Analysis of xx-top500-144-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: .....28..4..5.......1.........71..4.32...............51.....2...8..4.......6..3.. initial

Autosolve

position: 63.4.28514.2581..38513.642.5.8713.4232.95418..14268.351..83.2.428314.5...4.62.318 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # C7: 7,9 => CTR => C7: 5,6
* DIS # C9: 7,9 => CTR => C9: 5
* PRF # H2: 7,9 => SOL
* DIS # H2: 6 => CTR => H2: 7,9
* PRF # B7: 7,9 => SOL
* DIS # B7: 6 => CTR => B7: 7,9
* DIS # H2: 6,7 => CTR => H2: 9
* PRF # H2: 9 => SOL
* PRF # H2: 7,9 => SOL
* DIS # H2: 6 => CTR => H2: 7,9
* PRF # I8: 7,9 => SOL
* DIS # I8: 6 => CTR => I8: 7,9
* PRF # B7: 6,9 => SOL
* DIS # B7: 7 => CTR => B7: 6,9
* PRF # C7: 6,7 => SOL
* DIS # C7: 5,9 => CTR => C7: 6,7
* DIS # I8: 6,7 => CTR => I8: 9
* PRF # I8: 9 => SOL
* PRF # B7: 7,9 => SOL
* DIS # B7: 6 => CTR => B7: 7,9
* DIS # C7: 7,9 => CTR => C7: 5,6
* DIS # C9: 7,9 => CTR => C9: 5
* DIS # F9: 5 => CTR => F9: 7,9
* DIS # F7: 7,9 => CTR => F7: 5
* DIS # H8: 7,9 => CTR => H8: 6
* PRF # H8: 6 => SOL
* PRF # I8: 7,9 => SOL
* DIS # I8: 6 => CTR => I8: 7,9
* DIS # H8: 7,9 => CTR => H8: 6
* PRF # H8: 6 => SOL
* PRF # I8: 7,9 => SOL
* DIS # I8: 6 => CTR => I8: 7,9
* PRF # B7: 7,9 => SOL
* DIS # B7: 6 => CTR => B7: 7,9
* DIS # C7: 7,9 => CTR => C7: 5,6
* DIS # F7: 7,9 => CTR => F7: 5
* PRF # H2: 7,9 => SOL
* DIS # H2: 6 => CTR => H2: 7,9
* CNT  38 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 # C7: 7,9 => CTR => C7: 5,6
* DIS C7: 5,6 # C9: 7,9 => CTR => C9: 5
* PRF C7: 5,6 + C9: 5 => SOL
* STA C7: 5,6 + C9: 5
* CNT   3 HDP CHAINS /   2 HYP OPENED

