Analysis of xx-top500-271-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 46.8........2..1....3....9.27...........9.3......1....5..7....2.......4...1...... initial

Autosolve

position: 4698.127.8572.91.4123.7..9827.38.9.161..9.3..93..1.4..5967438123821..749741928... autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # I9: 3,5 => SOL
* DIS # I9: 6 => CTR => I9: 3,5
* PRF # H9: 3,6 => SOL
* DIS # H9: 5 => CTR => H9: 3,6
* DIS # F3: 5,6 => CTR => F3: 4
* DIS # C5: 8 => CTR => C5: 4,5
* DIS # F4: 4,5 => CTR => F4: 6
* PRF # F4: 6 => SOL
* DIS # C5: 4 => CTR => C5: 5,8
* DIS # F4: 4,5 => CTR => F4: 6
* PRF # F4: 6 => SOL
* DIS # C5: 8 => CTR => C5: 4,5
* DIS # D3: 4,5 => CTR => D3: 6
* PRF # D3: 6 => SOL
* DIS # F4: 4 => CTR => F4: 5,6
* DIS # I6: 7 => CTR => I6: 5,6
* DIS # D3: 4 => CTR => D3: 5,6
* DIS # I6: 7 => CTR => I6: 5,6
* DIS # F4: 4 => CTR => F4: 5,6
* DIS # H9: 5,6 => CTR => H9: 3
* PRF # H9: 3 => SOL
* DIS # I6: 5,7 => CTR => I6: 6
* PRF # I6: 6 => SOL
* DIS # F3: 5,6 => CTR => F3: 4
* DIS # H9: 5,6 => CTR => H9: 3
* PRF # H9: 3 => SOL
* PRF # I9: 5,6 => SOL
* DIS # I9: 3 => CTR => I9: 5,6
* CNT  28 HDP CHAINS /  40 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 # I9: 3,5 => SOL
* STA I9: 3,5
* CNT   1 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

46.8........2..1....3....9.27...........9.3......1....5..7....2.......4...1...... initial
4698.127.8572.91.4123.7..9827.38.9.161..9.3..93..1.4..5967438123821..749741928... autosolve
469851273857239164123674598274386951615492387938517426596743812382165749741928635 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (18)
E1: 3,5
E2: 3,6
I1: 3,5
H2: 3,6
G3: 5,6
C4: 4,5
C6: 5,8
D5: 4,5
F5: 2,7
D6: 5,6
F6: 2,7
H4: 5,6
H5: 2,8
I5: 5,7
H6: 2,8
E8: 5,6
F8: 5,6
G9: 5,6

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
F5,F6: 2.. / F5 = 2  => 14 pairs (_) / F6 = 2  =>  0 pairs (X)
H5,H6: 2.. / H5 = 2  =>  0 pairs (X) / H6 = 2  => 14 pairs (_)
F5,H5: 2.. / F5 = 2  => 14 pairs (_) / H5 = 2  =>  0 pairs (X)
F6,H6: 2.. / F6 = 2  =>  0 pairs (X) / H6 = 2  => 14 pairs (_)
E1,E2: 3.. / E1 = 3  =>  0 pairs (X) / E2 = 3  =>  0 pairs (_)
I1,H2: 3.. / I1 = 3  =>  0 pairs (*) / H2 = 3  =>  0 pairs (X)
H9,I9: 3.. / H9 = 3  =>  0 pairs (*) / I9 = 3  =>  0 pairs (X)
E1,I1: 3.. / E1 = 3  =>  0 pairs (X) / I1 = 3  =>  0 pairs (_)
E2,H2: 3.. / E2 = 3  =>  0 pairs (*) / H2 = 3  =>  0 pairs (X)
