Analysis of xx-top500-364-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: ...2..4....5...8...3..7.......1.8.3.1..4............5..24...1......5....6........ initial

Autosolve

position: 9..283475475.1.823832574.1.25.1.87341.74352..348.2..515243..1..7...5.34.6.3.4.59. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # D6: 6,9 => SOL
* DIS # D6: 7 => CTR => D6: 6,9
* DIS # F6: 6,9 => CTR => F6: 7
* PRF # F6: 7 => SOL
* PRF # F7: 6,9 => SOL
* DIS # F7: 7 => CTR => F7: 6,9
* DIS # I5: 6,9 => CTR => I5: 8
* PRF # I5: 8 => SOL
* DIS # I5: 6,9 => CTR => I5: 8
* PRF # I5: 8 => SOL
* PRF # D6: 6,9 => SOL
* DIS # D6: 7 => CTR => D6: 6,9
* DIS # F6: 6,9 => CTR => F6: 7
* PRF # F6: 7 => SOL
* PRF # I5: 6,8 => SOL
* DIS # I5: 9 => CTR => I5: 6,8
* DIS # I5: 6,9 => CTR => I5: 8
* PRF # I5: 8 => SOL
* PRF # D6: 6,9 => SOL
* DIS # D6: 7 => CTR => D6: 6,9
* DIS # F6: 6,9 => CTR => F6: 7
* PRF # F6: 7 => SOL
* PRF # B8: 1,9 => SOL
* DIS # B8: 8 => CTR => B8: 1,9
* PRF # B8: 1,8 => SOL
* DIS # B8: 9 => CTR => B8: 1,8
* PRF # F7: 6,9 => SOL
* DIS # F7: 7 => CTR => F7: 6,9
* DIS # I7: 6,8 => CTR => I7: 7
* PRF # I7: 7 => SOL
* CNT  30 HDP CHAINS /  30 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 # D6: 6,9 => SOL
* STA D6: 6,9
* CNT   1 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

...2..4....5...8...3..7.......1.8.3.1..4............5..24...1......5....6........ initial
9..283475475.1.823832574.1.25.1.87341.74352..348.2..515243..1..7...5.34.6.3.4.59. autosolve
961283475475916823832574619256198734197435268348627951524369187719852346683741592 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (21)
B1: 1,6
C1: 1,6
D2: 6,9
F2: 6,9
G3: 6,9
I3: 6,9
C4: 6,9
B5: 6,9
E4: 6,9
H5: 6,8
G6: 6,9
C8: 1,9
B9: 1,8
E7: 6,9
D8: 6,8
F8: 1,2
D9: 7,8
F9: 1,2
H7: 6,8
I8: 2,6
I9: 2,7

