Analysis of xx-top95-094-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: .....2.......7...17..3...9.8..7......2.89.6...13..6....9..5.824.....891.......... initial

Autosolve

position: .....2.......7...17..3...9.8..7..1...278916...13..6...39..57824.....891.......... autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # D1: 4,5 => SOL
* DIS # C3: 4,5 => CTR => C3: 1,2,6,8
* DIS # F4: 4,5 => CTR => F4: 3
* DIS # B4: 4,5 => CTR => B4: 6
* DIS # A1: 4,5 => CTR => A1: 1,6,9
* DIS # A9: 4,5 => CTR => A9: 1,2,6
* DIS # D6: 2,4 => CTR => D6: 5
* DIS # E8: 2,4 => CTR => E8: 3,6
* DIS # E9: 2,4 => CTR => E9: 1,3,6
* DIS # B4: 4,5 => CTR => B4: 6
* DIS # F4: 4,5 => CTR => F4: 3
* DIS # C9: 1,6 => CTR => C9: 2,4,5,8
* DIS # C1: 1,6 => CTR => C1: 4,5,8,9
* DIS # D9: 1,6 => CTR => D9: 2,4,9
* CNT  14 HDP CHAINS /  60 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 # D1: 4,5 => SOL
* STA D1: 4,5
* CNT   1 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

.....2.......7...17..3...9.8..7......2.89.6...13..6....9..5.824.....891.......... initial
.....2.......7...17..3...9.8..7..1...278916...13..6...39..57824.....891.......... autosolve
659412378238679451741385296865723149427891635913546782396157824574268913182934567 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (10)
F3: 4,5
A5: 4,5
E6: 2,4
H4: 4,5
I4: 2,9
I5: 3,5
G6: 2,7
H6: 7,8
C7: 1,6
D7: 1,6

