Analysis of xx-top500-070-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: .61..........3...9.......2.9......3....6..8.....5..7...5.1....63...2..........4.. initial

Autosolve

position: 2619..5.3...2316.9....6512.9.6.1.235...6..89....59.76..521.93.631..2695.6..35.412 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # H1: 7,8 => SOL
* DIS # H1: 4 => CTR => H1: 7,8
* DIS # H2: 7,8 => CTR => H2: 4
* PRF # H2: 4 => SOL
* DIS # A3: 7,8 => CTR => A3: 4
* PRF # A3: 4 => SOL
* PRF # D3: 7,8 => SOL
* DIS # D3: 4 => CTR => D3: 7,8
* DIS # B5: 4,7 => CTR => B5: 2,3
* PRF # D4: 4,7 => SOL
* PRF # D4: 4,7 => SOL
* DIS # B5: 4,7 => CTR => B5: 2,3
* DIS # E1: 4,7 => CTR => E1: 8
* DIS # B5: 4,7 => CTR => B5: 2,3
* DIS # E7: 7,8 => CTR => E7: 4
* PRF # F4: 7,8 => SOL
* DIS # E7: 7,8 => CTR => E7: 4
* PRF # H1: 7,8 => SOL
* DIS # H1: 4 => CTR => H1: 7,8
* DIS # H2: 7,8 => CTR => H2: 4
* PRF # H2: 4 => SOL
* DIS # C8: 7,8 => CTR => C8: 4
* CNT  22 HDP CHAINS /  53 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 # H1: 7,8 => SOL
* STA H1: 7,8
* CNT   1 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

.61..........3...9.......2.9......3....6..8.....5..7...5.1....63...2..........4.. initial
2619..5.3...2316.9....6512.9.6.1.235...6..89....59.76..521.93.631..2695.6..35.412 autosolve
261984573587231649439765128976418235125673894843592761752149386314826957698357412 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (12)
B3: 3,9
C3: 3,9
I3: 7,8
B4: 4,7
E5: 4,7
F5: 2,3
F6: 2,3
I5: 1,4
I6: 1,4
F9: 7,8
H7: 7,8
I8: 7,8

