Analysis of zz-www.sudokuwiki.org-0055-base.sdk

Contents

Sudoku from http://www.sudokuwiki.org/Print_Weekly_Sudoku.asp?unsolvable=55

level: hard

Sudoku from http://www.sudokuwiki.org/Print_Weekly_Sudoku.asp?unsolvable=55

position: ...7..4.....49.21......1.78..5....6..7.8.2.5..3....1..45.6......16.34.....9..7... initial

Autosolve

position: ...7..4.....49.21......1.78..5....6..7.8.2.5..3....1..45.6......16.34.....9..7... autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # A1: 3,9 => CTR => A1: 1,2,5,8
* CNT   1 HDP CHAINS /  31 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 # A1: 3,9 => CTR => A1: 1,2,5,8
* STA A1: 1,2,5,8
* CNT   1 HDP CHAINS /  63 HYP OPENED

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

Pair Reduction Position

position: ...7..4.....49.21......1.78..5....6..7.8.2.5..3....1..45.6......16.34.....9..7... pair_reduction
Pair Reduction

See section Pair Reduction for the HDP chains leading to this result.

Deep Pair Reduction

Deep Pair Reduction

Time used: 0:00:35.269807

The following important HDP chains were detected:

* PRF # B1: 6,8 # C7: 8 => SOL
* STA # B1: 6,8 + C7: 8
* CNT   1 HDP CHAINS /  38 HYP OPENED

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

Details

Positions

...7..4.....49.21......1.78..5....6..7.8.2.5..3....1..45.6......16.34.....9..7... initial
...7..4.....49.21......1.78..5....6..7.8.2.5..3....1..45.6......16.34.....9..7... autosolve
...7..4.....49.21......1.78..5....6..7.8.2.5..3....1..45.6......16.34.....9..7... pair_reduction
183725496567498213942361578295173864671842359834956127458619732716234985329587641 solved

Classification

level: hard

Pairing Analysis

--------------------------------------------------
* PAIRS (8)
B2: 6,8
H1: 3,9
C5: 1,4
F4: 3,9
D6: 5,9
G5: 3,9
B9: 2,8
F7: 8,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
A1,C1: 1.. / A1 = 1  =>  9 pairs (_) / C1 = 1  => 16 pairs (_)
I7,I9: 1.. / I7 = 1  =>  9 pairs (_) / I9 = 1  => 15 pairs (_)
E7,I7: 1.. / E7 = 1  => 15 pairs (_) / I7 = 1  =>  9 pairs (_)
C1,C5: 1.. / C1 = 1  => 16 pairs (_) / C5 = 1  =>  9 pairs (_)
D4,D9: 1.. / D4 = 1  => 12 pairs (_) / D9 = 1  => 16 pairs (_)
D4,F4: 3.. / D4 = 3  => 17 pairs (_) / F4 = 3  => 10 pairs (_)
G5,I5: 3.. / G5 = 3  =>  8 pairs (_) / I5 = 3  => 12 pairs (_)
C7,A9: 3.. / C7 = 3  => 18 pairs (_) / A9 = 3  =>  8 pairs (_)
D3,D4: 3.. / D3 = 3  => 10 pairs (_) / D4 = 3  => 17 pairs (_)
B3,C3: 4.. / B3 = 4  =>  9 pairs (_) / C3 = 4  => 11 pairs (_)
H9,I9: 4.. / H9 = 4  =>  8 pairs (_) / I9 = 4  => 18 pairs (_)
B3,B4: 4.. / B3 = 4  =>  9 pairs (_) / B4 = 4  => 11 pairs (_)
H6,H9: 4.. / H6 = 4  => 18 pairs (_) / H9 = 4  =>  8 pairs (_)
A5,A6: 6.. / A5 = 6  => 11 pairs (_) / A6 = 6  => 15 pairs (_)
G9,I9: 6.. / G9 = 6  =>  8 pairs (_) / I9 = 6  => 13 pairs (_)
A5,E5: 6.. / A5 = 6  => 11 pairs (_) / E5 = 6  => 15 pairs (_)
G3,G9: 6.. / G3 = 6  => 13 pairs (_) / G9 = 6  =>  8 pairs (_)
A2,C2: 7.. / A2 = 7  => 10 pairs (_) / C2 = 7  =>  8 pairs (_)
E4,E6: 7.. / E4 = 7  =>  9 pairs (_) / E6 = 7  =>  9 pairs (_)
C7,A8: 7.. / C7 = 7  => 10 pairs (_) / A8 = 7  =>  8 pairs (_)
E6,I6: 7.. / E6 = 7  =>  9 pairs (_) / I6 = 7  =>  9 pairs (_)
A2,A8: 7.. / A2 = 7  => 10 pairs (_) / A8 = 7  =>  8 pairs (_)
C2,C7: 7.. / C2 = 7  =>  8 pairs (_) / C7 = 7  => 10 pairs (_)
G4,H6: 8.. / G4 = 8  =>  8 pairs (_) / H6 = 8  => 11 pairs (_)
F7,D8: 9.. / F7 = 9  => 11 pairs (_) / D8 = 9  => 14 pairs (_)
* DURATION: 0:00:26.874199  START: 18:35:20.484109  END: 18:35:47.358308 2017-04-30
* CP COUNT: (25)
* INCONCLUSIVE

