Analysis of xx-top500-287-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 7.2....5.....41............16..3...4...2..58.............5..2..31........4....... initial

Autosolve

position: 7.23..451653.41..24.1.5236.16..35.2493421.58.52.4..13.87659421331.62..4.24.1.36.. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # F1: 6 => SOL
* DIS # D3: 8,9 => CTR => D3: 7
* PRF # F1: 6,8 => SOL
* DIS # F1: 9 => CTR => F1: 6,8
* PRF # E6: 6,8 => SOL
* DIS # E6: 7 => CTR => E6: 6,8
* DIS # G2: 7,9 => CTR => G2: 8
* DIS # D2: 8 => CTR => D2: 7,9
* DIS # F6: 7,8 => CTR => F6: 6,9
* DIS # F6: 6,7 => CTR => F6: 8,9
* DIS # D3: 8,9 => CTR => D3: 7
* DIS # F6: 6,7 => CTR => F6: 8,9
* PRF # I6: 7,9 => SOL
* DIS # I6: 6 => CTR => I6: 7,9
* DIS # G2: 7,9 => CTR => G2: 8
* PRF # I6: 6,7 => SOL
* DIS # I6: 9 => CTR => I6: 6,7
* DIS # I8: 7,8 => CTR => I8: 5,9
* DIS # I9: 5,9 => CTR => I9: 7,8
* DIS # I8: 7,8 => CTR => I8: 5,9
* DIS # F6: 7,8 => CTR => F6: 6,9
* DIS # I9: 5,9 => CTR => I9: 7,8
* PRF # E6: 6 => SOL
* DIS # I8: 7,9 => CTR => I8: 5,8
* DIS # I9: 7,9 => CTR => I9: 5,8
* CNT  25 HDP CHAINS /  50 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 # F1: 6 => SOL
* STA F1: 6
* CNT   1 HDP CHAINS /   2 HYP OPENED

