Analysis of zz-sudoku-de-635431-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: .6.....9.5.7.4.2.6..46.15...5.....8....3.6....7.....3...64.28..3.1.7.9.2.8.....4. initial

Autosolve

position: 168...394537849216924631578.53....8..193.6.2..721...3.796412853341578962285963.4. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # A6: 4,6 => CTR => A6: 8
* PRF # A6: 8 => SOL
* PRF # G4: 4,6 => SOL
* DIS # G4: 1 => CTR => G4: 4,6
* DIS # A6: 6 => CTR => A6: 4,8
* PRF # E6: 5,8 => SOL
* DIS # E6: 9 => CTR => E6: 5,8
* PRF # G4: 4,6 => SOL
* DIS # G4: 1 => CTR => G4: 4,6
* DIS # A6: 4,6 => CTR => A6: 8
* PRF # A6: 8 => SOL
* PRF # E6: 5,9 => SOL
* DIS # E6: 8 => CTR => E6: 5,9
* CNT  13 HDP CHAINS /  14 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 # A6: 4,6 => CTR => A6: 8
* PRF A6: 8 => SOL
* STA A6: 8
* CNT   2 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

.6.....9.5.7.4.2.6..46.15...5.....8....3.6....7.....3...64.28..3.1.7.9.2.8.....4. initial
168...394537849216924631578.53....8..193.6.2..721...3.796412853341578962285963.4. autosolve
168725394537849216924631578653297481419386725872154639796412853341578962285963147 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (17)
D1: 2,7
E1: 2,5
F1: 5,7
A4: 4,6
A5: 4,8
D4: 2,7
E4: 2,9
F4: 4,7
E5: 5,8
F6: 4,5
I4: 1,9
G5: 4,7
I5: 5,7
G6: 4,6
I6: 5,9
G9: 1,7
I9: 1,7