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

Details

Positions

.....28..4..5.......1.........71..4.32...............51.....2...8..4.......6..3.. initial
63.4.28514.2581..38513.642.5.8713.4232.95418..14268.351..83.2.428314.5...4.62.318 autosolve
639472851472581693851396427568713942327954186914268735196835274283147569745629318 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (15)
C1: 7,9
B2: 7,9
E1: 7,9
E3: 7,9
G2: 6,7
I3: 7,9
B4: 6,9
C5: 6,7
A6: 7,9
G4: 6,9
I5: 6,7
G6: 7,9
A9: 7,9
F8: 7,9
H7: 7,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
C7,C9: 5.. / C7 = 5  =>  0 pairs (X) / C9 = 5  => 16 pairs (_)
F7,F9: 5.. / F7 = 5  => 16 pairs (_) / F9 = 5  =>  0 pairs (X)
C7,F7: 5.. / C7 = 5  =>  0 pairs (X) / F7 = 5  => 16 pairs (_)
C9,F9: 5.. / C9 = 5  => 16 pairs (_) / F9 = 5  =>  0 pairs (X)
G2,H2: 6.. / G2 = 6  =>  0 pairs (*) / H2 = 6  =>  0 pairs (X)
B4,C5: 6.. / B4 = 6  =>  0 pairs (*) / C5 = 6  =>  0 pairs (X)
G4,I5: 6.. / G4 = 6  =>  0 pairs (X) / I5 = 6  =>  0 pairs (_)
B7,C7: 6.. / B7 = 6  =>  0 pairs (X) / C7 = 6  =>  0 pairs (_)
H8,I8: 6.. / H8 = 6  =>  0 pairs (*) / I8 = 6  =>  0 pairs (X)
B4,G4: 6.. / B4 = 6  =>  0 pairs (*) / G4 = 6  =>  0 pairs (X)
C5,I5: 6.. / C5 = 6  =>  0 pairs (X) / I5 = 6  =>  0 pairs (_)
B4,B7: 6.. / B4 = 6  =>  0 pairs (*) / B7 = 6  =>  0 pairs (X)
C5,C7: 6.. / C5 = 6  =>  0 pairs (X) / C7 = 6  =>  0 pairs (_)
G2,G4: 6.. / G2 = 6  =>  0 pairs (*) / G4 = 6  =>  0 pairs (X)
H2,H8: 6.. / H2 = 6  =>  0 pairs (X) / H8 = 6  =>  0 pairs (_)
I5,I8: 6.. / I5 = 6  =>  0 pairs (*) / I8 = 6  =>  0 pairs (X)
C1,B2: 7.. / C1 = 7  =>  0 pairs (X) / B2 = 7  =>  0 pairs (_)
E1,E3: 7.. / E1 = 7  =>  0 pairs (*) / E3 = 7  =>  0 pairs (X)
C5,A6: 7.. / C5 = 7  =>  0 pairs (*) / A6 = 7  =>  0 pairs (X)
I5,G6: 7.. / I5 = 7  =>  0 pairs (X) / G6 = 7  =>  0 pairs (_)
C1,E1: 7.. / C1 = 7  =>  0 pairs (X) / E1 = 7  =>  0 pairs (_)
E3,I3: 7.. / E3 = 7  =>  0 pairs (X) / I3 = 7  =>  0 pairs (_)
C5,I5: 7.. / C5 = 7  =>  0 pairs (*) / I5 = 7  =>  0 pairs (X)
A6,G6: 7.. / A6 = 7  =>  0 pairs (X) / G6 = 7  =>  0 pairs (_)
A6,A9: 7.. / A6 = 7  =>  0 pairs (X) / A9 = 7  =>  0 pairs (_)
B2,B7: 7.. / B2 = 7  =>  0 pairs (*) / B7 = 7  =>  0 pairs (X)
G2,G6: 7.. / G2 = 7  =>  0 pairs (X) / G6 = 7  =>  0 pairs (_)
C1,B2: 9.. / C1 = 9  =>  0 pairs (*) / B2 = 9  =>  0 pairs (X)
E1,E3: 9.. / E1 = 9  =>  0 pairs (X) / E3 = 9  =>  0 pairs (_)
H2,I3: 9.. / H2 = 9  =>  0 pairs (*) / I3 = 9  =>  0 pairs (X)
B4,A6: 9.. / B4 = 9  =>  0 pairs (X) / A6 = 9  =>  0 pairs (_)
G4,G6: 9.. / G4 = 9  =>  0 pairs (*) / G6 = 9  =>  0 pairs (X)
C1,E1: 9.. / C1 = 9  =>  0 pairs (*) / E1 = 9  =>  0 pairs (X)
B2,H2: 9.. / B2 = 9  =>  0 pairs (X) / H2 = 9  =>  0 pairs (_)
E3,I3: 9.. / E3 = 9  =>  0 pairs (*) / I3 = 9  =>  0 pairs (X)
B4,G4: 9.. / B4 = 9  =>  0 pairs (X) / G4 = 9  =>  0 pairs (_)
A6,G6: 9.. / A6 = 9  =>  0 pairs (*) / G6 = 9  =>  0 pairs (X)
A6,A9: 9.. / A6 = 9  =>  0 pairs (*) / A9 = 9  =>  0 pairs (X)
I3,I8: 9.. / I3 = 9  =>  0 pairs (X) / I8 = 9  =>  0 pairs (_)
* DURATION: 0:01:04.121364  START: 07:39:17.492098  END: 07:40:21.613462 2017-05-04
* CP COUNT: (39)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A6,A9,B2,B4,C1,C5,E1,E3,F8,G2,G4,G6,H7,I3,I5)
* 63.4.28514.2581..38513.642.5.8713.4232.95418..14268.351..83.2.428314.5...4.62.318
* PAIR C1: 7,9 COL C
C7: 7,9,5,6                              # reduction candidate for 7,9
C7: 7,9 => CTR
* 6394728514.2581..38513.642.5.8713.4232695418771426893516.8352.428314.5.6945627318
C7: 5,6                                  # 16 pairs
C9: 7,9,5                                # reduction candidate for 7,9
C9: 7,9 => CTR
* 6394728514.2581..38513.642.5.8713.4232695418771426893516583.2.428314.5.6947625318
C9: 5                                    # 16 pairs
* PAIR B2: 7,9 ROW 2
H2: 7,9,6                                # reduction candidate for 7,9
H2: 7,9 => SOLVED
