Analysis of xx-top500-098-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 3.7.9..........2..1...........1.3.....4....9..2....8.....24..3.65......1......... initial

Autosolve

position: 387.9261.4.5...2..1.2...3..976183542834.2.19.521...8.371824.93.65....42124....7.. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # D3: 4,5 => CTR => D3: 6,7,8
* DIS # I3: 4,5 => CTR => I3: 7,8,9
* DIS # I2: 7,8 => CTR => I2: 9
* DIS # H3: 7,8 => CTR => H3: 5
* DIS # D2: 7,8 => CTR => D2: 3,6
* DIS # F5: 6,7 => CTR => F5: 5
* DIS # E2: 6,7 => CTR => E2: 1,3
* DIS # F5: 6,7 => CTR => F5: 5
* DIS # D8: 3,9 => CTR => D8: 7,8
* DIS # D9: 5,6 => CTR => D9: 3,9
* DIS # D9: 5,6 => CTR => D9: 3,9
* DIS # F9: 5,6 => CTR => F9: 1,9
* DIS # F3: 5,6 => CTR => F3: 4,7,8
* DIS # E2: 3,7 => CTR => E2: 1,6
* PRF # I9: 5,6 => SOL
* CNT  15 HDP CHAINS /  41 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 # D3: 4,5 => CTR => D3: 6,7,8
* DIS D3: 6,7,8 # F3: 6,7,8 => CTR => F3: 4,5
* PRF D3: 6,7,8 + F3: 4,5 # D3: 7,8 => SOL
* STA D3: 6,7,8 + F3: 4,5 + D3: 7,8
* CNT   3 HDP CHAINS /   5 HYP OPENED

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

Details

Positions

3.7.9..........2..1...........1.3.....4....9..2....8.....24..3.65......1......... initial
387.9261.4.5...2..1.2...3..976183542834.2.19.521...8.371824.93.65....42124....7.. autosolve
387592614465318279192764358976183542834625197521479863718246935659837421243951786 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (15)
B2: 6,9
B3: 6,9
D1: 4,5
I1: 4,5
H2: 7,8
D6: 4,9
E6: 6,7
F6: 4,9
I5: 6,7
H6: 6,7
C8: 3,9
C9: 3,9
F7: 5,6
E8: 3,7
I7: 5,6

