Analysis of xx-top500-344-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: ..6....8479.................4.86....5.....9.1...3.....1....9......4...6.......2.. initial

Autosolve

position: 3.69...8479..486.348..36.9.943861...568..49312..39584613.6.94.88.941.36.6.4.83219 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # E1: 2,7 => CTR => E1: 5
* PRF # E1: 5 => SOL
* PRF # D3: 2,7 => SOL
* PRF # H4: 7 => SOL
* PRF # D3: 2,7 => SOL
* DIS # E1: 2,7 => CTR => E1: 5
* PRF # E1: 5 => SOL
* PRF # E7: 2,7 => SOL
* DIS # E7: 5 => CTR => E7: 2,7
* DIS # G1: 5,7 => CTR => G1: 1
* DIS # C7: 5,7 => CTR => C7: 2
* PRF # C7: 2 => SOL
* PRF # B8: 5,7 => SOL
* DIS # B8: 2 => CTR => B8: 5,7
* PRF # E7: 2,7 => SOL
* DIS # E7: 5 => CTR => E7: 2,7
* PRF # B8: 5 => SOL
* PRF # E7: 5,7 => SOL
* DIS # E7: 2 => CTR => E7: 5,7
* DIS # D3: 5,7 => CTR => D3: 1,2
* DIS # C7: 5,7 => CTR => C7: 2
* PRF # C7: 2 => SOL
* PRF # E7: 5,7 => SOL
* DIS # E7: 2 => CTR => E7: 5,7
* PRF # B8: 5,7 => SOL
* DIS # B8: 2 => CTR => B8: 5,7
* CNT  26 HDP CHAINS /  43 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 # E1: 2,7 => CTR => E1: 5
* PRF E1: 5 => SOL
* STA E1: 5
* CNT   2 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

..6....8479.................4.86....5.....9.1...3.....1....9......4...6.......2.. initial
3.69...8479..486.348..36.9.943861...568..49312..39584613.6.94.88.941.36.6.4.83219 autosolve
326957184795148623481236795943861572568724931217395846132679458859412367674583219 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (12)
F1: 2,7
H2: 2,5
B6: 1,7
C6: 1,7
D5: 2,7
E5: 2,7
G4: 5,7
B9: 5,7
F8: 2,7
D9: 5,7
H7: 5,7
I8: 5,7