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
C3,E3: 1.. / C3 = 1  => 17 pairs (_) / E3 = 1  =>  0 pairs (X)
C7,D7: 1.. / C7 = 1  =>  0 pairs (X) / D7 = 1  => 17 pairs (_)
A1,A9: 1.. / A1 = 1  =>  0 pairs (X) / A9 = 1  => 17 pairs (_)
E4,I4: 2.. / E4 = 2  => 11 pairs (_) / I4 = 2  => 21 pairs (_)
B1,B2: 3.. / B1 = 3  => 10 pairs (_) / B2 = 3  => 10 pairs (_)
E4,F4: 3.. / E4 = 3  =>  0 pairs (X) / F4 = 3  => 15 pairs (_)
H5,I5: 3.. / H5 = 3  => 11 pairs (_) / I5 = 3  => 15 pairs (_)
E8,I8: 3.. / E8 = 3  => 15 pairs (_) / I8 = 3  => 15 pairs (_)
F4,F9: 3.. / F4 = 3  => 15 pairs (_) / F9 = 3  =>  0 pairs (X)
H4,H5: 4.. / H4 = 4  => 13 pairs (_) / H5 = 4  => 13 pairs (_)
A5,H5: 4.. / A5 = 4  => 13 pairs (_) / H5 = 4  => 13 pairs (_)
F4,D6: 5.. / F4 = 5  =>  0 pairs (X) / D6 = 5  => 12 pairs (_)
A6,D6: 5.. / A6 = 5  =>  0 pairs (X) / D6 = 5  => 12 pairs (_)
B4,C4: 6.. / B4 = 6  => 10 pairs (_) / C4 = 6  =>  0 pairs (X)
C7,D7: 6.. / C7 = 6  => 17 pairs (_) / D7 = 6  =>  0 pairs (X)
B8,B9: 7.. / B8 = 7  => 10 pairs (_) / B9 = 7  =>  0 pairs (X)
B8,I8: 7.. / B8 = 7  => 10 pairs (_) / I8 = 7  =>  0 pairs (X)
E1,E3: 8.. / E1 = 8  => 11 pairs (_) / E3 = 8  => 17 pairs (_)
H6,I6: 8.. / H6 = 8  =>  9 pairs (_) / I6 = 8  => 11 pairs (_)
B9,C9: 8.. / B9 = 8  => 10 pairs (_) / C9 = 8  => 10 pairs (_)
C4,A6: 9.. / C4 = 9  => 21 pairs (_) / A6 = 9  => 11 pairs (_)
I4,I6: 9.. / I4 = 9  => 11 pairs (_) / I6 = 9  => 21 pairs (_)
D9,F9: 9.. / D9 = 9  => 11 pairs (_) / F9 = 9  => 17 pairs (_)
C4,I4: 9.. / C4 = 9  => 21 pairs (_) / I4 = 9  => 11 pairs (_)
A6,I6: 9.. / A6 = 9  => 11 pairs (_) / I6 = 9  => 21 pairs (_)
F2,F9: 9.. / F2 = 9  => 11 pairs (_) / F9 = 9  => 17 pairs (_)
* DURATION: 0:00:35.647595  START: 01:12:51.119083  END: 01:13:26.766678 2017-05-04
* CP COUNT: (26)
* CLUE FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A5,C7,D7,E6,F3,G6,H4,H6,I4,I5)
* .....2.......7...17..3...9.8..7..1...278916...13..6...39..57824.....891..........
* PAIR F3: 4,5 BLK 2
D1: 4,5,1,6,9                            # reduction candidate for 4,5
D1: 4,5 => SOLVED
* 659412378238679451741385296865723149427891635913546782396157824574268913182934567
D1: 1,6,9                                # 10 pairs
D2: 4,5,6,9                              # reduction candidate for 4,5
D2: 4,5                                  # 14 pairs
F2: 4,5,9                                # reduction candidate for 4,5
F2: 4,5                                  # 17 pairs
* PAIR F3: 4,5 ROW 3
B3: 4,5,6,8                              # reduction candidate for 4,5
B3: 4,5                                  # 13 pairs
C3: 4,5,1,2,6,8                          # reduction candidate for 4,5
C3: 4,5 => CTR
* ....82.......7...17..31..9686.7..1...278916...13..6..8396157824....68913.........
C3: 1,2,6,8                              # 10 pairs
G3: 4,5,2                                # reduction candidate for 4,5
G3: 4,5                                  # 12 pairs
* PAIR F3: 4,5 COL F
F4: 4,5,3                                # reduction candidate for 4,5
F4: 4,5 => CTR
* 9....2...6.2579..175.3.429.869735142427891635513..6789396157824275..89131..9235..
F4: 3                                    # 15 pairs
* PAIR A5: 4,5 BLK 4
B4: 4,5,6                                # reduction candidate for 4,5
B4: 4,5 => CTR
* 1....2.......7...17..31..9.8.672.1.9.278916..913546...391657824.....891..........
B4: 6                                    # 10 pairs
C4: 4,5,6,9                              # reduction candidate for 4,5
C4: 4,5                                  # 12 pairs
A6: 4,5,9                                # reduction candidate for 4,5
A6: 4,5                                  # 21 pairs
* PAIR A5: 4,5 ROW 5
H5: 4,5,3                                # reduction candidate for 4,5
H5: 4,5                                  # 15 pairs
H5: 3                                    # 11 pairs
* PAIR A5: 4,5 COL A
A1: 4,5,1,6,9                            # reduction candidate for 4,5
A1: 4,5 => CTR
* ..9612..86..97...17.138.296864723159.278916..913546..23961578242.54689131..239.6.
A1: 1,6,9                                # 10 pairs
A2: 4,5,2,6,9                            # reduction candidate for 4,5
A2: 4,5                                  # 15 pairs
A8: 4,5,2,6                              # reduction candidate for 4,5
A8: 4,5                                  # 14 pairs
A9: 4,5,1,2,6                            # reduction candidate for 4,5
A9: 4,5 => CTR
* 1...82...6...7...17..31..9686.7..1...278916..913546..83961578242..468913..1......
A9: 1,2,6                                # 10 pairs
* PAIR E6: 2,4 BLK 5
E4: 2,4,3                                # reduction candidate for 2,4
E4: 2,4                                  # 15 pairs
D6: 2,4,5                                # reduction candidate for 2,4
D6: 2,4 => CTR
* 9....2...6.2579..175.3.429.869735142427891635513..6789396157824275..89131..9235..
D6: 5                                    # 12 pairs
* PAIR E6: 2,4 COL E
E8: 2,4,3,6                              # reduction candidate for 2,4
