Analysis of xx-top500-337-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: .61.........2..8......5....3.....2...5..1.......7.........4..612..3.....8......4. initial

Autosolve

position: .61.38.2.4..2.18.6.2865.1..347586219652.1....18972.6.....842.6121436....8.61...42 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # B2: 7,9 => CTR => B2: 3
* DIS # H3: 7,9 => CTR => H3: 3
* DIS # A7: 7,9 => CTR => A7: 5
* DIS # F3: 7 => CTR => F3: 4,9
* PRF # G1: 5,7 => SOL
* DIS # F3: 4 => CTR => F3: 7,9
* DIS # B2: 7,9 => CTR => B2: 3
* DIS # F5: 4,9 => CTR => F5: 3
* DIS # F5: 9 => CTR => F5: 3,4
* DIS # I6: 5 => CTR => I6: 3,4
* DIS # I6: 4 => CTR => I6: 3,5
* DIS # F9: 7,9 => CTR => F9: 5
* DIS # G9: 7,9 => CTR => G9: 3,5
* CNT  13 HDP CHAINS /  35 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 # B2: 7,9 => CTR => B2: 3
* DIS B2: 3 # H3: 7,9 => CTR => H3: 3
* DIS B2: 3 + H3: 3 # F3: 4 => CTR => F3: 7,9
* PRF B2: 3 + H3: 3 + F3: 7,9 # G1: 5 => SOL
* STA B2: 3 + H3: 3 + F3: 7,9 + G1: 5
* CNT   4 HDP CHAINS /   8 HYP OPENED

