Analysis of xx-top95-010-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: .923.........8.1...........1.7.4...........658.........6.5.2...4.....7.....9..... initial

Autosolve

position: .92351.......8.1.....42....1.7.4...........658.629.....6.5.2...4.....7.....9.4... autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # A2: 6,7 => CTR => A2: 3,5
* PRF # A3: 6,7 => SOL
* DIS # I1: 6,7 => CTR => I1: 4,8
* DIS # B9: 1,8 => CTR => B9: 2,3,7
* PRF # B9: 2,3,7 => SOL
* PRF # F2: 6,7 => SOL
* DIS # A2: 6,7 => CTR => A2: 3,5
* DIS # I2: 6,7 => CTR => I2: 2,3,9
* PRF # I1: 6,8 => SOL
* DIS # G9: 6,8 => CTR => G9: 2,3,5
* PRF # F4: 6,8 => SOL
* DIS # F4: 3,5 => CTR => F4: 6,8
* DIS # E7: 1,3 => CTR => E7: 7
* DIS # E8: 1,3 => CTR => E8: 6
* DIS # F4: 3,5 => CTR => F4: 6,8
* PRF # F4: 6,8 => SOL
* DIS # B6: 4 => CTR => B6: 3,5
* DIS # G5: 3,4 => CTR => G5: 2,8
* DIS # B6: 5 => CTR => B6: 3,4
* PRF # D5: 1,8 => SOL
* DIS # D5: 7 => CTR => D5: 1,8
* PRF # F4: 3,8 => SOL
* DIS # F5: 3,8 => CTR => F5: 7
* PRF # F5: 7 => SOL
* CNT  24 HDP CHAINS /  42 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 # A2: 6,7 => CTR => A2: 3,5
* PRF A2: 3,5 # A3: 6,7 => SOL
* STA A2: 3,5 + A3: 6,7
* CNT   2 HDP CHAINS /   2 HYP OPENED

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

Details

Positions

.923.........8.1...........1.7.4...........658.........6.5.2...4.....7.....9..... initial
.92351.......8.1.....42....1.7.4...........658.629.....6.5.2...4.....7.....9.4... autosolve
792351648543786129681429537157648293924137865836295471368572914419863752275914386 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (13)
A1: 6,7
B3: 1,8
C3: 1,8
D2: 6,7
G1: 6,8
D4: 6,8
E5: 1,3
F6: 3,5
G6: 3,4
H6: 1,7
I6: 1,7
D8: 1,8
F8: 3,8

