Analysis of xx-top500-479-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: ...2.7..4.3.5.....6.....9..15..4.....2.....7.......3..8...6.......7...5.......... initial

Autosolve

position: ...2.7..4.3.5.6...6.....9..157.4.....2.....7.....7.3..8...6.......7...5.......... autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # C1: 5,9 => CTR => C1: 1,8
* DIS # A9: 5,9 => CTR => A9: 2,3,4,7
* PRF # A9: 2,3,4,7 => SOL
* PRF # A5: 4,9 => SOL
* DIS # B6: 4,9 => CTR => B6: 6,8
* DIS # C6: 4,9 => CTR => C6: 6,8
* DIS # H6: 1,2,6,8 => CTR => H6: 4,9
* DIS # A2: 4,9 => CTR => A2: 2,7
* DIS # A8: 4,9 => CTR => A8: 2,3
* DIS # A9: 4,9 => CTR => A9: 2,3,5,7
* CNT  10 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: 5,9 => CTR => C1: 1,8
* DIS C1: 1,8 # A9: 5,9 => CTR => A9: 2,3,4,7
* PRF C1: 1,8 + A9: 2,3,4,7 => SOL
* STA C1: 1,8 + A9: 2,3,4,7
* CNT   3 HDP CHAINS /   2 HYP OPENED

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

Details

Positions

...2.7..4.3.5.....6.....9..15..4.....2.....7.......3..8...6.......7...5.......... initial
...2.7..4.3.5.6...6.....9..157.4.....2.....7.....7.3..8...6.......7...5.......... autosolve
598217634234596718671834925157342869423689571986175342815463297349728156762951483 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (2)
A1: 5,9
A6: 4,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
F4,F6: 2.. / F4 = 2  =>  4 pairs (_) / F6 = 2  =>  0 pairs (X)
E8,E9: 2.. / E8 = 2  =>  0 pairs (*) / E9 = 2  =>  0 pairs (X)
A5,C5: 3.. / A5 = 3  =>  2 pairs (_) / C5 = 3  =>  0 pairs (*)
D4,F4: 3.. / D4 = 3  =>  2 pairs (_) / F4 = 3  =>  0 pairs (X)
E1,H1: 3.. / E1 = 3  =>  0 pairs (X) / H1 = 3  =>  0 pairs (_)
A2,C2: 4.. / A2 = 4  =>  0 pairs (X) / C2 = 4  =>  2 pairs (_)
D3,F3: 4.. / D3 = 4  =>  2 pairs (_) / F3 = 4  =>  2 pairs (_)
G5,H6: 4.. / G5 = 4  =>  0 pairs (X) / H6 = 4  =>  0 pairs (_)
G1,I3: 5.. / G1 = 5  =>  0 pairs (X) / I3 = 5  =>  0 pairs (_)
C3,I3: 5.. / C3 = 5  =>  0 pairs (X) / I3 = 5  =>  0 pairs (_)
F6,I6: 5.. / F6 = 5  =>  0 pairs (*) / I6 = 5  =>  0 pairs (X)
C7,F7: 5.. / C7 = 5  =>  0 pairs (*) / F7 = 5  =>  0 pairs (X)
A1,A9: 5.. / A1 = 5  =>  0 pairs (*) / A9 = 5  =>  0 pairs (X)
E5,E9: 5.. / E5 = 5  =>  0 pairs (X) / E9 = 5  =>  0 pairs (_)
G1,G5: 5.. / G1 = 5  =>  0 pairs (X) / G5 = 5  =>  0 pairs (_)
G1,H1: 6.. / G1 = 6  =>  0 pairs (*) / H1 = 6  =>  0 pairs (X)
A2,B3: 7.. / A2 = 7  =>  0 pairs (X) / B3 = 7  =>  0 pairs (_)
B3,I3: 7.. / B3 = 7  =>  0 pairs (*) / I3 = 7  =>  0 pairs (X)
A2,A9: 7.. / A2 = 7  =>  0 pairs (X) / A9 = 7  =>  0 pairs (_)
E1,E2: 9.. / E1 = 9  =>  0 pairs (X) / E2 = 9  =>  2 pairs (_)
* DURATION: 0:00:30.298146  START: 19:03:07.960831  END: 19:03:38.258977 2017-05-04
* CP COUNT: (20)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,A6)
* ...2.7..4.3.5.6...6.....9..157.4.....2.....7.....7.3..8...6.......7...5..........
* PAIR A1: 5,9 BLK 1
C1: 5,9,1,8                              # reduction candidate for 5,9
C1: 5,9 => CTR
* 5.92.7.3423459671867..3.925157342...4236895719..1753428.5.6329739.72..5676295..83
C1: 1,8                                  #  3 pairs
* PAIR A1: 5,9 COL A
A9: 5,9,2,3,4,7                          # reduction candidate for 5,9
A9: 5,9 => CTR
* ...2.7..4734596...6.2...9..157.4.....2.....7.....7.3..8...6.......7...5..........
A9: 2,3,4,7 => SOLVED
* 598217634234596718671834925157342869423689571986175342815463297349728156762951483
* PAIR A6: 4,9 BLK 4
A5: 4,9,3                                # reduction candidate for 4,9
A5: 4,9 => SOLVED
* 598217634234596718671834925157342869423689571986175342815463297349728156762951483
A5: 3                                    #  2 pairs
C5: 4,9,3,6,8                            # reduction candidate for 4,9
C5: 4,9                                  #  7 pairs
B6: 4,9,6,8                              # reduction candidate for 4,9
B6: 4,9 => CTR
* 9.123756473.5.6...6.5...9..157.4....32....47.....7.3..8...65......7...5.5........
B6: 6,8                                  #  3 pairs
C6: 4,9,6,8                              # reduction candidate for 4,9
C6: 4,9 => CTR
* 9..23756473.5.6...6.5...9..157.4....32....47.....7.3..8...65......7...5.5........
C6: 6,8                                  #  3 pairs
* PAIR A6: 4,9 ROW 6
H6: 4,9,1,2,6,8                          # reduction candidate for 4,9
H6: 1,2,6,8 => CTR
* 9..23756473.5.6...6.5...9..157.4.....2....47.....7.3..8...65......7...5.5........
H6: 4,9                                  #  8 pairs
* PAIR A6: 4,9 COL A
A2: 4,9,2,7                              # reduction candidate for 4,9
A2: 4,9 => CTR
* 5..2.7..4.3.5.6...67....9.5157.4.....2....57.....753428.5.6....2..7...5.7........
A2: 2,7                                  #  6 pairs
A8: 4,9,2,3                              # reduction candidate for 4,9
A8: 4,9 => CTR
* 5..2.7..4.34596...6.....9.5157.4....32.....7.....7.3..8...6.......7...5..........
A8: 2,3                                  #  3 pairs
A9: 4,9,2,3,5,7                          # reduction candidate for 4,9
A9: 4,9 => CTR
* 5..2.7..4734596...6.2...9..157.4.....2.....7.....7.3..8...6.......7...5..........
A9: 2,3,5,7                              #  2 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-479-base-pr-000.dot
* REASONING
* DIS # C1: 5,9 => CTR => C1: 1,8
* DIS # A9: 5,9 => CTR => A9: 2,3,4,7
* PRF # A9: 2,3,4,7 => SOL
* PRF # A5: 4,9 => SOL
* DIS # B6: 4,9 => CTR => B6: 6,8
* DIS # C6: 4,9 => CTR => C6: 6,8
* DIS # H6: 1,2,6,8 => CTR => H6: 4,9
* DIS # A2: 4,9 => CTR => A2: 2,7
* DIS # A8: 4,9 => CTR => A8: 2,3
* DIS # A9: 4,9 => CTR => A9: 2,3,5,7
* CNT  10 HDP CHAINS /  19 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,A6)
* ...2.7..4.3.5.6...6.....9..157.4.....2.....7.....7.3..8...6.......7...5..........
* PAIR A1: 5,9 BLK 1
C1: 5,9,1,8                              # reduction candidate for 5,9
C1: 5,9 => CTR
* 5.92.7.3423459671867..3.925157342...4236895719..1753428.5.6329739.72..5676295..83
* PAIR A1: 5,9 COL A
A9: 5,9,2,3,4,7                          # reduction candidate for 5,9
A9: 5,9 => CTR
* ...2.7..4734596...6.2...9..157.4.....2.....7.....7.3..8...6.......7...5..........
A9: 2,3,4,7 => SOLVED
* 598217634234596718671834925157342869423689571986175342815463297349728156762951483
* DURATION: 0:00:04.731159  START: 19:03:51.270777  END: 19:03:56.001936 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-479-base-pr-001.dot
* REASONING
* DIS # C1: 5,9 => CTR => C1: 1,8
* DIS C1: 1,8 # A9: 5,9 => CTR => A9: 2,3,4,7
* PRF C1: 1,8 + A9: 2,3,4,7 => SOL
* STA C1: 1,8 + A9: 2,3,4,7
* CNT   3 HDP CHAINS /   2 HYP OPENED