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

Details

Positions

.61.........2..8......5....3.....2...5..1.......7.........4..612..3.....8......4. initial
.61.38.2.4..2.18.6.2865.1..347586219652.1....18972.6.....842.6121436....8.61...42 autosolve
961438527435271896728659134347586219652913478189724653593842761214367985876195342 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (10)
C2: 3,5
A3: 7,9
D1: 4,9
E2: 7,9
D5: 4,9
F6: 3,4
G5: 4,7
H6: 3,5
C7: 3,5
E9: 7,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
B2,C2: 3.. / B2 = 3  => 14 pairs (_) / C2 = 3  =>  0 pairs (X)
H3,I3: 3.. / H3 = 3  => 16 pairs (_) / I3 = 3  =>  0 pairs (X)
F5,F6: 3.. / F5 = 3  => 13 pairs (_) / F6 = 3  =>  0 pairs (X)
G7,G9: 3.. / G7 = 3  =>  0 pairs (X) / G9 = 3  => 13 pairs (_)
B9,G9: 3.. / B9 = 3  =>  0 pairs (X) / G9 = 3  => 13 pairs (_)
C2,C7: 3.. / C2 = 3  =>  0 pairs (X) / C7 = 3  => 14 pairs (_)
D1,F3: 4.. / D1 = 4  => 13 pairs (_) / F3 = 4  =>  0 pairs (X)
F3,I3: 4.. / F3 = 4  =>  0 pairs (X) / I3 = 4  => 13 pairs (_)
F6,I6: 4.. / F6 = 4  => 13 pairs (_) / I6 = 4  =>  0 pairs (X)
D1,D5: 4.. / D1 = 4  => 13 pairs (_) / D5 = 4  =>  0 pairs (X)
G1,G5: 4.. / G1 = 4  =>  0 pairs (X) / G5 = 4  => 13 pairs (_)
A1,C2: 5.. / A1 = 5  =>  0 pairs (X) / C2 = 5  => 14 pairs (_)
H6,I6: 5.. / H6 = 5  => 14 pairs (_) / I6 = 5  =>  0 pairs (X)
A7,C7: 5.. / A7 = 5  => 14 pairs (_) / C7 = 5  =>  0 pairs (X)
F8,F9: 5.. / F8 = 5  =>  0 pairs (X) / F9 = 5  => 11 pairs (_)
C2,H2: 5.. / C2 = 5  => 14 pairs (_) / H2 = 5  =>  0 pairs (X)
F9,G9: 5.. / F9 = 5  => 11 pairs (_) / G9 = 5  =>  0 pairs (X)
A1,A7: 5.. / A1 = 5  =>  0 pairs (X) / A7 = 5  => 14 pairs (_)
C2,C7: 5.. / C2 = 5  => 14 pairs (_) / C7 = 5  =>  0 pairs (X)
E2,F3: 7.. / E2 = 7  => 16 pairs (_) / F3 = 7  =>  0 pairs (X)
E2,E9: 7.. / E2 = 7  => 16 pairs (_) / E9 = 7  =>  0 pairs (X)
H5,I5: 8.. / H5 = 8  => 10 pairs (_) / I5 = 8  => 12 pairs (_)
H8,I8: 8.. / H8 = 8  => 12 pairs (_) / I8 = 8  => 10 pairs (_)
H5,H8: 8.. / H5 = 8  => 10 pairs (_) / H8 = 8  => 12 pairs (_)
I5,I8: 8.. / I5 = 8  => 12 pairs (_) / I8 = 8  => 10 pairs (_)
D5,F5: 9.. / D5 = 9  => 13 pairs (_) / F5 = 9  =>  0 pairs (X)
D1,D5: 9.. / D1 = 9  =>  0 pairs (X) / D5 = 9  => 13 pairs (_)
E2,E9: 9.. / E2 = 9  =>  0 pairs (X) / E9 = 9  => 16 pairs (_)
* DURATION: 0:00:52.434366  START: 14:16:42.571177  END: 14:17:35.005543 2017-05-04
* CP COUNT: (28)
* CLUE FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A3,C2,C7,D1,D5,E2,E9,F6,G5,H6)
* .61.38.2.4..2.18.6.2865.1..347586219652.1....18972.6.....842.6121436....8.61...42
* PAIR A3: 7,9 BLK 1
A1: 7,9,5                                # reduction candidate for 7,9
A1: 7,9                                  # 14 pairs
B2: 7,9,3                                # reduction candidate for 7,9
B2: 7,9 => CTR
* 561.38.2.4.32.1856.2865.1.3347586219652.13...189724635..5842.6121436....8.61...42
B2: 3                                    # 14 pairs
* PAIR A3: 7,9 ROW 3
F3: 7,9,4                                # reduction candidate for 7,9
F3: 7,9                                  # 13 pairs
H3: 7,9,3                                # reduction candidate for 7,9
H3: 7,9 => CTR
* 7619384254.52718969286541733475862196524197381897236545..842.6121436..878.6197542
H3: 3                                    # 16 pairs
* PAIR A3: 7,9 COL A
A7: 7,9,5                                # reduction candidate for 7,9
A7: 7,9 => CTR
* 561.38.2.4.32.1856.2865.1.3347586219652.13...189724635..5842.6121436....8.61...42
A7: 5                                    # 14 pairs
* PAIR D1: 4,9 BLK 2
F3: 4,9,7                                # reduction candidate for 4,9
F3: 7 => CTR
* .614389254.52918769286571343475862196529134871897246535..842.6121436..988.6179542
F3: 4,9                                  # 16 pairs
* PAIR D1: 4,9 ROW 1
G1: 4,9,5,7                              # reduction candidate for 4,9
G1: 5,7 => SOLVED
* 961438527435271896728659134347586219652913478189724653593842761214367985876195342
G1: 4,9                                  # 14 pairs
* PAIR E2: 7,9 BLK 2
F3: 7,9,4                                # reduction candidate for 7,9
F3: 4 => CTR