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
B3,C3: 1.. / B3 = 1  =>  0 pairs (X) / C3 = 1  => 11 pairs (_)
D5,E5: 1.. / D5 = 1  =>  0 pairs (*) / E5 = 1  =>  0 pairs (X)
H6,I6: 1.. / H6 = 1  => 11 pairs (_) / I6 = 1  => 12 pairs (_)
D5,D8: 1.. / D5 = 1  =>  0 pairs (*) / D8 = 1  =>  0 pairs (X)
H2,I2: 2.. / H2 = 2  => 13 pairs (_) / I2 = 2  => 13 pairs (_)
A5,A9: 2.. / A5 = 2  =>  0 pairs (X) / A9 = 2  => 18 pairs (_)
B2,C2: 4.. / B2 = 4  =>  0 pairs (*) / C2 = 4  =>  0 pairs (X)
H1,I1: 4.. / H1 = 4  => 13 pairs (_) / I1 = 4  => 14 pairs (_)
G5,G6: 4.. / G5 = 4  =>  0 pairs (X) / G6 = 4  => 13 pairs (_)
H7,I7: 4.. / H7 = 4  => 14 pairs (_) / I7 = 4  => 13 pairs (_)
B6,G6: 4.. / B6 = 4  =>  0 pairs (X) / G6 = 4  => 13 pairs (_)
C2,C5: 4.. / C2 = 4  => 15 pairs (_) / C5 = 4  =>  0 pairs (*)
H1,H7: 4.. / H1 = 4  => 13 pairs (_) / H7 = 4  => 14 pairs (_)
I1,I7: 4.. / I1 = 4  => 14 pairs (_) / I7 = 4  => 13 pairs (_)
B4,B6: 5.. / B4 = 5  => 13 pairs (_) / B6 = 5  =>  0 pairs (X)
F4,F6: 5.. / F4 = 5  =>  0 pairs (X) / F6 = 5  => 13 pairs (_)
B4,F4: 5.. / B4 = 5  => 13 pairs (_) / F4 = 5  =>  0 pairs (X)
B6,F6: 5.. / B6 = 5  =>  0 pairs (X) / F6 = 5  => 13 pairs (_)
C8,H8: 5.. / C8 = 5  => 15 pairs (_) / H8 = 5  => 13 pairs (_)
G3,G9: 5.. / G3 = 5  => 13 pairs (_) / G9 = 5  => 15 pairs (_)
D4,F4: 6.. / D4 = 6  =>  0 pairs (*) / F4 = 6  =>  0 pairs (X)
E8,E9: 6.. / E8 = 6  => 13 pairs (_) / E9 = 6  =>  0 pairs (X)
E8,I8: 6.. / E8 = 6  => 13 pairs (_) / I8 = 6  =>  0 pairs (X)
D2,D4: 6.. / D2 = 6  =>  0 pairs (X) / D4 = 6  =>  0 pairs (_)
D5,F5: 7.. / D5 = 7  =>  0 pairs (X) / F5 = 7  =>  0 pairs (_)
H6,I6: 7.. / H6 = 7  => 12 pairs (_) / I6 = 7  => 11 pairs (_)
E7,E9: 7.. / E7 = 7  => 14 pairs (_) / E9 = 7  =>  0 pairs (X)
A7,E7: 7.. / A7 = 7  =>  0 pairs (X) / E7 = 7  => 14 pairs (_)
B2,B9: 7.. / B2 = 7  =>  0 pairs (X) / B9 = 7  =>  0 pairs (_)
D2,D5: 7.. / D2 = 7  =>  0 pairs (*) / D5 = 7  =>  0 pairs (X)
B3,C3: 8.. / B3 = 8  => 11 pairs (_) / C3 = 8  =>  0 pairs (X)
D8,F8: 8.. / D8 = 8  =>  0 pairs (*) / F8 = 8  =>  0 pairs (X)
B3,B9: 8.. / B3 = 8  => 11 pairs (_) / B9 = 8  =>  0 pairs (X)
F2,F3: 9.. / F2 = 9  => 14 pairs (_) / F3 = 9  =>  0 pairs (*)
A5,C5: 9.. / A5 = 9  => 19 pairs (_) / C5 = 9  => 18 pairs (_)
A5,A7: 9.. / A5 = 9  => 19 pairs (_) / A7 = 9  => 18 pairs (_)
* DURATION: 0:01:04.296412  START: 23:02:02.045038  END: 23:03:06.341450 2017-05-03
* CP COUNT: (36)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,B3,C3,D2,D4,D8,E5,F6,F8,G1,G6,H6,I6)
* .92351.......8.1.....42....1.7.4...........658.629.....6.5.2...4.....7.....9.4...
* PAIR A1: 6,7 BLK 1
A2: 6,7,3,5                              # reduction candidate for 6,7
A2: 6,7 => CTR
* .92351.......891..58142....1.764.......1378658.62954..36.5729..419863752275914...
A2: 3,5                                  # 14 pairs
A3: 6,7,3,5                              # reduction candidate for 6,7
A3: 6,7 => SOLVED
* 792351648543786129681429537157648293924137865836295471368572914419863752275914386
A3: 3,5                                  # 14 pairs
* PAIR A1: 6,7 ROW 1
I1: 6,7,4,8                              # reduction candidate for 6,7
I1: 6,7 => CTR
* .9235184....78.1...8142....1.764.......817.658.629.....6.572.1441...87...7.9.4...
I1: 4,8                                  # 14 pairs
* PAIR B3: 1,8 COL B
B9: 1,8,2,3,7                            # reduction candidate for 1,8
B9: 1,8 => CTR
* .92351....746891.....427...1.7846......7138658.62954...6.5.2...4..1.87.....9.4...
B9: 2,3,7 => SOLVED
* 792351648543786129681429537157648293924137865836295471368572914419863752275914386
* PAIR C3: 1,8 COL C
C7: 1,8,3,9                              # reduction candidate for 1,8
C7: 1,8                                  # 15 pairs
C9: 1,8,3,5                              # reduction candidate for 1,8
C9: 1,8                                  # 15 pairs
* PAIR D2: 6,7 BLK 2
F2: 6,7,9                                # reduction candidate for 6,7
F2: 6,7 => SOLVED
* 792351648543786129681429537157648293924137865836295471368572914419863752275914386
F2: 9                                    # 14 pairs
F3: 6,7,9                                # reduction candidate for 6,7
F3: 6,7                                  # 14 pairs
* PAIR D2: 6,7 ROW 2
A2: 6,7,3,5                              # reduction candidate for 6,7
A2: 6,7 => CTR
* .92351.......891..58142....1.764.......1378658.62954..36.5729..419863752275914...
A2: 3,5                                  # 14 pairs
I2: 6,7,2,3,9                            # reduction candidate for 6,7
I2: 6,7 => CTR
* .923516..5.3.8912..8142....1.764.......1378658.62954..36.5729..419863752275914...
I2: 2,3,9                                # 13 pairs
* PAIR G1: 6,8 BLK 3
I1: 6,8,4,7                              # reduction candidate for 6,8
