Analysis of xx-top500-117-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: .8..1.3.....6...4.....5.....4.2....7....3.1...........1..7........4...2.5.3...... initial

Autosolve

position: 785914362.3167..454..35.71.34.2.1.57.5.83.194.1.54.2..1.47.5....7.4.35215.31..47. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # C3: 2,9 => CTR => C3: 6
* PRF # C3: 6 => SOL
* DIS # C3: 2 => CTR => C3: 6,9
* DIS # B9: 6,9 => CTR => B9: 2
* PRF # G7: 8,9 => SOL
* DIS # G7: 6 => CTR => G7: 8,9
* PRF # I7: 8,9 => SOL
* DIS # C5: 7 => CTR => C5: 2,6
* DIS # F6: 7 => CTR => F6: 6,9
* DIS # C4: 6,9 => CTR => C4: 8
* PRF # C4: 8 => SOL
* PRF # F6: 6,7 => SOL
* DIS # F6: 9 => CTR => F6: 6,7
* DIS # C5: 6,7 => CTR => C5: 2
* PRF # I6: 3 => SOL
* PRF # C4: 6,8 => SOL
* DIS # C4: 9 => CTR => C4: 6,8
* DIS # G7: 9 => CTR => G7: 6,8
* PRF # I6: 3,8 => SOL
* DIS # I6: 6 => CTR => I6: 3,8
* DIS # A8: 6,9 => CTR => A8: 8
* DIS # B9: 6,9 => CTR => B9: 2
* DIS # F6: 7 => CTR => F6: 6,9
* PRF # I7: 6,9 => SOL
* CNT  24 HDP CHAINS /  40 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 # C3: 2,9 => CTR => C3: 6
* PRF C3: 6 => SOL
* STA C3: 6
* CNT   2 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

.8..1.3.....6...4.....5.....4.2....7....3.1...........1..7........4...2.5.3...... initial
785914362.3167..454..35.71.34.2.1.57.5.83.194.1.54.2..1.47.5....7.4.35215.31..47. autosolve
785914362231678945496352718348291657652837194917546283164725839879463521523189476 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (16)
A2: 2,9
B3: 6,9
F2: 2,8
F3: 2,8
G2: 8,9
I3: 8,9
A5: 2,6
E4: 6,9
F5: 6,7
G4: 6,8
H6: 3,8
E7: 2,8
E8: 6,9
E9: 2,8
F9: 6,9
H7: 3,8

