Analysis of xx-top500-227-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: .3.89....1......6............6....79....3.5..2.........5...13....46...........9.. initial

Autosolve

position: 63789.1..1.93...6.5.816..93386.1.4794917365..2754896318529713469146.3...763.4891. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # F2: 2,4 => SOL
* DIS # I2: 2,4 => CTR => I2: 5,7,8
* PRF # F3: 7 => SOL
* DIS # F2: 2,5 => CTR => F2: 4,7
* DIS # I2: 2,5 => CTR => I2: 4,7,8
* DIS # I1: 2,5 => CTR => I1: 4
* DIS # I2: 2,5 => CTR => I2: 4,7,8
* DIS # F1: 4 => CTR => F1: 2,5
* DIS # H8: 2,5 => CTR => H8: 8
* DIS # G2: 2,7 => CTR => G2: 8
* PRF # I2: 2,7 => SOL
* PRF # F3: 2,7 => SOL
* DIS # G8: 8 => CTR => G8: 2,7
* DIS # F2: 2,5 => CTR => F2: 4,7
* DIS # H8: 5 => CTR => H8: 2,8
* DIS # I2: 2,8 => CTR => I2: 4,5,7
* DIS # I8: 2,8 => CTR => I8: 5,7
* DIS # H8: 2,5 => CTR => H8: 8
* PRF # I8: 2,5 => SOL
* DIS # H8: 2,5 => CTR => H8: 8
* PRF # I8: 2,5 => SOL
* DIS # I1: 2,5 => CTR => I1: 4
* DIS # I2: 2,5 => CTR => I2: 4,7,8
* CNT  23 HDP CHAINS /  48 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 # F2: 2,4 => SOL
* STA F2: 2,4
* CNT   1 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

.3.89....1......6............6....79....3.5..2.........5...13....46...........9.. initial
63789.1..1.93...6.5.816..93386.1.4794917365..2754896318529713469146.3...763.4891. autosolve
637892154129354867548167293386215479491736528275489631852971346914623785763548912 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (12)
B2: 2,4
B3: 2,4
E2: 2,5
H1: 2,5
G3: 2,7
D4: 2,5
F4: 2,5
H5: 2,8
I5: 2,8
E8: 2,5
D9: 2,5
I9: 2,5

