Analysis of xx-top500-464-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: ...5..48.2.....5..1.........3.7.5......9................9.6...1.....1.6..8..2.... initial

Autosolve

position: ...513482243698517158274....3.7.51...1.9........1.....529.678.1374851269681.29... autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # A6: 7,9 => CTR => A6: 4,8
* PRF # C5: 6,7 => SOL
* DIS # C6: 6,7 => CTR => C6: 2,5
* DIS # G3: 3,9 => CTR => G3: 6
* PRF # G3: 6 => SOL
* DIS # H6: 3,9 => CTR => H6: 2,4,5,7
* PRF # G3: 3,6 => SOL
* DIS # G3: 9 => CTR => G3: 3,6
* DIS # I5: 3,6 => CTR => I5: 4,5,8
* DIS # I6: 3,6 => CTR => I6: 4,5,8
* DIS # C5: 2,6 => CTR => C5: 5,7
* DIS # C6: 2,6 => CTR => C6: 5,7
* DIS # G6: 3,7 => CTR => G6: 6,9
* DIS # A4: 4,8 => CTR => A4: 9
* PRF # A4: 9 => SOL
* DIS # I4: 4,8 => CTR => I4: 6
* PRF # I4: 6 => SOL
* DIS # C5: 2,6 => CTR => C5: 5,7
* DIS # C6: 2,6 => CTR => C6: 5,7
* DIS # H9: 3,4 => CTR => H9: 5,7
* DIS # H9: 3,4 => CTR => H9: 5,7
* DIS # H5: 3,4 => CTR => H5: 2,5,7
* DIS # H6: 3,4 => CTR => H6: 2,5,7,9
* DIS # G6: 3,7 => CTR => G6: 6,9
* CNT  24 HDP CHAINS /  47 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 # A6: 7,9 => CTR => A6: 4,8
* PRF A6: 4,8 # C5: 6,7 => SOL
* STA A6: 4,8 + C5: 6,7
* CNT   2 HDP CHAINS /   2 HYP OPENED

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

Details

Positions

...5..48.2.....5..1.........3.7.5......9................9.6...1.....1.6..8..2.... initial
...513482243698517158274....3.7.51...1.9........1.....529.678.1374851269681.29... autosolve
796513482243698517158274693932785146817946325465132978529467831374851269681329754 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (14)
A1: 7,9
B1: 6,9
C1: 6,7
H3: 3,9
I3: 3,6
C4: 2,6
B6: 6,9
E4: 4,8
F5: 2,6
F6: 2,6
D7: 3,4
D9: 3,4
H7: 3,4
G9: 3,7

