Analysis of zz-www.sudokuwiki.org-0285-base.sdk

Contents

Sudoku from http://www.sudokuwiki.org/Print_Weekly_Sudoku.asp?unsolvable=285

level: hard

Sudoku from http://www.sudokuwiki.org/Print_Weekly_Sudoku.asp?unsolvable=285

position: .2.3.....4...1......9..58..1...2......5..97...3.5...4.....5.6....6....7.....47.89 initial

Autosolve

position: .2.3.....4...1......9..58..1...2......5..97...3.5...4.....5.6....6....7....647.89 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # I3: 6,7 => CTR => I3: 1,2,3,4
* CNT   1 HDP CHAINS /  12 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 # I3: 6,7 => CTR => I3: 1,2,3,4
* STA I3: 1,2,3,4
* CNT   1 HDP CHAINS /  27 HYP OPENED

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

Pair Reduction Position

position: .2.3.....4...1......9..58..1...2......5..97...3.5...4.....5.6....6....7....647.89 pair_reduction
Pair Reduction

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

Deep Pair Reduction

Deep Pair Reduction

Time used: 0:00:20.961726

The following important HDP chains were detected:

* DIS # E1: 6,7 # A1: 6,7 => CTR => A1: 5,8
* DIS # E1: 6,7 + A1: 5,8 # I3: 1,3 => CTR => I3: 2,4
* DIS # E1: 6,7 + A1: 5,8 + I3: 2,4 # B4: 4,8 => CTR => B4: 6,9
* PRF # E1: 6,7 + A1: 5,8 + I3: 2,4 + B4: 6,9 # B5: 6 => SOL
* STA # E1: 6,7 + A1: 5,8 + I3: 2,4 + B4: 6,9 + B5: 6
* CNT   4 HDP CHAINS /  25 HYP OPENED

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

Details

Positions

.2.3.....4...1......9..58..1...2......5..97...3.5...4.....5.6....6....7.....47.89 initial
.2.3.....4...1......9..58..1...2......5..97...3.5...4.....5.6....6....7....647.89 autosolve
.2.3.....4...1......9..58..1...2......5..97...3.5...4.....5.6....6....7....647.89 pair_reduction
528364197473918562619275834194726358865439721732581946947852613286193475351647289 solved

Classification

level: hard

Pairing Analysis

--------------------------------------------------
* PAIRS (2)
E3: 6,7
B9: 1,5

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
C1,B3: 1.. / C1 = 1  =>  8 pairs (_) / B3 = 1  =>  3 pairs (_)
D5,F6: 1.. / D5 = 1  =>  4 pairs (_) / F6 = 1  =>  4 pairs (_)
C2,A3: 3.. / C2 = 3  =>  7 pairs (_) / A3 = 3  =>  4 pairs (_)
F4,E5: 3.. / F4 = 3  => 10 pairs (_) / E5 = 3  =>  3 pairs (_)
E5,E8: 3.. / E5 = 3  =>  3 pairs (_) / E8 = 3  => 10 pairs (_)
F1,D3: 4.. / F1 = 4  =>  3 pairs (_) / D3 = 4  =>  8 pairs (_)
D3,I3: 4.. / D3 = 4  =>  8 pairs (_) / I3 = 4  =>  3 pairs (_)
B5,D5: 4.. / B5 = 4  =>  4 pairs (_) / D5 = 4  =>  6 pairs (_)
C4,C7: 4.. / C4 = 4  =>  6 pairs (_) / C7 = 4  =>  3 pairs (_)
F1,F4: 4.. / F1 = 4  =>  3 pairs (_) / F4 = 4  =>  8 pairs (_)
G1,G8: 4.. / G1 = 4  => 15 pairs (_) / G8 = 4  =>  2 pairs (_)
A1,B2: 5.. / A1 = 5  =>  3 pairs (_) / B2 = 5  =>  7 pairs (_)
D4,E6: 7.. / D4 = 7  =>  5 pairs (_) / E6 = 7  => 14 pairs (_)
E1,D2: 9.. / E1 = 9  =>  3 pairs (_) / D2 = 9  =>  2 pairs (_)
B4,A6: 9.. / B4 = 9  =>  3 pairs (_) / A6 = 9  =>  3 pairs (_)
A6,G6: 9.. / A6 = 9  =>  3 pairs (_) / G6 = 9  =>  3 pairs (_)
E1,E8: 9.. / E1 = 9  =>  3 pairs (_) / E8 = 9  =>  2 pairs (_)
* DURATION: 0:00:10.892779  START: 14:50:42.677285  END: 14:50:53.570064 2019-04-28
* CP COUNT: (17)
* INCONCLUSIVE

* DEEP PAIR REDUCTION
* DURATION: 0:00:20.756813  START: 14:51:10.682154  END: 14:51:31.438967 2019-04-28
* SOLUTION FOUND
* SAVE PR GRAPH zz-www.sudokuwiki.org-0285-base-pr-002.dot
* REASONING
* DIS # E1: 6,7 # A1: 6,7 => CTR => A1: 5,8
* DIS # E1: 6,7 + A1: 5,8 # I3: 1,3 => CTR => I3: 2,4
* DIS # E1: 6,7 + A1: 5,8 + I3: 2,4 # B4: 4,8 => CTR => B4: 6,9
* PRF # E1: 6,7 + A1: 5,8 + I3: 2,4 + B4: 6,9 # B5: 6 => SOL
* STA # E1: 6,7 + A1: 5,8 + I3: 2,4 + B4: 6,9 + B5: 6
* CNT   4 HDP CHAINS /  25 HYP OPENED

