Analysis of zz-www.sudokuwiki.org-0047-base.sdk

Contents

Sudoku from http://www.sudokuwiki.org/Print_Weekly_Sudoku.asp?unsolvable=47

level: medium

Sudoku from http://www.sudokuwiki.org/Print_Weekly_Sudoku.asp?unsolvable=47

position: .9.7.2.3...1...9..3.......1.....465..5.9.1.8..678.....5.......4..9...3...8.1.9.2. initial

Autosolve

position: .9.712.3...1...9..3...9...1....7465..5.961.8..678.....5......94..9...3...8.1.9.2. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # A6: 2,4 => CTR => A6: 9
* DIS # G5: 2,4 => CTR => G5: 7
* DIS # A2: 2,4 => CTR => A2: 6,7,8
* DIS # C4: 2,3 => CTR => C4: 8
* DIS # I4: 2,3 => CTR => I4: 9
* DIS # E6: 2 => CTR => E6: 3,5
* DIS # G6: 2 => CTR => G6: 1,4
* DIS # G3: 5,7 => CTR => G3: 2,4,8
* CNT   8 HDP CHAINS /  27 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: 2,4 => CTR => A6: 9
* DIS A6: 9 # C5: 3 => CTR => C5: 2,4
* DIS A6: 9 + C5: 2,4 # A2: 2,4 => CTR => A2: 6,7,8
* PRF A6: 9 + C5: 2,4 + A2: 6,7,8 # H3: 6 => SOL
* STA A6: 9 + C5: 2,4 + A2: 6,7,8 + H3: 6
* CNT   4 HDP CHAINS /  14 HYP OPENED

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

Details

Positions

.9.7.2.3...1...9..3.......1.....465..5.9.1.8..678.....5.......4..9...3...8.1.9.2. initial
.9.712.3...1...9..3...9...1....7465..5.961.8..678.....5......94..9...3...8.1.9.2. autosolve
695712438821436975374598261138274659452961783967853142516327894249685317783149526 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (5)
A5: 2,4
D4: 2,3
F6: 3,5
H6: 1,4
G9: 5,7

