Analysis of xx-top500-110-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 4...2............1.......6.....4.27..16......8..........76.3....5....4.....8..3.. initial

Autosolve

position: 46.7218......6...11......6....146278.16......8.4...61..476.318.3582174966.18.43.7 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # A2: 5,9 => CTR => A2: 7
* PRF # A2: 7 => SOL
* DIS # C2: 5,9 => CTR => C2: 2,3
* DIS # C3: 5,9 => CTR => C3: 2,3
* DIS # I1: 3 => CTR => I1: 5,9
* DIS # C4: 3 => CTR => C4: 5,9
* DIS # H5: 3,5 => CTR => H5: 4
* PRF # H5: 4 => SOL
* DIS # C4: 3 => CTR => C4: 5,9
* DIS # A2: 5,9 => CTR => A2: 7
* PRF # A2: 7 => SOL
* DIS # C4: 5 => CTR => C4: 3,9
* DIS # B2: 3,9 => CTR => B2: 7,8
* PRF # B3: 3,9 => SOL
* DIS # I5: 5,9 => CTR => I5: 3,4
* DIS # D5: 3 => CTR => D5: 5,9
* DIS # G3: 5,9 => CTR => G3: 7
* CNT  17 HDP CHAINS /  34 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 # A2: 5,9 => CTR => A2: 7
* PRF A2: 7 => SOL
* STA A2: 7
* CNT   2 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

4...2............1.......6.....4.27..16......8..........76.3....5....4.....8..3.. initial
46.7218......6...11......6....146278.16......8.4...61..476.318.3582174966.18.43.7 autosolve
465721839783469521192385764539146278216578943874932615947653182358217496621894357 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (19)
C1: 5,9
E3: 3,8
H1: 3,5
H2: 2,4
I3: 2,4
A4: 5,9
B4: 3,9
A5: 2,7
B6: 2,7
E5: 7,8
F5: 2,8
E6: 3,7
G5: 5,9
A7: 2,9
B9: 2,9
E7: 5,9
E9: 5,9
I7: 2,5
H9: 2,5

