8.. / I8 = 8  =>  0 pairs (X) / I9 = 8  =>  0 pairs (_)
B1,G1: 8.. / B1 = 8  =>  0 pairs (X) / G1 = 8  =>  0 pairs (_)
B3,G3: 8.. / B3 = 8  =>  0 pairs (*) / G3 = 8  =>  0 pairs (X)
A8,I8: 8.. / A8 = 8  =>  0 pairs (*) / I8 = 8  =>  0 pairs (X)
A9,I9: 8.. / A9 = 8  =>  0 pairs (X) / I9 = 8  =>  0 pairs (_)
E4,D5: 9.. / E4 = 9  =>  0 pairs (*) / D5 = 9  =>  0 pairs (X)
I4,H5: 9.. / I4 = 9  =>  0 pairs (X) / H5 = 9  =>  0 pairs (_)
E4,I4: 9.. / E4 = 9  =>  0 pairs (*) / I4 = 9  =>  0 pairs (X)
D5,H5: 9.. / D5 = 9  =>  0 pairs (X) / H5 = 9  =>  0 pairs (_)
A6,A7: 9.. / A6 = 9  =>  0 pairs (X) / A7 = 9  =>  0 pairs (_)
E4,E8: 9.. / E4 = 9  =>  0 pairs (*) / E8 = 9  =>  0 pairs (X)
H1,H5: 9.. / H1 = 9  =>  0 pairs (X) / H5 = 9  =>  0 pairs (_)
* DURATION: 0:01:27.415908  START: 04:35:27.747877  END: 04:36:55.163785 2017-05-04
* CP COUNT: (48)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A2,A6,A7,A8,A9,D5,E4,E6,E8,F3,F9,G7,H1,H5,H6,I4,I8)
* 1...67..2....8..717...1..644273.168.538.261.7...7.82.3.74832.1....6..73....17.42.
* PAIR A2: 2,3 BLK 1
C2: 2,3,5,6,9                            # reduction candidate for 2,3
C2: 2,3 => CTR
* 143.678.226..8..7178..1..644273.168.538.261.7...7.82.3.74832.1....6..73....17.42.
C2: 5,6,9                                # 17 pairs
C3: 2,3,5,9                              # reduction candidate for 2,3
C3: 2,3 => CTR
* 18546739234628957179..1.8644273.168.538926147...748253.74832.15...6947388.3175426
C3: 5,9                                  # 18 pairs
* PAIR F3: 3,9 BLK 2
F2: 3,9,4                                # reduction candidate for 3,9
F2: 3,9 => CTR
* 1...673923...895717...13864427351689538926147...7482536748329152..694738893175426
F2: 4 => SOLVED
* 143967852269584371785213964427391685538426197691758243974832516812645739356179428
* PAIR F3: 3,9 ROW 3
C3: 3,9,2,5                              # reduction candidate for 3,9
C3: 3,9                                  # 20 pairs
G3: 3,9,5,8                              # reduction candidate for 3,9
G3: 3,9 => SOLVED
* 143967852269584371785213964427391685538426197691758243974832516812645739356179428
G3: 5,8                                  # 18 pairs
* PAIR H1: 5,9 BLK 3
G1: 5,9,3,8                              # reduction candidate for 5,9
G1: 5,9 => CTR
* 183467..2246.8..717..21.8644273.168.538926147...748253.74832.158.269.73....17.42.
G1: 3,8                                  # 18 pairs
G2: 5,9,3                                # reduction candidate for 5,9
G2: 5,9                                  # 20 pairs
G3: 5,9,3,8                              # reduction candidate for 5,9
G3: 5,9 => SOLVED
* 143967852269584371785213964427391685538426197691758243974832516812645739356179428
G3: 3,8                                  # 18 pairs
* PAIR H1: 5,9 ROW 1
B1: 5,9,4,8                              # reduction candidate for 5,9
B1: 5,9 => CTR
* 1..4678.2.46.8..7178..1..644273.168.538926147...748253.74832.15...6947388.3175426
B1: 4,8                                  # 18 pairs
C1: 5,9,3                                # reduction candidate for 5,9
C1: 5,9 => CTR
* 18546739234628957179..1.8644273.168.538926147...748253.74832.15...6947388.3175426
C1: 3 => SOLVED
* 143967852269584371785213964427391685538426197691758243974832516812645739356179428
D1: 5,9,4                                # reduction candidate for 5,9
D1: 5,9 => SOLVED
* 143967852269584371785213964427391685538426197691758243974832516812645739356179428
D1: 4 => CTR
* 1..4673923462895717.2513864427351689538926147.6.748253.74832.15...6947388.3175426
* PAIR A6: 6,9 BLK 4
B6: 6,9,1                                # reduction candidate for 6,9
B6: 6,9                                  # 18 pairs
C6: 6,9,1                                # reduction candidate for 6,9
C6: 6,9 => CTR
* 18.4673.23462895717.25138644273.168.538926147619748253974832.1.2.16..7388.317.42.
C6: 1                                    # 18 pairs
* PAIR D5: 4,9 COL D
D1: 4,9,5                                # reduction candidate for 4,9
D1: 4,9                                  # 20 pairs
D2: 4,9,2,5                              # reduction candidate for 4,9
D2: 4,9 => CTR
* 1..567.92....8..717..21..644273.1689538926147...748253.74832915...6947388.317.42.
D2: 2,5                                  # 18 pairs
* PAIR I4: 5,9 COL I
I7: 5,9,6                                # reduction candidate for 5,9
I7: 5,9 => CTR
* 18.4673.23462895717.25138644273.168.53892614796174825367483291521.6947388.317.426
I7: 6 => SOLVED
* 143967852269584371785213964427391685538426197691758243974832516812645739356179428
* PAIR A7: 6,9 BLK 7
B9: 6,9,5                                # reduction candidate for 6,9