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
B1,C1: 1.. / B1 = 1  =>  0 pairs (X) / C1 = 1  =>  0 pairs (_)
F8,F9: 1.. / F8 = 1  =>  0 pairs (X) / F9 = 1  =>  0 pairs (_)
B9,F9: 1.. / B9 = 1  =>  0 pairs (X) / F9 = 1  =>  0 pairs (_)
C1,C8: 1.. / C1 = 1  =>  0 pairs (*) / C8 = 1  =>  0 pairs (X)
F8,F9: 2.. / F8 = 2  =>  0 pairs (*) / F9 = 2  =>  0 pairs (X)
I8,I9: 2.. / I8 = 2  =>  0 pairs (X) / I9 = 2  =>  0 pairs (_)
F8,I8: 2.. / F8 = 2  =>  0 pairs (*) / I8 = 2  =>  0 pairs (X)
F9,I9: 2.. / F9 = 2  =>  0 pairs (X) / I9 = 2  =>  0 pairs (_)
B1,C1: 6.. / B1 = 6  =>  0 pairs (*) / C1 = 6  =>  0 pairs (X)
D2,F2: 6.. / D2 = 6  =>  0 pairs (X) / F2 = 6  => 22 pairs (_)
G3,I3: 6.. / G3 = 6  =>  0 pairs (*) / I3 = 6  =>  0 pairs (X)
C4,B5: 6.. / C4 = 6  =>  0 pairs (*) / B5 = 6  =>  0 pairs (X)
C4,E4: 6.. / C4 = 6  =>  0 pairs (*) / E4 = 6  =>  0 pairs (X)
D8,I8: 6.. / D8 = 6  =>  0 pairs (X) / I8 = 6  =>  0 pairs (_)
B1,B5: 6.. / B1 = 6  =>  0 pairs (*) / B5 = 6  =>  0 pairs (X)
C1,C4: 6.. / C1 = 6  =>  0 pairs (X) / C4 = 6  =>  0 pairs (_)
E4,E7: 6.. / E4 = 6  =>  0 pairs (X) / E7 = 6  =>  0 pairs (_)
G3,G6: 6.. / G3 = 6  =>  0 pairs (*) / G6 = 6  =>  0 pairs (X)
H5,H7: 6.. / H5 = 6  =>  0 pairs (*) / H7 = 6  =>  0 pairs (X)
D6,F6: 7.. / D6 = 7  =>  0 pairs (X) / F6 = 7  =>  0 pairs (_)
F7,D9: 7.. / F7 = 7  =>  0 pairs (X) / D9 = 7  =>  0 pairs (_)
I7,I9: 7.. / I7 = 7  =>  0 pairs (*) / I9 = 7  =>  0 pairs (X)
F7,I7: 7.. / F7 = 7  =>  0 pairs (X) / I7 = 7  =>  0 pairs (_)
D9,I9: 7.. / D9 = 7  =>  0 pairs (*) / I9 = 7  =>  0 pairs (X)
D6,D9: 7.. / D6 = 7  =>  0 pairs (X) / D9 = 7  =>  0 pairs (_)
F6,F7: 7.. / F6 = 7  =>  0 pairs (*) / F7 = 7  =>  0 pairs (X)
H5,I5: 8.. / H5 = 8  =>  0 pairs (X) / I5 = 8  =>  0 pairs (_)
B8,B9: 8.. / B8 = 8  =>  0 pairs (X) / B9 = 8  =>  0 pairs (_)
D8,D9: 8.. / D8 = 8  =>  0 pairs (*) / D9 = 8  =>  0 pairs (X)
H7,I7: 8.. / H7 = 8  =>  0 pairs (*) / I7 = 8  =>  0 pairs (X)
B8,D8: 8.. / B8 = 8  =>  0 pairs (X) / D8 = 8  =>  0 pairs (_)
B9,D9: 8.. / B9 = 8  =>  0 pairs (*) / D9 = 8  =>  0 pairs (X)
H5,H7: 8.. / H5 = 8  =>  0 pairs (X) / H7 = 8  =>  0 pairs (_)
I5,I7: 8.. / I5 = 8  =>  0 pairs (*) / I7 = 8  =>  0 pairs (X)
D2,F2: 9.. / D2 = 9  => 22 pairs (_) / F2 = 9  =>  0 pairs (X)
G3,I3: 9.. / G3 = 9  =>  0 pairs (X) / I3 = 9  =>  0 pairs (_)
C4,B5: 9.. / C4 = 9  =>  0 pairs (X) / B5 = 9  =>  0 pairs (_)
I5,G6: 9.. / I5 = 9  =>  0 pairs (X) / G6 = 9  =>  0 pairs (_)
B8,C8: 9.. / B8 = 9  =>  0 pairs (X) / C8 = 9  =>  0 pairs (_)
E7,F7: 9.. / E7 = 9  =>  0 pairs (X) / F7 = 9  =>  0 pairs (_)
C4,E4: 9.. / C4 = 9  =>  0 pairs (X) / E4 = 9  =>  0 pairs (_)
B5,I5: 9.. / B5 = 9  =>  0 pairs (*) / I5 = 9  =>  0 pairs (X)
B5,B8: 9.. / B5 = 9  =>  0 pairs (*) / B8 = 9  =>  0 pairs (X)
C4,C8: 9.. / C4 = 9  =>  0 pairs (X) / C8 = 9  =>  0 pairs (_)
D2,D6: 9.. / D2 = 9  => 22 pairs (_) / D6 = 9  =>  0 pairs (X)
E4,E7: 9.. / E4 = 9  =>  0 pairs (*) / E7 = 9  =>  0 pairs (X)
G3,G6: 9.. / G3 = 9  =>  0 pairs (X) / G6 = 9  =>  0 pairs (_)
I3,I5: 9.. / I3 = 9  =>  0 pairs (*) / I5 = 9  =>  0 pairs (X)
* DURATION: 0:01:28.619643  START: 15:15:03.816217  END: 15:16:32.435860 2017-05-04
* CP COUNT: (48)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B1,B5,B9,C1,C4,C8,D2,D8,D9,E4,E7,F2,F8,F9,G3,G6,H5,H7,I3,I8,I9)
* 9..283475475.1.823832574.1.25.1.87341.74352..348.2..515243..1..7...5.34.6.3.4.59.
* PAIR D2: 6,9 COL D
D6: 6,9,7                                # reduction candidate for 6,9
D6: 6,9 => SOLVED
* 961283475475916823832574619256198734197435268348627951524369187719852346683741592
D6: 7 => CTR
* 9..283475475916823832574.1.25.168734167435289348729651524397168791.5.34.6.3.4.59.
* PAIR F2: 6,9 COL F
F6: 6,9,7                                # reduction candidate for 6,9
F6: 6,9 => CTR
* 9..283475475916823832574.1.25.1687341674352893487296515243971687...5.34.6.384.597
F6: 7 => SOLVED
* 961283475475916823832574619256198734197435268348627951524369187719852346683741592
F7: 6,9,7                                # reduction candidate for 6,9
F7: 6,9 => SOLVED
* 961283475475916823832574619256198734197435268348627951524369187719852346683741592
F7: 7 => CTR
* 9..283475475916823832574.1.2591687341674352..348.2..515243971..7..65.3426.3842597
* PAIR I3: 6,9 COL I
I5: 6,9,8                                # reduction candidate for 6,9
I5: 6,9 => CTR
* 9..283475475916823832574.1.25.1687341674352893487296515243971687..65.3426.3842597
I5: 8 => SOLVED
* 961283475475916823832574619256198734197435268348627951524369187719852346683741592
* PAIR B5: 6,9 ROW 5
I5: 6,9,8                                # reduction candidate for 6,9
I5: 6,9 => CTR