* .619384254.52718969286541..3475862196524197..1897236545..842.6121436....8.619..42
F3: 7,9                                  # 13 pairs
* PAIR E2: 7,9 ROW 2
B2: 7,9,3                                # reduction candidate for 7,9
B2: 7,9 => CTR
* 561.38.2.4.32.1856.2865.1.3347586219652.13...189724635..5842.6121436....8.61...42
B2: 3                                    # 14 pairs
H2: 7,9,5                                # reduction candidate for 7,9
H2: 7,9                                  # 14 pairs
* PAIR D5: 4,9 BLK 5
F5: 4,9,3                                # reduction candidate for 4,9
F5: 4,9 => CTR
* .61.384254.52.18.6.286541..3475862196524197..18972365457384296121436.5..89617..42
F5: 3                                    # 13 pairs
* PAIR F6: 3,4 BLK 5
F5: 3,4,9                                # reduction candidate for 3,4
F5: 9 => CTR
* .619384254.52718969286541..3475862196524197..1897236545..842.6121436....8.619..42
F5: 3,4                                  # 13 pairs
* PAIR F6: 3,4 ROW 6
I6: 3,4,5                                # reduction candidate for 3,4
I6: 5 => CTR
* .61.38.2.4..2.18.6.2865.1..347586219652.1....189724635...842.6121436....8.61...42
I6: 3,4                                  # 14 pairs
* PAIR G5: 4,7 BLK 6
I5: 4,7,3,8                              # reduction candidate for 4,7
I5: 4,7                                  # 12 pairs
I5: 3,8                                  # 11 pairs
* PAIR G5: 4,7 COL G
G1: 4,7,5,9                              # reduction candidate for 4,7
G1: 4,7                                  # 17 pairs
G1: 5,9                                  # 16 pairs
* PAIR H6: 3,5 BLK 6
I6: 3,5,4                                # reduction candidate for 3,5
I6: 4 => CTR
* .61.384254.52.18.6.286541..3475862196524197..18972365457384296121436.5..89617..42
I6: 3,5                                  # 13 pairs
* PAIR E9: 7,9 BLK 8
F8: 7,9,5                                # reduction candidate for 7,9
F8: 7,9                                  # 11 pairs
F9: 7,9,5                                # reduction candidate for 7,9
F9: 7,9 => CTR
* 561.38.2.4.32.1856.2865.1.3347586219652.13...189724635..5842361214365...8361..542
F9: 5                                    # 11 pairs
* PAIR E9: 7,9 ROW 9
B9: 7,9,3                                # reduction candidate for 7,9
B9: 7,9                                  # 13 pairs
G9: 7,9,3,5                              # reduction candidate for 7,9
G9: 7,9 => CTR
* 561.38.2.4.32.1856.2865.1.3347586219652.13...189724635..584236121436.5..8361.5.42
G9: 3,5                                  # 11 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-337-base-pr-000.dot
* REASONING
* DIS # B2: 7,9 => CTR => B2: 3
* DIS # H3: 7,9 => CTR => H3: 3
* DIS # A7: 7,9 => CTR => A7: 5
* DIS # F3: 7 => CTR => F3: 4,9
* PRF # G1: 5,7 => SOL
* DIS # F3: 4 => CTR => F3: 7,9
* DIS # B2: 7,9 => CTR => B2: 3
* DIS # F5: 4,9 => CTR => F5: 3
* DIS # F5: 9 => CTR => F5: 3,4
* DIS # I6: 5 => CTR => I6: 3,4
* DIS # I6: 4 => CTR => I6: 3,5
* DIS # F9: 7,9 => CTR => F9: 5
* DIS # G9: 7,9 => CTR => G9: 3,5
* CNT  13 HDP CHAINS /  35 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A3,C2,C7,D1,D5,E2,E9,F6,G5,H6)
* .61.38.2.4..2.18.6.2865.1..347586219652.1....18972.6.....842.6121436....8.61...42
* PAIR A3: 7,9 BLK 1
A1: 7,9,5                                # reduction candidate for 7,9
A1: 7,9                                  # 14 pairs
B2: 7,9,3                                # reduction candidate for 7,9
B2: 7,9 => CTR
* 561.38.2.4.32.1856.2865.1.3347586219652.13...189724635..5842.6121436....8.61...42
* RESTART
* PAIR A3: 7,9 ROW 3
F3: 7,9,4                                # reduction candidate for 7,9
F3: 7,9                                  # 13 pairs
H3: 7,9,3                                # reduction candidate for 7,9
H3: 7,9 => CTR
* .61.38.2.4352.18.6.286541.3347586219652419738189723654573842961214367...8.61.5342
* RESTART
* PAIR A3: 7,9 ROW 3
F3: 7,9,4                                # reduction candidate for 7,9
F3: 4 => CTR
* .61.38.2.435271896928654137347586219652419783189723654573842961214367...8.61.5342
* PAIR RESTART