I1: 6,8 => SOLVED
* 792351648543786129681429537157648293924137865836295471368572914419863752275914386
I1: 4,7                                  # 14 pairs
* PAIR G1: 6,8 COL G
G9: 6,8,2,3,5                            # reduction candidate for 6,8
G9: 6,8 => CTR
* .92351......78.1...8142.5..1.764.......817.658.629.....6.572...41...87...7.9.4...
G9: 2,3,5                                # 13 pairs
* PAIR D4: 6,8 BLK 5
F4: 6,8,3,5                              # reduction candidate for 6,8
F4: 6,8 => SOLVED
* 792351648543786129681429537157648293924137865836295471368572914419863752275914386
F4: 3,5 => CTR
* .92351......78.1...8142....1.764.......817.658.629.....6.572...41...87...7.9.4...
* PAIR E5: 1,3 COL E
E7: 1,3,7                                # reduction candidate for 1,3
E7: 1,3 => CTR
* 6923518...746891.....427...1.7846...9.3....658.629....76.5.2...4.....7.....974...
E7: 7                                    # 14 pairs
E8: 1,3,6                                # reduction candidate for 1,3
E8: 1,3 => CTR
* .92351....746891.....427...1.7846...2.97138658.62954..96.5723..4251387967.3964...
E8: 6                                    # 13 pairs
E9: 1,3,6,7                              # reduction candidate for 1,3
E9: 1,3                                  # 15 pairs
* PAIR F6: 3,5 BLK 5
F4: 3,5,6,8                              # reduction candidate for 3,5
F4: 3,5 => CTR
* .92351......78.1...8142....1.764.......817.658.629.....6.572...41...87...7.9.4...
F4: 6,8 => SOLVED
* 792351648543786129681429537157648293924137865836295471368572914419863752275914386
* PAIR F6: 3,5 ROW 6
B6: 3,5,4                                # reduction candidate for 3,5
B6: 4 => CTR
* .92351.....478.1.....42....157643......8174658462953...6.5.2...4..1.87...7.9.4...
B6: 3,5                                  # 13 pairs
* PAIR G6: 3,4 BLK 6
G5: 3,4,2,8                              # reduction candidate for 3,4
G5: 3,4 => CTR
* .92351......78.1...8142....1.764.......817.658.629.....6.572...41...87...7.9.4...
G5: 2,8                                  # 15 pairs
* PAIR G6: 3,4 ROW 6
B6: 3,4,5                                # reduction candidate for 3,4
B6: 5 => CTR
* .92351......78.1.....42....1.7645......817.658562934...6.5.2...4..1.87...7.9.4...
B6: 3,4                                  # 13 pairs
* PAIR D8: 1,8 COL D
D5: 1,8,7                                # reduction candidate for 1,8
D5: 1,8 => SOLVED
* 792351648543786129681429537157648293924137865836295471368572914419863752275914386
D5: 7 => CTR
* 7923516...4.68.1..6..42....157846......7138658362954...6.5.2...42.1.87.....9.4...
* PAIR F8: 3,8 COL F
F4: 3,8,5,6                              # reduction candidate for 3,8
F4: 3,8 => SOLVED
* 792351648543786129681429537157648293924137865836295471368572914419863752275914386
F4: 5,6                                  # 14 pairs
F5: 3,8,7                                # reduction candidate for 3,8
F5: 3,8 => CTR
* 7923516...4.68.1..6..42....157846......7138658362954...6.5.2...42.1.87.....9.4...
F5: 7 => SOLVED
* 792351648543786129681429537157648293924137865836295471368572914419863752275914386
* INCONCLUSIVE
* SAVE PR GRAPH xx-top95-010-base-pr-000.dot
* REASONING
* DIS # A2: 6,7 => CTR => A2: 3,5
* PRF # A3: 6,7 => SOL
* DIS # I1: 6,7 => CTR => I1: 4,8
* DIS # B9: 1,8 => CTR => B9: 2,3,7
* PRF # B9: 2,3,7 => SOL
* PRF # F2: 6,7 => SOL
* DIS # A2: 6,7 => CTR => A2: 3,5
* DIS # I2: 6,7 => CTR => I2: 2,3,9
* PRF # I1: 6,8 => SOL
* DIS # G9: 6,8 => CTR => G9: 2,3,5
* PRF # F4: 6,8 => SOL
* DIS # F4: 3,5 => CTR => F4: 6,8
* DIS # E7: 1,3 => CTR => E7: 7
* DIS # E8: 1,3 => CTR => E8: 6
* DIS # F4: 3,5 => CTR => F4: 6,8
* PRF # F4: 6,8 => SOL
* DIS # B6: 4 => CTR => B6: 3,5
* DIS # G5: 3,4 => CTR => G5: 2,8
* DIS # B6: 5 => CTR => B6: 3,4
* PRF # D5: 1,8 => SOL
* DIS # D5: 7 => CTR => D5: 1,8
* PRF # F4: 3,8 => SOL
* DIS # F5: 3,8 => CTR => F5: 7
* PRF # F5: 7 => SOL
* CNT  24 HDP CHAINS /  42 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,B3,C3,D2,D4,D8,E5,F6,F8,G1,G6,H6,I6)
* .92351.......8.1.....42....1.7.4...........658.629.....6.5.2...4.....7.....9.4...
* PAIR A1: 6,7 BLK 1
A2: 6,7,3,5                              # reduction candidate for 6,7
A2: 6,7 => CTR
* .92351.......891..58142....1.764.......1378658.62954..36.5729..419863752275914...
A3: 6,7,3,5                              # reduction candidate for 6,7
A3: 6,7 => SOLVED
* 792351648543786129681429537157648293924137865836295471368572914419863752275914386
* DURATION: 0:00:04.085078  START: 23:03:52.670610  END: 23:03:56.755688 2017-05-03
* SOLUTION FOUND
* SAVE PR GRAPH xx-top95-010-base-pr-001.dot
* REASONING
* DIS # A2: 6,7 => CTR => A2: 3,5
* PRF A2: 3,5 # A3: 6,7 => SOL
* STA A2: 3,5 + A3: 6,7
* CNT   2 HDP CHAINS /   2 HYP OPENED