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

Details

Positions

7.2....5.....41............16..3...4...2..58.............5..2..31........4....... initial
7.23..451653.41..24.1.5236.16..35.2493421.58.52.4..13.87659421331.62..4.24.1.36.. autosolve
792386451653941872481752369167835924934217586528469137876594213319628745245173698 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (15)
B1: 8,9
B3: 8,9
E1: 6,8
H2: 7,9
C4: 7,8
C6: 7,8
D4: 8,9
F5: 6,7
G4: 7,9
I5: 6,7
C8: 5,9
C9: 5,9
F8: 7,8
E9: 7,8
H9: 7,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
C8,C9: 5.. / C8 = 5  =>  0 pairs (X) / C9 = 5  => 14 pairs (_)
I8,I9: 5.. / I8 = 5  => 14 pairs (_) / I9 = 5  =>  0 pairs (X)
C8,I8: 5.. / C8 = 5  =>  0 pairs (X) / I8 = 5  => 14 pairs (_)
C9,I9: 5.. / C9 = 5  => 14 pairs (_) / I9 = 5  =>  0 pairs (X)
E1,F1: 6.. / E1 = 6  => 18 pairs (_) / F1 = 6  =>  0 pairs (*)
I5,I6: 6.. / I5 = 6  =>  0 pairs (*) / I6 = 6  =>  0 pairs (X)
F5,I5: 6.. / F5 = 6  =>  0 pairs (X) / I5 = 6  =>  0 pairs (_)
E1,E6: 6.. / E1 = 6  => 18 pairs (_) / E6 = 6  =>  0 pairs (*)
D2,D3: 7.. / D2 = 7  =>  0 pairs (X) / D3 = 7  => 17 pairs (_)
C4,C6: 7.. / C4 = 7  =>  0 pairs (*) / C6 = 7  =>  0 pairs (X)
F8,E9: 7.. / F8 = 7  =>  0 pairs (X) / E9 = 7  =>  0 pairs (_)
D3,I3: 7.. / D3 = 7  => 17 pairs (_) / I3 = 7  =>  0 pairs (X)
C4,G4: 7.. / C4 = 7  =>  0 pairs (*) / G4 = 7  =>  0 pairs (X)
F5,I5: 7.. / F5 = 7  =>  0 pairs (*) / I5 = 7  =>  0 pairs (X)
E6,E9: 7.. / E6 = 7  =>  0 pairs (X) / E9 = 7  =>  0 pairs (_)
H2,H9: 7.. / H2 = 7  => 16 pairs (_) / H9 = 7  =>  0 pairs (X)
B1,B3: 8.. / B1 = 8  =>  0 pairs (X) / B3 = 8  =>  0 pairs (_)
G2,I3: 8.. / G2 = 8  => 20 pairs (_) / I3 = 8  =>  0 pairs (X)
C4,C6: 8.. / C4 = 8  =>  0 pairs (X) / C6 = 8  =>  0 pairs (_)
F8,E9: 8.. / F8 = 8  =>  0 pairs (*) / E9 = 8  =>  0 pairs (X)
D2,G2: 8.. / D2 = 8  =>  0 pairs (X) / G2 = 8  => 20 pairs (_)
C4,D4: 8.. / C4 = 8  =>  0 pairs (X) / D4 = 8  =>  0 pairs (_)
E9,I9: 8.. / E9 = 8  =>  0 pairs (X) / I9 = 8  =>  0 pairs (_)
G2,G8: 8.. / G2 = 8  => 20 pairs (_) / G8 = 8  =>  0 pairs (X)
B1,B3: 9.. / B1 = 9  =>  0 pairs (*) / B3 = 9  =>  0 pairs (X)
D4,F6: 9.. / D4 = 9  =>  0 pairs (X) / F6 = 9  =>  0 pairs (_)
G4,I6: 9.. / G4 = 9  =>  0 pairs (*) / I6 = 9  =>  0 pairs (X)
C8,C9: 9.. / C8 = 9  => 14 pairs (_) / C9 = 9  =>  0 pairs (X)
B1,F1: 9.. / B1 = 9  =>  0 pairs (*) / F1 = 9  =>  0 pairs (X)
D4,G4: 9.. / D4 = 9  =>  0 pairs (X) / G4 = 9  =>  0 pairs (_)
F6,I6: 9.. / F6 = 9  =>  0 pairs (*) / I6 = 9  =>  0 pairs (X)
F1,F6: 9.. / F1 = 9  =>  0 pairs (X) / F6 = 9  =>  0 pairs (_)
H2,H9: 9.. / H2 = 9  =>  0 pairs (X) / H9 = 9  => 16 pairs (_)
* DURATION: 0:01:03.608736  START: 12:44:43.474403  END: 12:45:47.083139 2017-05-04
* CP COUNT: (33)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B1,B3,C4,C6,C8,C9,D4,E1,E9,F5,F8,G4,H2,H9,I5)
* 7.23..451653.41..24.1.5236.16..35.2493421.58.52.4..13.87659421331.62..4.24.1.36..
* PAIR B1: 8,9 ROW 1
F1: 8,9,6                                # reduction candidate for 8,9
F1: 6 => SOLVED
* 792386451653941872481752369167835924934217586528469137876594213319628745245173698
F1: 8,9                                  # 18 pairs
* PAIR B3: 8,9 ROW 3
D3: 8,9,7                                # reduction candidate for 8,9
D3: 8,9 => CTR
* 7.23..4516537418924.1.5236716..357249342175865274..13987659421331.62894524.1.36..
D3: 7                                    # 17 pairs
I3: 8,9,7                                # reduction candidate for 8,9
I3: 8,9                                  # 17 pairs
* PAIR E1: 6,8 BLK 2