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
D2,D3: 1.. / D2 = 1  => 13 pairs (_) / D3 = 1  => 15 pairs (_)
G1,G3: 1.. / G1 = 1  => 13 pairs (_) / G3 = 1  =>  0 pairs (X)
B6,C6: 1.. / B6 = 1  => 13 pairs (_) / C6 = 1  =>  0 pairs (X)
B1,G1: 1.. / B1 = 1  =>  0 pairs (X) / G1 = 1  => 13 pairs (_)
C2,D2: 1.. / C2 = 1  => 15 pairs (_) / D2 = 1  => 13 pairs (_)
B1,B6: 1.. / B1 = 1  =>  0 pairs (X) / B6 = 1  => 13 pairs (_)
H2,I3: 2.. / H2 = 2  => 15 pairs (_) / I3 = 2  => 14 pairs (_)
D5,E5: 2.. / D5 = 2  =>  0 pairs (X) / E5 = 2  =>  0 pairs (_)
H4,I4: 2.. / H4 = 2  => 14 pairs (_) / I4 = 2  => 15 pairs (_)
C7,B8: 2.. / C7 = 2  =>  0 pairs (*) / B8 = 2  =>  0 pairs (X)
E7,F8: 2.. / E7 = 2  =>  0 pairs (X) / F8 = 2  =>  0 pairs (_)
C7,E7: 2.. / C7 = 2  =>  0 pairs (*) / E7 = 2  =>  0 pairs (X)
B8,F8: 2.. / B8 = 2  =>  0 pairs (X) / F8 = 2  =>  0 pairs (_)
B1,B8: 2.. / B1 = 2  =>  0 pairs (*) / B8 = 2  =>  0 pairs (X)
F1,F8: 2.. / F1 = 2  =>  0 pairs (X) / F8 = 2  =>  0 pairs (_)
H2,H4: 2.. / H2 = 2  => 15 pairs (_) / H4 = 2  => 14 pairs (_)
I3,I4: 2.. / I3 = 2  => 14 pairs (_) / I4 = 2  => 15 pairs (_)
E7,D9: 5.. / E7 = 5  =>  0 pairs (X) / D9 = 5  =>  0 pairs (_)
H7,I8: 5.. / H7 = 5  =>  0 pairs (*) / I8 = 5  =>  0 pairs (X)
B8,I8: 5.. / B8 = 5  =>  0 pairs (*) / I8 = 5  =>  0 pairs (X)
B9,D9: 5.. / B9 = 5  =>  0 pairs (X) / D9 = 5  =>  0 pairs (_)
E1,E7: 5.. / E1 = 5  =>  0 pairs (*) / E7 = 5  =>  0 pairs (X)
B6,C6: 7.. / B6 = 7  =>  0 pairs (X) / C6 = 7  => 13 pairs (_)
D5,E5: 7.. / D5 = 7  =>  0 pairs (*) / E5 = 7  =>  0 pairs (X)
H7,I8: 7.. / H7 = 7  => 16 pairs (_) / I8 = 7  =>  0 pairs (*)
B9,D9: 7.. / B9 = 7  =>  0 pairs (*) / D9 = 7  =>  0 pairs (X)
C6,C7: 7.. / C6 = 7  => 13 pairs (_) / C7 = 7  =>  0 pairs (X)
F1,F8: 7.. / F1 = 7  =>  0 pairs (*) / F8 = 7  =>  0 pairs (X)
H4,H7: 7.. / H4 = 7  =>  0 pairs (*) / H7 = 7  =>  0 pairs (X)
* DURATION: 0:01:01.794875  START: 14:29:10.572512  END: 14:30:12.367387 2017-05-04
* CP COUNT: (29)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B6,B9,C6,D5,D9,E5,F1,F8,G4,H2,H7,I8)
* 3.69...8479..486.348..36.9.943861...568..49312..39584613.6.94.88.941.36.6.4.83219
* PAIR F1: 2,7 BLK 2
E1: 2,7,5                                # reduction candidate for 2,7
E1: 2,7 => CTR
* 32697..8479..486.348..36.9.943861...568..49312..39584613.6594788.9412365654783219
E1: 5 => SOLVED
* 326957184795148623481236795943861572568724931217395846132679458859412367674583219
D3: 2,7,1,5                              # reduction candidate for 2,7
D3: 2,7 => SOLVED
* 326957184795148623481236795943861572568724931217395846132679458859412367674583219
D3: 1,5                                  # 14 pairs
* PAIR H2: 2,5 BLK 3
I3: 2,5,7                                # reduction candidate for 2,5
I3: 2,5                                  # 16 pairs
I3: 7                                    # 14 pairs
* PAIR H2: 2,5 ROW 2
C2: 2,5,1                                # reduction candidate for 2,5
C2: 2,5                                  # 13 pairs
D2: 2,5,1                                # reduction candidate for 2,5
D2: 2,5                                  # 15 pairs
* PAIR H2: 2,5 COL H
H4: 2,5,7                                # reduction candidate for 2,5
H4: 7 => SOLVED
* 326957184795148623481236795943861572568724931217395846132679458859412367674583219
H4: 2,5                                  # 16 pairs
* PAIR D5: 2,7 COL D
D3: 2,7,1,5                              # reduction candidate for 2,7
D3: 2,7 => SOLVED
* 326957184795148623481236795943861572568724931217395846132679458859412367674583219
D3: 1,5                                  # 14 pairs
* PAIR E5: 2,7 COL E
E1: 2,7,5                                # reduction candidate for 2,7
E1: 2,7 => CTR
* 32697..8479..486.348..36.9.943861...568..49312..39584613.6594788.9412365654783219
E1: 5 => SOLVED
* 326957184795148623481236795943861572568724931217395846132679458859412367674583219
E7: 2,7,5                                # reduction candidate for 2,7
E7: 2,7 => SOLVED
* 326957184795148623481236795943861572568724931217395846132679458859412367674583219
E7: 5 => CTR
* 32697..8479..486.348..36.9.943861...568..49312..3958461326594788.9412365654783219
* PAIR G4: 5,7 BLK 6
H4: 5,7,2                                # reduction candidate for 5,7
H4: 5,7                                  # 15 pairs
I4: 5,7,2                                # reduction candidate for 5,7
I4: 5,7                                  # 14 pairs
* PAIR G4: 5,7 COL G
G1: 5,7,1                                # reduction candidate for 5,7
G1: 5,7 => CTR
* 3169...8479.1486.348..3619.943861...568..49312713958461376294588.941.36.6.4.83219