Header Info

Top 95 Sudokus 010
[sudoku:top95] “95 Hard Puzzles”, http://magictour.free.fr/top95, or http://norvig.com/top95.txt

Solution

position: 792351648543786129681429537157648293924137865836295471368572914419863752275914386 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:

* DIS # A2: 6,7 => CTR => A2: 3,5
* INC # A2: 3,5 => UNS
* PRF # A3: 6,7 => SOL
* INC # A3: 3,5 => UNS
* DIS # I1: 6,7 => CTR => I1: 4,8
* INC # I1: 4,8 => UNS
* DIS # B9: 1,8 => CTR => B9: 2,3,7
* PRF # B9: 2,3,7 => SOL
* INC # C7: 1,8 => UNS
* INC # C9: 1,8 => UNS
* PRF # F2: 6,7 => SOL
* INC # F2: 9 => UNS
* INC # F3: 6,7 => UNS
* DIS # A2: 6,7 => CTR => A2: 3,5
* INC # A2: 3,5 => UNS
* DIS # I2: 6,7 => CTR => I2: 2,3,9
* INC # I2: 2,3,9 => UNS
* PRF # I1: 6,8 => SOL
* INC # I1: 4,7 => UNS
* DIS # G9: 6,8 => CTR => G9: 2,3,5
* INC # G9: 2,3,5 => UNS
* PRF # F4: 6,8 => SOL
* DIS # F4: 3,5 => CTR => F4: 6,8
* DIS # E7: 1,3 => CTR => E7: 7
* INC # E7: 7 => UNS
* DIS # E8: 1,3 => CTR => E8: 6
* INC # E8: 6 => UNS
* INC # E9: 1,3 => UNS
* DIS # F4: 3,5 => CTR => F4: 6,8
* PRF # F4: 6,8 => SOL
* INC # B6: 3,5 => UNS
* DIS # B6: 4 => CTR => B6: 3,5
* DIS # G5: 3,4 => CTR => G5: 2,8
* INC # G5: 2,8 => UNS
* INC # B6: 3,4 => UNS
* DIS # B6: 5 => CTR => B6: 3,4
* PRF # D5: 1,8 => SOL
* DIS # D5: 7 => CTR => D5: 1,8
* PRF # F4: 3,8 => SOL
* INC # F4: 5,6 => UNS
* DIS # F5: 3,8 => CTR => F5: 7
* PRF # F5: 7 => SOL
* CNT  42 HDP CHAINS /  42 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # A2: 6,7 => CTR => A2: 3,5
* PRF A2: 3,5 # A3: 6,7 => SOL
* STA A2: 3,5 + A3: 6,7
* CNT   2 HDP CHAINS /   2 HYP OPENED