Analysis of xx-top500-443-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 5.3......1..2..........6...4......35.6.7........8...1..2....7......3.2......1.... initial

Autosolve

position: 5.3......1.62........3.61..4......35.6.7........8...17.2....7......372......12... autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # D4: 1,9 => CTR => D4: 6
* PRF # F5: 1,9 => SOL
* DIS # F5: 3,4,5 => CTR => F5: 1,9
* DIS # C4: 1,9 => CTR => C4: 2,7,8
* DIS # F1: 1,9 => CTR => F1: 4,8
* DIS # B9: 4,7,8,9 => CTR => B9: 3,5
* CNT   6 HDP CHAINS /  11 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 # D4: 1,9 => CTR => D4: 6
* PRF D4: 6 # F5: 1,9 => SOL
* STA D4: 6 + F5: 1,9
* CNT   2 HDP CHAINS /   2 HYP OPENED

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

Details

Positions

5.3......1..2..........6...4......35.6.7........8...1..2....7......3.2......1.... initial
5.3......1.62........3.61..4......35.6.7........8...17.2....7......372......12... autosolve
573184962146295378892376154417629835368751429259843617921568743685437291734912586 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (5)
H1: 2,6
I1: 2,6
G2: 3,5
F4: 1,9
G9: 3,5

