Analysis of zz-www.sudokuwiki.org-0130-base.sdk

Contents

Sudoku from http://www.sudokuwiki.org/Print_Weekly_Sudoku.asp?unsolvable=130

level: medium

Sudoku from http://www.sudokuwiki.org/Print_Weekly_Sudoku.asp?unsolvable=130

position: .......2..182..7...2.746.....6..9....4.....5....3..8.....531.7...3...28..5....... initial

Autosolve

position: .......2..182..7...2.746..8..6..9....4.....5....3..8.....531.7.1.3...285.5....... autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # A1: 5,9 => SOL
* DIS # C1: 5,9 => CTR => C1: 4,7
* DIS # A2: 5,9 => CTR => A2: 3,4,6
* DIS # A3: 5,9 => CTR => A3: 3
* PRF # G3: 5,9 => SOL
* DIS # E1: 5,9 => CTR => E1: 1,8
* DIS # A2: 5,9 => CTR => A2: 3,4,6
* DIS # F1: 8 => CTR => F1: 3,5
* DIS # A2: 3,5 => CTR => A2: 4,6,9
* DIS # A5: 7,9 => CTR => A5: 2,3,8
* DIS # B1: 7,9 => CTR => B1: 3,6
* DIS # F6: 2,5 => CTR => F6: 4,7
* CNT  12 HDP CHAINS /  32 HYP OPENED

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

Pair Reduction

Pair Reduction

The following important HDP chains were detected:

* PRF # A1: 5,9 => SOL
* STA A1: 5,9
* CNT   1 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

.......2..182..7...2.746.....6..9....4.....5....3..8.....531.7...3...28..5....... initial
.......2..182..7...2.746..8..6..9....4.....5....3..8.....531.7.1.3...285.5....... autosolve
967183524418295763325746918536879142849612357271354896682531479193467285754928631 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (5)
C3: 5,9
E2: 5,9
F2: 3,5
B6: 7,9
F8: 4,7