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
C2,C3: 2.. / C2 = 2  =>  0 pairs (X) / C3 = 2  =>  0 pairs (_)
H2,I3: 2.. / H2 = 2  =>  0 pairs (*) / I3 = 2  =>  0 pairs (X)
A5,B6: 2.. / A5 = 2  =>  0 pairs (*) / B6 = 2  =>  0 pairs (X)
F5,F6: 2.. / F5 = 2  =>  0 pairs (X) / F6 = 2  =>  0 pairs (_)
A7,B9: 2.. / A7 = 2  =>  0 pairs (X) / B9 = 2  =>  0 pairs (_)
I7,H9: 2.. / I7 = 2  =>  0 pairs (*) / H9 = 2  =>  0 pairs (X)
C2,H2: 2.. / C2 = 2  =>  0 pairs (X) / H2 = 2  =>  0 pairs (_)
C3,I3: 2.. / C3 = 2  =>  0 pairs (*) / I3 = 2  =>  0 pairs (X)
A5,F5: 2.. / A5 = 2  =>  0 pairs (*) / F5 = 2  =>  0 pairs (X)
B6,F6: 2.. / B6 = 2  =>  0 pairs (X) / F6 = 2  =>  0 pairs (_)
A7,I7: 2.. / A7 = 2  =>  0 pairs (X) / I7 = 2  =>  0 pairs (_)
B9,H9: 2.. / B9 = 2  =>  0 pairs (*) / H9 = 2  =>  0 pairs (X)
A5,A7: 2.. / A5 = 2  =>  0 pairs (*) / A7 = 2  =>  0 pairs (X)
B6,B9: 2.. / B6 = 2  =>  0 pairs (X) / B9 = 2  =>  0 pairs (_)
H2,H9: 2.. / H2 = 2  =>  0 pairs (*) / H9 = 2  =>  0 pairs (X)
I3,I7: 2.. / I3 = 2  =>  0 pairs (X) / I7 = 2  =>  0 pairs (_)
H1,I1: 3.. / H1 = 3  => 20 pairs (_) / I1 = 3  =>  0 pairs (X)
B4,C4: 3.. / B4 = 3  => 22 pairs (_) / C4 = 3  =>  0 pairs (X)
E3,E6: 3.. / E3 = 3  =>  0 pairs (X) / E6 = 3  =>  0 pairs (_)
H1,H5: 3.. / H1 = 3  => 20 pairs (_) / H5 = 3  =>  0 pairs (X)
D2,D3: 4.. / D2 = 4  =>  0 pairs (*) / D3 = 4  =>  0 pairs (X)
H2,I3: 4.. / H2 = 4  =>  0 pairs (X) / I3 = 4  =>  0 pairs (_)
H5,I5: 4.. / H5 = 4  =>  0 pairs (*) / I5 = 4  =>  0 pairs (X)
D2,H2: 4.. / D2 = 4  =>  0 pairs (*) / H2 = 4  =>  0 pairs (X)
D3,I3: 4.. / D3 = 4  =>  0 pairs (X) / I3 = 4  =>  0 pairs (_)
H2,H5: 4.. / H2 = 4  =>  0 pairs (X) / H5 = 4  =>  0 pairs (_)
I3,I5: 4.. / I3 = 4  =>  0 pairs (*) / I5 = 4  =>  0 pairs (X)
A4,C4: 5.. / A4 = 5  => 20 pairs (_) / C4 = 5  =>  0 pairs (X)
E7,E9: 5.. / E7 = 5  =>  0 pairs (*) / E9 = 5  =>  0 pairs (X)
I7,H9: 5.. / I7 = 5  =>  0 pairs (X) / H9 = 5  =>  0 pairs (_)
E7,I7: 5.. / E7 = 5  =>  0 pairs (*) / I7 = 5  =>  0 pairs (X)
E9,H9: 5.. / E9 = 5  =>  0 pairs (X) / H9 = 5  =>  0 pairs (_)
A2,A4: 5.. / A2 = 5  =>  0 pairs (X) / A4 = 5  => 20 pairs (_)
G2,G3: 7.. / G2 = 7  =>  0 pairs (X) / G3 = 7  => 20 pairs (_)
A5,B6: 7.. / A5 = 7  =>  0 pairs (X) / B6 = 7  =>  0 pairs (_)
E5,E6: 7.. / E5 = 7  =>  0 pairs (*) / E6 = 7  =>  0 pairs (X)
B3,G3: 7.. / B3 = 7  =>  0 pairs (X) / G3 = 7  => 20 pairs (_)
A5,E5: 7.. / A5 = 7  =>  0 pairs (X) / E5 = 7  =>  0 pairs (_)
B6,E6: 7.. / B6 = 7  =>  0 pairs (*) / E6 = 7  =>  0 pairs (X)
A2,A5: 7.. / A2 = 7  =>  0 pairs (*) / A5 = 7  =>  0 pairs (X)
B2,B3: 8.. / B2 = 8  => 22 pairs (_) / B3 = 8  =>  0 pairs (X)
E5,F5: 8.. / E5 = 8  =>  0 pairs (X) / F5 = 8  =>  0 pairs (_)
B2,F2: 8.. / B2 = 8  => 22 pairs (_) / F2 = 8  =>  0 pairs (X)
E3,E5: 8.. / E3 = 8  =>  0 pairs (*) / E5 = 8  =>  0 pairs (X)
A7,B9: 9.. / A7 = 9  =>  0 pairs (*) / B9 = 9  =>  0 pairs (X)
E7,E9: 9.. / E7 = 9  =>  0 pairs (X) / E9 = 9  =>  0 pairs (_)
C1,I1: 9.. / C1 = 9  => 25 pairs (_) / I1 = 9  => 22 pairs (_)
A7,E7: 9.. / A7 = 9  =>  0 pairs (*) / E7 = 9  =>  0 pairs (X)
B9,E9: 9.. / B9 = 9  =>  0 pairs (X) / E9 = 9  =>  0 pairs (_)
* DURATION: 0:01:34.877266  START: 06:31:14.777106  END: 06:32:49.654372 2017-05-04
* CP COUNT: (49)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A4,A5,A7,B4,B6,B9,C1,E3,E5,E6,E7,E9,F5,G5,H1,H2,H9,I3,I7)
* 46.7218......6...11......6....146278.16......8.4...61..476.318.3582174966.18.43.7
* PAIR C1: 5,9 BLK 1
A2: 5,9,7                                # reduction candidate for 5,9
A2: 5,9 => CTR
* 46.7218....2.6..411..43..62.3.146278716.82..4824.7.61.247693185358217496691854327
A2: 7 => SOLVED
* 465721839783469521192385764539146278216578943874932615947653182358217496621894357
C2: 5,9,2,3                              # reduction candidate for 5,9
C2: 5,9 => CTR
* 46.72183....46..211.2....64593146278216.78.4.874...61..476.3182358217496621894357
C2: 2,3                                  # 20 pairs
C3: 5,9,2,3                              # reduction candidate for 5,9
C3: 5,9 => CTR
* 46.7218....2.6..411..4...62..3146278.16.....48.4...61.2476931853582174966918.43.7
C3: 2,3                                  # 20 pairs
* PAIR C1: 5,9 ROW 1
I1: 5,9,3                                # reduction candidate for 5,9
I1: 3 => CTR
* 469721853..256..411.543..62...146278.169..534824.75619247693185358217496691854327
I1: 5,9                                  # 20 pairs
* PAIR C1: 5,9 COL C
C4: 5,9,3                                # reduction candidate for 5,9