H2,H9: 3.. / H2 = 3  =>  0 pairs (X) / H9 = 3  =>  0 pairs (_)
I1,I9: 3.. / I1 = 3  =>  0 pairs (*) / I9 = 3  =>  0 pairs (X)
D3,F3: 4.. / D3 = 4  =>  0 pairs (X) / F3 = 4  => 19 pairs (_)
C4,C5: 4.. / C4 = 4  => 19 pairs (_) / C5 = 4  =>  0 pairs (X)
F4,D5: 4.. / F4 = 4  =>  0 pairs (X) / D5 = 4  => 19 pairs (_)
C4,F4: 4.. / C4 = 4  => 19 pairs (_) / F4 = 4  =>  0 pairs (X)
C5,D5: 4.. / C5 = 4  =>  0 pairs (X) / D5 = 4  => 19 pairs (_)
D3,D5: 4.. / D3 = 4  =>  0 pairs (X) / D5 = 4  => 19 pairs (_)
F3,F4: 4.. / F3 = 4  => 19 pairs (_) / F4 = 4  =>  0 pairs (X)
I1,G3: 5.. / I1 = 5  =>  0 pairs (X) / G3 = 5  =>  0 pairs (_)
E8,F8: 5.. / E8 = 5  =>  0 pairs (X) / F8 = 5  =>  0 pairs (_)
E1,I1: 5.. / E1 = 5  =>  0 pairs (*) / I1 = 5  =>  0 pairs (X)
E1,E8: 5.. / E1 = 5  =>  0 pairs (*) / E8 = 5  =>  0 pairs (X)
G3,G9: 5.. / G3 = 5  =>  0 pairs (*) / G9 = 5  =>  0 pairs (X)
H4,H9: 5.. / H4 = 5  =>  0 pairs (*) / H9 = 5  =>  0 pairs (X)
H2,G3: 6.. / H2 = 6  =>  0 pairs (*) / G3 = 6  =>  0 pairs (X)
F4,D6: 6.. / F4 = 6  =>  0 pairs (*) / D6 = 6  =>  0 pairs (X)
H4,I6: 6.. / H4 = 6  =>  0 pairs (X) / I6 = 6  =>  0 pairs (_)
E8,F8: 6.. / E8 = 6  =>  0 pairs (*) / F8 = 6  =>  0 pairs (X)
E2,H2: 6.. / E2 = 6  =>  0 pairs (X) / H2 = 6  =>  0 pairs (_)
F4,H4: 6.. / F4 = 6  =>  0 pairs (*) / H4 = 6  =>  0 pairs (X)
D6,I6: 6.. / D6 = 6  =>  0 pairs (X) / I6 = 6  =>  0 pairs (_)
D3,D6: 6.. / D3 = 6  =>  0 pairs (*) / D6 = 6  =>  0 pairs (X)
E2,E8: 6.. / E2 = 6  =>  0 pairs (X) / E8 = 6  =>  0 pairs (_)
G3,G9: 6.. / G3 = 6  =>  0 pairs (X) / G9 = 6  =>  0 pairs (_)
I6,I9: 6.. / I6 = 6  =>  0 pairs (*) / I9 = 6  =>  0 pairs (X)
F5,F6: 7.. / F5 = 7  =>  0 pairs (X) / F6 = 7  => 14 pairs (_)
I5,I6: 7.. / I5 = 7  => 14 pairs (_) / I6 = 7  =>  0 pairs (X)
F5,I5: 7.. / F5 = 7  =>  0 pairs (X) / I5 = 7  => 14 pairs (_)
F6,I6: 7.. / F6 = 7  => 14 pairs (_) / I6 = 7  =>  0 pairs (X)
C5,C6: 8.. / C5 = 8  =>  0 pairs (X) / C6 = 8  => 14 pairs (_)
H5,H6: 8.. / H5 = 8  => 14 pairs (_) / H6 = 8  =>  0 pairs (X)
C5,H5: 8.. / C5 = 8  =>  0 pairs (X) / H5 = 8  => 14 pairs (_)
C6,H6: 8.. / C6 = 8  => 14 pairs (_) / H6 = 8  =>  0 pairs (X)
* DURATION: 0:01:21.683869  START: 12:10:21.197647  END: 12:11:42.881516 2017-05-04
* CP COUNT: (43)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (C4,C6,D5,D6,E1,E2,E8,F5,F6,F8,G3,G9,H2,H4,H5,H6,I1,I5)
* 4698.127.8572.91.4123.7..9827.38.9.161..9.3..93..1.4..5967438123821..749741928...