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
B2,B3: 2.. / B2 = 2  =>  0 pairs (*) / B3 = 2  =>  0 pairs (X)
D4,F4: 2.. / D4 = 2  =>  0 pairs (*) / F4 = 2  =>  0 pairs (X)
H5,I5: 2.. / H5 = 2  => 12 pairs (_) / I5 = 2  =>  0 pairs (X)
E8,D9: 2.. / E8 = 2  =>  0 pairs (*) / D9 = 2  =>  0 pairs (X)
D9,I9: 2.. / D9 = 2  =>  0 pairs (X) / I9 = 2  =>  0 pairs (_)
D4,D9: 2.. / D4 = 2  =>  0 pairs (*) / D9 = 2  =>  0 pairs (X)
E2,E8: 2.. / E2 = 2  =>  0 pairs (X) / E8 = 2  =>  0 pairs (_)
B2,B3: 4.. / B2 = 4  => 12 pairs (_) / B3 = 4  =>  0 pairs (*)
I1,I2: 4.. / I1 = 4  => 15 pairs (_) / I2 = 4  =>  0 pairs (X)
F1,I1: 4.. / F1 = 4  =>  0 pairs (X) / I1 = 4  => 15 pairs (_)
B3,F3: 4.. / B3 = 4  =>  0 pairs (*) / F3 = 4  =>  0 pairs (X)
D4,F4: 5.. / D4 = 5  =>  0 pairs (X) / F4 = 5  =>  0 pairs (_)
E8,D9: 5.. / E8 = 5  =>  0 pairs (X) / D9 = 5  =>  0 pairs (_)
D9,I9: 5.. / D9 = 5  =>  0 pairs (*) / I9 = 5  =>  0 pairs (X)
D4,D9: 5.. / D4 = 5  =>  0 pairs (X) / D9 = 5  =>  0 pairs (_)
E2,E8: 5.. / E2 = 5  =>  0 pairs (*) / E8 = 5  =>  0 pairs (X)
H1,H8: 5.. / H1 = 5  => 14 pairs (_) / H8 = 5  =>  0 pairs (X)
F2,F3: 7.. / F2 = 7  => 14 pairs (_) / F3 = 7  =>  0 pairs (*)
G8,I8: 7.. / G8 = 7  =>  0 pairs (*) / I8 = 7  =>  0 pairs (X)
F3,G3: 7.. / F3 = 7  =>  0 pairs (*) / G3 = 7  =>  0 pairs (X)
I2,I8: 7.. / I2 = 7  =>  0 pairs (*) / I8 = 7  =>  0 pairs (X)
G2,I2: 8.. / G2 = 8  => 13 pairs (_) / I2 = 8  =>  0 pairs (X)
H5,I5: 8.. / H5 = 8  =>  0 pairs (X) / I5 = 8  => 12 pairs (_)
G2,G8: 8.. / G2 = 8  => 13 pairs (_) / G8 = 8  =>  0 pairs (X)
H5,H8: 8.. / H5 = 8  =>  0 pairs (X) / H8 = 8  => 12 pairs (_)
* DURATION: 0:00:40.512021  START: 10:36:45.650837  END: 10:37:26.162858 2017-05-04
* CP COUNT: (25)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B2,B3,D4,D9,E2,E8,F4,G3,H1,H5,I5,I9)
* 63789.1..1.93...6.5.816..93386.1.4794917365..2754896318529713469146.3...763.4891.
* PAIR B2: 2,4 ROW 2
F2: 2,4,5,7                              # reduction candidate for 2,4
F2: 2,4 => SOLVED
* 637892154129354867548167293386215479491736528275489631852971346914623785763548912
F2: 5,7                                  # 13 pairs
I2: 2,4,5,7,8                            # reduction candidate for 2,4
I2: 2,4 => CTR
* 63789.15.1.932.86.5.816.793386.1.4794917365..2754896318529713469146.32.7763248915
I2: 5,7,8                                # 15 pairs
* PAIR B3: 2,4 ROW 3
F3: 2,4,7                                # reduction candidate for 2,4
F3: 7 => SOLVED
* 637892154129354867548167293386215479491736528275489631852971346914623785763548912
F3: 2,4                                  # 14 pairs
* PAIR E2: 2,5 BLK 2
F1: 2,5,4                                # reduction candidate for 2,5
F1: 2,5                                  # 15 pairs
F2: 2,5,4,7                              # reduction candidate for 2,5
F2: 2,5 => CTR
* 63789.1..1.93...6.5.8167293386.1.4794917365..2754896318529713469146.3...763.4891.
F2: 4,7                                  # 13 pairs
* PAIR E2: 2,5 ROW 2
I2: 2,5,4,7,8                            # reduction candidate for 2,5
I2: 2,5 => CTR
* 63789.1541.932.86.5.816.793386.1.4794917365..2754896318529713469146.32.7763248915
I2: 4,7,8                                # 13 pairs
* PAIR H1: 2,5 BLK 3
I1: 2,5,4                                # reduction candidate for 2,5
I1: 2,5 => CTR
* 6378941..1293578645481627933862154794917365.8275489631852971346914623..7763.4891.
I1: 4                                    # 15 pairs
I2: 2,5,4,7,8                            # reduction candidate for 2,5
I2: 2,5 => CTR
* 63789.1541.932.86.5.816.793386.1.4794917365..2754896318529713469146.32.7763248915
I2: 4,7,8                                # 13 pairs
* PAIR H1: 2,5 ROW 1
F1: 2,5,4                                # reduction candidate for 2,5
F1: 4 => CTR
* 6378941..1293578645481627933862154794917365.8275489631852971346914623..7763.4891.
F1: 2,5                                  # 15 pairs
* PAIR H1: 2,5 COL H
H8: 2,5,8                                # reduction candidate for 2,5
H8: 2,5 => CTR
* 63789.1541.932..6.5.816..93386.1.4794917365822754896318529713469146.3...763248915
H8: 8                                    # 12 pairs
* PAIR G3: 2,7 BLK 3
G2: 2,7,8                                # reduction candidate for 2,7
G2: 2,7 => CTR
* 6378921541.935..685.816..93386.1.4794917365822754896318529713469146.3827763248915
G2: 8                                    # 13 pairs
I2: 2,7,4,5,8                            # reduction candidate for 2,7
I2: 2,7 => SOLVED