* DEEP PAIR REDUCTION
* DURATION: 0:00:34.968405  START: 18:36:50.479162  END: 18:37:25.447567 2017-04-30
* SOLUTION FOUND
* SAVE PR GRAPH zz-www.sudokuwiki.org-0055-base-pr-002.dot
* REASONING
* PRF # B1: 6,8 # C7: 8 => SOL
* STA # B1: 6,8 + C7: 8
* CNT   1 HDP CHAINS /  38 HYP OPENED

Header Info

http://www.sudokuwiki.org/Print_Weekly_Sudoku.asp?unsolvable=55

Solution

position: 183725496567498213942361578295173864671842359834956127458619732716234985329587641 solved
Solution

See section Deep 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 # B1: 6,8 => UNS
* INC # B1: 2,9 => UNS
* INC # F2: 6,8 => UNS
* INC # F2: 3,5 => UNS
* INC # I1: 3,9 => UNS
* INC # G3: 3,9 => UNS
* DIS # A1: 3,9 => CTR => A1: 1,2,5,8
* INC # A1: 1,2,5,8 => UNS
* INC # H7: 3,9 => UNS
* INC # H7: 2,8 => UNS
* INC # E5: 1,4 => UNS
* INC # E5: 6 => UNS
* INC # D4: 3,9 => UNS
* INC # D4: 1 => UNS
* INC # F6: 5,9 => UNS
* INC # F6: 6 => UNS
* INC # D8: 5,9 => UNS
* INC # D8: 2 => UNS
* INC # I5: 3,9 => UNS
* INC # I5: 4 => UNS
* INC # G3: 3,9 => UNS
* INC # G7: 3,9 => UNS
* INC # C7: 2,8 => UNS
* INC # A8: 2,8 => UNS
* INC # A9: 2,8 => UNS
* INC # E9: 2,8 => UNS
* INC # H9: 2,8 => UNS
* INC # B1: 2,8 => UNS
* INC # B4: 2,8 => UNS
* INC # G7: 8,9 => UNS
* INC # H7: 8,9 => UNS
* CNT  31 HDP CHAINS /  31 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # B1: 6,8 => UNS
* INC # B1: 2,9 => UNS
* INC # F2: 6,8 => UNS
* INC # F2: 3,5 => UNS
* INC # I1: 3,9 => UNS
* INC # G3: 3,9 => UNS
* DIS # A1: 3,9 => CTR => A1: 1,2,5,8
* INC A1: 1,2,5,8 # H7: 3,9 => UNS
* INC A1: 1,2,5,8 # H7: 2,8 => UNS
* INC A1: 1,2,5,8 # I1: 3,9 => UNS
* INC A1: 1,2,5,8 # G3: 3,9 => UNS
* INC A1: 1,2,5,8 # H7: 3,9 => UNS
* INC A1: 1,2,5,8 # H7: 2,8 => UNS
* INC A1: 1,2,5,8 # E5: 1,4 => UNS
* INC A1: 1,2,5,8 # E5: 6 => UNS
* INC A1: 1,2,5,8 # D4: 3,9 => UNS
* INC A1: 1,2,5,8 # D4: 1 => UNS
* INC A1: 1,2,5,8 # F6: 5,9 => UNS
* INC A1: 1,2,5,8 # F6: 6 => UNS
* INC A1: 1,2,5,8 # D8: 5,9 => UNS
* INC A1: 1,2,5,8 # D8: 2 => UNS
* INC A1: 1,2,5,8 # I5: 3,9 => UNS
* INC A1: 1,2,5,8 # I5: 4 => UNS
* INC A1: 1,2,5,8 # G3: 3,9 => UNS
* INC A1: 1,2,5,8 # G7: 3,9 => UNS
* INC A1: 1,2,5,8 # C7: 2,8 => UNS
* INC A1: 1,2,5,8 # A8: 2,8 => UNS
* INC A1: 1,2,5,8 # A9: 2,8 => UNS
* INC A1: 1,2,5,8 # E9: 2,8 => UNS
* INC A1: 1,2,5,8 # H9: 2,8 => UNS
* INC A1: 1,2,5,8 # B1: 2,8 => UNS
* INC A1: 1,2,5,8 # B4: 2,8 => UNS
* INC A1: 1,2,5,8 # G7: 8,9 => UNS
* INC A1: 1,2,5,8 # H7: 8,9 => UNS
* INC A1: 1,2,5,8 # B1: 6,8 => UNS
* INC A1: 1,2,5,8 # B1: 2,9 => UNS
* INC A1: 1,2,5,8 # F2: 6,8 => UNS
* INC A1: 1,2,5,8 # F2: 3,5 => UNS
* INC A1: 1,2,5,8 # I1: 3,9 => UNS
* INC A1: 1,2,5,8 # G3: 3,9 => UNS
* INC A1: 1,2,5,8 # H7: 3,9 => UNS
* INC A1: 1,2,5,8 # H7: 2,8 => UNS
* INC A1: 1,2,5,8 # E5: 1,4 => UNS
* INC A1: 1,2,5,8 # E5: 6 => UNS
* INC A1: 1,2,5,8 # D4: 3,9 => UNS
* INC A1: 1,2,5,8 # D4: 1 => UNS
* INC A1: 1,2,5,8 # F6: 5,9 => UNS
* INC A1: 1,2,5,8 # F6: 6 => UNS
* INC A1: 1,2,5,8 # D8: 5,9 => UNS
* INC A1: 1,2,5,8 # D8: 2 => UNS
* INC A1: 1,2,5,8 # I5: 3,9 => UNS
* INC A1: 1,2,5,8 # I5: 4 => UNS
* INC A1: 1,2,5,8 # G3: 3,9 => UNS
* INC A1: 1,2,5,8 # G7: 3,9 => UNS
* INC A1: 1,2,5,8 # C7: 2,8 => UNS
* INC A1: 1,2,5,8 # A8: 2,8 => UNS
* INC A1: 1,2,5,8 # A9: 2,8 => UNS
* INC A1: 1,2,5,8 # E9: 2,8 => UNS
* INC A1: 1,2,5,8 # H9: 2,8 => UNS
* INC A1: 1,2,5,8 # B1: 2,8 => UNS
* INC A1: 1,2,5,8 # B4: 2,8 => UNS
* INC A1: 1,2,5,8 # G7: 8,9 => UNS
* INC A1: 1,2,5,8 # H7: 8,9 => UNS
* STA A1: 1,2,5,8
* CNT  63 HDP CHAINS /  63 HYP OPENED