* PAIR I1: 3,5 COL I
I9: 3,5,6                                # reduction candidate for 3,5
I9: 3,5 => SOLVED
* 469851273857239164123674598274386951615492387938517426596743812382165749741928635
I9: 6 => CTR
* 4698.1273857239164123.7.59827.38695161..9.3..93..1.4..5967438123821..749741928...
* PAIR H2: 3,6 COL H
H9: 3,6,5                                # reduction candidate for 3,6
H9: 3,6 => SOLVED
* 469851273857239164123674598274386951615492387938517426596743812382165749741928635
H9: 5 => CTR
* 4698.127.8572.9134123.7.69827.38.96161..9.3..93.61.4..5967438123821.67497419285..
* PAIR G3: 5,6 ROW 3
D3: 5,6,4                                # reduction candidate for 5,6
D3: 5,6                                  # 19 pairs
F3: 5,6,4                                # reduction candidate for 5,6
F3: 5,6 => CTR
* 4698.127.8572.91.412347..9827.38496161459.3879386174255967438123821..749741928.5.
F3: 4                                    # 19 pairs
* PAIR C4: 4,5 BLK 4
C5: 4,5,8                                # reduction candidate for 4,5
C5: 8 => CTR
* 4698.127.8572.91.4123.7..9827438.9.161849.3259356124875967438123821..749741928.5.
C5: 4,5                                  # 14 pairs
* PAIR C4: 4,5 ROW 4
F4: 4,5,6                                # reduction candidate for 4,5
F4: 4,5 => CTR
* 4698.127.8572.91.4123.7..9827.38.96161..9.3..93.61.4..5967438123821..749741928.5.
F4: 6 => SOLVED
* 469851273857239164123674598274386951615492387938517426596743812382165749741928635
* PAIR C6: 5,8 BLK 4
C5: 5,8,4                                # reduction candidate for 5,8
C5: 4 => CTR
* 4698.127.8572.91.4123.7..9827.38.9.161459.3879386174255967438123821..749741928.5.
C5: 5,8                                  # 19 pairs
* PAIR D5: 4,5 BLK 5
F4: 4,5,6                                # reduction candidate for 4,5
F4: 4,5 => CTR
* 4698.127.8572.91.4123.7..9827.38.96161..9.3..93.61.4..5967438123821..749741928.5.
F4: 6 => SOLVED
* 469851273857239164123674598274386951615492387938517426596743812382165749741928635
* PAIR D5: 4,5 ROW 5
C5: 4,5,8                                # reduction candidate for 4,5
C5: 8 => CTR
* 4698.127.8572.91.4123.7..9827438.9.161849.3259356124875967438123821..749741928.5.
C5: 4,5                                  # 14 pairs
* PAIR D5: 4,5 COL D
D3: 4,5,6                                # reduction candidate for 4,5
D3: 4,5 => CTR
* 4698.1273857239164123.7..9827.38.9.161..9.3..93.61.4..5967438123821..749741928..6
D3: 6 => SOLVED
* 469851273857239164123674598274386951615492387938517426596743812382165749741928635
* PAIR D6: 5,6 BLK 5
F4: 5,6,4                                # reduction candidate for 5,6
F4: 4 => CTR
* 4698.127.8572.91.4123.7..9827.38496161459.3879386174255967438123821..749741928.5.