* 9..283475475916823832574.1.25.1687341674352893487296515243971687..65.3426.3842597
I5: 8 => SOLVED
* 961283475475916823832574619256198734197435268348627951524369187719852346683741592
* PAIR E4: 6,9 BLK 5
D6: 6,9,7                                # reduction candidate for 6,9
D6: 6,9 => SOLVED
* 961283475475916823832574619256198734197435268348627951524369187719852346683741592
D6: 7 => CTR
* 9..283475475916823832574.1.25.168734167435289348729651524397168791.5.34.6.3.4.59.
F6: 6,9,7                                # reduction candidate for 6,9
F6: 6,9 => CTR
* 9..283475475916823832574.1.25.1687341674352893487296515243971687...5.34.6.384.597
F6: 7 => SOLVED
* 961283475475916823832574619256198734197435268348627951524369187719852346683741592
* PAIR H5: 6,8 BLK 6
I5: 6,8,9                                # reduction candidate for 6,8
I5: 6,8 => SOLVED
* 961283475475916823832574619256198734197435268348627951524369187719852346683741592
I5: 9 => CTR
* 9..283475475.1.823832574.1.25.1.87341.7435289348.2.6515243..168791.5.34.6.3.4.59.
* PAIR G6: 6,9 BLK 6
I5: 6,9,8                                # reduction candidate for 6,9
I5: 6,9 => CTR
* 9..283475475916823832574.1.25.1687341674352893487296515243971687..65.3426.3842597
I5: 8 => SOLVED
* 961283475475916823832574619256198734197435268348627951524369187719852346683741592
* PAIR G6: 6,9 ROW 6
D6: 6,9,7                                # reduction candidate for 6,9
D6: 6,9 => SOLVED
* 961283475475916823832574619256198734197435268348627951524369187719852346683741592
D6: 7 => CTR
* 9..283475475916823832574.1.25.168734167435289348729651524397168791.5.34.6.3.4.59.
F6: 6,9,7                                # reduction candidate for 6,9
F6: 6,9 => CTR
* 9..283475475916823832574.1.25.1687341674352893487296515243971687...5.34.6.384.597
F6: 7 => SOLVED
* 961283475475916823832574619256198734197435268348627951524369187719852346683741592
* PAIR C8: 1,9 BLK 7
B8: 1,9,8                                # reduction candidate for 1,9
B8: 1,9 => SOLVED
* 961283475475916823832574619256198734197435268348627951524369187719852346683741592
B8: 8 => CTR
* 9..283475475.1.823832574.1.25.1.87341974352..348.2.9515243..1..789651342613842597
* PAIR B9: 1,8 BLK 7
B8: 1,8,9                                # reduction candidate for 1,8
B8: 1,8 => SOLVED
* 961283475475916823832574619256198734197435268348627951524369187719852346683741592
B8: 9 => CTR
* 916283475475.1.82383257461925916873416743528.348.2..515243..1..791852346683741592
* PAIR E7: 6,9 BLK 8
F7: 6,9,7                                # reduction candidate for 6,9
F7: 6,9 => SOLVED
* 961283475475916823832574619256198734197435268348627951524369187719852346683741592
F7: 7 => CTR
* 9..283475475916823832574.1.2591687341674352..348.2..515243971..7..65.3426.3842597
* PAIR H7: 6,8 BLK 9
I7: 6,8,7                                # reduction candidate for 6,8
I7: 6,8 => CTR
* 9..283475475.1.823832574.1.25.1.87341.74352..34872..515243971..789651342613842597
I7: 7 => SOLVED
* 961283475475916823832574619256198734197435268348627951524369187719852346683741592
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-364-base-pr-000.dot
* REASONING
* PRF # D6: 6,9 => SOL
* DIS # D6: 7 => CTR => D6: 6,9
* DIS # F6: 6,9 => CTR => F6: 7
* PRF # F6: 7 => SOL
* PRF # F7: 6,9 => SOL
* DIS # F7: 7 => CTR => F7: 6,9
* DIS # I5: 6,9 => CTR => I5: 8
* PRF # I5: 8 => SOL
* DIS # I5: 6,9 => CTR => I5: 8
* PRF # I5: 8 => SOL
* PRF # D6: 6,9 => SOL
* DIS # D6: 7 => CTR => D6: 6,9
* DIS # F6: 6,9 => CTR => F6: 7
* PRF # F6: 7 => SOL
* PRF # I5: 6,8 => SOL
* DIS # I5: 9 => CTR => I5: 6,8
* DIS # I5: 6,9 => CTR => I5: 8
* PRF # I5: 8 => SOL
* PRF # D6: 6,9 => SOL
* DIS # D6: 7 => CTR => D6: 6,9
* DIS # F6: 6,9 => CTR => F6: 7
* PRF # F6: 7 => SOL
* PRF # B8: 1,9 => SOL
* DIS # B8: 8 => CTR => B8: 1,9
* PRF # B8: 1,8 => SOL
* DIS # B8: 9 => CTR => B8: 1,8
* PRF # F7: 6,9 => SOL
* DIS # F7: 7 => CTR => F7: 6,9
* DIS # I7: 6,8 => CTR => I7: 7
* PRF # I7: 7 => SOL
* CNT  30 HDP CHAINS /  30 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B1,B5,B9,C1,C4,C8,D2,D8,D9,E4,E7,F2,F8,F9,G3,G6,H5,H7,I3,I8,I9)
* 9..283475475.1.823832574.1.25.1.87341.74352..348.2..515243..1..7...5.34.6.3.4.59.
* PAIR D2: 6,9 COL D
D6: 6,9,7                                # reduction candidate for 6,9
D6: 6,9 => SOLVED
* 961283475475916823832574619256198734197435268348627951524369187719852346683741592
* DURATION: 0:00:02.187607  START: 15:17:10.359358  END: 15:17:12.546965 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-364-base-pr-001.dot
* REASONING
* PRF # D6: 6,9 => SOL
* STA D6: 6,9
* CNT   1 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 364