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
F5,F6: 2.. / F5 = 2  =>  0 pairs (X) / F6 = 2  => 16 pairs (_)
C4,H4: 2.. / C4 = 2  =>  0 pairs (*) / H4 = 2  =>  0 pairs (X)
E5,E6: 3.. / E5 = 3  => 16 pairs (_) / E6 = 3  => 15 pairs (_)
D7,D9: 3.. / D7 = 3  => 13 pairs (_) / D9 = 3  =>  0 pairs (*)
D7,H7: 3.. / D7 = 3  => 13 pairs (_) / H7 = 3  =>  0 pairs (*)
D7,D9: 4.. / D7 = 4  =>  0 pairs (*) / D9 = 4  =>  0 pairs (X)
D7,H7: 4.. / D7 = 4  =>  0 pairs (*) / H7 = 4  =>  0 pairs (X)
C5,C6: 5.. / C5 = 5  => 14 pairs (_) / C6 = 5  => 14 pairs (_)
H9,I9: 5.. / H9 = 5  => 15 pairs (_) / I9 = 5  => 15 pairs (_)
B1,C1: 6.. / B1 = 6  =>  0 pairs (X) / C1 = 6  =>  0 pairs (_)
G3,I3: 6.. / G3 = 6  =>  0 pairs (*) / I3 = 6  =>  0 pairs (X)
F5,F6: 6.. / F5 = 6  => 16 pairs (_) / F6 = 6  =>  0 pairs (X)
C4,I4: 6.. / C4 = 6  =>  0 pairs (X) / I4 = 6  =>  0 pairs (_)
B1,B6: 6.. / B1 = 6  =>  0 pairs (X) / B6 = 6  =>  0 pairs (_)
A1,C1: 7.. / A1 = 7  =>  0 pairs (*) / C1 = 7  =>  0 pairs (X)
G9,H9: 7.. / G9 = 7  => 14 pairs (_) / H9 = 7  => 13 pairs (_)
A1,B1: 9.. / A1 = 9  =>  0 pairs (X) / B1 = 9  =>  0 pairs (_)
G3,H3: 9.. / G3 = 9  =>  0 pairs (X) / H3 = 9  =>  0 pairs (_)
A4,H4: 9.. / A4 = 9  =>  0 pairs (*) / H4 = 9  =>  0 pairs (X)
B1,B6: 9.. / B1 = 9  =>  0 pairs (*) / B6 = 9  =>  0 pairs (X)
G3,G6: 9.. / G3 = 9  =>  0 pairs (X) / G6 = 9  =>  0 pairs (_)
* DURATION: 0:00:40.439683  START: 18:34:48.165664  END: 18:35:28.605347 2017-05-04
* CP COUNT: (21)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,B1,B6,C1,C4,D7,D9,E4,F5,F6,G9,H3,H7,I3)
* ...513482243698517158274....3.7.51...1.9........1.....529.678.1374851269681.29...
* PAIR A1: 7,9 COL A
A6: 7,9,4,8                              # reduction candidate for 7,9
A6: 7,9 => CTR
* ...513482243698517158274..3.3.7.519..1.9........1.....529.678.1374851269681.29...
A6: 4,8                                  # 15 pairs
* PAIR C1: 6,7 COL C
C5: 6,7,2,5                              # reduction candidate for 6,7
C5: 6,7 => SOLVED
* 796513482243698517158274693932785146817946325465132978529467831374851269681329754
C5: 2,5                                  # 15 pairs
C6: 6,7,2,5                              # reduction candidate for 6,7
C6: 6,7 => CTR
* ...513482243698517158274693932785146.159.6.2886714293.529.678.1374851269681.29...
C6: 2,5                                  # 15 pairs
* PAIR H3: 3,9 BLK 3
G3: 3,9,6                                # reduction candidate for 3,9
G3: 3,9 => CTR
* ...513482243698517158274..6.367.512..1.9......9.1.....529.678.1374851269681.29...
G3: 6 => SOLVED
* 796513482243698517158274693932785146817946325465132978529467831374851269681329754
* PAIR H3: 3,9 COL H
H6: 3,9,2,4,5,7                          # reduction candidate for 3,9
H6: 3,9 => CTR
* ...513482243698517158274...93.7.512..1.9......6.1.....529.678.1374851269681.29...
H6: 2,4,5,7                              # 14 pairs
* PAIR I3: 3,6 BLK 3
G3: 3,6,9                                # reduction candidate for 3,6
G3: 3,6 => SOLVED
* 796513482243698517158274693932785146817946325465132978529467831374851269681329754
G3: 9 => CTR
* ...513482243698517158274936.367.512..1.9......9.1.....529367841374851269681429...
* PAIR I3: 3,6 COL I
I5: 3,6,4,5,8                            # reduction candidate for 3,6
I5: 3,6 => CTR
* ...513482243698517158274....367.512..1.9......9.1.....529.678.1374851269681.29...
I5: 4,5,8                                # 14 pairs
I6: 3,6,4,5,8                            # reduction candidate for 3,6
I6: 3,6 => CTR
* ...513482243698517158274....367.512..1.9......9.1.....529.678.1374851269681.29...
I6: 4,5,8                                # 14 pairs
* PAIR C4: 2,6 BLK 4
C5: 2,6,5,7                              # reduction candidate for 2,6
C5: 2,6 => CTR
* 967513482243698517158274936.3.7.519..1.9......951.....529.678.1374851269681.29...
C5: 5,7                                  # 15 pairs
C6: 2,6,5,7                              # reduction candidate for 2,6
C6: 2,6 => CTR
* 967513482243698517158274936.3.7.519..159......9.1.....529.678.1374851269681.29...
C6: 5,7                                  # 15 pairs
* PAIR B6: 6,9 ROW 6
G6: 6,9,3,7                              # reduction candidate for 6,9
G6: 3,7 => CTR
* ...513482243698517158274936.367.512..1.9..6...9.1.6...529367841374851269681429...
G6: 6,9                                  # 16 pairs
* PAIR E4: 4,8 BLK 5
E5: 4,8,3                                # reduction candidate for 4,8
E5: 4,8                                  # 15 pairs
E6: 4,8,3                                # reduction candidate for 4,8