E8: 2,4 => CTR
* ...1.2.......7...17.13...9.8..735142427891635513..6789396.57824.7...8913.........
E8: 3,6                                  # 11 pairs
E9: 2,4,1,3,6                            # reduction candidate for 2,4
E9: 2,4 => CTR
* 9....2...6...79.517..3...96869735142427891635513..6789396157824275468913...9.35..
E9: 1,3,6                                # 10 pairs
* PAIR H4: 4,5 BLK 6
H5: 4,5,3                                # reduction candidate for 4,5
H5: 4,5                                  # 15 pairs
H5: 3                                    # 11 pairs
* PAIR H4: 4,5 ROW 4
B4: 4,5,6                                # reduction candidate for 4,5
B4: 4,5 => CTR
* 1....2.......7...17..31..9.8.672.1.9.278916..913546...391657824.....891..........
B4: 6                                    # 10 pairs
C4: 4,5,6,9                              # reduction candidate for 4,5
C4: 4,5                                  # 12 pairs
F4: 4,5,3                                # reduction candidate for 4,5
F4: 4,5 => CTR
* 9....2...6.2579..175.3.429.869735142427891635513..6789396157824275..89131..9235..
F4: 3                                    # 15 pairs
* PAIR I4: 2,9 BLK 6
I6: 2,9,7,8                              # reduction candidate for 2,9
I6: 7,8                                  # 13 pairs
I6: 2,9                                  # 10 pairs
* PAIR I5: 3,5 BLK 6
H5: 3,5,4                                # reduction candidate for 3,5
H5: 4                                    # 13 pairs
H5: 3,5                                  # 13 pairs
* PAIR I5: 3,5 COL I
I1: 3,5,6,7,8                            # reduction candidate for 3,5
I1: 3,5                                  # 22 pairs
I8: 3,5,6,7                              # reduction candidate for 3,5
I8: 3,5                                  # 12 pairs
I9: 3,5,6,7                              # reduction candidate for 3,5
I9: 3,5                                  # 17 pairs
* PAIR G6: 2,7 BLK 6
I6: 2,7,8,9                              # reduction candidate for 2,7
I6: 8,9                                  # 11 pairs
I6: 2,7                                  # 11 pairs
* PAIR H6: 7,8 BLK 6
I6: 7,8,2,9                              # reduction candidate for 7,8
I6: 7,8                                  # 13 pairs
I6: 2,9                                  # 10 pairs
* PAIR H6: 7,8 COL H
H1: 7,8,3,5,6                            # reduction candidate for 7,8
H1: 7,8                                  # 11 pairs
H1: 3,5,6                                # 10 pairs
* PAIR C7: 1,6 BLK 7
A9: 1,6,2,4,5                            # reduction candidate for 1,6
A9: 1,6                                  # 11 pairs
C9: 1,6,2,4,5,8                          # reduction candidate for 1,6
C9: 1,6 => CTR
* 1...82...6...7..817.831.29686.7231.9.278916..913546...39..57824.7...891..8.....6.
C9: 2,4,5,8                              # 10 pairs
* PAIR C7: 1,6 COL C
C1: 1,6,4,5,8,9                          # reduction candidate for 1,6
C1: 1,6 => CTR
* ....82.......7...17..31..9686.7..1...278916...13..6..839..57824.....891........6.
C1: 4,5,8,9                              # 10 pairs
C3: 1,6,2,4,5,8                          # reduction candidate for 1,6
C3: 1,6                                  # 11 pairs
* PAIR D7: 1,6 BLK 8
D9: 1,6,2,4,9                            # reduction candidate for 1,6
D9: 1,6 => CTR
* .....2.......7...17..3...9.8..7.31...278916...135.6...39..57824...2.891......9...
D9: 2,4,9                                # 10 pairs
E9: 1,6,2,3,4                            # reduction candidate for 1,6
E9: 1,6                                  # 12 pairs
* PAIR D7: 1,6 COL D
D1: 1,6,4,5,9                            # reduction candidate for 1,6
D1: 4,5,9                                # 17 pairs
D1: 1,6                                  # 12 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top95-094-base-pr-000.dot
* REASONING
* PRF # D1: 4,5 => SOL
* DIS # C3: 4,5 => CTR => C3: 1,2,6,8
* DIS # F4: 4,5 => CTR => F4: 3
* DIS # B4: 4,5 => CTR => B4: 6
* DIS # A1: 4,5 => CTR => A1: 1,6,9
* DIS # A9: 4,5 => CTR => A9: 1,2,6
* DIS # D6: 2,4 => CTR => D6: 5
* DIS # E8: 2,4 => CTR => E8: 3,6
* DIS # E9: 2,4 => CTR => E9: 1,3,6
* DIS # B4: 4,5 => CTR => B4: 6
* DIS # F4: 4,5 => CTR => F4: 3
* DIS # C9: 1,6 => CTR => C9: 2,4,5,8
* DIS # C1: 1,6 => CTR => C1: 4,5,8,9
* DIS # D9: 1,6 => CTR => D9: 2,4,9
* CNT  14 HDP CHAINS /  60 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A5,C7,D7,E6,F3,G6,H4,H6,I4,I5)
* .....2.......7...17..3...9.8..7..1...278916...13..6...39..57824.....891..........
* PAIR F3: 4,5 BLK 2
D1: 4,5,1,6,9                            # reduction candidate for 4,5
D1: 4,5 => SOLVED
* 659412378238679451741385296865723149427891635913546782396157824574268913182934567
* DURATION: 0:00:02.686809  START: 01:14:09.885583  END: 01:14:12.572392 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top95-094-base-pr-001.dot
* REASONING
* PRF # D1: 4,5 => SOL
* STA D1: 4,5
* CNT   1 HDP CHAINS /   1 HYP OPENED