* 639472851472581693851396427568713942327954186914268735196835274283147569745629318
H2: 6 => CTR
* 63.4.2851492581763851376429568713.4232.95418..14268.351..83.2.428314.5...4.62.318
* PAIR B2: 7,9 COL B
B7: 7,9,6                                # reduction candidate for 7,9
B7: 7,9 => SOLVED
* 639472851472581693851396427568713942327954186914268735196835274283147569745629318
B7: 6 => CTR
* 63.4.28514725816938513964275.8713.4232.95418..14268.351..83.2.428314.5...4.62.318
* PAIR G2: 6,7 BLK 3
H2: 6,7,9                                # reduction candidate for 6,7
H2: 6,7 => CTR
* 63.4.2851492581..38513.642956871394232795418..14268.351..83.2.428314.5...4.62.318
H2: 9 => SOLVED
* 639472851472581693851396427568713942327954186914268735196835274283147569745629318
* PAIR I3: 7,9 BLK 3
H2: 7,9,6                                # reduction candidate for 7,9
H2: 7,9 => SOLVED
* 639472851472581693851396427568713942327954186914268735196835274283147569745629318
H2: 6 => CTR
* 63.4.2851492581763851376429568713.4232.95418..14268.351..83.2.428314.5...4.62.318
* PAIR I3: 7,9 COL I
I8: 7,9,6                                # reduction candidate for 7,9
I8: 7,9 => SOLVED
* 639472851472581693851396427568713942327954186914268735196835274283147569745629318
I8: 6 => CTR
* 6394728514.2581..38513.64295.8713.4232.9541877142689351..83.2.428314.5.694.62.318
* PAIR B4: 6,9 COL B
B7: 6,9,7                                # reduction candidate for 6,9
B7: 6,9 => SOLVED
* 639472851472581693851396427568713942327954186914268735196835274283147569745629318
B7: 7 => CTR
* 63.4.28514.2581..38513.642.56871394232795418691426873517.83.2.428314.5...4.62.318
* PAIR C5: 6,7 COL C
C7: 6,7,5,9                              # reduction candidate for 6,7
C7: 6,7 => SOLVED
* 639472851472581693851396427568713942327954186914268735196835274283147569745629318
C7: 5,9 => CTR
* 6394728514.2581..38513.642.5.8713.4232695418771426893516.83.2.428314.5.6947625318
* PAIR I5: 6,7 COL I
I8: 6,7,9                                # reduction candidate for 6,7
I8: 6,7 => CTR
* 63.492851492581..385137642956871394232795418..14268.351..83.2.428314.5...4.62.318
I8: 9 => SOLVED
* 639472851472581693851396427568713942327954186914268735196835274283147569745629318
* PAIR A9: 7,9 BLK 7
B7: 7,9,6                                # reduction candidate for 7,9
B7: 7,9 => SOLVED
* 639472851472581693851396427568713942327954186914268735196835274283147569745629318
B7: 6 => CTR
* 63.4.28514725816938513964275.8713.4232.95418..14268.351..83.2.428314.5...4.62.318
C7: 7,9,5,6                              # reduction candidate for 7,9
C7: 7,9 => CTR
* 6394728514.2581..38513.642.5.8713.4232695418771426893516.8352.428314.5.6945627318
C7: 5,6                                  # 16 pairs
C9: 7,9,5                                # reduction candidate for 7,9
C9: 7,9 => CTR
* 6394728514.2581..38513.642.5.8713.4232695418771426893516583.2.428314.5.6947625318
C9: 5                                    # 16 pairs
* PAIR A9: 7,9 ROW 9
F9: 7,9,5                                # reduction candidate for 7,9
F9: 5 => CTR
* 6394728514.2581..38513.642.5.8713.4232695418771426893516583.2.428314.5.6947625318
F9: 7,9                                  # 16 pairs
* PAIR F8: 7,9 BLK 8
F7: 7,9,5                                # reduction candidate for 7,9
F7: 7,9 => CTR
* 6394728514.2581..38513.642.5.8713.4232695418771426893516583.2.428314.5.6947625318
F7: 5                                    # 16 pairs
F9: 7,9,5                                # reduction candidate for 7,9
F9: 7,9                                  # 16 pairs
* PAIR F8: 7,9 ROW 8
H8: 7,9,6                                # reduction candidate for 7,9
H8: 7,9 => CTR
* 63.4.28514.2581.638513.64295.871364232695418771426893516.83.2.428314.5.694.62.318
H8: 6 => SOLVED
* 639472851472581693851396427568713942327954186914268735196835274283147569745629318
I8: 7,9,6                                # reduction candidate for 7,9
I8: 7,9 => SOLVED