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
A4,B4: 1.. / A4 = 1  =>  9 pairs (_) / B4 = 1  =>  0 pairs (X)
G6,H6: 1.. / G6 = 1  => 18 pairs (_) / H6 = 1  =>  0 pairs (X)
G7,H8: 1.. / G7 = 1  =>  0 pairs (X) / H8 = 1  => 18 pairs (_)
B7,G7: 1.. / B7 = 1  => 18 pairs (_) / G7 = 1  =>  0 pairs (X)
A4,A8: 1.. / A4 = 1  =>  9 pairs (_) / A8 = 1  =>  0 pairs (X)
G6,G7: 1.. / G6 = 1  => 18 pairs (_) / G7 = 1  =>  0 pairs (X)
H6,H8: 1.. / H6 = 1  =>  0 pairs (X) / H8 = 1  => 18 pairs (_)
I2,G3: 2.. / I2 = 2  =>  0 pairs (X) / G3 = 2  => 12 pairs (_)
D4,E6: 2.. / D4 = 2  => 10 pairs (_) / E6 = 2  =>  0 pairs (X)
C5,I5: 3.. / C5 = 3  =>  0 pairs (X) / I5 = 3  => 15 pairs (_)
C9,E9: 3.. / C9 = 3  => 17 pairs (_) / E9 = 3  =>  0 pairs (X)
B4,B7: 3.. / B4 = 3  => 14 pairs (_) / B7 = 3  =>  0 pairs (X)
C1,C3: 5.. / C1 = 5  => 11 pairs (_) / C3 = 5  =>  7 pairs (_)
E6,F6: 5.. / E6 = 5  =>  9 pairs (_) / F6 = 5  =>  6 pairs (_)
G5,I5: 7.. / G5 = 7  => 12 pairs (_) / I5 = 7  =>  0 pairs (X)
F7,F8: 7.. / F7 = 7  =>  6 pairs (_) / F8 = 7  =>  0 pairs (X)
A4,C4: 8.. / A4 = 8  =>  0 pairs (X) / C4 = 8  =>  5 pairs (_)
G7,I8: 8.. / G7 = 8  => 18 pairs (_) / I8 = 8  =>  8 pairs (_)
A4,A6: 9.. / A4 = 9  =>  0 pairs (X) / A6 = 9  =>  8 pairs (_)
I4,I6: 9.. / I4 = 9  =>  8 pairs (_) / I6 = 9  =>  0 pairs (X)
A4,I4: 9.. / A4 = 9  =>  0 pairs (X) / I4 = 9  =>  8 pairs (_)
A6,I6: 9.. / A6 = 9  =>  8 pairs (_) / I6 = 9  =>  0 pairs (X)
* DURATION: 0:00:30.808459  START: 04:21:19.016264  END: 04:21:49.824723 2017-05-01
* CP COUNT: (22)
* CLUE FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A5,D4,F6,G9,H6)
* .9.712.3...1...9..3...9...1....7465..5.961.8..678.....5......94..9...3...8.1.9.2.
* PAIR A5: 2,4 BLK 4
C5: 2,4,3                                # reduction candidate for 2,4
C5: 2,4                                  # 15 pairs
A6: 2,4,9                                # reduction candidate for 2,4
A6: 2,4 => CTR
* .9.712.3...134.97537.59.241918274653.53961.82267853419532687194149.25368.8.139.2.
A6: 9                                    #  8 pairs
* PAIR A5: 2,4 ROW 5
G5: 2,4,7                                # reduction candidate for 2,4
G5: 2,4 => CTR
* .94712.3...1...9..3.5.9...1..8.7465..53961.87.678...1.532687194..9..53.8.86139.25
G5: 7                                    # 12 pairs
* PAIR A5: 2,4 COL A
A2: 2,4,6,7,8                            # reduction candidate for 2,4
A2: 2,4 => CTR
* 89.712435..1...9.83.5.982.1138274659.5.9617839678..14251..27894.2948531..8413952.
A2: 6,7,8                                #  5 pairs
A8: 2,4,1,6,7                            # reduction candidate for 2,4
A8: 2,4                                  # 14 pairs
* PAIR D4: 2,3 BLK 5
E6: 2,3,5                                # reduction candidate for 2,3
E6: 5                                    #  9 pairs
E6: 2,3                                  #  6 pairs
* PAIR D4: 2,3 ROW 4
B4: 2,3,1                                # reduction candidate for 2,3
B4: 2,3                                  #  9 pairs
C4: 2,3,8                                # reduction candidate for 2,3
C4: 2,3 => CTR
* .9.712.3...13489.53...9.241813274659.5.96178396785341253268719414952.3.8.8.139.2.
C4: 8                                    #  5 pairs
I4: 2,3,9                                # reduction candidate for 2,3
I4: 2,3 => CTR
* .9.712.3...134.97537.59.241918274653.53961.82267853419532687194149.25368.8.139.2.
I4: 9                                    #  8 pairs
* PAIR D4: 2,3 COL D
D7: 2,3,6                                # reduction candidate for 2,3
D7: 6                                    #  7 pairs
D7: 2,3                                  #  6 pairs
* PAIR F6: 3,5 BLK 5
E6: 3,5,2                                # reduction candidate for 3,5
E6: 2 => CTR
* .9.712.3...1..39..3...98..1...374659453961.8.96782541353..87194..9..6378784139526
E6: 3,5                                  # 10 pairs
* PAIR F6: 3,5 COL F
F2: 3,5,6,8                              # reduction candidate for 3,5
F2: 3,5                                  #  7 pairs
F2: 6,8                                  #  6 pairs
* PAIR H6: 1,4 BLK 6
G6: 1,4,2                                # reduction candidate for 1,4
G6: 2 => CTR
* .94712.3..71...9.2325.9...19182746532539614874678..2195326..194..9...3.8.8.1.9.2.
G6: 1,4                                  #  8 pairs
* PAIR G9: 5,7 BLK 9
I8: 5,7,6,8                              # reduction candidate for 5,7
I8: 5,7                                  # 18 pairs
I9: 5,7,6                                # reduction candidate for 5,7
I9: 5,7                                  # 12 pairs
* PAIR G9: 5,7 COL G
G3: 5,7,2,4,8                            # reduction candidate for 5,7
G3: 5,7 => CTR
* .9.71283...1...9.23...9...1....7465..53961.87.678...1.53..87194..9...3.8.8.139.2.
G3: 2,4,8                                #  5 pairs
* INCONCLUSIVE
* SAVE PR GRAPH zz-www.sudokuwiki.org-0047-base-pr-000.dot
* REASONING
* DIS # A6: 2,4 => CTR => A6: 9
* DIS # G5: 2,4 => CTR => G5: 7
* DIS # A2: 2,4 => CTR => A2: 6,7,8
* DIS # C4: 2,3 => CTR => C4: 8
* DIS # I4: 2,3 => CTR => I4: 9
* DIS # E6: 2 => CTR => E6: 3,5
* DIS # G6: 2 => CTR => G6: 1,4
* DIS # G3: 5,7 => CTR => G3: 2,4,8
* CNT   8 HDP CHAINS /  27 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A5,D4,F6,G9,H6)
* .9.712.3...1...9..3...9...1....7465..5.961.8..678.....5......94..9...3...8.1.9.2.
* PAIR A5: 2,4 BLK 4
C5: 2,4,3                                # reduction candidate for 2,4
C5: 2,4                                  # 15 pairs
A6: 2,4,9                                # reduction candidate for 2,4
A6: 2,4 => CTR
* .9.712.3...134.97537.59.241918274653.53961.82267853419532687194149.25368.8.139.2.
* RESTART
* PAIR A5: 2,4 BLK 4
C5: 2,4,3                                # reduction candidate for 2,4
C5: 3 => CTR
* .9.712.3...1..39..3...9...1...374659453961.8.96782541353..87194..9..6378784139526
* PAIR A5: 2,4 COL A
A2: 2,4,6,7,8                            # reduction candidate for 2,4
A2: 2,4 => CTR
* 89.712435..1...9.83.5.982.1138274659.5.9617839678..14251..27894.2948531..8413952.
A8: 2,4,1,6,7                            # reduction candidate for 2,4
A8: 2,4                                  # 19 pairs
* RESTART
* PAIR A5: 2,4 COL A
A8: 2,4,1,6,7                            # reduction candidate for 2,4
A8: 2,4                                  # 19 pairs
A8: 1,6,7                                # 16 pairs
* PAIR RESTART
* PAIR A5: 2,4 COL A
A8: 2,4,1,6,7                            # reduction candidate for 2,4
A8: 2,4                                  # 19 pairs
A8: 1,6,7                                # 16 pairs
* PAIR F6: 3,5 COL F
F2: 3,5,6,8                              # reduction candidate for 3,5
F2: 3,5                                  # 17 pairs
F2: 6,8                                  # 16 pairs

