Analysis of xx-top500-467-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: ....68.7.52....9.............1.7.......5..2...4.......8.......69..2.......6....3. initial

Autosolve

position: .93.68572528...96..67925...351.72.9.6895..2.7742......8.5....269.42.6...2.6.5..39 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # I3: 1,4 => SOL
* DIS # D2: 1,4 => CTR => D2: 3,7
* DIS # D7: 1,4 => CTR => D7: 3,7
* DIS # D9: 1,4 => CTR => D9: 7,8
* PRF # I3: 1,4 => SOL
* DIS # D2: 1,4 => CTR => D2: 3,7
* DIS # E6: 1,9 => CTR => E6: 8
* DIS # G6: 6,8 => CTR => G6: 1,3
* DIS # D4: 6,8 => CTR => D4: 4
* PRF # D4: 4 => SOL
* DIS # D4: 6 => CTR => D4: 4,8
* PRF # H3: 8 => SOL
* DIS # D9: 1,7 => CTR => D9: 4,8
* CNT  13 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:

* PRF # I3: 1,4 => SOL
* STA I3: 1,4
* CNT   1 HDP CHAINS /   2 HYP OPENED

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

Details

Positions

....68.7.52....9.............1.7.......5..2...4.......8.......69..2.......6....3. initial
.93.68572528...96..67925...351.72.9.6895..2.7742......8.5....269.42.6...2.6.5..39 autosolve
493168572528347961167925384351472698689513247742689153835791426974236815216854739 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (9)
A1: 1,4
A3: 1,4
D1: 1,4
I2: 1,4
F6: 1,9
G4: 6,8
I4: 4,8
H5: 1,4
B9: 1,7