F4: 5,6                                  # 19 pairs
* PAIR D6: 5,6 ROW 6
I6: 5,6,7                                # reduction candidate for 5,6
I6: 7 => CTR
* 4698.127.8572.91.4123.7..9827.38.96161..9.3.593.61.4.75967438123821..749741928.5.
I6: 5,6                                  # 14 pairs
* PAIR D6: 5,6 COL D
D3: 5,6,4                                # reduction candidate for 5,6
D3: 4 => CTR
* 4698.127.8572.91.412347..9827.38496161459.3879386174255967438123821..749741928.5.
D3: 5,6                                  # 19 pairs
* PAIR H4: 5,6 BLK 6
I6: 5,6,7                                # reduction candidate for 5,6
I6: 7 => CTR
* 4698.127.8572.91.4123.7..9827.38.96161..9.3.593.61.4.75967438123821..749741928.5.
I6: 5,6                                  # 14 pairs
* PAIR H4: 5,6 ROW 4
F4: 5,6,4                                # reduction candidate for 5,6
F4: 4 => CTR
* 4698.127.8572.91.4123.7..9827.38496161459.3879386174255967438123821..749741928.5.
F4: 5,6                                  # 19 pairs
* PAIR H4: 5,6 COL H
H9: 5,6,3                                # reduction candidate for 5,6
H9: 5,6 => CTR
* 4698.127.8572.9134123.7.69827.38.9.161..9.3..93.61.4..5967438123821.67497419285..
H9: 3 => SOLVED
* 469851273857239164123674598274386951615492387938517426596743812382165749741928635
* PAIR I5: 5,7 BLK 6
I6: 5,7,6                                # reduction candidate for 5,7
I6: 5,7 => CTR
* 4698.127.8572.91.4123.7..9827.38.96161..9.3..93.61.4..5967438123821..749741928.5.
I6: 6 => SOLVED
* 469851273857239164123674598274386951615492387938517426596743812382165749741928635
* PAIR F8: 5,6 COL F
F3: 5,6,4                                # reduction candidate for 5,6
F3: 5,6 => CTR
* 4698.127.8572.91.412347..9827.38496161459.3879386174255967438123821..749741928.5.
F3: 4                                    # 19 pairs
F4: 5,6,4                                # reduction candidate for 5,6
F4: 5,6                                  # 19 pairs
* PAIR G9: 5,6 BLK 9
H9: 5,6,3                                # reduction candidate for 5,6
H9: 5,6 => CTR
* 4698.127.8572.9134123.7.69827.38.9.161..9.3..93.61.4..5967438123821.67497419285..
H9: 3 => SOLVED
* 469851273857239164123674598274386951615492387938517426596743812382165749741928635
I9: 5,6,3                                # reduction candidate for 5,6
I9: 5,6 => SOLVED
* 469851273857239164123674598274386951615492387938517426596743812382165749741928635
I9: 3 => CTR
* 469831275857269134123.7.69827.38695161.49.3.793.51.4.65967438123821..749741928..3
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-271-base-pr-000.dot
* REASONING
* PRF # I9: 3,5 => SOL
* DIS # I9: 6 => CTR => I9: 3,5
* PRF # H9: 3,6 => SOL
* DIS # H9: 5 => CTR => H9: 3,6
* DIS # F3: 5,6 => CTR => F3: 4
* DIS # C5: 8 => CTR => C5: 4,5
* DIS # F4: 4,5 => CTR => F4: 6
* PRF # F4: 6 => SOL
* DIS # C5: 4 => CTR => C5: 5,8
* DIS # F4: 4,5 => CTR => F4: 6
* PRF # F4: 6 => SOL
* DIS # C5: 8 => CTR => C5: 4,5
* DIS # D3: 4,5 => CTR => D3: 6
* PRF # D3: 6 => SOL
* DIS # F4: 4 => CTR => F4: 5,6
* DIS # I6: 7 => CTR => I6: 5,6
* DIS # D3: 4 => CTR => D3: 5,6
* DIS # I6: 7 => CTR => I6: 5,6
* DIS # F4: 4 => CTR => F4: 5,6
* DIS # H9: 5,6 => CTR => H9: 3
* PRF # H9: 3 => SOL
* DIS # I6: 5,7 => CTR => I6: 6
* PRF # I6: 6 => SOL
* DIS # F3: 5,6 => CTR => F3: 4
* DIS # H9: 5,6 => CTR => H9: 3
* PRF # H9: 3 => SOL
* PRF # I9: 5,6 => SOL
* DIS # I9: 3 => CTR => I9: 5,6
* CNT  28 HDP CHAINS /  40 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (C4,C6,D5,D6,E1,E2,E8,F5,F6,F8,G3,G9,H2,H4,H5,H6,I1,I5)
* 4698.127.8572.91.4123.7..9827.38.9.161..9.3..93..1.4..5967438123821..749741928...