* LEVEL 0 PASS 1 ROUND 2 (AUTO SOLVE) (A1,A3,B7,B9,E2,E9,F3,F8,G7,H2,H5,I1,I5)
* .61438.2.4352.18.6.2865.1343475862196529134..1897246535.3842.6121436....8.61.5342
* PAIR A1: 7,9 ROW 1
G1: 7,9,5                                # reduction candidate for 7,9
G1: 5 => SOLVED
* 961438527435271896728659134347586219652913478189724653593842761214367985876195342
* DURATION: 0:00:10.313103  START: 14:18:11.276246  END: 14:18:21.589349 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-337-base-pr-001.dot
* REASONING
* DIS # B2: 7,9 => CTR => B2: 3
* DIS B2: 3 # H3: 7,9 => CTR => H3: 3
* DIS B2: 3 + H3: 3 # F3: 4 => CTR => F3: 7,9
* PRF B2: 3 + H3: 3 + F3: 7,9 # G1: 5 => SOL
* STA B2: 3 + H3: 3 + F3: 7,9 + G1: 5
* CNT   4 HDP CHAINS /   8 HYP OPENED

Header Info

Top 500 Minimum 17 337

solution: 961438527435271896728659134347586219652913478189724653593842761214367985876195342
info: 3103     FNBTWXY  S8.f     21708

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

Solution

position: 961438527435271896728659134347586219652913478189724653593842761214367985876195342 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 # A1: 7,9 => UNS
* DIS # B2: 7,9 => CTR => B2: 3
* INC # B2: 3 => UNS
* INC # F3: 7,9 => UNS
* DIS # H3: 7,9 => CTR => H3: 3
* INC # H3: 3 => UNS
* DIS # A7: 7,9 => CTR => A7: 5
* INC # A7: 5 => UNS
* INC # F3: 4,9 => UNS
* DIS # F3: 7 => CTR => F3: 4,9
* INC # G1: 4,9 => UNS
* PRF # G1: 5,7 => SOL
* INC # F3: 7,9 => UNS
* DIS # F3: 4 => CTR => F3: 7,9
* DIS # B2: 7,9 => CTR => B2: 3
* INC # B2: 3 => UNS
* INC # H2: 7,9 => UNS
* DIS # F5: 4,9 => CTR => F5: 3
* INC # F5: 3 => UNS
* INC # F5: 3,4 => UNS
* DIS # F5: 9 => CTR => F5: 3,4
* INC # I6: 3,4 => UNS
* DIS # I6: 5 => CTR => I6: 3,4
* INC # I5: 4,7 => UNS
* INC # I5: 3,8 => UNS
* INC # G1: 4,7 => UNS
* INC # G1: 5,9 => UNS
* INC # I6: 3,5 => UNS
* DIS # I6: 4 => CTR => I6: 3,5
* INC # F8: 7,9 => UNS
* DIS # F9: 7,9 => CTR => F9: 5
* INC # F9: 5 => UNS
* INC # B9: 7,9 => UNS
* DIS # G9: 7,9 => CTR => G9: 3,5
* INC # G9: 3,5 => UNS
* CNT  35 HDP CHAINS /  35 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # A1: 7,9 => UNS
* DIS # B2: 7,9 => CTR => B2: 3
* INC B2: 3 # F3: 7,9 => UNS
* DIS B2: 3 # H3: 7,9 => CTR => H3: 3
* INC B2: 3 + H3: 3 # F3: 7,9 => UNS
* DIS B2: 3 + H3: 3 # F3: 4 => CTR => F3: 7,9
* INC B2: 3 + H3: 3 + F3: 7,9 # G1: 7,9 => UNS
* PRF B2: 3 + H3: 3 + F3: 7,9 # G1: 5 => SOL
* STA B2: 3 + H3: 3 + F3: 7,9 + G1: 5
* CNT   8 HDP CHAINS /   8 HYP OPENED