Analysis of xx-top500-370-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: .41..........23.......9....6......54...8...1.3........2.....9.....1..3...7.5..... initial

Autosolve

position: 941....325...231...32.915..618937254.298...1335.21.8..2.53..9.1.9.1.23.51735.942. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # I3: 6 => SOL
* DIS # D3: 4 => CTR => D3: 6,7
* PRF # D3: 4,7 => SOL
* DIS # D3: 6 => CTR => D3: 4,7
* DIS # I3: 8 => CTR => I3: 6,7
* DIS # F5: 4,6 => CTR => F5: 5
* DIS # F7: 8 => CTR => F7: 4,6
* DIS # I6: 9 => CTR => I6: 6,7
* DIS # I6: 6,9 => CTR => I6: 7
* PRF # I6: 7 => SOL
* DIS # E7: 6,8 => CTR => E7: 4,7
* PRF # H7: 6,8 => SOL
* DIS # E7: 6,8 => CTR => E7: 4,7
* PRF # E8: 6,8 => SOL
* PRF # H7: 6,8 => SOL
* DIS # I3: 7 => CTR => I3: 6,8
* CNT  16 HDP CHAINS /  32 HYP OPENED

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

Pair Reduction

Pair Reduction

The following important HDP chains were detected:

* PRF # I3: 6 => SOL
* STA I3: 6
* CNT   1 HDP CHAINS /   2 HYP OPENED

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

Details

Positions

.41..........23.......9....6......54...8...1.3........2.....9.....1..3...7.5..... initial
941....325...231...32.915..618937254.298...1335.21.8..2.53..9.1.9.1.23.51735.942. autosolve
941658732567423189832791546618937254729845613354216897285374961496182375173569428 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (18)
B2: 6,8
C2: 6,7
A3: 7,8
D1: 6,7
E1: 5,8
F1: 5,8
D2: 4,7
G1: 6,7
A5: 4,7
C6: 4,7
F6: 4,6
G5: 6,7
H6: 6,9
B7: 6,8
A8: 4,8
C8: 4,6
E9: 6,8
I9: 6,8