F1: 6,8,9                                # reduction candidate for 6,8
F1: 6,8 => SOLVED
* 792386451653941872481752369167835924934217586528469137876594213319628745245173698
F1: 9 => CTR
* 7.2369451653.41..2491.5236.16.93572493421758652748613987659421331.62894724.1.36..
* PAIR E1: 6,8 COL E
E6: 6,8,7                                # reduction candidate for 6,8
E6: 6,8 => SOLVED
* 792386451653941872481752369167835924934217586528469137876594213319628745245173698
E6: 7 => CTR
* 7.236.451653.41..24.1.5236.16783592493421.58.52.47.13.87659421331.627.4.24.1836..
* PAIR H2: 7,9 BLK 3
G2: 7,9,8                                # reduction candidate for 7,9
G2: 7,9 => CTR
* 7.23..451653841..24.17523681689357249342175865274..13987659421331.628.4.24.1.36..
G2: 8                                    # 20 pairs
I3: 7,9,8                                # reduction candidate for 7,9
I3: 7,9                                  # 20 pairs
* PAIR H2: 7,9 ROW 2
D2: 7,9,8                                # reduction candidate for 7,9
D2: 8 => CTR
* 7.23..451653841..24.17523681689357249342175865274..13987659421331.628.4.24.1.36..
D2: 7,9                                  # 20 pairs
* PAIR C6: 7,8 ROW 6
E6: 7,8,6                                # reduction candidate for 7,8
E6: 7,8                                  # 18 pairs
F6: 7,8,6,9                              # reduction candidate for 7,8
F6: 7,8 => CTR
* 7.23.9451653.41..2491.5236.16.93572493421.58.52.4..13.87659421331.62..4.24.1.36..
F6: 6,9                                  # 16 pairs
* PAIR D4: 8,9 BLK 5
F6: 8,9,6,7                              # reduction candidate for 8,9
F6: 6,7 => CTR
* 7.23.9451653.41..2491.5236.16.93572493421758652748613987659421331.62894724.1.36..
F6: 8,9                                  # 17 pairs
* PAIR D4: 8,9 COL D
D2: 8,9,7                                # reduction candidate for 8,9
D2: 8,9                                  # 17 pairs
D3: 8,9,7                                # reduction candidate for 8,9
D3: 8,9 => CTR
* 7.23..4516537418924.1.5236716..357249342175865274..13987659421331.62894524.1.36..
D3: 7                                    # 17 pairs
* PAIR F5: 6,7 BLK 5
E6: 6,7,8                                # reduction candidate for 6,7
E6: 6,7                                  # 17 pairs
F6: 6,7,8,9                              # reduction candidate for 6,7
F6: 6,7 => CTR
* 7.23.9451653.41..2491.5236.16.93572493421758652748613987659421331.62894724.1.36..
F6: 8,9                                  # 17 pairs
* PAIR G4: 7,9 BLK 6
I6: 7,9,6                                # reduction candidate for 7,9
I6: 7,9 => SOLVED
* 792386451653941872481752369167835924934217586528469137876594213319628745245173698
I6: 6 => CTR
* 792368451653.417924.1.5236.16..3592493421.58752.4.913687659421331.62784.24.18367.
* PAIR G4: 7,9 COL G
G2: 7,9,8                                # reduction candidate for 7,9
G2: 7,9 => CTR
* 7.23..451653841..24.17523681689357249342175865274..13987659421331.628.4.24.1.36..
G2: 8                                    # 20 pairs
G8: 7,9,8                                # reduction candidate for 7,9
G8: 7,9                                  # 20 pairs
* PAIR I5: 6,7 BLK 6
I6: 6,7,9                                # reduction candidate for 6,7
I6: 6,7 => SOLVED
* 792386451653941872481752369167835924934217586528469137876594213319628745245173698
I6: 9 => CTR
* 7.23.9451653.41..2491.5236.16.9357249342175865274.613987659421331.62894724.1.36..
* PAIR C8: 5,9 ROW 8
I8: 5,9,7,8                              # reduction candidate for 5,9