* LEVEL 0 PASS 1 ROUND 2 (AUTO SOLVE) (A4,A5,B3,B4,C4,C5,D7,E6,E9,F6,G1,G6,G7,H6,I9)
* .9.712.3..21...9..3...9.2.1...274659.5.9617839678....25......94..9...3...8.1.952.
* PAIR B3: 4,7 ROW 3
H3: 4,7,6                                # reduction candidate for 4,7
H3: 6 => SOLVED
* 695712438821436975374598261138274659452961783967853142516327894249685317783149526
* DURATION: 0:00:13.325712  START: 04:22:08.756941  END: 04:22:22.082653 2017-05-01
* SOLUTION FOUND
* SAVE PR GRAPH zz-www.sudokuwiki.org-0047-base-pr-001.dot
* REASONING
* DIS # A6: 2,4 => CTR => A6: 9
* DIS A6: 9 # C5: 3 => CTR => C5: 2,4
* DIS A6: 9 + C5: 2,4 # A2: 2,4 => CTR => A2: 6,7,8
* PRF A6: 9 + C5: 2,4 + A2: 6,7,8 # H3: 6 => SOL
* STA A6: 9 + C5: 2,4 + A2: 6,7,8 + H3: 6
* CNT   4 HDP CHAINS /  14 HYP OPENED

Header Info

http://www.sudokuwiki.org/Print_Weekly_Sudoku.asp?unsolvable=47

Solution

position: 695712438821436975374598261138274659452961783967853142516327894249685317783149526 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 # C5: 2,4 => UNS
* DIS # A6: 2,4 => CTR => A6: 9
* INC # A6: 9 => UNS
* DIS # G5: 2,4 => CTR => G5: 7
* INC # G5: 7 => UNS
* DIS # A2: 2,4 => CTR => A2: 6,7,8
* INC # A2: 6,7,8 => UNS
* INC # A8: 2,4 => UNS
* INC # E6: 2,3 => UNS
* INC # E6: 5 => UNS
* INC # B4: 2,3 => UNS
* DIS # C4: 2,3 => CTR => C4: 8
* INC # C4: 8 => UNS
* DIS # I4: 2,3 => CTR => I4: 9
* INC # I4: 9 => UNS
* INC # D7: 2,3 => UNS
* INC # D7: 6 => UNS
* INC # E6: 3,5 => UNS
* DIS # E6: 2 => CTR => E6: 3,5
* INC # F2: 3,5 => UNS
* INC # F2: 6,8 => UNS
* INC # G6: 1,4 => UNS
* DIS # G6: 2 => CTR => G6: 1,4
* INC # I8: 5,7 => UNS
* INC # I9: 5,7 => UNS
* DIS # G3: 5,7 => CTR => G3: 2,4,8
* INC # G3: 2,4,8 => UNS
* CNT  27 HDP CHAINS /  27 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # C5: 2,4 => UNS
* DIS # A6: 2,4 => CTR => A6: 9
* INC A6: 9 # C5: 2,4 => UNS
* DIS A6: 9 # C5: 3 => CTR => C5: 2,4
* DIS A6: 9 + C5: 2,4 # A2: 2,4 => CTR => A2: 6,7,8
* INC A6: 9 + C5: 2,4 + A2: 6,7,8 # A8: 2,4 => UNS
* INC A6: 9 + C5: 2,4 + A2: 6,7,8 # A8: 2,4 => UNS
* INC A6: 9 + C5: 2,4 + A2: 6,7,8 # A8: 1,6,7 => UNS
* INC A6: 9 + C5: 2,4 + A2: 6,7,8 # A8: 2,4 => UNS
* INC A6: 9 + C5: 2,4 + A2: 6,7,8 # A8: 1,6,7 => UNS
* INC A6: 9 + C5: 2,4 + A2: 6,7,8 # F2: 3,5 => UNS
* INC A6: 9 + C5: 2,4 + A2: 6,7,8 # F2: 6,8 => UNS
* INC A6: 9 + C5: 2,4 + A2: 6,7,8 # H3: 4,7 => UNS
* PRF A6: 9 + C5: 2,4 + A2: 6,7,8 # H3: 6 => SOL
* STA A6: 9 + C5: 2,4 + A2: 6,7,8 + H3: 6
* CNT  14 HDP CHAINS /  14 HYP OPENED