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
G4,I4: 1.. / G4 = 1  =>  0 pairs (X) / I4 = 1  =>  0 pairs (_)
G9,I9: 1.. / G9 = 1  =>  0 pairs (*) / I9 = 1  =>  0 pairs (X)
G4,G9: 1.. / G4 = 1  =>  0 pairs (X) / G9 = 1  =>  0 pairs (_)
I4,I9: 1.. / I4 = 1  =>  0 pairs (*) / I9 = 1  =>  0 pairs (X)
D1,E1: 2.. / D1 = 2  =>  0 pairs (X) / E1 = 2  =>  0 pairs (_)
D4,E4: 2.. / D4 = 2  =>  0 pairs (*) / E4 = 2  =>  0 pairs (X)
D1,D4: 2.. / D1 = 2  =>  0 pairs (X) / D4 = 2  =>  0 pairs (_)
E1,E4: 2.. / E1 = 2  =>  0 pairs (*) / E4 = 2  =>  0 pairs (X)
F4,F6: 4.. / F4 = 4  =>  0 pairs (X) / F6 = 4  =>  0 pairs (_)
A5,G5: 4.. / A5 = 4  =>  0 pairs (*) / G5 = 4  =>  0 pairs (X)
E1,F1: 5.. / E1 = 5  =>  0 pairs (X) / F1 = 5  =>  0 pairs (_)
I5,I6: 5.. / I5 = 5  =>  0 pairs (*) / I6 = 5  =>  0 pairs (X)
E5,I5: 5.. / E5 = 5  =>  0 pairs (X) / I5 = 5  =>  0 pairs (_)
F1,F6: 5.. / F1 = 5  =>  0 pairs (*) / F6 = 5  =>  0 pairs (X)
A4,A6: 6.. / A4 = 6  => 17 pairs (_) / A6 = 6  =>  0 pairs (X)
G4,G6: 6.. / G4 = 6  =>  0 pairs (X) / G6 = 6  => 17 pairs (_)
A4,G4: 6.. / A4 = 6  => 17 pairs (_) / G4 = 6  =>  0 pairs (X)
A6,G6: 6.. / A6 = 6  =>  0 pairs (X) / G6 = 6  => 17 pairs (_)
D1,F1: 7.. / D1 = 7  =>  0 pairs (*) / F1 = 7  =>  0 pairs (X)
D4,F4: 7.. / D4 = 7  =>  0 pairs (X) / F4 = 7  =>  0 pairs (_)
G5,I5: 7.. / G5 = 7  =>  0 pairs (*) / I5 = 7  =>  0 pairs (X)
G9,I9: 7.. / G9 = 7  =>  0 pairs (X) / I9 = 7  =>  0 pairs (_)
D1,D4: 7.. / D1 = 7  =>  0 pairs (*) / D4 = 7  =>  0 pairs (X)
F1,F4: 7.. / F1 = 7  =>  0 pairs (X) / F4 = 7  =>  0 pairs (_)
G5,G9: 7.. / G5 = 7  =>  0 pairs (*) / G9 = 7  =>  0 pairs (X)
I5,I9: 7.. / I5 = 7  =>  0 pairs (X) / I9 = 7  =>  0 pairs (_)
A5,A6: 8.. / A5 = 8  =>  0 pairs (X) / A6 = 8  =>  0 pairs (_)
E5,E6: 8.. / E5 = 8  =>  0 pairs (*) / E6 = 8  =>  0 pairs (X)
A5,E5: 8.. / A5 = 8  =>  0 pairs (X) / E5 = 8  =>  0 pairs (_)
A6,E6: 8.. / A6 = 8  =>  0 pairs (*) / E6 = 8  =>  0 pairs (X)
E4,E6: 9.. / E4 = 9  =>  0 pairs (*) / E6 = 9  =>  0 pairs (X)
I4,I6: 9.. / I4 = 9  =>  0 pairs (X) / I6 = 9  =>  0 pairs (_)
E4,I4: 9.. / E4 = 9  =>  0 pairs (*) / I4 = 9  =>  0 pairs (X)
E6,I6: 9.. / E6 = 9  =>  0 pairs (X) / I6 = 9  =>  0 pairs (_)
* DURATION: 0:00:58.114843  START: 07:27:12.790399  END: 07:28:10.905242 2017-05-01
* CP COUNT: (34)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A4,A5,D1,D4,E1,E4,E5,F1,F4,F6,G5,G6,G9,I4,I5,I6,I9)
* 168...394537849216924631578.53....8..193.6.2..721...3.796412853341578962285963.4.
* PAIR A4: 4,6 BLK 4
A6: 4,6,8                                # reduction candidate for 4,6
A6: 4,6 => CTR
* 168...394537849216924631578.53....8.819356427.72184.3.796412853341578962285963.4.
A6: 8 => SOLVED
* 168725394537849216924631578653297481419386725872154639796412853341578962285963147
* PAIR A4: 4,6 ROW 4
G4: 4,6,1                                # reduction candidate for 4,6
G4: 4,6 => SOLVED
* 168725394537849216924631578653297481419386725872154639796412853341578962285963147
G4: 1 => CTR
* 168...394537849216924631578653..4189.193.6.2..72195.3.796412853341578962285963.4.
* PAIR A5: 4,8 BLK 4
A6: 4,8,6                                # reduction candidate for 4,8
A6: 6 => CTR
* 168...394537849216924631578.53....8.8193564276721...3.796412853341578962285963.4.
A6: 4,8                                  # 17 pairs
* PAIR E5: 5,8 BLK 5
E6: 5,8,9                                # reduction candidate for 5,8
E6: 5,8 => SOLVED
* 168725394537849216924631578653297481419386725872154639796412853341578962285963147
E6: 9 => CTR
* 168...394537849216924631578.53....8..19386.2587219..3.796412853341578962285963.4.
* PAIR G6: 4,6 BLK 6
G4: 4,6,1                                # reduction candidate for 4,6
G4: 4,6 => SOLVED
* 168725394537849216924631578653297481419386725872154639796412853341578962285963147
G4: 1 => CTR
* 168...394537849216924631578653..4189.193.6.2..72195.3.796412853341578962285963.4.
* PAIR G6: 4,6 ROW 6
A6: 4,6,8                                # reduction candidate for 4,6
A6: 4,6 => CTR
* 168...394537849216924631578.53....8.819356427.72184.3.796412853341578962285963.4.
A6: 8 => SOLVED
* 168725394537849216924631578653297481419386725872154639796412853341578962285963147
* PAIR I6: 5,9 ROW 6
E6: 5,9,8                                # reduction candidate for 5,9
E6: 5,9 => SOLVED
* 168725394537849216924631578653297481419386725872154639796412853341578962285963147
E6: 8 => CTR
* 168...394537849216924631578.53.9..81.193.6.2..7218..39796412853341578962285963147
* INCONCLUSIVE
* SAVE PR GRAPH zz-sudoku-de-635431-base-pr-000.dot
* REASONING
* DIS # A6: 4,6 => CTR => A6: 8
* PRF # A6: 8 => SOL
* PRF # G4: 4,6 => SOL
* DIS # G4: 1 => CTR => G4: 4,6
* DIS # A6: 6 => CTR => A6: 4,8
* PRF # E6: 5,8 => SOL
* DIS # E6: 9 => CTR => E6: 5,8
* PRF # G4: 4,6 => SOL
* DIS # G4: 1 => CTR => G4: 4,6
* DIS # A6: 4,6 => CTR => A6: 8
* PRF # A6: 8 => SOL
* PRF # E6: 5,9 => SOL
* DIS # E6: 8 => CTR => E6: 5,9
* CNT  13 HDP CHAINS /  14 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A4,A5,D1,D4,E1,E4,E5,F1,F4,F6,G5,G6,G9,I4,I5,I6,I9)
* 168...394537849216924631578.53....8..193.6.2..721...3.796412853341578962285963.4.
* PAIR A4: 4,6 BLK 4
A6: 4,6,8                                # reduction candidate for 4,6
A6: 4,6 => CTR
* 168...394537849216924631578.53....8.819356427.72184.3.796412853341578962285963.4.
A6: 8 => SOLVED
* 168725394537849216924631578653297481419386725872154639796412853341578962285963147
* DURATION: 0:00:02.960571  START: 07:28:27.448858  END: 07:28:30.409429 2017-05-01
* SOLUTION FOUND
* SAVE PR GRAPH zz-sudoku-de-635431-base-pr-001.dot
* REASONING
* DIS # A6: 4,6 => CTR => A6: 8
* PRF A6: 8 => SOL
* STA A6: 8
* CNT   2 HDP CHAINS /   1 HYP OPENED

