Analysis of xx-top95-032-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: ...5...........5.697.....2...48.2...25.1...3..8..3.........4.7..13.5..9..2...31.. initial

Autosolve

position: ...52..4..423..5.6975....2...48.2...25.1...3..8..35.......14.7..13.5..9..2...31.. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # A1: 1,8 => SOL
* DIS # B4: 9 => CTR => B4: 3,6
* PRF # A1: 1,8 => SOL
* PRF # F3: 1,8 => SOL
* DIS # F3: 6 => CTR => F3: 1,8
* PRF # A1: 1,8 => SOL
* DIS # E5: 7,9 => CTR => E5: 4,6
* DIS # E9: 7,9 => CTR => E9: 6,8
* DIS # F5: 6 => CTR => F5: 7,9
* PRF # E3: 4,6 => SOL
* DIS # E3: 8 => CTR => E3: 4,6
* DIS # G5: 7,9 => CTR => G5: 4,6,8
* DIS # G6: 7,9 => CTR => G6: 2,4,6
* DIS # I4: 7,9 => CTR => I4: 1,5
* PRF # I6: 7,9 => SOL
* DIS # I3: 3 => CTR => I3: 1,8
* DIS # I3: 3,8 => CTR => I3: 1
* DIS # A6: 1,6 => CTR => A6: 7
* DIS # C9: 6,9 => CTR => C9: 7,8
* CNT  19 HDP CHAINS /  51 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: 1,8 => SOL
* STA A1: 1,8
* CNT   1 HDP CHAINS /   2 HYP OPENED

