Analysis of xx-top500-057-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: ...6..39..1.2.....7........5...87....6.....1..........4.....7........5.8.2.1..... initial

Autosolve

position: ...67139..1.2...7.7.....1..5.1.872...6.....17.7..16...4.....7.11..7..5.8.271..... autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # C1: 2,8 => CTR => C1: 4,5
* PRF # A6: 2,8 => SOL
* DIS # A6: 3,9 => CTR => A6: 2,8
* DIS # F3: 5,8 => CTR => F3: 3,4,9
* DIS # B7: 3,9 => CTR => B7: 5,8
* DIS # C7: 3,9 => CTR => C7: 5,6,8
* DIS # E8: 3,9 => CTR => E8: 2,4,6
* DIS # F8: 3,9 => CTR => F8: 2,4
* DIS # B4: 3,9 => CTR => B4: 4
* CNT   9 HDP CHAINS /  19 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 # C1: 2,8 => CTR => C1: 4,5
* PRF C1: 4,5 # A6: 2,8 => SOL
* STA C1: 4,5 + A6: 2,8
* CNT   2 HDP CHAINS /   2 HYP OPENED

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

Details

Positions

...6..39..1.2.....7........5...87....6.....1..........4.....7........5.8.2.1..... initial
...67139..1.2...7.7.....1..5.1.872...6.....17.7..16...4.....7.11..7..5.8.271..... autosolve
854671392619235874732894156541987263968523417273416985485369721196742538327158649 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (6)
A1: 2,8
C3: 2,6
H3: 5,8
I3: 2,6
H6: 5,8
B8: 3,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
I1,I3: 2.. / I1 = 2  =>  0 pairs (*) / I3 = 2  =>  0 pairs (X)
A6,C6: 2.. / A6 = 2  =>  0 pairs (*) / C6 = 2  =>  0 pairs (X)
E5,F5: 2.. / E5 = 2  =>  6 pairs (_) / F5 = 2  =>  6 pairs (_)
H7,H8: 2.. / H7 = 2  =>  6 pairs (_) / H8 = 2  =>  7 pairs (_)
C3,I3: 2.. / C3 = 2  =>  0 pairs (*) / I3 = 2  =>  0 pairs (X)
A1,A6: 2.. / A1 = 2  =>  0 pairs (X) / A6 = 2  =>  0 pairs (_)
H6,I6: 5.. / H6 = 5  =>  0 pairs (X) / I6 = 5  =>  0 pairs (_)
B7,C7: 5.. / B7 = 5  =>  0 pairs (X) / C7 = 5  =>  6 pairs (_)
E9,F9: 5.. / E9 = 5  =>  6 pairs (_) / F9 = 5  =>  0 pairs (X)
D3,D5: 5.. / D3 = 5  =>  0 pairs (X) / D5 = 5  =>  6 pairs (_)
H3,H6: 5.. / H3 = 5  =>  0 pairs (*) / H6 = 5  =>  0 pairs (X)
H4,I4: 6.. / H4 = 6  =>  0 pairs (*) / I4 = 6  =>  0 pairs (X)
C3,I3: 6.. / C3 = 6  =>  0 pairs (X) / I3 = 6  =>  0 pairs (_)
A2,A9: 6.. / A2 = 6  =>  0 pairs (*) / A9 = 6  =>  0 pairs (X)
G2,G9: 6.. / G2 = 6  =>  0 pairs (X) / G9 = 6  =>  0 pairs (_)
G2,H3: 8.. / G2 = 8  =>  0 pairs (*) / H3 = 8  =>  0 pairs (X)
F2,G2: 8.. / F2 = 8  =>  0 pairs (X) / G2 = 8  =>  0 pairs (_)
A9,F9: 8.. / A9 = 8  =>  0 pairs (X) / F9 = 8  =>  0 pairs (_)
B1,B7: 8.. / B1 = 8  =>  0 pairs (X) / B7 = 8  =>  0 pairs (_)
D3,D7: 8.. / D3 = 8  =>  0 pairs (*) / D7 = 8  =>  0 pairs (X)
H3,H6: 8.. / H3 = 8  =>  0 pairs (X) / H6 = 8  =>  0 pairs (_)
G9,I9: 9.. / G9 = 9  =>  0 pairs (X) / I9 = 9  =>  8 pairs (_)
* DURATION: 0:00:39.705048  START: 04:38:06.676613  END: 04:38:46.381661 2017-05-04
* CP COUNT: (22)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,B8,C3,H3,H6,I3)
* ...67139..1.2...7.7.....1..5.1.872...6.....17.7..16...4.....7.11..7..5.8.271.....
* PAIR A1: 2,8 BLK 1
C1: 2,8,4,5                              # reduction candidate for 2,8
C1: 2,8 => CTR
* ...67139..1.2...7.7.6...1.25.1.872...6.....17.7..16...485...7.11..7..5.86271.8...
C1: 4,5                                  #  7 pairs
* PAIR A1: 2,8 COL A
A6: 2,8,3,9                              # reduction candidate for 2,8
A6: 2,8 => SOLVED
* 854671392619235874732894156541987263968523417273416985485369721196742538327158649
A6: 3,9 => CTR
* 2..67139..1.2...7.7.6...1.25.1.872...6.....17.72.16...4.....7.11..7..5.86271.8...
* PAIR H3: 5,8 ROW 3
D3: 5,8,3,4,9                            # reduction candidate for 5,8
D3: 5,8                                  #  9 pairs
F3: 5,8,3,4,9                            # reduction candidate for 5,8
F3: 5,8 => CTR
* 28.67139.61.2...7.7.....1..5.1.872...6.5...17.7..16...4..8..7.11..7..5.88271.....
F3: 3,4,9                                #  6 pairs
* PAIR B8: 3,9 BLK 7
B7: 3,9,5,8                              # reduction candidate for 3,9
B7: 3,9 => CTR
* 28467139561.2...7.75....18.541.872...6.5...17.7..16.5.4.58..7.11..7..5.88271.....
B7: 5,8                                  #  7 pairs
C7: 3,9,5,6,8                            # reduction candidate for 3,9
C7: 3,9 => CTR
* 28.67139.61.2...7.7.....1..5.1.872...6.....17.7..16...45....7.11..7..5.88271.....
C7: 5,6,8                                #  6 pairs
C8: 3,9,6                                # reduction candidate for 3,9
C8: 3,9                                  # 10 pairs
* PAIR B8: 3,9 ROW 8
E8: 3,9,2,4,6                            # reduction candidate for 3,9
E8: 3,9 => CTR
* 8546713926192.3874732...1.65.1.8726.96..2..1727..169..485.6.7.119673.5.83271.8649
E8: 2,4,6                                #  6 pairs
F8: 3,9,2,4                              # reduction candidate for 3,9
F8: 3,9 => CTR
* 85467139261923.87473289415654198726.96.....1727..169..485.6.7.11967.35.83271.8649
F8: 2,4                                  #  7 pairs
* PAIR B8: 3,9 COL B
B3: 3,9,4,5                              # reduction candidate for 3,9
B3: 3,9                                  # 12 pairs
B4: 3,9,4                                # reduction candidate for 3,9
B4: 3,9 => CTR
* ...67139..1.2...7.7.6...1.25.1.872...6.....17.7..16...4.....7.11..7..5.86271.8...
B4: 4                                    # 10 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-057-base-pr-000.dot
* REASONING
* DIS # C1: 2,8 => CTR => C1: 4,5
* PRF # A6: 2,8 => SOL
* DIS # A6: 3,9 => CTR => A6: 2,8
* DIS # F3: 5,8 => CTR => F3: 3,4,9
* DIS # B7: 3,9 => CTR => B7: 5,8
* DIS # C7: 3,9 => CTR => C7: 5,6,8
* DIS # E8: 3,9 => CTR => E8: 2,4,6
* DIS # F8: 3,9 => CTR => F8: 2,4
* DIS # B4: 3,9 => CTR => B4: 4
* CNT   9 HDP CHAINS /  19 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,B8,C3,H3,H6,I3)
* ...67139..1.2...7.7.....1..5.1.872...6.....17.7..16...4.....7.11..7..5.8.271.....
* PAIR A1: 2,8 BLK 1
C1: 2,8,4,5                              # reduction candidate for 2,8
C1: 2,8 => CTR
* ...67139..1.2...7.7.6...1.25.1.872...6.....17.7..16...485...7.11..7..5.86271.8...
* PAIR A1: 2,8 COL A
A6: 2,8,3,9                              # reduction candidate for 2,8
A6: 2,8 => SOLVED
* 854671392619235874732894156541987263968523417273416985485369721196742538327158649
* DURATION: 0:00:04.371649  START: 04:39:04.546092  END: 04:39:08.917741 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-057-base-pr-001.dot
* REASONING
* DIS # C1: 2,8 => CTR => C1: 4,5
* PRF C1: 4,5 # A6: 2,8 => SOL
* STA C1: 4,5 + A6: 2,8
* CNT   2 HDP CHAINS /   2 HYP OPENED