B9: 6,9                                  # 20 pairs
C9: 6,9,3,5                              # reduction candidate for 6,9
C9: 6,9 => SOLVED
* 143967852269584371785213964427391685538426197691758243974832516812645739356179428
C9: 3,5                                  # 18 pairs
* PAIR A7: 6,9 ROW 7
I7: 6,9,5                                # reduction candidate for 6,9
I7: 6,9 => SOLVED
* 143967852269584371785213964427391685538426197691758243974832516812645739356179428
I7: 5 => CTR
* 1...673923...8.5717...138644273516895389261479..7482536748329152..694738893175426
* PAIR E8: 4,9 BLK 8
F8: 4,9,5                                # reduction candidate for 4,9
F8: 4,9 => CTR
* 18.4673.23462895717.25138644273.168.538926147...748253.7483291525169473889317542.
F8: 5 => SOLVED
* 143967852269584371785213964427391685538426197691758243974832516812645739356179428
* PAIR F9: 5,9 BLK 8
F8: 5,9,4                                # reduction candidate for 5,9
F8: 5,9 => SOLVED
* 143967852269584371785213964427391685538426197691758243974832516812645739356179428
F8: 4 => CTR
* 1...673923...895717...13864427351689538926147...7482536748329152..694738893175426
* PAIR F9: 5,9 ROW 9
B9: 5,9,6                                # reduction candidate for 5,9
B9: 5,9                                  # 20 pairs
C9: 5,9,3,6                              # reduction candidate for 5,9
C9: 5,9 => CTR
* 143.67..22.6.8..717..213.644273916855384261976.1758243974832516812645739365179428
C9: 3,6                                  # 18 pairs
* PAIR G7: 5,9 BLK 9
I7: 5,9,6                                # reduction candidate for 5,9
I7: 5,9 => CTR
* 18.4673.23462895717.25138644273.168.53892614796174825367483291521.6947388.317.426
I7: 6 => SOLVED
* 143967852269584371785213964427391685538426197691758243974832516812645739356179428
* PAIR G7: 5,9 COL G
G1: 5,9,3,8                              # reduction candidate for 5,9
G1: 5,9 => CTR
* 183467..2246.8..717..21.8644273.168.538926147...748253.74832.158.269.73....17.42.
G1: 3,8                                  # 18 pairs
G2: 5,9,3                                # reduction candidate for 5,9
G2: 5,9                                  # 20 pairs
G3: 5,9,3,8                              # reduction candidate for 5,9
G3: 5,9 => SOLVED
* 143967852269584371785213964427391685538426197691758243974832516812645739356179428
G3: 3,8                                  # 18 pairs
* PAIR I8: 8,9 BLK 9
I9: 8,9,6                                # reduction candidate for 8,9
I9: 8,9 => SOLVED
* 143967852269584371785213964427391685538426197691758243974832516812645739356179428
I9: 6 => CTR
* 18.4673.23462895717.25138644273.168.53892614796174825367483291521.6947388.317.426
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-056-base-pr-000.dot
* REASONING
* DIS # C2: 2,3 => CTR => C2: 5,6,9
* DIS # C3: 2,3 => CTR => C3: 5,9
* DIS # F2: 3,9 => CTR => F2: 4
* PRF # F2: 4 => SOL
* PRF # G3: 3,9 => SOL
* DIS # G1: 5,9 => CTR => G1: 3,8
* PRF # G3: 5,9 => SOL
* DIS # B1: 5,9 => CTR => B1: 4,8
* DIS # C1: 5,9 => CTR => C1: 3
* PRF # C1: 3 => SOL
* PRF # D1: 5,9 => SOL
* DIS # D1: 4 => CTR => D1: 5,9
* DIS # C6: 6,9 => CTR => C6: 1
* DIS # D2: 4,9 => CTR => D2: 2,5
* DIS # I7: 5,9 => CTR => I7: 6
* PRF # I7: 6 => SOL
* PRF # C9: 6,9 => SOL
* PRF # I7: 6,9 => SOL
* DIS # I7: 5 => CTR => I7: 6,9
* DIS # F8: 4,9 => CTR => F8: 5
* PRF # F8: 5 => SOL
* PRF # F8: 5,9 => SOL
* DIS # F8: 4 => CTR => F8: 5,9
* DIS # C9: 5,9 => CTR => C9: 3,6
* DIS # I7: 5,9 => CTR => I7: 6
* PRF # I7: 6 => SOL
* DIS # G1: 5,9 => CTR => G1: 3,8
* PRF # G3: 5,9 => SOL
* PRF # I9: 8,9 => SOL
* DIS # I9: 6 => CTR => I9: 8,9
* CNT  30 HDP CHAINS /  49 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A2,A6,A7,A8,A9,D5,E4,E6,E8,F3,F9,G7,H1,H5,H6,I4,I8)
* 1...67..2....8..717...1..644273.168.538.261.7...7.82.3.74832.1....6..73....17.42.
* PAIR A2: 2,3 BLK 1
C2: 2,3,5,6,9                            # reduction candidate for 2,3
C2: 2,3 => CTR
* 143.678.226..8..7178..1..644273.168.538.261.7...7.82.3.74832.1....6..73....17.42.
C3: 2,3,5,9                              # reduction candidate for 2,3
C3: 2,3 => CTR
* 18546739234628957179..1.8644273.168.538926147...748253.74832.15...6947388.3175426
C3: 5,9 => SOLVED
* 143967852269584371785213964427391685538426197691758243974832516812645739356179428
* DURATION: 0:00:02.959184  START: 04:37:48.467626  END: 04:37:51.426810 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-056-base-pr-001.dot
* REASONING
* DIS # C2: 2,3 => CTR => C2: 5,6,9
* DIS C2: 5,6,9 # C3: 2,3 => CTR => C3: 5,9
* PRF C2: 5,6,9 + C3: 5,9 => SOL
* STA C2: 5,6,9 + C3: 5,9
* CNT   3 HDP CHAINS /   2 HYP OPENED