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

Details

Positions

...5...........5.697.....2...48.2...25.1...3..8..3.........4.7..13.5..9..2...31.. initial
...52..4..423..5.6975....2...48.2...25.1...3..8..35.......14.7..13.5..9..2...31.. autosolve
836521947142379586975648321364892715259167438781435269598214673413756892627983154 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (12)
B1: 3,6
A2: 1,8
F1: 1,8
E2: 7,9
F2: 7,9
D3: 4,6
G1: 7,9
I1: 7,9
H2: 1,8
G3: 3,8
H6: 1,6
B7: 6,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
F1,F3: 1.. / F1 = 1  => 22 pairs (_) / F3 = 1  =>  0 pairs (X)
H2,I3: 1.. / H2 = 1  =>  0 pairs (X) / I3 = 1  => 22 pairs (_)
A2,H2: 1.. / A2 = 1  => 22 pairs (_) / H2 = 1  =>  0 pairs (X)
F3,I3: 1.. / F3 = 1  =>  0 pairs (X) / I3 = 1  => 22 pairs (_)
C1,C6: 1.. / C1 = 1  =>  0 pairs (X) / C6 = 1  => 26 pairs (_)
G6,I6: 2.. / G6 = 2  => 12 pairs (_) / I6 = 2  => 13 pairs (_)
D7,D8: 2.. / D7 = 2  => 13 pairs (_) / D8 = 2  => 17 pairs (_)
A1,B1: 3.. / A1 = 3  => 13 pairs (_) / B1 = 3  => 18 pairs (_)
G3,I3: 3.. / G3 = 3  => 12 pairs (_) / I3 = 3  =>  0 pairs (X)
A4,B4: 3.. / A4 = 3  => 18 pairs (_) / B4 = 3  => 13 pairs (_)
G7,I7: 3.. / G7 = 3  =>  0 pairs (X) / I7 = 3  => 12 pairs (_)
A1,A4: 3.. / A1 = 3  => 13 pairs (_) / A4 = 3  => 18 pairs (_)
B1,B4: 3.. / B1 = 3  => 18 pairs (_) / B4 = 3  => 13 pairs (_)
G3,G7: 3.. / G3 = 3  => 12 pairs (_) / G7 = 3  =>  0 pairs (X)
I3,I7: 3.. / I3 = 3  =>  0 pairs (X) / I7 = 3  => 12 pairs (_)
D3,E3: 4.. / D3 = 4  => 14 pairs (_) / E3 = 4  =>  0 pairs (*)
E5,D6: 4.. / E5 = 4  => 14 pairs (_) / D6 = 4  =>  0 pairs (*)
A8,A9: 4.. / A8 = 4  => 14 pairs (_) / A9 = 4  => 13 pairs (_)
A9,I9: 4.. / A9 = 4  => 13 pairs (_) / I9 = 4  => 14 pairs (_)
D3,D6: 4.. / D3 = 4  => 14 pairs (_) / D6 = 4  =>  0 pairs (*)
E3,E5: 4.. / E3 = 4  =>  0 pairs (*) / E5 = 4  =>  0 pairs (X)
H4,I4: 5.. / H4 = 5  => 15 pairs (_) / I4 = 5  => 22 pairs (_)
A7,A9: 5.. / A7 = 5  => 12 pairs (_) / A9 = 5  =>  0 pairs (X)
A7,I7: 5.. / A7 = 5  => 12 pairs (_) / I7 = 5  =>  0 pairs (X)
H4,H9: 5.. / H4 = 5  => 15 pairs (_) / H9 = 5  => 22 pairs (_)
E2,F2: 7.. / E2 = 7  => 12 pairs (_) / F2 = 7  => 13 pairs (_)
G1,I1: 7.. / G1 = 7  => 11 pairs (_) / I1 = 7  => 11 pairs (_)
G5,I5: 8.. / G5 = 8  => 14 pairs (_) / I5 = 8  => 15 pairs (_)
F8,E9: 8.. / F8 = 8  =>  0 pairs (X) / E9 = 8  =>  0 pairs (_)
A2,H2: 8.. / A2 = 8  =>  0 pairs (X) / H2 = 8  => 22 pairs (_)
E3,E9: 8.. / E3 = 8  =>  0 pairs (X) / E9 = 8  =>  0 pairs (_)
H2,H9: 8.. / H2 = 8  => 22 pairs (_) / H9 = 8  =>  0 pairs (X)
E2,F2: 9.. / E2 = 9  => 13 pairs (_) / F2 = 9  => 12 pairs (_)
G1,I1: 9.. / G1 = 9  => 11 pairs (_) / I1 = 9  => 11 pairs (_)
B4,B7: 9.. / B4 = 9  =>  0 pairs (X) / B7 = 9  => 14 pairs (_)
F2,F5: 9.. / F2 = 9  => 12 pairs (_) / F5 = 9  => 13 pairs (_)
* DURATION: 0:01:00.940471  START: 23:28:22.759056  END: 23:29:23.699527 2017-05-03
* CP COUNT: (36)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A2,B1,B7,D3,E2,F1,F2,G1,G3,H2,H6,I1)
* ...52..4..423..5.6975....2...48.2...25.1...3..8..35.......14.7..13.5..9..2...31..
* PAIR B1: 3,6 BLK 1
A1: 3,6,1,8                              # reduction candidate for 3,6
A1: 1,8 => SOLVED
* 836521947142379586975648321364892715259167438781435269598214673413756892627983154
A1: 3,6                                  # 14 pairs
* PAIR B1: 3,6 COL B
B4: 3,6,9                                # reduction candidate for 3,6
B4: 9 => CTR
* 63.52.947.423..5.6975486321394862715256147839.8.935462569214.7..13.5.69..2.6.31..
B4: 3,6                                  # 14 pairs
* PAIR A2: 1,8 BLK 1
A1: 1,8,3,6                              # reduction candidate for 1,8
A1: 1,8 => SOLVED
* 836521947142379586975648321364892715259167438781435269598214673413756892627983154
A1: 3,6                                  # 14 pairs
C1: 1,8,6                                # reduction candidate for 1,8
C1: 1,8                                  # 14 pairs
* PAIR F1: 1,8 BLK 2
F3: 1,8,6                                # reduction candidate for 1,8
F3: 1,8 => SOLVED
* 836521947142379586975648321364892715259167438781435269598214673413756892627983154
F3: 6 => CTR
* ..8521.4.142379586975486321394862715256147.3.781935.6.569214873413758692827693154
* PAIR F1: 1,8 ROW 1
A1: 1,8,3,6                              # reduction candidate for 1,8
A1: 1,8 => SOLVED
* 836521947142379586975648321364892715259167438781435269598214673413756892627983154
A1: 3,6                                  # 14 pairs
C1: 1,8,6                                # reduction candidate for 1,8
C1: 1,8                                  # 14 pairs
* PAIR E2: 7,9 COL E
E4: 7,9,6                                # reduction candidate for 7,9
E4: 7,9                                  # 15 pairs
E5: 7,9,4,6                              # reduction candidate for 7,9
E5: 7,9 => CTR
* .68521.4.1423..586975648321.3486291525.1...3..81435.6.5...14673.13.56.9..2..83154
E5: 4,6                                  # 13 pairs
E9: 7,9,6,8                              # reduction candidate for 7,9
E9: 7,9 => CTR
* ..8521.4.142379586975486321394862715256147.3.781935.6.569214873413758692827693154
E9: 6,8                                  # 13 pairs