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
E2,F2: 1.. / E2 = 1  => 15 pairs (_) / F2 = 1  =>  0 pairs (X)
E9,F9: 1.. / E9 = 1  =>  0 pairs (X) / F9 = 1  => 15 pairs (_)
E2,E9: 1.. / E2 = 1  => 15 pairs (_) / E9 = 1  =>  0 pairs (X)
F2,F9: 1.. / F2 = 1  =>  0 pairs (X) / F9 = 1  => 15 pairs (_)
D2,E2: 3.. / D2 = 3  => 15 pairs (_) / E2 = 3  =>  0 pairs (X)
C8,C9: 3.. / C8 = 3  =>  0 pairs (X) / C9 = 3  => 14 pairs (_)
I1,I3: 4.. / I1 = 4  => 12 pairs (_) / I3 = 4  =>  0 pairs (X)
D6,F6: 4.. / D6 = 4  => 12 pairs (_) / F6 = 4  => 13 pairs (_)
D1,I1: 4.. / D1 = 4  =>  0 pairs (X) / I1 = 4  => 12 pairs (_)
F3,F6: 4.. / F3 = 4  => 12 pairs (_) / F6 = 4  => 13 pairs (_)
D5,F5: 5.. / D5 = 5  =>  0 pairs (X) / F5 = 5  => 12 pairs (_)
D1,I1: 5.. / D1 = 5  => 12 pairs (_) / I1 = 5  =>  0 pairs (X)
F7,I7: 5.. / F7 = 5  =>  0 pairs (X) / I7 = 5  => 12 pairs (_)
E3,E9: 5.. / E3 = 5  =>  0 pairs (X) / E9 = 5  => 12 pairs (_)
H3,H9: 5.. / H3 = 5  => 12 pairs (_) / H9 = 5  =>  0 pairs (X)
B2,B3: 6.. / B2 = 6  => 13 pairs (_) / B3 = 6  =>  0 pairs (X)
I5,H6: 6.. / I5 = 6  =>  0 pairs (X) / H6 = 6  => 20 pairs (_)
E6,H6: 6.. / E6 = 6  =>  0 pairs (X) / H6 = 6  => 20 pairs (_)
F7,I7: 6.. / F7 = 6  => 12 pairs (_) / I7 = 6  =>  0 pairs (X)
H6,H9: 6.. / H6 = 6  => 20 pairs (_) / H9 = 6  =>  0 pairs (X)
I5,H6: 7.. / I5 = 7  => 20 pairs (_) / H6 = 7  =>  0 pairs (X)
E6,H6: 7.. / E6 = 7  => 20 pairs (_) / H6 = 7  =>  0 pairs (X)
D8,F8: 8.. / D8 = 8  => 16 pairs (_) / F8 = 8  => 15 pairs (_)
H9,I9: 8.. / H9 = 8  =>  0 pairs (*) / I9 = 8  =>  0 pairs (X)
B2,B3: 9.. / B2 = 9  =>  0 pairs (X) / B3 = 9  => 13 pairs (_)
I2,I3: 9.. / I2 = 9  => 13 pairs (_) / I3 = 9  =>  0 pairs (X)
D6,F6: 9.. / D6 = 9  => 13 pairs (_) / F6 = 9  => 12 pairs (_)
C8,C9: 9.. / C8 = 9  => 14 pairs (_) / C9 = 9  =>  0 pairs (X)
B2,I2: 9.. / B2 = 9  =>  0 pairs (X) / I2 = 9  => 13 pairs (_)
B3,I3: 9.. / B3 = 9  => 13 pairs (_) / I3 = 9  =>  0 pairs (X)
* DURATION: 0:00:53.297003  START: 06:07:19.235139  END: 06:08:12.532142 2017-05-04
* CP COUNT: (30)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B2,B3,C8,C9,D1,D6,E6,E8,F6,F7,H2,H6,I1,I5,I7)
* 387.9261.4.5...2..1.2...3..976183542834.2.19.521...8.371824.93.65....42124....7..
* PAIR D1: 4,5 BLK 2
D3: 4,5,6,7,8                            # reduction candidate for 4,5
D3: 4,5 => CTR
* 387.9261.4.5...2..1.2...3..976183542834.2519.5219.48.371824693565..3.42124....7..
D3: 6,7,8                                # 15 pairs
F3: 4,5,6,7,8                            # reduction candidate for 4,5
F3: 4,5                                  # 12 pairs
* PAIR I1: 4,5 BLK 3
I3: 4,5,7,8,9                            # reduction candidate for 4,5
I3: 4,5 => CTR
* 387.9261.46531.2.9192.5.3.497618354283452.197521.7.86371824.936659.3.421243..1758
I3: 7,8,9                                # 12 pairs
* PAIR H2: 7,8 BLK 3
I2: 7,8,9                                # reduction candidate for 7,8
I2: 7,8 => CTR
* 387592614495.1.2..162.7.359976183542834.2519.521.6.87371824693565..374212439517..
I2: 9                                    # 13 pairs
H3: 7,8,5                                # reduction candidate for 7,8
H3: 7,8 => CTR
* 3874926154.5...2..1.2.5.3.497618354283452619752197486371824593665..3.421243619758
H3: 5                                    # 12 pairs
I3: 7,8,4,5,9                            # reduction candidate for 7,8
I3: 7,8                                  # 12 pairs
* PAIR H2: 7,8 ROW 2
D2: 7,8,3,6                              # reduction candidate for 7,8
D2: 7,8 => CTR
* 387.9261.465.312.9192.5.3..976183542834.2.19.521.6.87371824.93.65..7.42124..1.7..
D2: 3,6                                  # 16 pairs
F2: 7,8,1,6                              # reduction candidate for 7,8
F2: 7,8                                  # 14 pairs
* PAIR E6: 6,7 BLK 5
D5: 6,7,5                                # reduction candidate for 6,7
D5: 6,7                                  # 12 pairs
F5: 6,7,5                                # reduction candidate for 6,7
F5: 6,7 => CTR
* 3874926154.5...2.9192.5.3.497618354283452619752197486371824593665..3.421243619758
F5: 5                                    # 12 pairs
* PAIR E6: 6,7 COL E
E2: 6,7,1,3                              # reduction candidate for 6,7