G1: 1                                    # 13 pairs
G3: 5,7,1                                # reduction candidate for 5,7
G3: 5,7                                  # 13 pairs
* PAIR B9: 5,7 BLK 7
C7: 5,7,2                                # reduction candidate for 5,7
C7: 5,7 => CTR
* 35697..8479..486.348..36.9.943861...568..49312..39584613.6294.8829417365674583219
C7: 2 => SOLVED
* 326957184795148623481236795943861572568724931217395846132679458859412367674583219
B8: 5,7,2                                # reduction candidate for 5,7
B8: 5,7 => SOLVED
* 326957184795148623481236795943861572568724931217395846132679458859412367674583219
B8: 2 => CTR
* 3569.218479.148653481736.9.943861...568..49312..39584613.6.94.8829417365674583219
* PAIR F8: 2,7 BLK 8
E7: 2,7,5                                # reduction candidate for 2,7
E7: 2,7 => SOLVED
* 326957184795148623481236795943861572568724931217395846132679458859412367674583219
E7: 5 => CTR
* 32697..8479..486.348..36.9.943861...568..49312..3958461326594788.9412365654783219
* PAIR F8: 2,7 ROW 8
B8: 2,7,5                                # reduction candidate for 2,7
B8: 5 => SOLVED
* 326957184795148623481236795943861572568724931217395846132679458859412367674583219
B8: 2,7                                  # 16 pairs
* PAIR D9: 5,7 BLK 8
E7: 5,7,2                                # reduction candidate for 5,7
E7: 5,7 => SOLVED
* 326957184795148623481236795943861572568724931217395846132679458859412367674583219
E7: 2 => CTR
* 3.695..8479..486.348..36.9.943861...568.749312..39584613.6294.88294173656.4.83219
* PAIR D9: 5,7 COL D
D3: 5,7,1,2                              # reduction candidate for 5,7
D3: 5,7 => CTR
* 3569...8479.1486.348..36.9.943861...5682749312..39584613.6294.8829417365674583219
D3: 1,2                                  # 14 pairs
* PAIR H7: 5,7 ROW 7
C7: 5,7,2                                # reduction candidate for 5,7
C7: 5,7 => CTR
* 35697..8479..486.348..36.9.943861...568..49312..39584613.6294.8829417365674583219
C7: 2 => SOLVED
* 326957184795148623481236795943861572568724931217395846132679458859412367674583219
E7: 5,7,2                                # reduction candidate for 5,7
E7: 5,7 => SOLVED
* 326957184795148623481236795943861572568724931217395846132679458859412367674583219
E7: 2 => CTR
* 3.695..8479..486.348..36.9.943861...568.749312..39584613.6294.88294173656.4.83219
* PAIR H7: 5,7 COL H
H4: 5,7,2                                # reduction candidate for 5,7
H4: 5,7                                  # 15 pairs
H4: 2                                    # 14 pairs
* PAIR I8: 5,7 ROW 8
B8: 5,7,2                                # reduction candidate for 5,7
B8: 5,7 => SOLVED
* 326957184795148623481236795943861572568724931217395846132679458859412367674583219
B8: 2 => CTR
* 3569.218479.148653481736.9.943861...568..49312..39584613.6.94.8829417365674583219
* PAIR I8: 5,7 COL I
I3: 5,7,2                                # reduction candidate for 5,7
I3: 5,7                                  # 15 pairs
I4: 5,7,2                                # reduction candidate for 5,7
I4: 5,7                                  # 14 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-344-base-pr-000.dot
* REASONING
* DIS # E1: 2,7 => CTR => E1: 5
* PRF # E1: 5 => SOL
* PRF # D3: 2,7 => SOL
* PRF # H4: 7 => SOL
* PRF # D3: 2,7 => SOL
* DIS # E1: 2,7 => CTR => E1: 5
* PRF # E1: 5 => SOL
* PRF # E7: 2,7 => SOL
* DIS # E7: 5 => CTR => E7: 2,7
* DIS # G1: 5,7 => CTR => G1: 1
* DIS # C7: 5,7 => CTR => C7: 2
* PRF # C7: 2 => SOL
* PRF # B8: 5,7 => SOL
* DIS # B8: 2 => CTR => B8: 5,7
* PRF # E7: 2,7 => SOL
* DIS # E7: 5 => CTR => E7: 2,7
* PRF # B8: 5 => SOL
* PRF # E7: 5,7 => SOL
* DIS # E7: 2 => CTR => E7: 5,7
* DIS # D3: 5,7 => CTR => D3: 1,2
* DIS # C7: 5,7 => CTR => C7: 2
* PRF # C7: 2 => SOL
* PRF # E7: 5,7 => SOL
* DIS # E7: 2 => CTR => E7: 5,7
* PRF # B8: 5,7 => SOL
* DIS # B8: 2 => CTR => B8: 5,7
* CNT  26 HDP CHAINS /  43 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B6,B9,C6,D5,D9,E5,F1,F8,G4,H2,H7,I8)
* 3.69...8479..486.348..36.9.943861...568..49312..39584613.6.94.88.941.36.6.4.83219
* PAIR F1: 2,7 BLK 2
E1: 2,7,5                                # reduction candidate for 2,7
E1: 2,7 => CTR
* 32697..8479..486.348..36.9.943861...568..49312..39584613.6594788.9412365654783219
E1: 5 => SOLVED
* 326957184795148623481236795943861572568724931217395846132679458859412367674583219
* DURATION: 0:00:01.939969  START: 14:31:10.563373  END: 14:31:12.503342 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-344-base-pr-001.dot
* REASONING
* DIS # E1: 2,7 => CTR => E1: 5
* PRF E1: 5 => SOL
* STA E1: 5
* CNT   2 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 344