* PAIR I1: 3,5 COL I
I9: 3,5,6                                # reduction candidate for 3,5
I9: 3,5 => SOLVED
* 469851273857239164123674598274386951615492387938517426596743812382165749741928635
* DURATION: 0:00:02.163387  START: 12:12:28.952397  END: 12:12:31.115784 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-271-base-pr-001.dot
* REASONING
* PRF # I9: 3,5 => SOL
* STA I9: 3,5
* CNT   1 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 271

solution: 469851273857239164123674598274386951615492387938517426596743812382165749741928635
info: 2200     FNBHWXY  S8.f     43202

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

Solution

position: 469851273857239164123674598274386951615492387938517426596743812382165749741928635 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 # I9: 3,5 => SOL
* DIS # I9: 6 => CTR => I9: 3,5
* PRF # H9: 3,6 => SOL
* DIS # H9: 5 => CTR => H9: 3,6
* INC # D3: 5,6 => UNS
* DIS # F3: 5,6 => CTR => F3: 4
* INC # F3: 4 => UNS
* INC # C5: 4,5 => UNS
* DIS # C5: 8 => CTR => C5: 4,5
* DIS # F4: 4,5 => CTR => F4: 6
* PRF # F4: 6 => SOL
* INC # C5: 5,8 => UNS
* DIS # C5: 4 => CTR => C5: 5,8
* DIS # F4: 4,5 => CTR => F4: 6
* PRF # F4: 6 => SOL
* INC # C5: 4,5 => UNS
* DIS # C5: 8 => CTR => C5: 4,5
* DIS # D3: 4,5 => CTR => D3: 6
* PRF # D3: 6 => SOL
* INC # F4: 5,6 => UNS
* DIS # F4: 4 => CTR => F4: 5,6
* INC # I6: 5,6 => UNS
* DIS # I6: 7 => CTR => I6: 5,6
* INC # D3: 5,6 => UNS
* DIS # D3: 4 => CTR => D3: 5,6
* INC # I6: 5,6 => UNS
* DIS # I6: 7 => CTR => I6: 5,6
* INC # F4: 5,6 => UNS
* DIS # F4: 4 => CTR => F4: 5,6
* DIS # H9: 5,6 => CTR => H9: 3
* PRF # H9: 3 => SOL
* DIS # I6: 5,7 => CTR => I6: 6
* PRF # I6: 6 => SOL
* DIS # F3: 5,6 => CTR => F3: 4
* INC # F3: 4 => UNS
* INC # F4: 5,6 => UNS
* DIS # H9: 5,6 => CTR => H9: 3
* PRF # H9: 3 => SOL
* PRF # I9: 5,6 => SOL
* DIS # I9: 3 => CTR => I9: 5,6
* CNT  40 HDP CHAINS /  40 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* PRF # I9: 3,5 => SOL
* STA I9: 3,5
* CNT   1 HDP CHAINS /   1 HYP OPENED