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
A1,A3: 1.. / A1 = 1  =>  0 pairs (X) / A3 = 1  => 10 pairs (_)
A1,D1: 1.. / A1 = 1  =>  0 pairs (X) / D1 = 1  => 10 pairs (_)
G3,I3: 3.. / G3 = 3  => 11 pairs (_) / I3 = 3  => 10 pairs (_)
E5,F5: 3.. / E5 = 3  => 16 pairs (_) / F5 = 3  => 10 pairs (_)
G6,I6: 3.. / G6 = 3  => 10 pairs (_) / I6 = 3  => 11 pairs (_)
B7,B8: 3.. / B7 = 3  => 17 pairs (_) / B8 = 3  => 12 pairs (_)
B8,E8: 3.. / B8 = 3  => 12 pairs (_) / E8 = 3  => 17 pairs (_)
D2,D7: 3.. / D2 = 3  => 11 pairs (_) / D7 = 3  => 12 pairs (_)
G3,G6: 3.. / G3 = 3  => 11 pairs (_) / G6 = 3  => 10 pairs (_)
I3,I6: 3.. / I3 = 3  => 10 pairs (_) / I6 = 3  => 11 pairs (_)
A1,A3: 4.. / A1 = 4  => 10 pairs (_) / A3 = 4  =>  0 pairs (X)
I4,H5: 4.. / I4 = 4  =>  0 pairs (X) / H5 = 4  =>  0 pairs (_)
G7,G9: 4.. / G7 = 4  =>  9 pairs (_) / G9 = 4  => 17 pairs (_)
A1,D1: 4.. / A1 = 4  => 10 pairs (_) / D1 = 4  =>  0 pairs (X)
D4,I4: 4.. / D4 = 4  =>  0 pairs (*) / I4 = 4  =>  0 pairs (X)
H3,H5: 4.. / H3 = 4  =>  0 pairs (X) / H5 = 4  =>  0 pairs (_)
H6,I6: 5.. / H6 = 5  => 10 pairs (_) / I6 = 5  => 13 pairs (_)
H8,I8: 5.. / H8 = 5  => 13 pairs (_) / I8 = 5  => 10 pairs (_)
H6,H8: 5.. / H6 = 5  => 10 pairs (_) / H8 = 5  => 13 pairs (_)
I6,I8: 5.. / I6 = 5  => 13 pairs (_) / I8 = 5  => 10 pairs (_)
D4,D6: 6.. / D4 = 6  =>  0 pairs (X) / D6 = 6  =>  9 pairs (_)
G4,G6: 6.. / G4 = 6  =>  9 pairs (_) / G6 = 6  =>  0 pairs (X)
D4,G4: 6.. / D4 = 6  =>  0 pairs (X) / G4 = 6  =>  9 pairs (_)
D6,G6: 6.. / D6 = 6  =>  9 pairs (_) / G6 = 6  =>  0 pairs (X)
D2,F2: 7.. / D2 = 7  => 12 pairs (_) / F2 = 7  => 10 pairs (_)
B8,G8: 7.. / B8 = 7  => 13 pairs (_) / G8 = 7  => 11 pairs (_)
E8,D9: 8.. / E8 = 8  =>  0 pairs (X) / D9 = 8  => 15 pairs (_)
D9,G9: 8.. / D9 = 8  => 15 pairs (_) / G9 = 8  =>  0 pairs (X)
E6,E8: 8.. / E6 = 8  => 15 pairs (_) / E8 = 8  =>  0 pairs (X)
E6,F6: 9.. / E6 = 9  =>  0 pairs (X) / F6 = 9  =>  9 pairs (_)
E7,F7: 9.. / E7 = 9  =>  9 pairs (_) / F7 = 9  =>  0 pairs (X)
E6,E7: 9.. / E6 = 9  =>  0 pairs (X) / E7 = 9  =>  9 pairs (_)
F6,F7: 9.. / F6 = 9  =>  9 pairs (_) / F7 = 9  =>  0 pairs (X)
* DURATION: 0:01:07.767745  START: 18:39:51.557943  END: 18:40:59.325688 2017-05-04
* CP COUNT: (33)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,A3,B9,D1,F6,G4,H5,I2,I4)
* .93.68572528...96..67925...351.72.9.6895..2.7742......8.5....269.42.6...2.6.5..39
* PAIR A3: 1,4 ROW 3
H3: 1,4,8                                # reduction candidate for 1,4
H3: 1,4                                  # 14 pairs
I3: 1,4,3,8                              # reduction candidate for 1,4
I3: 1,4 => SOLVED
* 493168572528347961167925384351472698689513247742689153835791426974236815216854739
I3: 3,8                                  # 10 pairs
* PAIR D1: 1,4 BLK 2
D2: 1,4,3,7                              # reduction candidate for 1,4
D2: 1,4 => CTR
* .93.68572528.3796..67925...3518726946895432177426..3..8753..426934286751216754839
D2: 3,7                                  # 10 pairs
E2: 1,4,3                                # reduction candidate for 1,4
E2: 1,4                                  # 12 pairs
F2: 1,4,3,7                              # reduction candidate for 1,4
F2: 1,4                                  # 14 pairs
* PAIR D1: 1,4 COL D
D7: 1,4,3,7                              # reduction candidate for 1,4
D7: 1,4 => CTR
* .93.685725283.796..67925...3518726946895432177426..3..875139426934286751216754839
D7: 3,7                                  # 10 pairs
D9: 1,4,7,8                              # reduction candidate for 1,4
D9: 1,4 => CTR
* .93.68572528...96..67925...3518726946895..2177426..3..8.5...4269342867512.6.5.839
D9: 7,8                                  # 10 pairs
* PAIR I2: 1,4 BLK 3
H3: 1,4,8                                # reduction candidate for 1,4
H3: 1,4                                  # 14 pairs
I3: 1,4,3,8                              # reduction candidate for 1,4
I3: 1,4 => SOLVED
* 493168572528347961167925384351472698689513247742689153835791426974236815216854739
I3: 3,8                                  # 10 pairs
* PAIR I2: 1,4 ROW 2
D2: 1,4,3,7                              # reduction candidate for 1,4
D2: 1,4 => CTR
* .93.68572528.3796..67925...3518726946895432177426..3..8753..426934286751216754839
D2: 3,7                                  # 10 pairs
E2: 1,4,3                                # reduction candidate for 1,4
E2: 1,4                                  # 12 pairs
F2: 1,4,3,7                              # reduction candidate for 1,4
F2: 1,4                                  # 14 pairs
* PAIR F6: 1,9 BLK 5
E6: 1,9,8                                # reduction candidate for 1,9
E6: 1,9 => CTR
* .93.68572528...96..67925...3518726946895..2177426..3..8.5...4269342867512.6.5.839
E6: 8                                    # 15 pairs
* PAIR F6: 1,9 COL F
F7: 1,9,3,4,7                            # reduction candidate for 1,9
F7: 1,9                                  # 12 pairs
F7: 3,4,7                                #  9 pairs
* PAIR G4: 6,8 BLK 6
G6: 6,8,1,3                              # reduction candidate for 6,8
G6: 6,8 => CTR
* 493168572528...96..67925348351.728946895..217742.896538.5.9..269.42.6.852.685..39
G6: 1,3                                  # 10 pairs
* PAIR G4: 6,8 ROW 4
D4: 6,8,4                                # reduction candidate for 6,8
D4: 6,8 => CTR
* 493168572528...961167925.4.351.72.946895..217742......8.5....269.42.6...2.6.5..39
D4: 4 => SOLVED
* 493168572528347961167925384351472698689513247742689153835791426974236815216854739
* PAIR I4: 4,8 ROW 4
D4: 4,8,6                                # reduction candidate for 4,8
D4: 6 => CTR
* .93.68572528...9611679253483516728946895..2177421896538.5.9..269.42167852.685..39
D4: 4,8                                  #  9 pairs
* PAIR I4: 4,8 COL I
I3: 4,8,1,3                              # reduction candidate for 4,8
I3: 4,8                                  # 10 pairs
I3: 1,3                                  # 10 pairs
* PAIR H5: 1,4 ROW 5
E5: 1,4,3                                # reduction candidate for 1,4
E5: 1,4                                  # 10 pairs
F5: 1,4,3                                # reduction candidate for 1,4
F5: 1,4                                  # 16 pairs
* PAIR H5: 1,4 COL H
H3: 1,4,8                                # reduction candidate for 1,4
H3: 8 => SOLVED
* 493168572528347961167925384351472698689513247742689153835791426974236815216854739
H3: 1,4                                  # 14 pairs
* PAIR B9: 1,7 BLK 7
B7: 1,7,3                                # reduction candidate for 1,7
B7: 1,7                                  # 12 pairs
B8: 1,7,3                                # reduction candidate for 1,7
B8: 1,7                                  # 17 pairs
* PAIR B9: 1,7 ROW 9
D9: 1,7,4,8                              # reduction candidate for 1,7
D9: 1,7 => CTR
* .93.68572528...96..67925...3518726946895432177426..3..8.5...4269342867512.6.54839
D9: 4,8                                  # 12 pairs
F9: 1,7,4                                # reduction candidate for 1,7
F9: 1,7                                  # 14 pairs
G9: 1,7,4,8                              # reduction candidate for 1,7
G9: 1,7                                  # 17 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-467-base-pr-000.dot
* REASONING
* PRF # I3: 1,4 => SOL
* DIS # D2: 1,4 => CTR => D2: 3,7
* DIS # D7: 1,4 => CTR => D7: 3,7
* DIS # D9: 1,4 => CTR => D9: 7,8
* PRF # I3: 1,4 => SOL
* DIS # D2: 1,4 => CTR => D2: 3,7
* DIS # E6: 1,9 => CTR => E6: 8
* DIS # G6: 6,8 => CTR => G6: 1,3
* DIS # D4: 6,8 => CTR => D4: 4
* PRF # D4: 4 => SOL
* DIS # D4: 6 => CTR => D4: 4,8
* PRF # H3: 8 => SOL
* DIS # D9: 1,7 => CTR => D9: 4,8
* CNT  13 HDP CHAINS /  40 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,A3,B9,D1,F6,G4,H5,I2,I4)
* .93.68572528...96..67925...351.72.9.6895..2.7742......8.5....269.42.6...2.6.5..39
* PAIR A3: 1,4 ROW 3
H3: 1,4,8                                # reduction candidate for 1,4
H3: 1,4                                  # 14 pairs
I3: 1,4,3,8                              # reduction candidate for 1,4
I3: 1,4 => SOLVED
* 493168572528347961167925384351472698689513247742689153835791426974236815216854739
* DURATION: 0:00:03.456191  START: 18:41:44.224276  END: 18:41:47.680467 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-467-base-pr-001.dot
* REASONING
* PRF # I3: 1,4 => SOL
* STA I3: 1,4
* CNT   1 HDP CHAINS /   2 HYP OPENED