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
D1,F1: 1.. / D1 = 1  =>  7 pairs (_) / F1 = 1  =>  0 pairs (X)
I7,I8: 1.. / I7 = 1  =>  0 pairs (X) / I8 = 1  =>  0 pairs (_)
C5,F5: 1.. / C5 = 1  =>  0 pairs (X) / F5 = 1  =>  0 pairs (_)
C7,I7: 1.. / C7 = 1  =>  0 pairs (*) / I7 = 1  =>  0 pairs (X)
B4,B8: 1.. / B4 = 1  =>  0 pairs (*) / B8 = 1  =>  0 pairs (X)
D1,D4: 1.. / D1 = 1  =>  7 pairs (_) / D4 = 1  =>  0 pairs (X)
A3,C3: 2.. / A3 = 2  =>  6 pairs (_) / C3 = 2  =>  6 pairs (_)
H1,I1: 2.. / H1 = 2  =>  3 pairs (_) / I1 = 2  =>  3 pairs (_)
E4,E6: 2.. / E4 = 2  =>  5 pairs (_) / E6 = 2  =>  0 pairs (X)
H5,I5: 2.. / H5 = 2  =>  3 pairs (_) / I5 = 2  =>  3 pairs (_)
C4,E4: 2.. / C4 = 2  =>  0 pairs (X) / E4 = 2  =>  5 pairs (_)
A3,A6: 2.. / A3 = 2  =>  6 pairs (_) / A6 = 2  =>  6 pairs (_)
H1,H5: 2.. / H1 = 2  =>  3 pairs (_) / H5 = 2  =>  3 pairs (_)
I1,I5: 2.. / I1 = 2  =>  3 pairs (_) / I5 = 2  =>  3 pairs (_)
G2,I2: 3.. / G2 = 3  =>  5 pairs (_) / I2 = 3  =>  0 pairs (X)
F5,F6: 3.. / F5 = 3  =>  0 pairs (X) / F6 = 3  =>  0 pairs (_)
A5,F5: 3.. / A5 = 3  =>  0 pairs (*) / F5 = 3  =>  0 pairs (X)
A7,I7: 3.. / A7 = 3  =>  0 pairs (X) / I7 = 3  =>  0 pairs (_)
B6,B9: 3.. / B6 = 3  =>  0 pairs (X) / B9 = 3  =>  0 pairs (_)
G2,G9: 3.. / G2 = 3  =>  5 pairs (_) / G9 = 3  =>  0 pairs (X)
E3,H3: 5.. / E3 = 5  =>  0 pairs (X) / H3 = 5  =>  3 pairs (_)
G2,G9: 5.. / G2 = 5  =>  0 pairs (X) / G9 = 5  =>  5 pairs (_)
H1,I1: 6.. / H1 = 6  =>  3 pairs (_) / I1 = 6  =>  3 pairs (_)
G4,G6: 6.. / G4 = 6  =>  0 pairs (X) / G6 = 6  =>  7 pairs (_)
E6,G6: 6.. / E6 = 6  =>  0 pairs (X) / G6 = 6  =>  7 pairs (_)
H2,H3: 7.. / H2 = 7  =>  5 pairs (_) / H3 = 7  =>  0 pairs (X)
B4,C4: 7.. / B4 = 7  =>  0 pairs (X) / C4 = 7  =>  5 pairs (_)
B1,E1: 7.. / B1 = 7  =>  7 pairs (_) / E1 = 7  =>  5 pairs (_)
A3,A9: 7.. / A3 = 7  =>  9 pairs (_) / A9 = 7  =>  5 pairs (_)
E7,F7: 8.. / E7 = 8  =>  0 pairs (X) / F7 = 8  =>  5 pairs (_)
* DURATION: 0:00:48.478559  START: 17:53:46.450296  END: 17:54:34.928855 2017-05-04
* CP COUNT: (30)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (F4,G2,G9,H1,I1)
* 5.3......1.62........3.61..4......35.6.7........8...17.2....7......372......12...
* PAIR F4: 1,9 BLK 5
D4: 1,9,6                                # reduction candidate for 1,9
D4: 1,9 => CTR
* 5.3......1.62.5......3.61..4......35.617.3....358.4.1732....7.1.1..372...5..123..
D4: 6                                    # 10 pairs
F5: 1,9,3,4,5                            # reduction candidate for 1,9
F5: 1,9 => SOLVED
* 573184962146295378892376154417629835368751429259843617921568743685437291734912586
F5: 3,4,5 => CTR
* 5.3......1.62.5......3.61..4......35.617.3....358...1732....7.1.1..372...5..123..
* PAIR F4: 1,9 ROW 4
B4: 1,9,7,8                              # reduction candidate for 1,9
B4: 1,9                                  # 16 pairs
C4: 1,9,2,7,8                            # reduction candidate for 1,9
C4: 1,9 => CTR
* 58317....1.62..573...3561..47.621835.6.7.3....3.8..61732..687.1.1..372...5..123..
C4: 2,7,8                                #  5 pairs
* PAIR F4: 1,9 COL F
F1: 1,9,4,8                              # reduction candidate for 1,9
F1: 1,9 => CTR
* 5.3......1.62........3.61..4......35.617.3....358.4.1732...87.1.1..372...5..123..
F1: 4,8                                  #  8 pairs
* PAIR G9: 3,5 ROW 9
B9: 3,5,4,7,8,9                          # reduction candidate for 3,5
B9: 4,7,8,9 => CTR
* 5.3......1.62........3.61..417.2..35.6.7......3.8...17.2....7...5..372......12...
B9: 3,5                                  #  6 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-443-base-pr-000.dot
* REASONING
* DIS # D4: 1,9 => CTR => D4: 6
* PRF # F5: 1,9 => SOL
* DIS # F5: 3,4,5 => CTR => F5: 1,9
* DIS # C4: 1,9 => CTR => C4: 2,7,8
* DIS # F1: 1,9 => CTR => F1: 4,8
* DIS # B9: 4,7,8,9 => CTR => B9: 3,5
* CNT   6 HDP CHAINS /  11 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (F4,G2,G9,H1,I1)
* 5.3......1.62........3.61..4......35.6.7........8...17.2....7......372......12...
* PAIR F4: 1,9 BLK 5
D4: 1,9,6                                # reduction candidate for 1,9
D4: 1,9 => CTR
* 5.3......1.62.5......3.61..4......35.617.3....358.4.1732....7.1.1..372...5..123..
F5: 1,9,3,5                              # reduction candidate for 1,9
F5: 1,9 => SOLVED
* 573184962146295378892376154417629835368751429259843617921568743685437291734912586
* DURATION: 0:00:03.890067  START: 17:54:45.248859  END: 17:54:49.138926 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-443-base-pr-001.dot
* REASONING
* DIS # D4: 1,9 => CTR => D4: 6
* PRF D4: 6 # F5: 1,9 => SOL
* STA D4: 6 + F5: 1,9
* CNT   2 HDP CHAINS /   2 HYP OPENED

Header Info

Top 500 Minimum 17 443

solution: 573184962146295378892376154417629835368751429259843617921568743685437291734912586
info: 95317    FNBHYK   S8.f     39355

http://www.sfsudoku.com/su17ExtremeDiff500.txt from http://www.minimumsudoku.com/

Solution

position: 573184962146295378892376154417629835368751429259843617921568743685437291734912586 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 # D4: 1,9 => CTR => D4: 6
* INC # D4: 6 => UNS
* PRF # F5: 1,9 => SOL
* DIS # F5: 3,4,5 => CTR => F5: 1,9
* INC # B4: 1,9 => UNS
* DIS # C4: 1,9 => CTR => C4: 2,7,8
* INC # C4: 2,7,8 => UNS
* DIS # F1: 1,9 => CTR => F1: 4,8
* INC # F1: 4,8 => UNS
* INC # B9: 3,5 => UNS
* DIS # B9: 4,7,8,9 => CTR => B9: 3,5
* CNT  11 HDP CHAINS /  11 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # D4: 1,9 => CTR => D4: 6
* PRF D4: 6 # F5: 1,9 => SOL
* STA D4: 6 + F5: 1,9
* CNT   2 HDP CHAINS /   2 HYP OPENED