* PAIR F2: 7,9 COL F
F5: 7,9,6                                # reduction candidate for 7,9
F5: 6 => CTR
* ...521.4.142379586975468321..4892.1525.146.3.68.735....9..14.73.13.57.9..2.9831..
F5: 7,9                                  # 14 pairs
* PAIR D3: 4,6 BLK 2
E3: 4,6,8                                # reduction candidate for 4,6
E3: 4,6 => SOLVED
* 836521947142379586975648321364892715259167438781435269598214673413756892627983154
E3: 8 => CTR
* ..8521.4.142379586975486321394862715256147.3.781935.6.569214873413758692827693154
* PAIR D3: 4,6 COL D
D6: 4,6,7,9                              # reduction candidate for 4,6
D6: 4,6                                  # 19 pairs
D6: 7,9                                  # 16 pairs
* PAIR G1: 7,9 COL G
G4: 7,9,6                                # reduction candidate for 7,9
G4: 7,9                                  # 13 pairs
G5: 7,9,4,6,8                            # reduction candidate for 7,9
G5: 7,9 => CTR
* ..1528.4.8423..5.69754...21..48.265.25.14..38.8..35.1.....14.73.13.5..9.42...3165
G5: 4,6,8                                # 12 pairs
G6: 7,9,2,4,6                            # reduction candidate for 7,9
G6: 7,9 => CTR
* ...521.4.1423..586975648321..48.2.1525.1...3..814359625...14673.13.56298.2..83154
G6: 2,4,6                                # 12 pairs
* PAIR I1: 7,9 COL I
I4: 7,9,1,5                              # reduction candidate for 7,9
I4: 7,9 => CTR
* 361528.4.8423..516975..1.2.1348.2.5.25.1...3..8..35.61.9..14.7..13.5..9..2..831..
I4: 1,5                                  # 13 pairs
I5: 7,9,4,8                              # reduction candidate for 7,9
I5: 7,9                                  # 20 pairs
I6: 7,9,1,2,4                            # reduction candidate for 7,9
I6: 7,9 => SOLVED
* 836521947142379586975648321364892715259167438781435269598214673413756892627983154
I6: 1,2,4                                # 12 pairs
* PAIR H2: 1,8 BLK 3
I3: 1,8,3                                # reduction candidate for 1,8
I3: 3 => CTR
* ...52..4..423..516975..1823..48.2...25.1...38.8..35.6.....1437..13.5.69..2..8315.
I3: 1,8                                  # 12 pairs
* PAIR G3: 3,8 BLK 3
I3: 3,8,1                                # reduction candidate for 3,8
I3: 3,8 => CTR
* ...528.4.8423..516975..1.2...48.2.5.25.1...3..8..35.6...8.14.7..13.5..9..2...318.
I3: 1                                    # 22 pairs
* PAIR G3: 3,8 COL G
G7: 3,8,2,6                              # reduction candidate for 3,8
G7: 3,8                                  # 16 pairs
G7: 2,6                                  # 14 pairs
* PAIR H6: 1,6 BLK 6
H4: 1,6,5                                # reduction candidate for 1,6
H4: 1,6                                  # 22 pairs
H4: 5                                    # 15 pairs
* PAIR H6: 1,6 ROW 6
A6: 1,6,7                                # reduction candidate for 1,6
A6: 1,6 => CTR
* ..1528.4.8423..516975..1.2...48.2..125.1...3.18..35.6.....14.7..13.5..9..2..8315.
A6: 7                                    # 16 pairs
C6: 1,6,7,9                              # reduction candidate for 1,6
C6: 1,6                                  # 20 pairs
* PAIR B7: 6,9 BLK 7
C7: 6,9,8                                # reduction candidate for 6,9
C7: 6,9                                  # 21 pairs
C9: 6,9,7,8                              # reduction candidate for 6,9
C9: 6,9 => CTR
* ..1528.4.8423..516975..1.2...48.2..125.1...3.18..35.6.5.8.14.7..13.5..9..2..8315.
C9: 7,8                                  # 14 pairs
* PAIR B7: 6,9 ROW 7
D7: 6,9,2                                # reduction candidate for 6,9
D7: 6,9                                  # 17 pairs
D7: 2                                    # 13 pairs
* PAIR B7: 6,9 COL B
B4: 6,9,3                                # reduction candidate for 6,9
B4: 6,9                                  # 18 pairs
B4: 3                                    # 13 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top95-032-base-pr-000.dot
* REASONING
* PRF # A1: 1,8 => SOL
* DIS # B4: 9 => CTR => B4: 3,6
* PRF # A1: 1,8 => SOL
* PRF # F3: 1,8 => SOL
* DIS # F3: 6 => CTR => F3: 1,8
* PRF # A1: 1,8 => SOL
* DIS # E5: 7,9 => CTR => E5: 4,6
* DIS # E9: 7,9 => CTR => E9: 6,8
* DIS # F5: 6 => CTR => F5: 7,9
* PRF # E3: 4,6 => SOL
* DIS # E3: 8 => CTR => E3: 4,6
* DIS # G5: 7,9 => CTR => G5: 4,6,8
* DIS # G6: 7,9 => CTR => G6: 2,4,6
* DIS # I4: 7,9 => CTR => I4: 1,5
* PRF # I6: 7,9 => SOL
* DIS # I3: 3 => CTR => I3: 1,8
* DIS # I3: 3,8 => CTR => I3: 1
* DIS # A6: 1,6 => CTR => A6: 7
* DIS # C9: 6,9 => CTR => C9: 7,8
* CNT  19 HDP CHAINS /  51 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A2,B1,B7,D3,E2,F1,F2,G1,G3,H2,H6,I1)
* ...52..4..423..5.6975....2...48.2...25.1...3..8..35.......14.7..13.5..9..2...31..
* PAIR B1: 3,6 BLK 1
A1: 3,6,1,8                              # reduction candidate for 3,6
A1: 1,8 => SOLVED
* 836521947142379586975648321364892715259167438781435269598214673413756892627983154
* DURATION: 0:00:03.321742  START: 23:30:13.210508  END: 23:30:16.532250 2017-05-03
* SOLUTION FOUND
* SAVE PR GRAPH xx-top95-032-base-pr-001.dot
* REASONING
* PRF # A1: 1,8 => SOL
* STA A1: 1,8
* CNT   1 HDP CHAINS /   2 HYP OPENED