Header Info

Top 500 Minimum 17 467

solution: 493168572528347961167925384351472698689513247742689153835791426974236815216854739
info: 95591    FNBXYK   S8.f     5535

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

Solution

position: 493168572528347961167925384351472698689513247742689153835791426974236815216854739 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 # H3: 1,4 => UNS
* PRF # I3: 1,4 => SOL
* INC # I3: 3,8 => UNS
* DIS # D2: 1,4 => CTR => D2: 3,7
* INC # D2: 3,7 => UNS
* INC # E2: 1,4 => UNS
* INC # F2: 1,4 => UNS
* DIS # D7: 1,4 => CTR => D7: 3,7
* INC # D7: 3,7 => UNS
* DIS # D9: 1,4 => CTR => D9: 7,8
* INC # D9: 7,8 => UNS
* INC # H3: 1,4 => UNS
* PRF # I3: 1,4 => SOL
* INC # I3: 3,8 => UNS
* DIS # D2: 1,4 => CTR => D2: 3,7
* INC # D2: 3,7 => UNS
* INC # E2: 1,4 => UNS
* INC # F2: 1,4 => UNS
* DIS # E6: 1,9 => CTR => E6: 8
* INC # E6: 8 => UNS
* INC # F7: 1,9 => UNS
* INC # F7: 3,4,7 => UNS
* DIS # G6: 6,8 => CTR => G6: 1,3
* INC # G6: 1,3 => UNS
* DIS # D4: 6,8 => CTR => D4: 4
* PRF # D4: 4 => SOL
* INC # D4: 4,8 => UNS
* DIS # D4: 6 => CTR => D4: 4,8
* INC # I3: 4,8 => UNS
* INC # I3: 1,3 => UNS
* INC # E5: 1,4 => UNS
* INC # F5: 1,4 => UNS
* INC # H3: 1,4 => UNS
* PRF # H3: 8 => SOL
* INC # B7: 1,7 => UNS
* INC # B8: 1,7 => UNS
* DIS # D9: 1,7 => CTR => D9: 4,8
* INC # D9: 4,8 => UNS
* INC # F9: 1,7 => UNS
* INC # G9: 1,7 => UNS
* CNT  40 HDP CHAINS /  40 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # H3: 1,4 => UNS
* PRF # I3: 1,4 => SOL
* STA I3: 1,4
* CNT   2 HDP CHAINS /   2 HYP OPENED