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
D1,E1: 1.. / D1 = 1  =>  8 pairs (_) / E1 = 1  =>  6 pairs (_)
G3,H3: 1.. / G3 = 1  =>  8 pairs (_) / H3 = 1  =>  6 pairs (_)
C5,C6: 1.. / C5 = 1  =>  6 pairs (_) / C6 = 1  =>  7 pairs (_)
A7,C7: 2.. / A7 = 2  => 11 pairs (_) / C7 = 2  =>  5 pairs (_)
E9,F9: 2.. / E9 = 2  =>  6 pairs (_) / F9 = 2  =>  6 pairs (_)
F1,F2: 3.. / F1 = 3  => 20 pairs (_) / F2 = 3  =>  5 pairs (_)
B1,B4: 3.. / B1 = 3  =>  0 pairs (X) / B4 = 3  => 17 pairs (_)
D4,F6: 4.. / D4 = 4  =>  0 pairs (X) / F6 = 4  => 17 pairs (_)
D8,F8: 4.. / D8 = 4  => 17 pairs (_) / F8 = 4  =>  0 pairs (X)
D4,D8: 4.. / D4 = 4  =>  0 pairs (X) / D8 = 4  => 17 pairs (_)
F6,F8: 4.. / F6 = 4  => 17 pairs (_) / F8 = 4  =>  0 pairs (X)
G1,G3: 5.. / G1 = 5  =>  6 pairs (_) / G3 = 5  =>  0 pairs (X)
A4,E4: 5.. / A4 = 5  => 11 pairs (_) / E4 = 5  =>  8 pairs (_)
A7,B7: 8.. / A7 = 8  =>  0 pairs (X) / B7 = 8  =>  6 pairs (_)
B4,B7: 8.. / B4 = 8  =>  0 pairs (X) / B7 = 8  =>  6 pairs (_)
* DURATION: 0:00:17.865607  START: 05:56:51.083403  END: 05:57:08.949010 2017-05-01
* CP COUNT: (15)
* CLUE FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B6,C3,E2,F2,F8)
* .......2..182..7...2.746..8..6..9....4.....5....3..8.....531.7.1.3...285.5.......
* PAIR C3: 5,9 BLK 1
A1: 5,9,3,4,6,7                          # reduction candidate for 5,9
A1: 5,9 => SOLVED
* 967183524418295763325746918536879142849612357271354896682531479193467285754928631
A1: 3,4,6,7                              #  5 pairs
C1: 5,9,4,7                              # reduction candidate for 5,9
C1: 5,9 => CTR
* .6.183.2.4182957..32.746..8.368.9...84.6.2.5.97.354862.82531.7.193467285.5.928..1
C1: 4,7                                  #  6 pairs
A2: 5,9,3,4,6                            # reduction candidate for 5,9
A2: 5,9 => CTR
* .....5.2.5182937..329746518.3685914.84...2.5...5314896.82531.7.193467285.5.928.31
A2: 3,4,6                                #  6 pairs
A3: 5,9,3                                # reduction candidate for 5,9
A3: 5,9 => CTR
* .....352.3182957...2.746..8.36..9....4.....53...3.48...8.531.7.193467285.5.9....1
A3: 3                                    # 19 pairs
* PAIR C3: 5,9 ROW 3
G3: 5,9,1,3                              # reduction candidate for 5,9
G3: 5,9 => SOLVED
* 967183524418295763325746918536879142849612357271354896682531479193467285754928631
G3: 1,3                                  #  7 pairs
* PAIR C3: 5,9 COL C
C6: 5,9,1,2,7                            # reduction candidate for 5,9
C6: 5,9                                  #  9 pairs
C6: 1,2,7                                #  7 pairs
* PAIR E2: 5,9 BLK 2
E1: 5,9,1,8                              # reduction candidate for 5,9
E1: 5,9 => CTR
* .3.198.2..182537..925746..85864.9...34.....5....3.58..8.2531.7.1.3..4285.5.......
E1: 1,8                                  #  6 pairs
* PAIR E2: 5,9 ROW 2
A2: 5,9,3,4,6                            # reduction candidate for 5,9
A2: 5,9 => CTR
* .....5.2.5182937..329746518.3685914.84...2.5...5314896.82531.7.193467285.5.928.31
A2: 3,4,6                                #  6 pairs
* PAIR F2: 3,5 BLK 2
F1: 3,5,8                                # reduction candidate for 3,5
F1: 8 => CTR
* .3...8.2..182537..925746..85864.9...34.....5....3.58..8.2531.7.1.3..4285.5.......
F1: 3,5                                  #  8 pairs
* PAIR F2: 3,5 ROW 2
A2: 3,5,4,6,9                            # reduction candidate for 3,5
A2: 3,5 => CTR
* .6.18..2..1829.764925746..8.368.9..2849612357.71354896.82531.79193467285.5.928.31
A2: 4,6,9                                #  6 pairs
* PAIR B6: 7,9 BLK 4
A5: 7,9,2,3,8                            # reduction candidate for 7,9
A5: 7,9 => CTR
* .......2..182..7...2.746..8..6..9....4.....5....3..8.....531.7.1.3...285.5.......
A5: 2,3,8                                #  5 pairs
C5: 7,9,1,2                              # reduction candidate for 7,9
C5: 7,9                                  # 13 pairs
A6: 7,9,2,5                              # reduction candidate for 7,9
A6: 7,9                                  # 11 pairs
C6: 7,9,1,2,5                            # reduction candidate for 7,9
C6: 7,9                                  # 14 pairs
* PAIR B6: 7,9 ROW 6
I6: 7,9,1,2,4,6                          # reduction candidate for 7,9
I6: 7,9                                  #  7 pairs
I6: 1,2,4,6                              #  5 pairs
* PAIR B6: 7,9 COL B
B1: 7,9,3,6                              # reduction candidate for 7,9
B1: 7,9 => CTR
* ...918.2..1825.7...2.746..8.368.9...84.....5....3.48...8.531.7.163497285.5.6....1
B1: 3,6                                  #  6 pairs
B8: 7,9,6                                # reduction candidate for 7,9
B8: 7,9                                  # 12 pairs
* PAIR F8: 4,7 COL F
F6: 4,7,2,5                              # reduction candidate for 4,7
F6: 2,5 => CTR
* .3.....2..182.37...2.746..8..64.9...34.....5....3..8.....531.7.1.3..4285.5.......
F6: 4,7                                  # 11 pairs
* INCONCLUSIVE
* SAVE PR GRAPH zz-www.sudokuwiki.org-0130-base-pr-000.dot
* REASONING
* PRF # A1: 5,9 => SOL
* DIS # C1: 5,9 => CTR => C1: 4,7
* DIS # A2: 5,9 => CTR => A2: 3,4,6
* DIS # A3: 5,9 => CTR => A3: 3
* PRF # G3: 5,9 => SOL
* DIS # E1: 5,9 => CTR => E1: 1,8
* DIS # A2: 5,9 => CTR => A2: 3,4,6
* DIS # F1: 8 => CTR => F1: 3,5
* DIS # A2: 3,5 => CTR => A2: 4,6,9
* DIS # A5: 7,9 => CTR => A5: 2,3,8
* DIS # B1: 7,9 => CTR => B1: 3,6
* DIS # F6: 2,5 => CTR => F6: 4,7
* CNT  12 HDP CHAINS /  32 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B6,C3,E2,F2,F8)
* .......2..182..7...2.746..8..6..9....4.....5....3..8.....531.7.1.3...285.5.......
* PAIR C3: 5,9 BLK 1
A1: 5,9,3,4,6,7                          # reduction candidate for 5,9
A1: 5,9 => SOLVED
* 967183524418295763325746918536879142849612357271354896682531479193467285754928631
* DURATION: 0:00:02.839150  START: 05:57:32.568632  END: 05:57:35.407782 2017-05-01
* SOLUTION FOUND
* SAVE PR GRAPH zz-www.sudokuwiki.org-0130-base-pr-001.dot
* REASONING
* PRF # A1: 5,9 => SOL
* STA A1: 5,9
* CNT   1 HDP CHAINS /   1 HYP OPENED