* 637892154129354867548167293386215479491736528275489631852971346914623785763548912
I2: 4,5,8                                # 13 pairs
* PAIR G3: 2,7 ROW 3
F3: 2,7,4                                # reduction candidate for 2,7
F3: 2,7 => SOLVED
* 637892154129354867548167293386215479491736528275489631852971346914623785763548912
F3: 4                                    # 12 pairs
* PAIR G3: 2,7 COL G
G8: 2,7,8                                # reduction candidate for 2,7
G8: 8 => CTR
* 6378921541.935..685.816..93386.1.4794917365822754896318529713469146.3827763248915
G8: 2,7                                  # 13 pairs
* PAIR F4: 2,5 COL F
F1: 2,5,4                                # reduction candidate for 2,5
F1: 2,5                                  # 15 pairs
F2: 2,5,4,7                              # reduction candidate for 2,5
F2: 2,5 => CTR
* 63789.1..1.93...6.5.8167293386.1.4794917365..2754896318529713469146.3...763.4891.
F2: 4,7                                  # 13 pairs
* PAIR H5: 2,8 COL H
H8: 2,8,5                                # reduction candidate for 2,8
H8: 5 => CTR
* 63789.1..1.93...6.5.816..93386.1.4794917365822754896318529713469146.325.763.4891.
H8: 2,8                                  # 14 pairs
* PAIR I5: 2,8 COL I
I2: 2,8,4,5,7                            # reduction candidate for 2,8
I2: 2,8 => CTR
* 63789.1541.93...6.5.816..933865124794917365..2754896318529713469146.3..7763.48915
I2: 4,5,7                                # 13 pairs
I8: 2,8,5,7                              # reduction candidate for 2,8
I8: 2,8 => CTR
* 63789215412935..675.8167293386.1.4794917365..2754896318529713469146.37..763.4891.
I8: 5,7                                  # 13 pairs
* PAIR E8: 2,5 ROW 8
H8: 2,5,8                                # reduction candidate for 2,5
H8: 2,5 => CTR
* 63789.1541.932..6.5.816..93386.1.4794917365822754896318529713469146.3...763248915
H8: 8                                    # 12 pairs
I8: 2,5,7,8                              # reduction candidate for 2,5
I8: 2,5 => SOLVED
* 637892154129354867548167293386215479491736528275489631852971346914623785763548912
I8: 7,8                                  # 13 pairs
* PAIR I9: 2,5 BLK 9
H8: 2,5,8                                # reduction candidate for 2,5
H8: 2,5 => CTR
* 63789.1541.932..6.5.816..93386.1.4794917365822754896318529713469146.3...763248915
H8: 8                                    # 12 pairs
I8: 2,5,7,8                              # reduction candidate for 2,5
I8: 2,5 => SOLVED
* 637892154129354867548167293386215479491736528275489631852971346914623785763548912
I8: 7,8                                  # 13 pairs
* PAIR I9: 2,5 COL I
I1: 2,5,4                                # reduction candidate for 2,5
I1: 2,5 => CTR
* 6378941..1293578645481627933862154794917365.8275489631852971346914623..7763.4891.
I1: 4                                    # 15 pairs
I2: 2,5,4,7,8                            # reduction candidate for 2,5
I2: 2,5 => CTR
* 63789.1541.932.86.5.816.793386.1.4794917365..2754896318529713469146.32.7763248915
I2: 4,7,8                                # 13 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-227-base-pr-000.dot
* REASONING
* PRF # F2: 2,4 => SOL
* DIS # I2: 2,4 => CTR => I2: 5,7,8
* PRF # F3: 7 => SOL
* DIS # F2: 2,5 => CTR => F2: 4,7
* DIS # I2: 2,5 => CTR => I2: 4,7,8
* DIS # I1: 2,5 => CTR => I1: 4
* DIS # I2: 2,5 => CTR => I2: 4,7,8
* DIS # F1: 4 => CTR => F1: 2,5
* DIS # H8: 2,5 => CTR => H8: 8
* DIS # G2: 2,7 => CTR => G2: 8
* PRF # I2: 2,7 => SOL
* PRF # F3: 2,7 => SOL
* DIS # G8: 8 => CTR => G8: 2,7
* DIS # F2: 2,5 => CTR => F2: 4,7
* DIS # H8: 5 => CTR => H8: 2,8
* DIS # I2: 2,8 => CTR => I2: 4,5,7
* DIS # I8: 2,8 => CTR => I8: 5,7
* DIS # H8: 2,5 => CTR => H8: 8
* PRF # I8: 2,5 => SOL
* DIS # H8: 2,5 => CTR => H8: 8
* PRF # I8: 2,5 => SOL
* DIS # I1: 2,5 => CTR => I1: 4
* DIS # I2: 2,5 => CTR => I2: 4,7,8
* CNT  23 HDP CHAINS /  48 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B2,B3,D4,D9,E2,E8,F4,G3,H1,H5,I5,I9)
* 63789.1..1.93...6.5.816..93386.1.4794917365..2754896318529713469146.3...763.4891.
* PAIR B2: 2,4 ROW 2
F2: 2,4,5,7                              # reduction candidate for 2,4
F2: 2,4 => SOLVED
* 637892154129354867548167293386215479491736528275489631852971346914623785763548912
* DURATION: 0:00:01.883764  START: 10:38:13.757563  END: 10:38:15.641327 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-227-base-pr-001.dot
* REASONING
* PRF # F2: 2,4 => SOL
* STA F2: 2,4
* CNT   1 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 227