* 639472851472581693851396427568713942327954186914268735196835274283147569745629318
I8: 6 => CTR
* 6394728514.2581..38513.64295.8713.4232.9541877142689351..83.2.428314.5.694.62.318
* PAIR H7: 7,9 BLK 9
H8: 7,9,6                                # reduction candidate for 7,9
H8: 7,9 => CTR
* 63.4.28514.2581.638513.64295.871364232695418771426893516.83.2.428314.5.694.62.318
H8: 6 => SOLVED
* 639472851472581693851396427568713942327954186914268735196835274283147569745629318
I8: 7,9,6                                # reduction candidate for 7,9
I8: 7,9 => SOLVED
* 639472851472581693851396427568713942327954186914268735196835274283147569745629318
I8: 6 => CTR
* 6394728514.2581..38513.64295.8713.4232.9541877142689351..83.2.428314.5.694.62.318
* PAIR H7: 7,9 ROW 7
B7: 7,9,6                                # reduction candidate for 7,9
B7: 7,9 => SOLVED
* 639472851472581693851396427568713942327954186914268735196835274283147569745629318
B7: 6 => CTR
* 63.4.28514725816938513964275.8713.4232.95418..14268.351..83.2.428314.5...4.62.318
C7: 7,9,5,6                              # reduction candidate for 7,9
C7: 7,9 => CTR
* 6394728514.2581..38513.642.5.8713.4232695418771426893516.8352.428314.5.6945627318
C7: 5,6                                  # 16 pairs
F7: 7,9,5                                # reduction candidate for 7,9
F7: 7,9 => CTR
* 6394728514.2581..38513.642.5.8713.4232695418771426893516583.2.428314.5.6947625318
F7: 5                                    # 16 pairs
* PAIR H7: 7,9 COL H
H2: 7,9,6                                # reduction candidate for 7,9
H2: 7,9 => SOLVED
* 639472851472581693851396427568713942327954186914268735196835274283147569745629318
H2: 6 => CTR
* 63.4.2851492581763851376429568713.4232.95418..14268.351..83.2.428314.5...4.62.318
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-144-base-pr-000.dot
* REASONING
* DIS # C7: 7,9 => CTR => C7: 5,6
* DIS # C9: 7,9 => CTR => C9: 5
* PRF # H2: 7,9 => SOL
* DIS # H2: 6 => CTR => H2: 7,9
* PRF # B7: 7,9 => SOL
* DIS # B7: 6 => CTR => B7: 7,9
* DIS # H2: 6,7 => CTR => H2: 9
* PRF # H2: 9 => SOL
* PRF # H2: 7,9 => SOL
* DIS # H2: 6 => CTR => H2: 7,9
* PRF # I8: 7,9 => SOL
* DIS # I8: 6 => CTR => I8: 7,9
* PRF # B7: 6,9 => SOL
* DIS # B7: 7 => CTR => B7: 6,9
* PRF # C7: 6,7 => SOL
* DIS # C7: 5,9 => CTR => C7: 6,7
* DIS # I8: 6,7 => CTR => I8: 9
* PRF # I8: 9 => SOL
* PRF # B7: 7,9 => SOL
* DIS # B7: 6 => CTR => B7: 7,9
* DIS # C7: 7,9 => CTR => C7: 5,6
* DIS # C9: 7,9 => CTR => C9: 5
* DIS # F9: 5 => CTR => F9: 7,9
* DIS # F7: 7,9 => CTR => F7: 5
* DIS # H8: 7,9 => CTR => H8: 6
* PRF # H8: 6 => SOL
* PRF # I8: 7,9 => SOL
* DIS # I8: 6 => CTR => I8: 7,9
* DIS # H8: 7,9 => CTR => H8: 6
* PRF # H8: 6 => SOL
* PRF # I8: 7,9 => SOL
* DIS # I8: 6 => CTR => I8: 7,9
* PRF # B7: 7,9 => SOL
* DIS # B7: 6 => CTR => B7: 7,9
* DIS # C7: 7,9 => CTR => C7: 5,6
* DIS # F7: 7,9 => CTR => F7: 5
* PRF # H2: 7,9 => SOL
* DIS # H2: 6 => CTR => H2: 7,9
* CNT  38 HDP CHAINS /  47 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A6,A9,B2,B4,C1,C5,E1,E3,F8,G2,G4,G6,H7,I3,I5)
* 63.4.28514.2581..38513.642.5.8713.4232.95418..14268.351..83.2.428314.5...4.62.318
* PAIR C1: 7,9 COL C
C7: 7,9,5,6                              # reduction candidate for 7,9
C7: 7,9 => CTR
* 6394728514.2581..38513.642.5.8713.4232695418771426893516.8352.428314.5.6945627318
C9: 7,9,5                                # reduction candidate for 7,9
C9: 7,9 => CTR
* 6394728514.2581..38513.642.5.8713.4232695418771426893516583.2.428314.5.6947625318
C9: 5 => SOLVED
* 639472851472581693851396427568713942327954186914268735196835274283147569745629318
* DURATION: 0:00:02.834715  START: 07:41:11.396276  END: 07:41:14.230991 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-144-base-pr-001.dot
* REASONING
* DIS # C7: 7,9 => CTR => C7: 5,6
* DIS C7: 5,6 # C9: 7,9 => CTR => C9: 5
* PRF C7: 5,6 + C9: 5 => SOL
* STA C7: 5,6 + C9: 5
* CNT   3 HDP CHAINS /   2 HYP OPENED