Header Info

Top 500 Minimum 17 057

solution: 854671392619235874732894156541987263968523417273416985485369721196742538327158649
info: 1427     FNBHWXY  S8.f     10625

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

Solution

position: 854671392619235874732894156541987263968523417273416985485369721196742538327158649 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 # C1: 2,8 => CTR => C1: 4,5
* INC # C1: 4,5 => UNS
* PRF # A6: 2,8 => SOL
* DIS # A6: 3,9 => CTR => A6: 2,8
* INC # D3: 5,8 => UNS
* DIS # F3: 5,8 => CTR => F3: 3,4,9
* INC # F3: 3,4,9 => UNS
* DIS # B7: 3,9 => CTR => B7: 5,8
* INC # B7: 5,8 => UNS
* DIS # C7: 3,9 => CTR => C7: 5,6,8
* INC # C7: 5,6,8 => UNS
* INC # C8: 3,9 => UNS
* DIS # E8: 3,9 => CTR => E8: 2,4,6
* INC # E8: 2,4,6 => UNS
* DIS # F8: 3,9 => CTR => F8: 2,4
* INC # F8: 2,4 => UNS
* INC # B3: 3,9 => UNS
* DIS # B4: 3,9 => CTR => B4: 4
* INC # B4: 4 => UNS
* CNT  19 HDP CHAINS /  19 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # C1: 2,8 => CTR => C1: 4,5
* PRF C1: 4,5 # A6: 2,8 => SOL
* STA C1: 4,5 + A6: 2,8
* CNT   2 HDP CHAINS /   2 HYP OPENED