Header Info

http://www.sudokus.de/635431.html
sehr schwierig

--------------------------------------------------
level: medium

* PAIR REDUCTION ..
* ROUND 1: 168...394537849216924631578.53....8..193.6.2..721...3.796412853341578962285963.4.
D1: 2,7
E1: 2,5
F1: 5,7
A4: 4,6
A6: 4,6,8                                # reduction candidate for 4,6
A6: 4,6 => CTR
* 168...394537849216924631578.53....8.819356427.72184.3.796412853341578962285963.4.
A6: 8 => SOLVED
* 168725394537849216924631578653297481419386725872154639796412853341578962285963147
* SOLVED!

--------------------------------------------------
* AUTO ..
Q5: 7.. = D4,F4: 7.. => G4,I4 != 7
* UNSOLVED!

A5 = 8 => E6 = 8 & E5,A6 != 8 => E5 = 5
A6,G6 = 4,6 => F6 = 5
E5,F6 = 5 => CTR
=> A5 != 8 # forcing chain

* SOLVED

Solution

position: 168725394537849216924631578653297481419386725872154639796412853341578962285963147 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 # A6: 4,6 => CTR => A6: 8
* PRF # A6: 8 => SOL
* PRF # G4: 4,6 => SOL
* DIS # G4: 1 => CTR => G4: 4,6
* INC # A6: 4,8 => UNS
* DIS # A6: 6 => CTR => A6: 4,8
* PRF # E6: 5,8 => SOL
* DIS # E6: 9 => CTR => E6: 5,8
* PRF # G4: 4,6 => SOL
* DIS # G4: 1 => CTR => G4: 4,6
* DIS # A6: 4,6 => CTR => A6: 8
* PRF # A6: 8 => SOL
* PRF # E6: 5,9 => SOL
* DIS # E6: 8 => CTR => E6: 5,9
* CNT  14 HDP CHAINS /  14 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # A6: 4,6 => CTR => A6: 8
* PRF A6: 8 => SOL
* STA A6: 8
* CNT   2 HDP CHAINS /   1 HYP OPENED