Header Info

http://www.sudokuwiki.org/Print_Weekly_Sudoku.asp?unsolvable=285

Solution

position: 528364197473918562619275834194726358865439721732581946947852613286193475351647289 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 # E1: 6,7 => UNS
* INC # E1: 8,9 => UNS
* INC # A3: 6,7 => UNS
* INC # B3: 6,7 => UNS
* DIS # I3: 6,7 => CTR => I3: 1,2,3,4
* INC # I3: 1,2,3,4 => UNS
* INC # E6: 6,7 => UNS
* INC # E6: 8 => UNS
* INC # B8: 1,5 => UNS
* INC # B8: 4,8,9 => UNS
* INC # G9: 1,5 => UNS
* INC # G9: 2,3 => UNS
* CNT  12 HDP CHAINS /  12 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # E1: 6,7 => UNS
* INC # E1: 8,9 => UNS
* INC # A3: 6,7 => UNS
* INC # B3: 6,7 => UNS
* DIS # I3: 6,7 => CTR => I3: 1,2,3,4
* INC I3: 1,2,3,4 # E6: 6,7 => UNS
* INC I3: 1,2,3,4 # E6: 8 => UNS
* INC I3: 1,2,3,4 # E1: 6,7 => UNS
* INC I3: 1,2,3,4 # E1: 8,9 => UNS
* INC I3: 1,2,3,4 # A3: 6,7 => UNS
* INC I3: 1,2,3,4 # B3: 6,7 => UNS
* INC I3: 1,2,3,4 # E6: 6,7 => UNS
* INC I3: 1,2,3,4 # E6: 8 => UNS
* INC I3: 1,2,3,4 # B8: 1,5 => UNS
* INC I3: 1,2,3,4 # B8: 4,8,9 => UNS
* INC I3: 1,2,3,4 # G9: 1,5 => UNS
* INC I3: 1,2,3,4 # G9: 2,3 => UNS
* INC I3: 1,2,3,4 # E1: 6,7 => UNS
* INC I3: 1,2,3,4 # E1: 8,9 => UNS
* INC I3: 1,2,3,4 # A3: 6,7 => UNS
* INC I3: 1,2,3,4 # B3: 6,7 => UNS
* INC I3: 1,2,3,4 # E6: 6,7 => UNS
* INC I3: 1,2,3,4 # E6: 8 => UNS
* INC I3: 1,2,3,4 # B8: 1,5 => UNS
* INC I3: 1,2,3,4 # B8: 4,8,9 => UNS
* INC I3: 1,2,3,4 # G9: 1,5 => UNS
* INC I3: 1,2,3,4 # G9: 2,3 => UNS
* STA I3: 1,2,3,4
* CNT  27 HDP CHAINS /  27 HYP OPENED

A3. Deep Pair Reduction

Full list of HDP chains traversed:

* INC # E1: 6,7 => UNS
* INC # E1: 8,9 => UNS
* INC # A3: 6,7 => UNS
* INC # B3: 6,7 => UNS
* INC # E6: 6,7 => UNS
* INC # E6: 8 => UNS
* INC # B8: 1,5 => UNS
* INC # B8: 4,8,9 => UNS
* INC # G9: 1,5 => UNS
* INC # G9: 2,3 => UNS
* DIS # E1: 6,7 # A1: 6,7 => CTR => A1: 5,8
* INC # E1: 6,7 + A1: 5,8 # I1: 6,7 => UNS
* INC # E1: 6,7 + A1: 5,8 # I1: 6,7 => UNS
* INC # E1: 6,7 + A1: 5,8 # I1: 1,4,5 => UNS
* INC # E1: 6,7 + A1: 5,8 # I1: 6,7 => UNS
* INC # E1: 6,7 + A1: 5,8 # I1: 1,4,5 => UNS
* INC # E1: 6,7 + A1: 5,8 # I3: 2,4 => UNS
* DIS # E1: 6,7 + A1: 5,8 # I3: 1,3 => CTR => I3: 2,4
* INC # E1: 6,7 + A1: 5,8 + I3: 2,4 # A3: 6,7 => UNS
* INC # E1: 6,7 + A1: 5,8 + I3: 2,4 # B3: 6,7 => UNS
* DIS # E1: 6,7 + A1: 5,8 + I3: 2,4 # B4: 4,8 => CTR => B4: 6,9
* INC # E1: 6,7 + A1: 5,8 + I3: 2,4 + B4: 6,9 # B5: 4,8 => UNS
* INC # E1: 6,7 + A1: 5,8 + I3: 2,4 + B4: 6,9 # B5: 4,8 => UNS
* PRF # E1: 6,7 + A1: 5,8 + I3: 2,4 + B4: 6,9 # B5: 6 => SOL
* STA # E1: 6,7 + A1: 5,8 + I3: 2,4 + B4: 6,9 + B5: 6
* CNT  24 HDP CHAINS /  25 HYP OPENED