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
A5,A6: 1.. / A5 = 1  => 16 pairs (_) / A6 = 1  => 11 pairs (_)
I5,I6: 1.. / I5 = 1  => 11 pairs (_) / I6 = 1  => 16 pairs (_)
A5,I5: 1.. / A5 = 1  => 16 pairs (_) / I5 = 1  => 11 pairs (_)
A6,I6: 1.. / A6 = 1  => 11 pairs (_) / I6 = 1  => 16 pairs (_)
B5,B6: 2.. / B5 = 2  => 10 pairs (_) / B6 = 2  => 11 pairs (_)
F5,F6: 2.. / F5 = 2  => 11 pairs (_) / F6 = 2  => 10 pairs (_)
B5,F5: 2.. / B5 = 2  => 10 pairs (_) / F5 = 2  => 11 pairs (_)
B6,F6: 2.. / B6 = 2  => 11 pairs (_) / F6 = 2  => 10 pairs (_)
B3,C3: 3.. / B3 = 3  => 11 pairs (_) / C3 = 3  => 14 pairs (_)
F5,F6: 3.. / F5 = 3  => 10 pairs (_) / F6 = 3  => 11 pairs (_)
H1,H2: 4.. / H1 = 4  =>  0 pairs (X) / H2 = 4  =>  0 pairs (_)
I5,I6: 4.. / I5 = 4  => 16 pairs (_) / I6 = 4  => 11 pairs (_)
A7,C8: 4.. / A7 = 4  =>  0 pairs (X) / C8 = 4  => 21 pairs (_)
E7,D8: 4.. / E7 = 4  => 21 pairs (_) / D8 = 4  =>  0 pairs (X)
A3,D3: 4.. / A3 = 4  =>  0 pairs (*) / D3 = 4  =>  0 pairs (X)
A7,E7: 4.. / A7 = 4  =>  0 pairs (X) / E7 = 4  => 21 pairs (_)
C8,D8: 4.. / C8 = 4  => 21 pairs (_) / D8 = 4  =>  0 pairs (X)
F1,F4: 4.. / F1 = 4  =>  0 pairs (*) / F4 = 4  =>  0 pairs (X)
A2,C2: 5.. / A2 = 5  => 13 pairs (_) / C2 = 5  => 11 pairs (_)
A5,C5: 5.. / A5 = 5  => 11 pairs (_) / C5 = 5  => 13 pairs (_)
A2,A5: 5.. / A2 = 5  => 13 pairs (_) / A5 = 5  => 11 pairs (_)
C2,C5: 5.. / C2 = 5  => 11 pairs (_) / C5 = 5  => 13 pairs (_)
H7,I8: 7.. / H7 = 7  => 18 pairs (_) / I8 = 7  => 21 pairs (_)
I3,I8: 7.. / I3 = 7  => 18 pairs (_) / I8 = 7  => 21 pairs (_)
D4,F4: 8.. / D4 = 8  => 16 pairs (_) / F4 = 8  =>  0 pairs (*)
H7,I8: 8.. / H7 = 8  => 21 pairs (_) / I8 = 8  => 18 pairs (_)
E1,E7: 8.. / E1 = 8  => 16 pairs (_) / E7 = 8  =>  0 pairs (X)
I3,I8: 8.. / I3 = 8  => 21 pairs (_) / I8 = 8  => 18 pairs (_)
B3,C3: 9.. / B3 = 9  => 14 pairs (_) / C3 = 9  => 11 pairs (_)
B9,C9: 9.. / B9 = 9  => 11 pairs (_) / C9 = 9  => 14 pairs (_)
B3,B9: 9.. / B3 = 9  => 14 pairs (_) / B9 = 9  => 11 pairs (_)
C3,C9: 9.. / C3 = 9  => 11 pairs (_) / C9 = 9  => 14 pairs (_)
* DURATION: 0:00:59.168753  START: 05:04:22.590095  END: 05:05:21.758848 2017-05-04
* CP COUNT: (32)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B3,B4,C3,E5,F5,F6,F9,H7,I3,I5,I6,I8)
* 2619..5.3...2316.9....6512.9.6.1.235...6..89....59.76..521.93.631..2695.6..35.412
* PAIR I3: 7,8 BLK 3
H1: 7,8,4                                # reduction candidate for 7,8
H1: 7,8 => SOLVED
* 261984573587231649439765128976418235125673894843592761752149386314826957698357412
H1: 4 => CTR
* 261987543...2316898..465127976814235...67.89..8359276.7521493.63147269586..358412
H2: 7,8,4                                # reduction candidate for 7,8
H2: 7,8 => CTR
* 261987543...2316898..465127976814235...67.89..8359276.7521493.63147269586..358412
H2: 4 => SOLVED
* 261984573587231649439765128976418235125673894843592761752149386314826957698357412
* PAIR I3: 7,8 ROW 3
A3: 7,8,4                                # reduction candidate for 7,8
A3: 7,8 => CTR
* 261987543...2316898..465127976814235...67.89..8359276.7521493.63147269586..358412
A3: 4 => SOLVED
* 261984573587231649439765128976418235125673894843592761752149386314826957698357412
D3: 7,8,4                                # reduction candidate for 7,8
D3: 7,8 => SOLVED
* 261984573587231649439765128976418235125673894843592761752149386314826957698357412
D3: 4 => CTR
* 261987543...2316898..465127976814235...67.89..8359276.7521493.63147269586..358412
* PAIR B4: 4,7 BLK 4
A5: 4,7,1,5                              # reduction candidate for 4,7
A5: 4,7                                  # 13 pairs
B5: 4,7,2,3                              # reduction candidate for 4,7
B5: 4,7 => CTR
* 261987543.852316.9.39.6512.9.6.1.2355.36.2891128593764852149376314726958697358412
B5: 2,3                                  # 13 pairs
C5: 4,7,3,5                              # reduction candidate for 4,7
C5: 4,7                                  # 13 pairs
* PAIR B4: 4,7 ROW 4
D4: 4,7,8                                # reduction candidate for 4,7
D4: 4,7 => SOLVED
* 261984573587231649439765128976418235125673894843592761752149386314826957698357412
D4: 8                                    # 16 pairs
F4: 4,7,8                                # reduction candidate for 4,7
F4: 4,7                                  # 16 pairs
* PAIR B4: 4,7 COL B
B2: 4,7,8                                # reduction candidate for 4,7
B2: 8                                    # 17 pairs
B2: 4,7                                  # 15 pairs
* PAIR E5: 4,7 BLK 5
D4: 4,7,8                                # reduction candidate for 4,7
D4: 4,7 => SOLVED
* 261984573587231649439765128976418235125673894843592761752149386314826957698357412
D4: 8                                    # 16 pairs
F4: 4,7,8                                # reduction candidate for 4,7
F4: 4,7                                  # 16 pairs
* PAIR E5: 4,7 ROW 5
A5: 4,7,1,5                              # reduction candidate for 4,7
A5: 4,7                                  # 13 pairs
B5: 4,7,2,3                              # reduction candidate for 4,7
B5: 4,7 => CTR