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
A2,C3: 2.. / A2 = 2  => 16 pairs (_) / C3 = 2  =>  0 pairs (X)
F2,F3: 2.. / F2 = 2  =>  0 pairs (X) / F3 = 2  => 16 pairs (_)
A5,C5: 2.. / A5 = 2  =>  0 pairs (X) / C5 = 2  => 16 pairs (_)
B7,B9: 2.. / B7 = 2  =>  0 pairs (X) / B9 = 2  => 16 pairs (_)
E7,E9: 2.. / E7 = 2  => 16 pairs (_) / E9 = 2  =>  0 pairs (X)
A2,F2: 2.. / A2 = 2  => 16 pairs (_) / F2 = 2  =>  0 pairs (X)
C3,F3: 2.. / C3 = 2  =>  0 pairs (X) / F3 = 2  => 16 pairs (_)
B7,E7: 2.. / B7 = 2  =>  0 pairs (X) / E7 = 2  => 16 pairs (_)
B9,E9: 2.. / B9 = 2  => 16 pairs (_) / E9 = 2  =>  0 pairs (X)
A2,A5: 2.. / A2 = 2  => 16 pairs (_) / A5 = 2  =>  0 pairs (X)
C3,C5: 2.. / C3 = 2  =>  0 pairs (X) / C5 = 2  => 16 pairs (_)
H6,I6: 3.. / H6 = 3  => 16 pairs (_) / I6 = 3  =>  0 pairs (*)
H7,I7: 3.. / H7 = 3  =>  0 pairs (*) / I7 = 3  =>  0 pairs (X)
H6,H7: 3.. / H6 = 3  => 16 pairs (_) / H7 = 3  =>  0 pairs (*)
I6,I7: 3.. / I6 = 3  =>  0 pairs (*) / I7 = 3  =>  0 pairs (X)
B3,C3: 6.. / B3 = 6  =>  0 pairs (X) / C3 = 6  =>  0 pairs (_)
G4,I6: 6.. / G4 = 6  =>  0 pairs (*) / I6 = 6  =>  0 pairs (X)
E8,F9: 6.. / E8 = 6  =>  0 pairs (*) / F9 = 6  =>  0 pairs (X)
E4,E8: 6.. / E4 = 6  =>  0 pairs (X) / E8 = 6  =>  0 pairs (_)
G4,G7: 6.. / G4 = 6  =>  0 pairs (*) / G7 = 6  =>  0 pairs (X)
C5,C6: 7.. / C5 = 7  =>  0 pairs (X) / C6 = 7  => 19 pairs (_)
F5,F6: 7.. / F5 = 7  => 19 pairs (_) / F6 = 7  =>  0 pairs (X)
C5,F5: 7.. / C5 = 7  =>  0 pairs (X) / F5 = 7  => 19 pairs (_)
C6,F6: 7.. / C6 = 7  => 19 pairs (_) / F6 = 7  =>  0 pairs (X)
F2,F3: 8.. / F2 = 8  => 16 pairs (_) / F3 = 8  =>  0 pairs (X)
G2,I3: 8.. / G2 = 8  =>  0 pairs (X) / I3 = 8  => 16 pairs (_)
A8,C8: 8.. / A8 = 8  => 20 pairs (_) / C8 = 8  =>  0 pairs (X)
E7,E9: 8.. / E7 = 8  =>  0 pairs (X) / E9 = 8  => 16 pairs (_)
F2,G2: 8.. / F2 = 8  => 16 pairs (_) / G2 = 8  =>  0 pairs (X)
F3,I3: 8.. / F3 = 8  =>  0 pairs (X) / I3 = 8  => 16 pairs (_)
C4,G4: 8.. / C4 = 8  =>  0 pairs (*) / G4 = 8  =>  0 pairs (X)
E9,I9: 8.. / E9 = 8  => 16 pairs (_) / I9 = 8  =>  0 pairs (X)
A6,A8: 8.. / A6 = 8  =>  0 pairs (X) / A8 = 8  => 20 pairs (_)
H6,H7: 8.. / H6 = 8  =>  0 pairs (*) / H7 = 8  =>  0 pairs (X)
G2,I3: 9.. / G2 = 9  => 16 pairs (_) / I3 = 9  =>  0 pairs (X)
E4,F6: 9.. / E4 = 9  =>  0 pairs (*) / F6 = 9  =>  0 pairs (X)
E8,F9: 9.. / E8 = 9  =>  0 pairs (X) / F9 = 9  =>  0 pairs (_)
A2,G2: 9.. / A2 = 9  =>  0 pairs (X) / G2 = 9  => 16 pairs (_)
C4,E4: 9.. / C4 = 9  =>  0 pairs (X) / E4 = 9  =>  0 pairs (_)
E4,E8: 9.. / E4 = 9  =>  0 pairs (*) / E8 = 9  =>  0 pairs (X)
F6,F9: 9.. / F6 = 9  =>  0 pairs (X) / F9 = 9  =>  0 pairs (_)
G2,G7: 9.. / G2 = 9  => 16 pairs (_) / G7 = 9  =>  0 pairs (X)
* DURATION: 0:01:44.326248  START: 06:46:22.361476  END: 06:48:06.687724 2017-05-04
* CP COUNT: (42)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A2,A5,B3,E4,E7,E8,E9,F2,F3,F5,F9,G2,G4,H6,H7,I3)
* 785914362.3167..454..35.71.34.2.1.57.5.83.194.1.54.2..1.47.5....7.4.35215.31..47.
* PAIR A2: 2,9 BLK 1
C3: 2,9,6                                # reduction candidate for 2,9
C3: 2,9 => CTR
* 78591436293167..4546.35.71.34.261857.5.837194.175492361.47.5683.784935215.3186479
C3: 6 => SOLVED
* 785914362231678945496352718348291657652837194917546283164725839879463521523189476
* PAIR B3: 6,9 BLK 1
C3: 6,9,2                                # reduction candidate for 6,9
C3: 2 => CTR
* 7859143629316728454623587193482.1.5725.83.194.1.54.2..1.47.59.6.7.4.3521593126478
C3: 6,9                                  # 16 pairs
* PAIR B3: 6,9 COL B
B7: 6,9,2                                # reduction candidate for 6,9
B7: 6,9                                  # 16 pairs
B9: 6,9,2                                # reduction candidate for 6,9
B9: 6,9 => CTR
* 785914362.3167.8454..358719348291657.5.83.194.1.54.28312478593687946352156312.478
B9: 2                                    # 16 pairs
* PAIR G2: 8,9 COL G
G7: 8,9,6                                # reduction candidate for 8,9
G7: 8,9 => SOLVED
* 785914362231678945496352718348291657652837194917546283164725839879463521523189476
G7: 6 => CTR
* 7859143622316789454..35271834.2.1857652837194.1754923619472568387.4.35215.318.479
* PAIR I3: 8,9 COL I
I7: 8,9,3,6                              # reduction candidate for 8,9
I7: 8,9 => SOLVED
* 785914362231678945496352718348291657652837194917546283164725839879463521523189476
I7: 3,6                                  # 17 pairs
I9: 8,9,6                                # reduction candidate for 8,9
I9: 8,9                                  # 20 pairs
* PAIR A5: 2,6 BLK 4
C5: 2,6,7                                # reduction candidate for 2,6
C5: 7 => CTR
* 785914362.3167..454.235871934.2.1.57257836194.1.5472..1.47.59...7.4635215931..47.
C5: 2,6                                  # 19 pairs
* PAIR E4: 6,9 BLK 5
F6: 6,9,7                                # reduction candidate for 6,9