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
D2,D3: 4.. / D2 = 4  => 19 pairs (_) / D3 = 4  =>  0 pairs (X)
H2,H3: 4.. / H2 = 4  =>  0 pairs (X) / H3 = 4  => 19 pairs (_)
A5,C6: 4.. / A5 = 4  =>  0 pairs (X) / C6 = 4  =>  0 pairs (_)
A8,C8: 4.. / A8 = 4  =>  0 pairs (*) / C8 = 4  =>  0 pairs (X)
E7,F7: 4.. / E7 = 4  => 21 pairs (_) / F7 = 4  =>  0 pairs (*)
D2,H2: 4.. / D2 = 4  => 19 pairs (_) / H2 = 4  =>  0 pairs (X)
D3,H3: 4.. / D3 = 4  =>  0 pairs (X) / H3 = 4  => 19 pairs (_)
C6,F6: 4.. / C6 = 4  =>  0 pairs (*) / F6 = 4  =>  0 pairs (X)
A5,A8: 4.. / A5 = 4  =>  0 pairs (X) / A8 = 4  =>  0 pairs (_)
C6,C8: 4.. / C6 = 4  =>  0 pairs (*) / C8 = 4  =>  0 pairs (X)
E5,E7: 4.. / E5 = 4  =>  0 pairs (*) / E7 = 4  =>  0 pairs (X)
E1,F1: 5.. / E1 = 5  => 18 pairs (_) / F1 = 5  =>  0 pairs (X)
E5,F5: 5.. / E5 = 5  =>  0 pairs (X) / F5 = 5  => 18 pairs (_)
E1,E5: 5.. / E1 = 5  => 18 pairs (_) / E5 = 5  =>  0 pairs (X)
F1,F5: 5.. / F1 = 5  =>  0 pairs (X) / F5 = 5  => 18 pairs (_)
B2,C2: 6.. / B2 = 6  =>  0 pairs (*) / C2 = 6  =>  0 pairs (X)
D1,D3: 6.. / D1 = 6  =>  0 pairs (*) / D3 = 6  =>  0 pairs (X)
B7,C8: 6.. / B7 = 6  =>  0 pairs (X) / C8 = 6  =>  0 pairs (_)
D1,G1: 6.. / D1 = 6  =>  0 pairs (*) / G1 = 6  =>  0 pairs (X)
E9,I9: 6.. / E9 = 6  => 24 pairs (_) / I9 = 6  => 24 pairs (_)
B2,B7: 6.. / B2 = 6  =>  0 pairs (*) / B7 = 6  =>  0 pairs (X)
C2,C8: 6.. / C2 = 6  =>  0 pairs (X) / C8 = 6  =>  0 pairs (_)
G1,G5: 6.. / G1 = 6  =>  0 pairs (X) / G5 = 6  =>  0 pairs (_)
C2,A3: 7.. / C2 = 7  =>  0 pairs (*) / A3 = 7  =>  0 pairs (X)
A5,C6: 7.. / A5 = 7  =>  0 pairs (*) / C6 = 7  =>  0 pairs (X)
G5,I6: 7.. / G5 = 7  =>  0 pairs (X) / I6 = 7  =>  0 pairs (_)
E7,E8: 7.. / E7 = 7  =>  0 pairs (*) / E8 = 7  =>  0 pairs (X)
H7,H8: 7.. / H7 = 7  => 19 pairs (_) / H8 = 7  =>  0 pairs (*)
D1,G1: 7.. / D1 = 7  =>  0 pairs (X) / G1 = 7  =>  0 pairs (_)
A5,G5: 7.. / A5 = 7  =>  0 pairs (*) / G5 = 7  =>  0 pairs (X)
C6,I6: 7.. / C6 = 7  =>  0 pairs (X) / I6 = 7  =>  0 pairs (_)
E7,H7: 7.. / E7 = 7  =>  0 pairs (*) / H7 = 7  =>  0 pairs (X)
E8,H8: 7.. / E8 = 7  => 19 pairs (_) / H8 = 7  =>  0 pairs (*)
A3,A5: 7.. / A3 = 7  =>  0 pairs (X) / A5 = 7  =>  0 pairs (_)
C2,C6: 7.. / C2 = 7  =>  0 pairs (*) / C6 = 7  =>  0 pairs (X)
G1,G5: 7.. / G1 = 7  =>  0 pairs (*) / G5 = 7  =>  0 pairs (X)
B2,A3: 8.. / B2 = 8  =>  0 pairs (X) / A3 = 8  =>  0 pairs (_)
E1,F1: 8.. / E1 = 8  =>  0 pairs (X) / F1 = 8  => 18 pairs (_)
B7,A8: 8.. / B7 = 8  =>  0 pairs (*) / A8 = 8  =>  0 pairs (X)
E9,I9: 8.. / E9 = 8  => 24 pairs (_) / I9 = 8  => 24 pairs (_)
A3,A8: 8.. / A3 = 8  =>  0 pairs (*) / A8 = 8  =>  0 pairs (X)
B2,B7: 8.. / B2 = 8  =>  0 pairs (X) / B7 = 8  =>  0 pairs (_)
F1,F7: 8.. / F1 = 8  => 18 pairs (_) / F7 = 8  =>  0 pairs (X)
H2,I2: 9.. / H2 = 9  =>  0 pairs (X) / I2 = 9  => 19 pairs (_)
H6,I6: 9.. / H6 = 9  => 19 pairs (_) / I6 = 9  =>  0 pairs (X)
H2,H6: 9.. / H2 = 9  =>  0 pairs (X) / H6 = 9  => 19 pairs (_)
I2,I6: 9.. / I2 = 9  => 19 pairs (_) / I6 = 9  =>  0 pairs (X)
* DURATION: 0:01:41.347122  START: 15:29:31.459242  END: 15:31:12.806364 2017-05-04
* CP COUNT: (47)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A3,A5,A8,B2,B7,C2,C6,C8,D1,D2,E1,E9,F1,F6,G1,G5,H6,I9)
* 941....325...231...32.915..618937254.298...1335.21.8..2.53..9.1.9.1.23.51735.942.
* PAIR A3: 7,8 ROW 3
I3: 7,8,6                                # reduction candidate for 7,8
I3: 6 => SOLVED
* 941658732567423189832791546618937254729845613354216897285374961496182375173569428
I3: 7,8                                  # 21 pairs
* PAIR D1: 6,7 BLK 2
D3: 6,7,4                                # reduction candidate for 6,7
D3: 4 => CTR
* 9416..7325..7231497324915..6189372544298..61335721.8..2.53..9.1.9.1.23.51735.942.
D3: 6,7                                  # 19 pairs
* PAIR D2: 4,7 BLK 2
D3: 4,7,6                                # reduction candidate for 4,7
D3: 4,7 => SOLVED
* 941658732567423189832791546618937254729845613354216897285374961496182375173569428
D3: 6 => CTR
* 9417..6325..4231...3269154.618937254.298..7133572148..2.534.971.94172365173569428
* PAIR G1: 6,7 BLK 3
I3: 6,7,8                                # reduction candidate for 6,7
I3: 8 => CTR