E6: 4,8                                  # 16 pairs
* PAIR E4: 4,8 ROW 4
A4: 4,8,9                                # reduction candidate for 4,8
A4: 4,8 => CTR
* ...513482243698517158274936.3.7.519..1.9........1.....529.678.1374851269681.29...
A4: 9 => SOLVED
* 796513482243698517158274693932785146817946325465132978529467831374851269681329754
I4: 4,8,6                                # reduction candidate for 4,8
I4: 4,8 => CTR
* ...513482243698517158274....367.512..1.9......9.1.....529.678.1374851269681.29...
I4: 6 => SOLVED
* 796513482243698517158274693932785146817946325465132978529467831374851269681329754
* PAIR F5: 2,6 ROW 5
C5: 2,6,5,7                              # reduction candidate for 2,6
C5: 2,6 => CTR
* 967513482243698517158274936.3.7.519..1.9......951.....529.678.1374851269681.29...
C5: 5,7                                  # 15 pairs
* PAIR F6: 2,6 ROW 6
C6: 2,6,5,7                              # reduction candidate for 2,6
C6: 2,6 => CTR
* 967513482243698517158274936.3.7.519..159......9.1.....529.678.1374851269681.29...
C6: 5,7                                  # 15 pairs
* PAIR D9: 3,4 ROW 9
H9: 3,4,5,7                              # reduction candidate for 3,4
H9: 3,4 => CTR
* ...513482243698517158274.9.93.7.512..1.9......6.1.....529.678.1374851269681.297.5
H9: 5,7                                  # 15 pairs
I9: 3,4,5                                # reduction candidate for 3,4
I9: 3,4                                  # 15 pairs
* PAIR H7: 3,4 BLK 9
H9: 3,4,5,7                              # reduction candidate for 3,4
H9: 3,4 => CTR
* ...513482243698517158274.9.93.7.512..1.9......6.1.....529.678.1374851269681.297.5
H9: 5,7                                  # 15 pairs
I9: 3,4,5                                # reduction candidate for 3,4
I9: 3,4                                  # 15 pairs
* PAIR H7: 3,4 COL H
H5: 3,4,2,5,7                            # reduction candidate for 3,4
H5: 3,4 => CTR
* ...513482243698517158274.9.93.7.512..1.9......6.1.....529.678.1374851269681.29...
H5: 2,5,7                                # 14 pairs
H6: 3,4,2,5,7,9                          # reduction candidate for 3,4
H6: 3,4 => CTR
* ...513482243698517158274.9.93.7.512..1.9......6.1.....529.678.1374851269681.29...
H6: 2,5,7,9                              # 14 pairs
* PAIR G9: 3,7 BLK 9
H9: 3,7,4,5                              # reduction candidate for 3,7
H9: 4,5                                  # 15 pairs
H9: 3,7                                  # 13 pairs
* PAIR G9: 3,7 COL G
G5: 3,7,6                                # reduction candidate for 3,7
G5: 3,7                                  # 16 pairs
G6: 3,7,6,9                              # reduction candidate for 3,7
G6: 3,7 => CTR
* ...513482243698517158274936.367.512..1.9..6...9.1.6...529367841374851269681429...
G6: 6,9                                  # 16 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-464-base-pr-000.dot
* REASONING
* DIS # A6: 7,9 => CTR => A6: 4,8
* PRF # C5: 6,7 => SOL
* DIS # C6: 6,7 => CTR => C6: 2,5
* DIS # G3: 3,9 => CTR => G3: 6
* PRF # G3: 6 => SOL
* DIS # H6: 3,9 => CTR => H6: 2,4,5,7
* PRF # G3: 3,6 => SOL
* DIS # G3: 9 => CTR => G3: 3,6
* DIS # I5: 3,6 => CTR => I5: 4,5,8
* DIS # I6: 3,6 => CTR => I6: 4,5,8
* DIS # C5: 2,6 => CTR => C5: 5,7
* DIS # C6: 2,6 => CTR => C6: 5,7
* DIS # G6: 3,7 => CTR => G6: 6,9
* DIS # A4: 4,8 => CTR => A4: 9
* PRF # A4: 9 => SOL
* DIS # I4: 4,8 => CTR => I4: 6
* PRF # I4: 6 => SOL
* DIS # C5: 2,6 => CTR => C5: 5,7
* DIS # C6: 2,6 => CTR => C6: 5,7
* DIS # H9: 3,4 => CTR => H9: 5,7
* DIS # H9: 3,4 => CTR => H9: 5,7
* DIS # H5: 3,4 => CTR => H5: 2,5,7
* DIS # H6: 3,4 => CTR => H6: 2,5,7,9
* DIS # G6: 3,7 => CTR => G6: 6,9
* CNT  24 HDP CHAINS /  47 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,B1,B6,C1,C4,D7,D9,E4,F5,F6,G9,H3,H7,I3)
* ...513482243698517158274....3.7.51...1.9........1.....529.678.1374851269681.29...
* PAIR A1: 7,9 COL A
A6: 7,9,4,8                              # reduction candidate for 7,9
A6: 7,9 => CTR
* ...513482243698517158274..3.3.7.519..1.9........1.....529.678.1374851269681.29...
* PAIR RESTART
* PAIR C1: 6,7 COL C
C5: 6,7,2,5                              # reduction candidate for 6,7
C5: 6,7 => SOLVED
* 796513482243698517158274693932785146817946325465132978529467831374851269681329754
* DURATION: 0:00:04.332000  START: 18:36:17.272955  END: 18:36:21.604955 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-464-base-pr-001.dot
* REASONING
* DIS # A6: 7,9 => CTR => A6: 4,8
* PRF A6: 4,8 # C5: 6,7 => SOL
* STA A6: 4,8 + C5: 6,7
* CNT   2 HDP CHAINS /   2 HYP OPENED