F6: 7 => CTR
* 785914362.3167..454..35.71.34.291.572578361946195472..1.47.5....7.4635215.31.947.
F6: 6,9                                  # 19 pairs
* PAIR E4: 6,9 ROW 4
C4: 6,9,8                                # reduction candidate for 6,9
C4: 6,9 => CTR
* 785914362.316789454..35271834.2.1857.52837194.17549236194725683.78493521523186479
C4: 8 => SOLVED
* 785914362231678945496352718348291657652837194917546283164725839879463521523189476
* PAIR F5: 6,7 BLK 5
F6: 6,7,9                                # reduction candidate for 6,7
F6: 6,7 => SOLVED
* 785914362231678945496352718348291657652837194917546283164725839879463521523189476
F6: 9 => CTR
* 78591436293167284546235.71.34.2.1.57.5.837194.175492..1.47.5....7.4935215.31.647.
* PAIR F5: 6,7 ROW 5
C5: 6,7,2                                # reduction candidate for 6,7
C5: 6,7 => CTR
* 7859143629316728454623587193482.1.5725.83.194.1.54.2..1.47.59...7.4.3521593126478
C5: 2                                    # 16 pairs
* PAIR G4: 6,8 BLK 6
I6: 6,8,3                                # reduction candidate for 6,8
I6: 3 => SOLVED
* 785914362231678945496352718348291657652837194917546283164725839879463521523189476
I6: 6,8                                  # 16 pairs
* PAIR G4: 6,8 ROW 4
C4: 6,8,9                                # reduction candidate for 6,8
C4: 6,8 => SOLVED
* 785914362231678945496352718348291657652837194917546283164725839879463521523189476
C4: 9 => CTR
* 785914362.3167..454..35.71.349261857.5.837194.175492361.47.5683.784935215.3186479
* PAIR G4: 6,8 COL G
G7: 6,8,9                                # reduction candidate for 6,8
G7: 9 => CTR
* 78591436293167284546235871934829165725.83.19461954.2..1.47.59...7.4635215.31.947.
G7: 6,8                                  # 16 pairs
* PAIR H6: 3,8 BLK 6
I6: 3,8,6                                # reduction candidate for 3,8
I6: 3,8 => SOLVED
* 785914362231678945496352718348291657652837194917546283164725839879463521523189476
I6: 6 => CTR
* 785914362.3167.9454..35.71834.2.1857.5.83.194.1.549236194725683.7.493521523186479
* PAIR E8: 6,9 ROW 8
A8: 6,9,8                                # reduction candidate for 6,9
A8: 6,9 => CTR
* 785914362.3167.9454..35.71834.2.1857.5.83.19481.549236194725683678493521523186479
A8: 8                                    # 20 pairs
C8: 6,9,8                                # reduction candidate for 6,9
C8: 6,9                                  # 20 pairs
* PAIR F9: 6,9 ROW 9
B9: 6,9,2                                # reduction candidate for 6,9
B9: 6,9 => CTR
* 785914362.3167.8454..358719348291657.5.83.194.1.54.28312478593687946352156312.478
B9: 2                                    # 16 pairs
I9: 6,9,8                                # reduction candidate for 6,9
I9: 6,9                                  # 16 pairs
* PAIR F9: 6,9 COL F
F6: 6,9,7                                # reduction candidate for 6,9
F6: 7 => CTR
* 785914362.3167..454..35.71.34.291.572578361946195472..1.47.5....7.4635215.31.947.
F6: 6,9                                  # 19 pairs
* PAIR H7: 3,8 BLK 9
I7: 3,8,6,9                              # reduction candidate for 3,8
I7: 6,9 => SOLVED
* 785914362231678945496352718348291657652837194917546283164725839879463521523189476
I7: 3,8                                  # 18 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-117-base-pr-000.dot
* REASONING
* DIS # C3: 2,9 => CTR => C3: 6
* PRF # C3: 6 => SOL
* DIS # C3: 2 => CTR => C3: 6,9
* DIS # B9: 6,9 => CTR => B9: 2
* PRF # G7: 8,9 => SOL
* DIS # G7: 6 => CTR => G7: 8,9
* PRF # I7: 8,9 => SOL
* DIS # C5: 7 => CTR => C5: 2,6
* DIS # F6: 7 => CTR => F6: 6,9
* DIS # C4: 6,9 => CTR => C4: 8
* PRF # C4: 8 => SOL
* PRF # F6: 6,7 => SOL
* DIS # F6: 9 => CTR => F6: 6,7
* DIS # C5: 6,7 => CTR => C5: 2
* PRF # I6: 3 => SOL
* PRF # C4: 6,8 => SOL
* DIS # C4: 9 => CTR => C4: 6,8
* DIS # G7: 9 => CTR => G7: 6,8
* PRF # I6: 3,8 => SOL
* DIS # I6: 6 => CTR => I6: 3,8
* DIS # A8: 6,9 => CTR => A8: 8
* DIS # B9: 6,9 => CTR => B9: 2
* DIS # F6: 7 => CTR => F6: 6,9
* PRF # I7: 6,9 => SOL
* CNT  24 HDP CHAINS /  40 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A2,A5,B3,E4,E7,E8,E9,F2,F3,F5,F9,G2,G4,H6,H7,I3)
* 785914362.3167..454..35.71.34.2.1.57.5.83.194.1.54.2..1.47.5....7.4.35215.31..47.
* PAIR A2: 2,9 BLK 1
C3: 2,9,6                                # reduction candidate for 2,9
C3: 2,9 => CTR
* 78591436293167..4546.35.71.34.261857.5.837194.175492361.47.5683.784935215.3186479
C3: 6 => SOLVED
* 785914362231678945496352718348291657652837194917546283164725839879463521523189476
* DURATION: 0:00:03.931309  START: 06:49:05.268696  END: 06:49:09.200005 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-117-base-pr-001.dot
* REASONING
* DIS # C3: 2,9 => CTR => C3: 6
* PRF C3: 6 => SOL
* STA C3: 6
* CNT   2 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 117