* 261987543.852316.9.39.6512.9.6.1.2355.36.2891128593764852149376314726958697358412
B5: 2,3                                  # 13 pairs
C5: 4,7,3,5                              # reduction candidate for 4,7
C5: 4,7                                  # 13 pairs
* PAIR E5: 4,7 COL E
E1: 4,7,8                                # reduction candidate for 4,7
E1: 4,7 => CTR
* 261974583...2316494...6512.9.6.1.235...6..89....59.76..5218937631.4269586..357412
E1: 8                                    # 16 pairs
E7: 4,7,8                                # reduction candidate for 4,7
E7: 4,7                                  # 16 pairs
* PAIR F5: 2,3 ROW 5
B5: 2,3,4,7                              # reduction candidate for 2,3
B5: 4,7 => CTR
* 261987543.852316.9.39.6512.9.6.1.2355.36.2891128593764852149376314726958697358412
B5: 2,3                                  # 13 pairs
* PAIR F6: 2,3 ROW 6
B6: 2,3,4,8                              # reduction candidate for 2,3
B6: 2,3                                  # 14 pairs
B6: 4,8                                  # 10 pairs
* PAIR I5: 1,4 ROW 5
A5: 1,4,5,7                              # reduction candidate for 1,4
A5: 1,4                                  # 18 pairs
A5: 5,7                                  # 12 pairs
* PAIR I6: 1,4 ROW 6
A6: 1,4,8                                # reduction candidate for 1,4
A6: 8                                    # 19 pairs
A6: 1,4                                  # 14 pairs
* PAIR F9: 7,8 BLK 8
E7: 7,8,4                                # reduction candidate for 7,8
E7: 7,8 => CTR
* 2619..5.3...2316.9....6512.9.6.1.235...6..89....59.76.4521.93.631.42695.6..35.412
E7: 4                                    # 21 pairs
D8: 7,8,4                                # reduction candidate for 7,8
D8: 7,8                                  # 21 pairs
* PAIR F9: 7,8 ROW 9
B9: 7,8,9                                # reduction candidate for 7,8
B9: 7,8                                  # 14 pairs
C9: 7,8,9                                # reduction candidate for 7,8
C9: 7,8                                  # 11 pairs
* PAIR F9: 7,8 COL F
F1: 7,8,4                                # reduction candidate for 7,8
F1: 7,8                                  # 18 pairs
F4: 7,8,4                                # reduction candidate for 7,8
F4: 7,8 => SOLVED
* 261984573587231649439765128976418235125673894843592761752149386314826957698357412
F4: 4                                    # 18 pairs
* PAIR H7: 7,8 ROW 7
A7: 7,8,4                                # reduction candidate for 7,8
A7: 7,8                                  # 21 pairs
E7: 7,8,4                                # reduction candidate for 7,8
E7: 7,8 => CTR
* 2619..5.3...2316.9....6512.9.6.1.235...6..89....59.76.4521.93.631.42695.6..35.412
E7: 4                                    # 21 pairs
* PAIR H7: 7,8 COL H
H1: 7,8,4                                # reduction candidate for 7,8
H1: 7,8 => SOLVED
* 261984573587231649439765128976418235125673894843592761752149386314826957698357412
H1: 4 => CTR
* 261987543...2316898..465127976814235...67.89..8359276.7521493.63147269586..358412
H2: 7,8,4                                # reduction candidate for 7,8
H2: 7,8 => CTR
* 261987543...2316898..465127976814235...67.89..8359276.7521493.63147269586..358412
H2: 4 => SOLVED
* 261984573587231649439765128976418235125673894843592761752149386314826957698357412
* PAIR I8: 7,8 ROW 8
C8: 7,8,4                                # reduction candidate for 7,8
C8: 7,8 => CTR
* 2619..5.3...2316.9....6512.9.6.1.235...6..89....59.76.4521.93.631.42695.6..35.412
C8: 4                                    # 21 pairs
D8: 7,8,4                                # reduction candidate for 7,8
D8: 7,8                                  # 21 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-070-base-pr-000.dot
* REASONING
* PRF # H1: 7,8 => SOL
* DIS # H1: 4 => CTR => H1: 7,8
* DIS # H2: 7,8 => CTR => H2: 4
* PRF # H2: 4 => SOL
* DIS # A3: 7,8 => CTR => A3: 4
* PRF # A3: 4 => SOL
* PRF # D3: 7,8 => SOL
* DIS # D3: 4 => CTR => D3: 7,8
* DIS # B5: 4,7 => CTR => B5: 2,3
* PRF # D4: 4,7 => SOL
* PRF # D4: 4,7 => SOL
* DIS # B5: 4,7 => CTR => B5: 2,3
* DIS # E1: 4,7 => CTR => E1: 8
* DIS # B5: 4,7 => CTR => B5: 2,3
* DIS # E7: 7,8 => CTR => E7: 4
* PRF # F4: 7,8 => SOL
* DIS # E7: 7,8 => CTR => E7: 4
* PRF # H1: 7,8 => SOL
* DIS # H1: 4 => CTR => H1: 7,8
* DIS # H2: 7,8 => CTR => H2: 4
* PRF # H2: 4 => SOL
* DIS # C8: 7,8 => CTR => C8: 4
* CNT  22 HDP CHAINS /  53 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B3,B4,C3,E5,F5,F6,F9,H7,I3,I5,I6,I8)
* 2619..5.3...2316.9....6512.9.6.1.235...6..89....59.76..521.93.631..2695.6..35.412
* PAIR I3: 7,8 BLK 3
H1: 7,8,4                                # reduction candidate for 7,8
H1: 7,8 => SOLVED
* 261984573587231649439765128976418235125673894843592761752149386314826957698357412
* DURATION: 0:00:02.404396  START: 05:06:20.174829  END: 05:06:22.579225 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-070-base-pr-001.dot
* REASONING
* PRF # H1: 7,8 => SOL
* STA H1: 7,8
* CNT   1 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 070