E2: 6,7 => CTR
* 3874926154.53.128.1.2.5.37497618354283452.197521974863718245936659738421243619758
E2: 1,3                                  # 16 pairs
E3: 6,7,5                                # reduction candidate for 6,7
E3: 6,7                                  # 12 pairs
* PAIR I5: 6,7 ROW 5
D5: 6,7,5                                # reduction candidate for 6,7
D5: 6,7                                  # 12 pairs
F5: 6,7,5                                # reduction candidate for 6,7
F5: 6,7 => CTR
* 3874926154.5...2.9192.5.3.497618354283452619752197486371824593665..3.421243619758
F5: 5                                    # 12 pairs
* PAIR C8: 3,9 ROW 8
D8: 3,9,7,8                              # reduction candidate for 3,9
D8: 3,9 => CTR
* 387.9261.4.5...28.1.285.3..976183542834.2.19.521.6.87371824.93.65..7842124....768
D8: 7,8                                  # 16 pairs
* PAIR C9: 3,9 ROW 9
D9: 3,9,5,6                              # reduction candidate for 3,9
D9: 5,6 => CTR
* 3874926154.5.612.91.2.5.3.497618354283452.19.5219.486371824593665....42124.6..758
D9: 3,9                                  # 16 pairs
* PAIR F7: 5,6 BLK 8
D9: 5,6,3,9                              # reduction candidate for 5,6
D9: 5,6 => CTR
* 3874926154.5.612.91.2.5.3.497618354283452.19.5219.486371824593665....42124.6..758
D9: 3,9                                  # 16 pairs
E9: 5,6,1,3                              # reduction candidate for 5,6
E9: 5,6                                  # 12 pairs
F9: 5,6,1,9                              # reduction candidate for 5,6
F9: 5,6 => CTR
* 3874926154.5..12..1.2.5.3.497618354283452.19.5219.486371824593665...9421249316758
F9: 1,9                                  # 16 pairs
* PAIR F7: 5,6 COL F
F3: 5,6,4,7,8                            # reduction candidate for 5,6
F3: 5,6 => CTR
* 387.9261.4.5...2..1.2...3..97618354283452719652196487371824693565....42124.351768
F3: 4,7,8                                # 15 pairs
F5: 5,6,7                                # reduction candidate for 5,6
F5: 5,6                                  # 17 pairs
* PAIR E8: 3,7 BLK 8
D8: 3,7,8,9                              # reduction candidate for 3,7
D8: 8,9                                  # 16 pairs
D8: 3,7                                  # 14 pairs
* PAIR E8: 3,7 COL E
E2: 3,7,1,6                              # reduction candidate for 3,7
E2: 3,7 => CTR
* 387.9261.4.5..12..1.2.5.3..976183542834.2.19.521.6.87371824.93.65....42124..1.7..
E2: 1,6                                  # 16 pairs
* PAIR I7: 5,6 BLK 9
H9: 5,6,8                                # reduction candidate for 5,6
H9: 5,6                                  # 17 pairs
I9: 5,6,8                                # reduction candidate for 5,6
I9: 5,6 => SOLVED
* 387592614465318279192764358976183542834625197521479863718246935659837421243951786
I9: 8                                    # 17 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-098-base-pr-000.dot
* REASONING
* DIS # D3: 4,5 => CTR => D3: 6,7,8
* DIS # I3: 4,5 => CTR => I3: 7,8,9
* DIS # I2: 7,8 => CTR => I2: 9
* DIS # H3: 7,8 => CTR => H3: 5
* DIS # D2: 7,8 => CTR => D2: 3,6
* DIS # F5: 6,7 => CTR => F5: 5
* DIS # E2: 6,7 => CTR => E2: 1,3
* DIS # F5: 6,7 => CTR => F5: 5
* DIS # D8: 3,9 => CTR => D8: 7,8
* DIS # D9: 5,6 => CTR => D9: 3,9
* DIS # D9: 5,6 => CTR => D9: 3,9
* DIS # F9: 5,6 => CTR => F9: 1,9
* DIS # F3: 5,6 => CTR => F3: 4,7,8
* DIS # E2: 3,7 => CTR => E2: 1,6
* PRF # I9: 5,6 => SOL
* CNT  15 HDP CHAINS /  41 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B2,B3,C8,C9,D1,D6,E6,E8,F6,F7,H2,H6,I1,I5,I7)
* 387.9261.4.5...2..1.2...3..976183542834.2.19.521...8.371824.93.65....42124....7..
* PAIR D1: 4,5 BLK 2
D3: 4,5,6,7,8                            # reduction candidate for 4,5
D3: 4,5 => CTR
* 387.9261.4.5...2..1.2...3..976183542834.2519.5219.48.371824693565..3.42124....7..
F3: 4,5,6,7,8                            # reduction candidate for 4,5
F3: 4,5                                  # 12 pairs
* RESTART
* PAIR D1: 4,5 BLK 2
F3: 4,5,6,7,8                            # reduction candidate for 4,5
F3: 6,7,8 => CTR
* 3874926154.5...2.9192.5.3.497618354283452619752197486371824593665..3.421243619758