A3. Deep Pair Reduction

Full list of HDP chains traversed:

* INC # B1: 6,8 => UNS
* INC # B1: 2,9 => UNS
* INC # F2: 6,8 => UNS
* INC # F2: 3,5 => UNS
* INC # I1: 3,9 => UNS
* INC # G3: 3,9 => UNS
* INC # H7: 3,9 => UNS
* INC # H7: 2,8 => UNS
* INC # E5: 1,4 => UNS
* INC # E5: 6 => UNS
* INC # D4: 3,9 => UNS
* INC # D4: 1 => UNS
* INC # F6: 5,9 => UNS
* INC # F6: 6 => UNS
* INC # D8: 5,9 => UNS
* INC # D8: 2 => UNS
* INC # I5: 3,9 => UNS
* INC # I5: 4 => UNS
* INC # G3: 3,9 => UNS
* INC # G7: 3,9 => UNS
* INC # C7: 2,8 => UNS
* INC # A8: 2,8 => UNS
* INC # A9: 2,8 => UNS
* INC # E9: 2,8 => UNS
* INC # H9: 2,8 => UNS
* INC # B1: 2,8 => UNS
* INC # B4: 2,8 => UNS
* INC # G7: 8,9 => UNS
* INC # H7: 8,9 => UNS
* INC # B1: 6,8 # E1: 6,8 => UNS
* INC # B1: 6,8 # F1: 6,8 => UNS
* INC # B1: 6,8 # F2: 6,8 => UNS
* INC # B1: 6,8 # F2: 3,5 => UNS
* INC # B1: 6,8 # A2: 3,7 => UNS
* INC # B1: 6,8 # A2: 5 => UNS
* INC # B1: 6,8 # C7: 3,7 => UNS
* PRF # B1: 6,8 # C7: 8 => SOL
* STA # B1: 6,8 + C7: 8
* CNT  37 HDP CHAINS /  38 HYP OPENED