I8: 7,8 => CTR
* 7.23..451653.418924.1.5236716.9357249342175865274..13987659421331562894.2491.3675
I8: 5,9                                  # 17 pairs
* PAIR C9: 5,9 ROW 9
I9: 5,9,7,8                              # reduction candidate for 5,9
I9: 5,9 => CTR
* 7.236.451653.41.924.1.5236.16783592493421.58.52.47.13.87659421331.627.4.24.18367.
I9: 7,8                                  # 16 pairs
* PAIR F8: 7,8 ROW 8
G8: 7,8,9                                # reduction candidate for 7,8
G8: 7,8                                  # 17 pairs
I8: 7,8,5,9                              # reduction candidate for 7,8
I8: 7,8 => CTR
* 7.23..451653.418924.1.5236716.9357249342175865274..13987659421331562894.2491.3675
I8: 5,9                                  # 17 pairs
* PAIR F8: 7,8 COL F
F6: 7,8,6,9                              # reduction candidate for 7,8
F6: 7,8 => CTR
* 7.23.9451653.41..2491.5236.16.93572493421.58.52.4..13.87659421331.62..4.24.1.36..
F6: 6,9                                  # 16 pairs
* PAIR E9: 7,8 ROW 9
I9: 7,8,5,9                              # reduction candidate for 7,8
I9: 5,9 => CTR
* 7.236.451653.41.924.1.5236.16783592493421.58.52.47.13.87659421331.627.4.24.18367.
I9: 7,8                                  # 16 pairs
* PAIR E9: 7,8 COL E
E6: 7,8,6                                # reduction candidate for 7,8
E6: 6 => SOLVED
* 792386451653941872481752369167835924934217586528469137876594213319628745245173698
E6: 7,8                                  # 18 pairs
* PAIR H9: 7,9 BLK 9
G8: 7,9,8                                # reduction candidate for 7,9
G8: 7,9                                  # 20 pairs
I8: 7,9,5,8                              # reduction candidate for 7,9
I8: 7,9 => CTR
* 782369451653.41.924.1.5236816..35.2493421.58.52.47.13.876594213315627849249183675
I8: 5,8                                  # 16 pairs
I9: 7,9,5,8                              # reduction candidate for 7,9
I9: 7,9 => CTR
* 782369451653841..249175236816..35.2493421.58.52.47.13.8765942133196278452451836..
I9: 5,8                                  # 16 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-287-base-pr-000.dot
* REASONING
* PRF # F1: 6 => SOL
* DIS # D3: 8,9 => CTR => D3: 7
* PRF # F1: 6,8 => SOL
* DIS # F1: 9 => CTR => F1: 6,8
* PRF # E6: 6,8 => SOL
* DIS # E6: 7 => CTR => E6: 6,8
* DIS # G2: 7,9 => CTR => G2: 8
* DIS # D2: 8 => CTR => D2: 7,9
* DIS # F6: 7,8 => CTR => F6: 6,9
* DIS # F6: 6,7 => CTR => F6: 8,9
* DIS # D3: 8,9 => CTR => D3: 7
* DIS # F6: 6,7 => CTR => F6: 8,9
* PRF # I6: 7,9 => SOL
* DIS # I6: 6 => CTR => I6: 7,9
* DIS # G2: 7,9 => CTR => G2: 8
* PRF # I6: 6,7 => SOL
* DIS # I6: 9 => CTR => I6: 6,7
* DIS # I8: 7,8 => CTR => I8: 5,9
* DIS # I9: 5,9 => CTR => I9: 7,8
* DIS # I8: 7,8 => CTR => I8: 5,9
* DIS # F6: 7,8 => CTR => F6: 6,9
* DIS # I9: 5,9 => CTR => I9: 7,8
* PRF # E6: 6 => SOL
* DIS # I8: 7,9 => CTR => I8: 5,8
* DIS # I9: 7,9 => CTR => I9: 5,8
* CNT  25 HDP CHAINS /  50 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B1,B3,C4,C6,C8,C9,D4,E1,E9,F5,F8,G4,H2,H9,I5)
* 7.23..451653.41..24.1.5236.16..35.2493421.58.52.4..13.87659421331.62..4.24.1.36..
* PAIR B1: 8,9 ROW 1
F1: 8,9,6                                # reduction candidate for 8,9
F1: 6 => SOLVED
* 792386451653941872481752369167835924934217586528469137876594213319628745245173698
* DURATION: 0:00:02.942394  START: 12:46:40.862157  END: 12:46:43.804551 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-287-base-pr-001.dot
* REASONING
* PRF # F1: 6 => SOL
* STA F1: 6
* CNT   1 HDP CHAINS /   2 HYP OPENED