* LEVEL 0 PASS 1 ROUND 2 (AUTO SOLVE) (D5,D8,E3,E6,F2,F8,H2,H6,H9,I3,I5,I9)
* 38759261446531.2.9192..435.976183542834.2519.5214.98.3718246935659.3.4212439517..
* PAIR F2: 7,8 BLK 2
D3: 7,8,6                                # reduction candidate for 7,8
D3: 7,8 => SOLVED
* 387592614465318279192764358976183542834625197521479863718246935659837421243951786
* DURATION: 0:00:07.116046  START: 06:08:52.049314  END: 06:08:59.165360 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-098-base-pr-001.dot
* REASONING
* DIS # D3: 4,5 => CTR => D3: 6,7,8
* DIS D3: 6,7,8 # F3: 6,7,8 => CTR => F3: 4,5
* PRF D3: 6,7,8 + F3: 4,5 # D3: 7,8 => SOL
* STA D3: 6,7,8 + F3: 4,5 + D3: 7,8
* CNT   3 HDP CHAINS /   5 HYP OPENED

Header Info

Top 500 Minimum 17 098

solution: 387592614465318279192764358976183542834625197521479863718246935659837421243951786
info: 1575     FNBTWXY  S8.f     44954

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

Solution

position: 387592614465318279192764358976183542834625197521479863718246935659837421243951786 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 # D3: 4,5 => CTR => D3: 6,7,8
* INC # D3: 6,7,8 => UNS
* INC # F3: 4,5 => UNS
* DIS # I3: 4,5 => CTR => I3: 7,8,9
* INC # I3: 7,8,9 => UNS
* DIS # I2: 7,8 => CTR => I2: 9
* INC # I2: 9 => UNS
* DIS # H3: 7,8 => CTR => H3: 5
* INC # H3: 5 => UNS
* INC # I3: 7,8 => UNS
* DIS # D2: 7,8 => CTR => D2: 3,6
* INC # D2: 3,6 => UNS
* INC # F2: 7,8 => UNS
* INC # D5: 6,7 => UNS
* DIS # F5: 6,7 => CTR => F5: 5
* INC # F5: 5 => UNS
* DIS # E2: 6,7 => CTR => E2: 1,3
* INC # E2: 1,3 => UNS
* INC # E3: 6,7 => UNS
* INC # D5: 6,7 => UNS
* DIS # F5: 6,7 => CTR => F5: 5
* INC # F5: 5 => UNS
* DIS # D8: 3,9 => CTR => D8: 7,8
* INC # D8: 7,8 => UNS
* INC # D9: 3,9 => UNS
* DIS # D9: 5,6 => CTR => D9: 3,9
* DIS # D9: 5,6 => CTR => D9: 3,9
* INC # D9: 3,9 => UNS
* INC # E9: 5,6 => UNS
* DIS # F9: 5,6 => CTR => F9: 1,9
* INC # F9: 1,9 => UNS
* DIS # F3: 5,6 => CTR => F3: 4,7,8
* INC # F3: 4,7,8 => UNS
* INC # F5: 5,6 => UNS
* INC # D8: 3,7 => UNS
* INC # D8: 8,9 => UNS
* DIS # E2: 3,7 => CTR => E2: 1,6
* INC # E2: 1,6 => UNS
* INC # H9: 5,6 => UNS
* PRF # I9: 5,6 => SOL
* INC # I9: 8 => UNS
* CNT  41 HDP CHAINS /  41 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # D3: 4,5 => CTR => D3: 6,7,8
* INC D3: 6,7,8 # F3: 4,5 => UNS
* INC D3: 6,7,8 # F3: 4,5 => UNS
* DIS D3: 6,7,8 # F3: 6,7,8 => CTR => F3: 4,5
* PRF D3: 6,7,8 + F3: 4,5 # D3: 7,8 => SOL
* STA D3: 6,7,8 + F3: 4,5 + D3: 7,8
* CNT   5 HDP CHAINS /   5 HYP OPENED