solution: 961283475475916823832574619256198734197435268348627951524369187719852346683741592
info: 4952     FNBHWY   S8.f     48881

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

Solution

position: 961283475475916823832574619256198734197435268348627951524369187719852346683741592 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 # D6: 6,9 => SOL
* DIS # D6: 7 => CTR => D6: 6,9
* DIS # F6: 6,9 => CTR => F6: 7
* PRF # F6: 7 => SOL
* PRF # F7: 6,9 => SOL
* DIS # F7: 7 => CTR => F7: 6,9
* DIS # I5: 6,9 => CTR => I5: 8
* PRF # I5: 8 => SOL
* DIS # I5: 6,9 => CTR => I5: 8
* PRF # I5: 8 => SOL
* PRF # D6: 6,9 => SOL
* DIS # D6: 7 => CTR => D6: 6,9
* DIS # F6: 6,9 => CTR => F6: 7
* PRF # F6: 7 => SOL
* PRF # I5: 6,8 => SOL
* DIS # I5: 9 => CTR => I5: 6,8
* DIS # I5: 6,9 => CTR => I5: 8
* PRF # I5: 8 => SOL
* PRF # D6: 6,9 => SOL
* DIS # D6: 7 => CTR => D6: 6,9
* DIS # F6: 6,9 => CTR => F6: 7
* PRF # F6: 7 => SOL
* PRF # B8: 1,9 => SOL
* DIS # B8: 8 => CTR => B8: 1,9
* PRF # B8: 1,8 => SOL
* DIS # B8: 9 => CTR => B8: 1,8
* PRF # F7: 6,9 => SOL
* DIS # F7: 7 => CTR => F7: 6,9
* DIS # I7: 6,8 => CTR => I7: 7
* PRF # I7: 7 => SOL
* CNT  30 HDP CHAINS /  30 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* PRF # D6: 6,9 => SOL
* STA D6: 6,9
* CNT   1 HDP CHAINS /   1 HYP OPENED