solution: 785914362231678945496352718348291657652837194917546283164725839879463521523189476
info: 1765     FNBTHWXY S8.f     23521

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

Solution

position: 785914362231678945496352718348291657652837194917546283164725839879463521523189476 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 # C3: 2,9 => CTR => C3: 6
* PRF # C3: 6 => SOL
* INC # C3: 6,9 => UNS
* DIS # C3: 2 => CTR => C3: 6,9
* INC # B7: 6,9 => UNS
* DIS # B9: 6,9 => CTR => B9: 2
* INC # B9: 2 => UNS
* PRF # G7: 8,9 => SOL
* DIS # G7: 6 => CTR => G7: 8,9
* PRF # I7: 8,9 => SOL
* INC # I7: 3,6 => UNS
* INC # I9: 8,9 => UNS
* INC # C5: 2,6 => UNS
* DIS # C5: 7 => CTR => C5: 2,6
* INC # F6: 6,9 => UNS
* DIS # F6: 7 => CTR => F6: 6,9
* DIS # C4: 6,9 => CTR => C4: 8
* PRF # C4: 8 => SOL
* PRF # F6: 6,7 => SOL
* DIS # F6: 9 => CTR => F6: 6,7
* DIS # C5: 6,7 => CTR => C5: 2
* INC # C5: 2 => UNS
* INC # I6: 6,8 => UNS
* PRF # I6: 3 => SOL
* PRF # C4: 6,8 => SOL
* DIS # C4: 9 => CTR => C4: 6,8
* INC # G7: 6,8 => UNS
* DIS # G7: 9 => CTR => G7: 6,8
* PRF # I6: 3,8 => SOL
* DIS # I6: 6 => CTR => I6: 3,8
* DIS # A8: 6,9 => CTR => A8: 8
* INC # A8: 8 => UNS
* INC # C8: 6,9 => UNS
* DIS # B9: 6,9 => CTR => B9: 2
* INC # B9: 2 => UNS
* INC # I9: 6,9 => UNS
* INC # F6: 6,9 => UNS
* DIS # F6: 7 => CTR => F6: 6,9
* INC # I7: 3,8 => UNS
* PRF # I7: 6,9 => SOL
* CNT  40 HDP CHAINS /  40 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # C3: 2,9 => CTR => C3: 6
* PRF C3: 6 => SOL
* STA C3: 6
* CNT   2 HDP CHAINS /   1 HYP OPENED