Header Info

Top 500 Minimum 17 287

solution: 792386451653941872481752369167835924934217586528469137876594213319628745245173698
info: 2334     FNBTWXY  S8.f     37281

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

Solution

position: 792386451653941872481752369167835924934217586528469137876594213319628745245173698 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 # F1: 8,9 => UNS
* PRF # F1: 6 => SOL
* DIS # D3: 8,9 => CTR => D3: 7
* INC # D3: 7 => UNS
* INC # I3: 8,9 => UNS
* PRF # F1: 6,8 => SOL
* DIS # F1: 9 => CTR => F1: 6,8
* PRF # E6: 6,8 => SOL
* DIS # E6: 7 => CTR => E6: 6,8
* DIS # G2: 7,9 => CTR => G2: 8
* INC # G2: 8 => UNS
* INC # I3: 7,9 => UNS
* INC # D2: 7,9 => UNS
* DIS # D2: 8 => CTR => D2: 7,9
* INC # E6: 7,8 => UNS
* DIS # F6: 7,8 => CTR => F6: 6,9
* INC # F6: 6,9 => UNS
* INC # F6: 8,9 => UNS
* DIS # F6: 6,7 => CTR => F6: 8,9
* INC # D2: 8,9 => UNS
* DIS # D3: 8,9 => CTR => D3: 7
* INC # D3: 7 => UNS
* INC # E6: 6,7 => UNS
* DIS # F6: 6,7 => CTR => F6: 8,9
* INC # F6: 8,9 => UNS
* PRF # I6: 7,9 => SOL
* DIS # I6: 6 => CTR => I6: 7,9
* DIS # G2: 7,9 => CTR => G2: 8
* INC # G2: 8 => UNS
* INC # G8: 7,9 => UNS
* PRF # I6: 6,7 => SOL
* DIS # I6: 9 => CTR => I6: 6,7
* INC # I8: 5,9 => UNS
* DIS # I8: 7,8 => CTR => I8: 5,9
* DIS # I9: 5,9 => CTR => I9: 7,8
* INC # I9: 7,8 => UNS
* INC # G8: 7,8 => UNS
* DIS # I8: 7,8 => CTR => I8: 5,9
* INC # I8: 5,9 => UNS
* DIS # F6: 7,8 => CTR => F6: 6,9
* INC # F6: 6,9 => UNS
* INC # I9: 7,8 => UNS
* DIS # I9: 5,9 => CTR => I9: 7,8
* INC # E6: 7,8 => UNS
* PRF # E6: 6 => SOL
* INC # G8: 7,9 => UNS
* DIS # I8: 7,9 => CTR => I8: 5,8
* INC # I8: 5,8 => UNS
* DIS # I9: 7,9 => CTR => I9: 5,8
* INC # I9: 5,8 => UNS
* CNT  50 HDP CHAINS /  50 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # F1: 8,9 => UNS
* PRF # F1: 6 => SOL
* STA F1: 6
* CNT   2 HDP CHAINS /   2 HYP OPENED