Header Info

Top 500 Minimum 17 464

solution: 796513482243698517158274693932785146817946325465132978529467831374851269681329754
info: 95546    FNBTYK   S8.f     41846

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

Solution

position: 796513482243698517158274693932785146817946325465132978529467831374851269681329754 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 # A6: 7,9 => CTR => A6: 4,8
* INC # A6: 4,8 => UNS
* PRF # C5: 6,7 => SOL
* INC # C5: 2,5 => UNS
* DIS # C6: 6,7 => CTR => C6: 2,5
* INC # C6: 2,5 => UNS
* DIS # G3: 3,9 => CTR => G3: 6
* PRF # G3: 6 => SOL
* DIS # H6: 3,9 => CTR => H6: 2,4,5,7
* INC # H6: 2,4,5,7 => UNS
* PRF # G3: 3,6 => SOL
* DIS # G3: 9 => CTR => G3: 3,6
* DIS # I5: 3,6 => CTR => I5: 4,5,8
* INC # I5: 4,5,8 => UNS
* DIS # I6: 3,6 => CTR => I6: 4,5,8
* INC # I6: 4,5,8 => UNS
* DIS # C5: 2,6 => CTR => C5: 5,7
* INC # C5: 5,7 => UNS
* DIS # C6: 2,6 => CTR => C6: 5,7
* INC # C6: 5,7 => UNS
* INC # G6: 6,9 => UNS
* DIS # G6: 3,7 => CTR => G6: 6,9
* INC # E5: 4,8 => UNS
* INC # E6: 4,8 => UNS
* DIS # A4: 4,8 => CTR => A4: 9
* PRF # A4: 9 => SOL
* DIS # I4: 4,8 => CTR => I4: 6
* PRF # I4: 6 => SOL
* DIS # C5: 2,6 => CTR => C5: 5,7
* INC # C5: 5,7 => UNS
* DIS # C6: 2,6 => CTR => C6: 5,7
* INC # C6: 5,7 => UNS
* DIS # H9: 3,4 => CTR => H9: 5,7
* INC # H9: 5,7 => UNS
* INC # I9: 3,4 => UNS
* DIS # H9: 3,4 => CTR => H9: 5,7
* INC # H9: 5,7 => UNS
* INC # I9: 3,4 => UNS
* DIS # H5: 3,4 => CTR => H5: 2,5,7
* INC # H5: 2,5,7 => UNS
* DIS # H6: 3,4 => CTR => H6: 2,5,7,9
* INC # H6: 2,5,7,9 => UNS
* INC # H9: 3,7 => UNS
* INC # H9: 4,5 => UNS
* INC # G5: 3,7 => UNS
* DIS # G6: 3,7 => CTR => G6: 6,9
* INC # G6: 6,9 => UNS
* CNT  47 HDP CHAINS /  47 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # A6: 7,9 => CTR => A6: 4,8
* PRF A6: 4,8 # C5: 6,7 => SOL
* STA A6: 4,8 + C5: 6,7
* CNT   2 HDP CHAINS /   2 HYP OPENED