solution: 637892154129354867548167293386215479491736528275489631852971346914623785763548912
info: 2064     FNWXY    S8.f     18110

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

Solution

position: 637892154129354867548167293386215479491736528275489631852971346914623785763548912 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:

* PRF # F2: 2,4 => SOL
* INC # F2: 5,7 => UNS
* DIS # I2: 2,4 => CTR => I2: 5,7,8
* INC # I2: 5,7,8 => UNS
* INC # F3: 2,4 => UNS
* PRF # F3: 7 => SOL
* INC # F1: 2,5 => UNS
* DIS # F2: 2,5 => CTR => F2: 4,7
* INC # F2: 4,7 => UNS
* DIS # I2: 2,5 => CTR => I2: 4,7,8
* INC # I2: 4,7,8 => UNS
* DIS # I1: 2,5 => CTR => I1: 4
* INC # I1: 4 => UNS
* DIS # I2: 2,5 => CTR => I2: 4,7,8
* INC # I2: 4,7,8 => UNS
* INC # F1: 2,5 => UNS
* DIS # F1: 4 => CTR => F1: 2,5
* DIS # H8: 2,5 => CTR => H8: 8
* INC # H8: 8 => UNS
* DIS # G2: 2,7 => CTR => G2: 8
* INC # G2: 8 => UNS
* PRF # I2: 2,7 => SOL
* INC # I2: 4,5,8 => UNS
* PRF # F3: 2,7 => SOL
* INC # F3: 4 => UNS
* INC # G8: 2,7 => UNS
* DIS # G8: 8 => CTR => G8: 2,7
* INC # F1: 2,5 => UNS
* DIS # F2: 2,5 => CTR => F2: 4,7
* INC # F2: 4,7 => UNS
* INC # H8: 2,8 => UNS
* DIS # H8: 5 => CTR => H8: 2,8
* DIS # I2: 2,8 => CTR => I2: 4,5,7
* INC # I2: 4,5,7 => UNS
* DIS # I8: 2,8 => CTR => I8: 5,7
* INC # I8: 5,7 => UNS
* DIS # H8: 2,5 => CTR => H8: 8
* INC # H8: 8 => UNS
* PRF # I8: 2,5 => SOL
* INC # I8: 7,8 => UNS
* DIS # H8: 2,5 => CTR => H8: 8
* INC # H8: 8 => UNS
* PRF # I8: 2,5 => SOL
* INC # I8: 7,8 => UNS
* DIS # I1: 2,5 => CTR => I1: 4
* INC # I1: 4 => UNS
* DIS # I2: 2,5 => CTR => I2: 4,7,8
* INC # I2: 4,7,8 => UNS
* CNT  48 HDP CHAINS /  48 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* PRF # F2: 2,4 => SOL
* STA F2: 2,4
* CNT   1 HDP CHAINS /   1 HYP OPENED