Header Info

Top 500 Minimum 17 479

solution: 598217634234596718671834925157342869423689571986175342815463297349728156762951483
info: 95777    FNBWXYK  S8.f     7910

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

Solution

position: 598217634234596718671834925157342869423689571986175342815463297349728156762951483 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: 5,9 => CTR => C1: 1,8
* INC # C1: 1,8 => UNS
* DIS # A9: 5,9 => CTR => A9: 2,3,4,7
* PRF # A9: 2,3,4,7 => SOL
* PRF # A5: 4,9 => SOL
* INC # A5: 3 => UNS
* INC # C5: 4,9 => UNS
* DIS # B6: 4,9 => CTR => B6: 6,8
* INC # B6: 6,8 => UNS
* DIS # C6: 4,9 => CTR => C6: 6,8
* INC # C6: 6,8 => UNS
* INC # H6: 4,9 => UNS
* DIS # H6: 1,2,6,8 => CTR => H6: 4,9
* DIS # A2: 4,9 => CTR => A2: 2,7
* INC # A2: 2,7 => UNS
* DIS # A8: 4,9 => CTR => A8: 2,3
* INC # A8: 2,3 => UNS
* DIS # A9: 4,9 => CTR => A9: 2,3,5,7
* INC # A9: 2,3,5,7 => UNS
* CNT  19 HDP CHAINS /  19 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # C1: 5,9 => CTR => C1: 1,8
* DIS C1: 1,8 # A9: 5,9 => CTR => A9: 2,3,4,7
* PRF C1: 1,8 + A9: 2,3,4,7 => SOL
* STA C1: 1,8 + A9: 2,3,4,7
* CNT   3 HDP CHAINS /   2 HYP OPENED