solution: 326957184795148623481236795943861572568724931217395846132679458859412367674583219
info: 3422     FNBHWXY  S8.f     42260

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

Solution

position: 326957184795148623481236795943861572568724931217395846132679458859412367674583219 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 # E1: 2,7 => CTR => E1: 5
* PRF # E1: 5 => SOL
* PRF # D3: 2,7 => SOL
* INC # D3: 1,5 => UNS
* INC # I3: 2,5 => UNS
* INC # I3: 7 => UNS
* INC # C2: 2,5 => UNS
* INC # D2: 2,5 => UNS
* INC # H4: 2,5 => UNS
* PRF # H4: 7 => SOL
* PRF # D3: 2,7 => SOL
* INC # D3: 1,5 => UNS
* DIS # E1: 2,7 => CTR => E1: 5
* PRF # E1: 5 => SOL
* PRF # E7: 2,7 => SOL
* DIS # E7: 5 => CTR => E7: 2,7
* INC # H4: 5,7 => UNS
* INC # I4: 5,7 => UNS
* DIS # G1: 5,7 => CTR => G1: 1
* INC # G1: 1 => UNS
* INC # G3: 5,7 => UNS
* DIS # C7: 5,7 => CTR => C7: 2
* PRF # C7: 2 => SOL
* PRF # B8: 5,7 => SOL
* DIS # B8: 2 => CTR => B8: 5,7
* PRF # E7: 2,7 => SOL
* DIS # E7: 5 => CTR => E7: 2,7
* INC # B8: 2,7 => UNS
* PRF # B8: 5 => SOL
* PRF # E7: 5,7 => SOL
* DIS # E7: 2 => CTR => E7: 5,7
* DIS # D3: 5,7 => CTR => D3: 1,2
* INC # D3: 1,2 => UNS
* DIS # C7: 5,7 => CTR => C7: 2
* PRF # C7: 2 => SOL
* PRF # E7: 5,7 => SOL
* DIS # E7: 2 => CTR => E7: 5,7
* INC # H4: 5,7 => UNS
* INC # H4: 2 => UNS
* PRF # B8: 5,7 => SOL
* DIS # B8: 2 => CTR => B8: 5,7
* INC # I3: 5,7 => UNS
* INC # I4: 5,7 => UNS
* CNT  43 HDP CHAINS /  43 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # E1: 2,7 => CTR => E1: 5
* PRF E1: 5 => SOL
* STA E1: 5
* CNT   2 HDP CHAINS /   1 HYP OPENED