C4: 3 => CTR
* 46.72183.78..6..211.2...764593146278216.78.4.874.3261.947653182358217496621894357
C4: 5,9                                  # 22 pairs
* PAIR E3: 3,8 ROW 3
B3: 3,8,7,9                              # reduction candidate for 3,8
B3: 7,9                                  # 24 pairs
B3: 3,8                                  # 22 pairs
* PAIR H1: 3,5 BLK 3
I1: 3,5,9                                # reduction candidate for 3,5
I1: 3,5                                  # 25 pairs
I1: 9                                    # 22 pairs
* PAIR H1: 3,5 COL H
H5: 3,5,4                                # reduction candidate for 3,5
H5: 3,5 => CTR
* 46.7218....236..411..4...62.3.146278716.82..4824.7.61.247693185358217496691854327
H5: 4 => SOLVED
* 465721839783469521192385764539146278216578943874932615947653182358217496621894357
* PAIR A4: 5,9 BLK 4
C4: 5,9,3                                # reduction candidate for 5,9
C4: 3 => CTR
* 46.72183.78..6..211.2...764593146278216.78.4.874.3261.947653182358217496621894357
C4: 5,9                                  # 22 pairs
* PAIR A4: 5,9 COL A
A2: 5,9,7                                # reduction candidate for 5,9
A2: 5,9 => CTR
* 46.7218....2.6..411..43..62.3.146278716.82..4824.7.61.247693185358217496691854327
A2: 7 => SOLVED
* 465721839783469521192385764539146278216578943874932615947653182358217496621894357
* PAIR B4: 3,9 BLK 4
C4: 3,9,5                                # reduction candidate for 3,9
C4: 5 => CTR
* 4697218535.236...11......6.935146278716.82...824.7.61.247693185358217496691854327
C4: 3,9                                  # 20 pairs
* PAIR B4: 3,9 COL B
B2: 3,9,7,8                              # reduction candidate for 3,9
B2: 3,9 => CTR
* 46.7218......68..118..3.76....146278.16.82...8.4...61..476.318.3582174966.18.43.7
B2: 7,8                                  # 22 pairs
B3: 3,9,7,8                              # reduction candidate for 3,9
B3: 3,9 => SOLVED
* 465721839783469521192385764539146278216578943874932615947653182358217496621894357
B3: 7,8                                  # 20 pairs
* PAIR G5: 5,9 BLK 6
I5: 5,9,3,4                              # reduction candidate for 5,9
I5: 5,9 => CTR
* 46.7218......6...11......64...146278.16....4.8.4...613.476.3182358217496621894357
I5: 3,4                                  # 20 pairs
I6: 5,9,3                                # reduction candidate for 5,9
I6: 5,9                                  # 23 pairs
* PAIR G5: 5,9 ROW 5
D5: 5,9,3                                # reduction candidate for 5,9
D5: 3 => CTR
* 4657218399.2.6...11...3..6....146278716382...824.7.613247693185358217496691854327
D5: 5,9                                  # 23 pairs
* PAIR G5: 5,9 COL G
G2: 5,9,7                                # reduction candidate for 5,9
G2: 5,9                                  # 20 pairs
G3: 5,9,7                                # reduction candidate for 5,9
G3: 5,9 => CTR
* 46.7218...8236.7.117.....6....146278716.82...824.7.61.247693185358217496691854327
G3: 7                                    # 20 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-110-base-pr-000.dot
* REASONING
* DIS # A2: 5,9 => CTR => A2: 7
* PRF # A2: 7 => SOL
* DIS # C2: 5,9 => CTR => C2: 2,3
* DIS # C3: 5,9 => CTR => C3: 2,3
* DIS # I1: 3 => CTR => I1: 5,9
* DIS # C4: 3 => CTR => C4: 5,9
* DIS # H5: 3,5 => CTR => H5: 4
* PRF # H5: 4 => SOL
* DIS # C4: 3 => CTR => C4: 5,9
* DIS # A2: 5,9 => CTR => A2: 7
* PRF # A2: 7 => SOL
* DIS # C4: 5 => CTR => C4: 3,9
* DIS # B2: 3,9 => CTR => B2: 7,8
* PRF # B3: 3,9 => SOL
* DIS # I5: 5,9 => CTR => I5: 3,4
* DIS # D5: 3 => CTR => D5: 5,9
* DIS # G3: 5,9 => CTR => G3: 7
* CNT  17 HDP CHAINS /  34 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A4,A5,A7,B4,B6,B9,C1,E3,E5,E6,E7,E9,F5,G5,H1,H2,H9,I3,I7)
* 46.7218......6...11......6....146278.16......8.4...61..476.318.3582174966.18.43.7
* PAIR C1: 5,9 BLK 1
A2: 5,9,7                                # reduction candidate for 5,9
A2: 5,9 => CTR
* 46.7218....2.6..411..43..62.3.146278716.82..4824.7.61.247693185358217496691854327
A2: 7 => SOLVED
* 465721839783469521192385764539146278216578943874932615947653182358217496621894357
* DURATION: 0:00:01.943864  START: 06:33:26.059203  END: 06:33:28.003067 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-110-base-pr-001.dot
* REASONING
* DIS # A2: 5,9 => CTR => A2: 7
* PRF A2: 7 => SOL
* STA A2: 7
* CNT   2 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 110