solution: 261984573587231649439765128976418235125673894843592761752149386314826957698357412
info: 1453     FNBTHWX  S8.f     21683

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

Solution

position: 261984573587231649439765128976418235125673894843592761752149386314826957698357412 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 # H1: 7,8 => SOL
* DIS # H1: 4 => CTR => H1: 7,8
* DIS # H2: 7,8 => CTR => H2: 4
* PRF # H2: 4 => SOL
* DIS # A3: 7,8 => CTR => A3: 4
* PRF # A3: 4 => SOL
* PRF # D3: 7,8 => SOL
* DIS # D3: 4 => CTR => D3: 7,8
* INC # A5: 4,7 => UNS
* DIS # B5: 4,7 => CTR => B5: 2,3
* INC # B5: 2,3 => UNS
* INC # C5: 4,7 => UNS
* PRF # D4: 4,7 => SOL
* INC # D4: 8 => UNS
* INC # F4: 4,7 => UNS
* INC # B2: 4,7 => UNS
* INC # B2: 8 => UNS
* PRF # D4: 4,7 => SOL
* INC # D4: 8 => UNS
* INC # F4: 4,7 => UNS
* INC # A5: 4,7 => UNS
* DIS # B5: 4,7 => CTR => B5: 2,3
* INC # B5: 2,3 => UNS
* INC # C5: 4,7 => UNS
* DIS # E1: 4,7 => CTR => E1: 8
* INC # E1: 8 => UNS
* INC # E7: 4,7 => UNS
* INC # B5: 2,3 => UNS
* DIS # B5: 4,7 => CTR => B5: 2,3
* INC # B6: 2,3 => UNS
* INC # B6: 4,8 => UNS
* INC # A5: 1,4 => UNS
* INC # A5: 5,7 => UNS
* INC # A6: 1,4 => UNS
* INC # A6: 8 => UNS
* DIS # E7: 7,8 => CTR => E7: 4
* INC # E7: 4 => UNS
* INC # D8: 7,8 => UNS
* INC # B9: 7,8 => UNS
* INC # C9: 7,8 => UNS
* INC # F1: 7,8 => UNS
* PRF # F4: 7,8 => SOL
* INC # F4: 4 => UNS
* INC # A7: 7,8 => UNS
* DIS # E7: 7,8 => CTR => E7: 4
* INC # E7: 4 => UNS
* PRF # H1: 7,8 => SOL
* DIS # H1: 4 => CTR => H1: 7,8
* DIS # H2: 7,8 => CTR => H2: 4
* PRF # H2: 4 => SOL
* DIS # C8: 7,8 => CTR => C8: 4
* INC # C8: 4 => UNS
* INC # D8: 7,8 => UNS
* CNT  53 HDP CHAINS /  53 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* PRF # H1: 7,8 => SOL
* STA H1: 7,8
* CNT   1 HDP CHAINS /   1 HYP OPENED