Header Info

Top 95 Sudokus 094
[sudoku:top95] “95 Hard Puzzles”, http://magictour.free.fr/top95, or http://norvig.com/top95.txt

Solution

position: 659412378238679451741385296865723149427891635913546782396157824574268913182934567 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 # D1: 4,5 => SOL
* INC # D1: 1,6,9 => UNS
* INC # D2: 4,5 => UNS
* INC # F2: 4,5 => UNS
* INC # B3: 4,5 => UNS
* DIS # C3: 4,5 => CTR => C3: 1,2,6,8
* INC # C3: 1,2,6,8 => UNS
* INC # G3: 4,5 => UNS
* DIS # F4: 4,5 => CTR => F4: 3
* INC # F4: 3 => UNS
* DIS # B4: 4,5 => CTR => B4: 6
* INC # B4: 6 => UNS
* INC # C4: 4,5 => UNS
* INC # A6: 4,5 => UNS
* INC # H5: 4,5 => UNS
* INC # H5: 3 => UNS
* DIS # A1: 4,5 => CTR => A1: 1,6,9
* INC # A1: 1,6,9 => UNS
* INC # A2: 4,5 => UNS
* INC # A8: 4,5 => UNS
* DIS # A9: 4,5 => CTR => A9: 1,2,6
* INC # A9: 1,2,6 => UNS
* INC # E4: 2,4 => UNS
* DIS # D6: 2,4 => CTR => D6: 5
* INC # D6: 5 => UNS
* DIS # E8: 2,4 => CTR => E8: 3,6
* INC # E8: 3,6 => UNS
* DIS # E9: 2,4 => CTR => E9: 1,3,6
* INC # E9: 1,3,6 => UNS
* INC # H5: 4,5 => UNS
* INC # H5: 3 => UNS
* DIS # B4: 4,5 => CTR => B4: 6
* INC # B4: 6 => UNS
* INC # C4: 4,5 => UNS
* DIS # F4: 4,5 => CTR => F4: 3
* INC # F4: 3 => UNS
* INC # I6: 2,9 => UNS
* INC # I6: 7,8 => UNS
* INC # H5: 3,5 => UNS
* INC # H5: 4 => UNS
* INC # I1: 3,5 => UNS
* INC # I8: 3,5 => UNS
* INC # I9: 3,5 => UNS
* INC # I6: 2,7 => UNS
* INC # I6: 8,9 => UNS
* INC # I6: 7,8 => UNS
* INC # I6: 2,9 => UNS
* INC # H1: 7,8 => UNS
* INC # H1: 3,5,6 => UNS
* INC # A9: 1,6 => UNS
* DIS # C9: 1,6 => CTR => C9: 2,4,5,8
* INC # C9: 2,4,5,8 => UNS
* DIS # C1: 1,6 => CTR => C1: 4,5,8,9
* INC # C1: 4,5,8,9 => UNS
* INC # C3: 1,6 => UNS
* DIS # D9: 1,6 => CTR => D9: 2,4,9
* INC # D9: 2,4,9 => UNS
* INC # E9: 1,6 => UNS
* INC # D1: 1,6 => UNS
* INC # D1: 4,5,9 => UNS
* CNT  60 HDP CHAINS /  60 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* PRF # D1: 4,5 => SOL
* STA D1: 4,5
* CNT   1 HDP CHAINS /   1 HYP OPENED