Header Info

http://www.sudokuwiki.org/Print_Weekly_Sudoku.asp?unsolvable=130

Solution

position: 967183524418295763325746918536879142849612357271354896682531479193467285754928631 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:

* PRF # A1: 5,9 => SOL
* INC # A1: 3,4,6,7 => UNS
* DIS # C1: 5,9 => CTR => C1: 4,7
* INC # C1: 4,7 => UNS
* DIS # A2: 5,9 => CTR => A2: 3,4,6
* INC # A2: 3,4,6 => UNS
* DIS # A3: 5,9 => CTR => A3: 3
* INC # A3: 3 => UNS
* PRF # G3: 5,9 => SOL
* INC # G3: 1,3 => UNS
* INC # C6: 5,9 => UNS
* INC # C6: 1,2,7 => UNS
* DIS # E1: 5,9 => CTR => E1: 1,8
* INC # E1: 1,8 => UNS
* DIS # A2: 5,9 => CTR => A2: 3,4,6
* INC # A2: 3,4,6 => UNS
* INC # F1: 3,5 => UNS
* DIS # F1: 8 => CTR => F1: 3,5
* DIS # A2: 3,5 => CTR => A2: 4,6,9
* INC # A2: 4,6,9 => UNS
* DIS # A5: 7,9 => CTR => A5: 2,3,8
* INC # A5: 2,3,8 => UNS
* INC # C5: 7,9 => UNS
* INC # A6: 7,9 => UNS
* INC # C6: 7,9 => UNS
* INC # I6: 7,9 => UNS
* INC # I6: 1,2,4,6 => UNS
* DIS # B1: 7,9 => CTR => B1: 3,6
* INC # B1: 3,6 => UNS
* INC # B8: 7,9 => UNS
* INC # F6: 4,7 => UNS
* DIS # F6: 2,5 => CTR => F6: 4,7
* CNT  32 HDP CHAINS /  32 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* PRF # A1: 5,9 => SOL
* STA A1: 5,9
* CNT   1 HDP CHAINS /   1 HYP OPENED