Header Info

Top 95 Sudokus 032
[sudoku:top95] “95 Hard Puzzles”, http://magictour.free.fr/top95, or http://norvig.com/top95.txt

Solution

position: 836521947142379586975648321364892715259167438781435269598214673413756892627983154 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 # A1: 3,6 => UNS
* PRF # A1: 1,8 => SOL
* INC # B4: 3,6 => UNS
* DIS # B4: 9 => CTR => B4: 3,6
* PRF # A1: 1,8 => SOL
* INC # A1: 3,6 => UNS
* INC # C1: 1,8 => UNS
* PRF # F3: 1,8 => SOL
* DIS # F3: 6 => CTR => F3: 1,8
* PRF # A1: 1,8 => SOL
* INC # A1: 3,6 => UNS
* INC # C1: 1,8 => UNS
* INC # E4: 7,9 => UNS
* DIS # E5: 7,9 => CTR => E5: 4,6
* INC # E5: 4,6 => UNS
* DIS # E9: 7,9 => CTR => E9: 6,8
* INC # E9: 6,8 => UNS
* INC # F5: 7,9 => UNS
* DIS # F5: 6 => CTR => F5: 7,9
* PRF # E3: 4,6 => SOL
* DIS # E3: 8 => CTR => E3: 4,6
* INC # D6: 4,6 => UNS
* INC # D6: 7,9 => UNS
* INC # G4: 7,9 => UNS
* DIS # G5: 7,9 => CTR => G5: 4,6,8
* INC # G5: 4,6,8 => UNS
* DIS # G6: 7,9 => CTR => G6: 2,4,6
* INC # G6: 2,4,6 => UNS
* DIS # I4: 7,9 => CTR => I4: 1,5
* INC # I4: 1,5 => UNS
* INC # I5: 7,9 => UNS
* PRF # I6: 7,9 => SOL
* INC # I6: 1,2,4 => UNS
* INC # I3: 1,8 => UNS
* DIS # I3: 3 => CTR => I3: 1,8
* DIS # I3: 3,8 => CTR => I3: 1
* INC # I3: 1 => UNS
* INC # G7: 3,8 => UNS
* INC # G7: 2,6 => UNS
* INC # H4: 1,6 => UNS
* INC # H4: 5 => UNS
* DIS # A6: 1,6 => CTR => A6: 7
* INC # A6: 7 => UNS
* INC # C6: 1,6 => UNS
* INC # C7: 6,9 => UNS
* DIS # C9: 6,9 => CTR => C9: 7,8
* INC # C9: 7,8 => UNS
* INC # D7: 6,9 => UNS
* INC # D7: 2 => UNS
* INC # B4: 6,9 => UNS
* INC # B4: 3 => UNS
* CNT  51 HDP CHAINS /  51 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # A1: 3,6 => UNS
* PRF # A1: 1,8 => SOL
* STA A1: 1,8
* CNT   2 HDP CHAINS /   2 HYP OPENED