Header Info

Top 500 Minimum 17 056

solution: 143967852269584371785213964427391685538426197691758243974832516812645739356179428
info: 1420     FNBTHWY  S8.f     46656

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

Solution

position: 143967852269584371785213964427391685538426197691758243974832516812645739356179428 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 # C2: 2,3 => CTR => C2: 5,6,9
* INC # C2: 5,6,9 => UNS
* DIS # C3: 2,3 => CTR => C3: 5,9
* INC # C3: 5,9 => UNS
* DIS # F2: 3,9 => CTR => F2: 4
* PRF # F2: 4 => SOL
* INC # C3: 3,9 => UNS
* PRF # G3: 3,9 => SOL
* INC # G3: 5,8 => UNS
* DIS # G1: 5,9 => CTR => G1: 3,8
* INC # G1: 3,8 => UNS
* INC # G2: 5,9 => UNS
* PRF # G3: 5,9 => SOL
* INC # G3: 3,8 => UNS
* DIS # B1: 5,9 => CTR => B1: 4,8
* INC # B1: 4,8 => UNS
* DIS # C1: 5,9 => CTR => C1: 3
* PRF # C1: 3 => SOL
* PRF # D1: 5,9 => SOL
* DIS # D1: 4 => CTR => D1: 5,9
* INC # B6: 6,9 => UNS
* DIS # C6: 6,9 => CTR => C6: 1
* INC # C6: 1 => UNS
* INC # D1: 4,9 => UNS
* DIS # D2: 4,9 => CTR => D2: 2,5
* INC # D2: 2,5 => UNS
* DIS # I7: 5,9 => CTR => I7: 6
* PRF # I7: 6 => SOL
* INC # B9: 6,9 => UNS
* PRF # C9: 6,9 => SOL
* INC # C9: 3,5 => UNS
* PRF # I7: 6,9 => SOL
* DIS # I7: 5 => CTR => I7: 6,9
* DIS # F8: 4,9 => CTR => F8: 5
* PRF # F8: 5 => SOL
* PRF # F8: 5,9 => SOL
* DIS # F8: 4 => CTR => F8: 5,9
* INC # B9: 5,9 => UNS
* DIS # C9: 5,9 => CTR => C9: 3,6
* INC # C9: 3,6 => UNS
* DIS # I7: 5,9 => CTR => I7: 6
* PRF # I7: 6 => SOL
* DIS # G1: 5,9 => CTR => G1: 3,8
* INC # G1: 3,8 => UNS
* INC # G2: 5,9 => UNS
* PRF # G3: 5,9 => SOL
* INC # G3: 3,8 => UNS
* PRF # I9: 8,9 => SOL
* DIS # I9: 6 => CTR => I9: 8,9
* CNT  49 HDP CHAINS /  49 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # C2: 2,3 => CTR => C2: 5,6,9
* DIS C2: 5,6,9 # C3: 2,3 => CTR => C3: 5,9
* PRF C2: 5,6,9 + C3: 5,9 => SOL
* STA C2: 5,6,9 + C3: 5,9
* CNT   3 HDP CHAINS /   2 HYP OPENED