solution: 465721839783469521192385764539146278216578943874932615947653182358217496621894357
info: 1630     FNBTHY   S8.f     30636

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

Solution

position: 465721839783469521192385764539146278216578943874932615947653182358217496621894357 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 # A2: 5,9 => CTR => A2: 7
* PRF # A2: 7 => SOL
* DIS # C2: 5,9 => CTR => C2: 2,3
* INC # C2: 2,3 => UNS
* DIS # C3: 5,9 => CTR => C3: 2,3
* INC # C3: 2,3 => UNS
* INC # I1: 5,9 => UNS
* DIS # I1: 3 => CTR => I1: 5,9
* INC # C4: 5,9 => UNS
* DIS # C4: 3 => CTR => C4: 5,9
* INC # B3: 3,8 => UNS
* INC # B3: 7,9 => UNS
* INC # I1: 3,5 => UNS
* INC # I1: 9 => UNS
* DIS # H5: 3,5 => CTR => H5: 4
* PRF # H5: 4 => SOL
* INC # C4: 5,9 => UNS
* DIS # C4: 3 => CTR => C4: 5,9
* DIS # A2: 5,9 => CTR => A2: 7
* PRF # A2: 7 => SOL
* INC # C4: 3,9 => UNS
* DIS # C4: 5 => CTR => C4: 3,9
* DIS # B2: 3,9 => CTR => B2: 7,8
* INC # B2: 7,8 => UNS
* PRF # B3: 3,9 => SOL
* INC # B3: 7,8 => UNS
* DIS # I5: 5,9 => CTR => I5: 3,4
* INC # I5: 3,4 => UNS
* INC # I6: 5,9 => UNS
* INC # D5: 5,9 => UNS
* DIS # D5: 3 => CTR => D5: 5,9
* INC # G2: 5,9 => UNS
* DIS # G3: 5,9 => CTR => G3: 7
* INC # G3: 7 => UNS
* CNT  34 HDP CHAINS /  34 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # A2: 5,9 => CTR => A2: 7
* PRF A2: 7 => SOL
* STA A2: 7
* CNT   2 HDP CHAINS /   1 HYP OPENED