* 941.58.32586.231..732.915.86189372544298657133572148692653..9.18941.23.5173589426
I3: 6,7                                  # 21 pairs
* PAIR F6: 4,6 BLK 5
E5: 4,6,5                                # reduction candidate for 4,6
E5: 4,6                                  # 18 pairs
F5: 4,6,5                                # reduction candidate for 4,6
F5: 4,6 => CTR
* 941.85.32586.231..732.9158661893725442985..1335.21.8..2.5348971894172365173569428
F5: 5                                    # 18 pairs
* PAIR F6: 4,6 COL F
F7: 4,6,8                                # reduction candidate for 4,6
F7: 8 => CTR
* 941.85.32586.231..732.915866189372544298...1335.21.8..2.5348971894172365173569428
F7: 4,6                                  # 18 pairs
* PAIR G5: 6,7 BLK 6
I6: 6,7,9                                # reduction candidate for 6,7
I6: 9 => CTR
* 941....325...231...32.915..618937254.298..7133572148692.534.971.941.23.51735.942.
I6: 6,7                                  # 19 pairs
* PAIR H6: 6,9 BLK 6
I6: 6,9,7                                # reduction candidate for 6,9
I6: 6,9 => CTR
* 9417856325.64231.7.32.915..618937254.298..7133572148..2.534.971.94172365173569428
I6: 7 => SOLVED
* 941658732567423189832791546618937254729845613354216897285374961496182375173569428
* PAIR B7: 6,8 ROW 7
E7: 6,8,4,7                              # reduction candidate for 6,8
E7: 6,8 => CTR
* 941658732567.231...32.915..618937254.298456133542168972.53.4971496172385173589426
E7: 4,7                                  # 19 pairs
F7: 6,8,4                                # reduction candidate for 6,8
F7: 6,8                                  # 21 pairs
H7: 6,8,7                                # reduction candidate for 6,8
H7: 6,8 => SOLVED
* 941658732567423189832791546618937254729845613354216897285374961496182375173569428
H7: 7                                    # 19 pairs
* PAIR E9: 6,8 BLK 8
E7: 6,8,4,7                              # reduction candidate for 6,8
E7: 6,8 => CTR
* 941658732567.231...32.915..618937254.298456133542168972.53.4971496172385173589426
E7: 4,7                                  # 19 pairs
F7: 6,8,4                                # reduction candidate for 6,8
F7: 6,8                                  # 21 pairs
E8: 6,8,7                                # reduction candidate for 6,8
E8: 6,8 => SOLVED
* 941658732567423189832791546618937254729845613354216897285374961496182375173569428
E8: 7                                    # 19 pairs
* PAIR I9: 6,8 BLK 9
H7: 6,8,7                                # reduction candidate for 6,8
H7: 6,8 => SOLVED
* 941658732567423189832791546618937254729845613354216897285374961496182375173569428
H7: 7                                    # 19 pairs
H8: 6,8,7                                # reduction candidate for 6,8
H8: 6,8                                  # 19 pairs
* PAIR I9: 6,8 COL I
I3: 6,8,7                                # reduction candidate for 6,8
I3: 7 => CTR
* 941....325...231...32.915.76189372547298..61335.21.8..2.53..9.1.9.1.23.51735.942.
I3: 6,8                                  # 21 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-370-base-pr-000.dot
* REASONING
* PRF # I3: 6 => SOL
* DIS # D3: 4 => CTR => D3: 6,7
* PRF # D3: 4,7 => SOL
* DIS # D3: 6 => CTR => D3: 4,7
* DIS # I3: 8 => CTR => I3: 6,7
* DIS # F5: 4,6 => CTR => F5: 5
* DIS # F7: 8 => CTR => F7: 4,6
* DIS # I6: 9 => CTR => I6: 6,7
* DIS # I6: 6,9 => CTR => I6: 7
* PRF # I6: 7 => SOL
* DIS # E7: 6,8 => CTR => E7: 4,7
* PRF # H7: 6,8 => SOL
* DIS # E7: 6,8 => CTR => E7: 4,7
* PRF # E8: 6,8 => SOL
* PRF # H7: 6,8 => SOL
* DIS # I3: 7 => CTR => I3: 6,8
* CNT  16 HDP CHAINS /  32 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A3,A5,A8,B2,B7,C2,C6,C8,D1,D2,E1,E9,F1,F6,G1,G5,H6,I9)
* 941....325...231...32.915..618937254.298...1335.21.8..2.53..9.1.9.1.23.51735.942.
* PAIR A3: 7,8 ROW 3
I3: 7,8,6                                # reduction candidate for 7,8
I3: 6 => SOLVED
* 941658732567423189832791546618937254729845613354216897285374961496182375173569428
* DURATION: 0:00:03.499575  START: 15:31:53.710878  END: 15:31:57.210453 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-370-base-pr-001.dot
* REASONING
* PRF # I3: 6 => SOL
* STA I3: 6
* CNT   1 HDP CHAINS /   2 HYP OPENED

Header Info

Top 500 Minimum 17 370

solution: 941658732567423189832791546618937254729845613354216897285374961496182375173569428
info: 5414     FNBTWXY  S8.f     19270

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

Solution

position: 941658732567423189832791546618937254729845613354216897285374961496182375173569428 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 # I3: 7,8 => UNS
* PRF # I3: 6 => SOL
* INC # D3: 6,7 => UNS
* DIS # D3: 4 => CTR => D3: 6,7
* PRF # D3: 4,7 => SOL
* DIS # D3: 6 => CTR => D3: 4,7
* INC # I3: 6,7 => UNS
* DIS # I3: 8 => CTR => I3: 6,7
* INC # E5: 4,6 => UNS
* DIS # F5: 4,6 => CTR => F5: 5
* INC # F5: 5 => UNS
* INC # F7: 4,6 => UNS
* DIS # F7: 8 => CTR => F7: 4,6
* INC # I6: 6,7 => UNS
* DIS # I6: 9 => CTR => I6: 6,7
* DIS # I6: 6,9 => CTR => I6: 7
* PRF # I6: 7 => SOL
* DIS # E7: 6,8 => CTR => E7: 4,7
* INC # E7: 4,7 => UNS
* INC # F7: 6,8 => UNS
* PRF # H7: 6,8 => SOL
* INC # H7: 7 => UNS
* DIS # E7: 6,8 => CTR => E7: 4,7
* INC # E7: 4,7 => UNS
* INC # F7: 6,8 => UNS
* PRF # E8: 6,8 => SOL
* INC # E8: 7 => UNS
* PRF # H7: 6,8 => SOL
* INC # H7: 7 => UNS
* INC # H8: 6,8 => UNS
* INC # I3: 6,8 => UNS
* DIS # I3: 7 => CTR => I3: 6,8
* CNT  32 HDP CHAINS /  32 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # I3: 7,8 => UNS
* PRF # I3: 6 => SOL
* STA I3: 6
* CNT   2 HDP CHAINS /   2 HYP OPENED