Header Info

Top 500 Minimum 17 144

solution: 639472851472581693851396427568713942327954186914268735196835274283147569745629318
info: 1814     FNBWY    S8.f     39723

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

Solution

position: 639472851472581693851396427568713942327954186914268735196835274283147569745629318 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 # C7: 7,9 => CTR => C7: 5,6
* INC # C7: 5,6 => UNS
* DIS # C9: 7,9 => CTR => C9: 5
* INC # C9: 5 => UNS
* PRF # H2: 7,9 => SOL
* DIS # H2: 6 => CTR => H2: 7,9
* PRF # B7: 7,9 => SOL
* DIS # B7: 6 => CTR => B7: 7,9
* DIS # H2: 6,7 => CTR => H2: 9
* PRF # H2: 9 => SOL
* PRF # H2: 7,9 => SOL
* DIS # H2: 6 => CTR => H2: 7,9
* PRF # I8: 7,9 => SOL
* DIS # I8: 6 => CTR => I8: 7,9
* PRF # B7: 6,9 => SOL
* DIS # B7: 7 => CTR => B7: 6,9
* PRF # C7: 6,7 => SOL
* DIS # C7: 5,9 => CTR => C7: 6,7
* DIS # I8: 6,7 => CTR => I8: 9
* PRF # I8: 9 => SOL
* PRF # B7: 7,9 => SOL
* DIS # B7: 6 => CTR => B7: 7,9
* DIS # C7: 7,9 => CTR => C7: 5,6
* INC # C7: 5,6 => UNS
* DIS # C9: 7,9 => CTR => C9: 5
* INC # C9: 5 => UNS
* INC # F9: 7,9 => UNS
* DIS # F9: 5 => CTR => F9: 7,9
* DIS # F7: 7,9 => CTR => F7: 5
* INC # F7: 5 => UNS
* INC # F9: 7,9 => UNS
* DIS # H8: 7,9 => CTR => H8: 6
* PRF # H8: 6 => SOL
* PRF # I8: 7,9 => SOL
* DIS # I8: 6 => CTR => I8: 7,9
* DIS # H8: 7,9 => CTR => H8: 6
* PRF # H8: 6 => SOL
* PRF # I8: 7,9 => SOL
* DIS # I8: 6 => CTR => I8: 7,9
* PRF # B7: 7,9 => SOL
* DIS # B7: 6 => CTR => B7: 7,9
* DIS # C7: 7,9 => CTR => C7: 5,6
* INC # C7: 5,6 => UNS
* DIS # F7: 7,9 => CTR => F7: 5
* INC # F7: 5 => UNS
* PRF # H2: 7,9 => SOL
* DIS # H2: 6 => CTR => H2: 7,9
* CNT  47 HDP CHAINS /  47 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # C7: 7,9 => CTR => C7: 5,6
* DIS C7: 5,6 # C9: 7,9 => CTR => C9: 5
* PRF C7: 5,6 + C9: 5 => SOL
* STA C7: 5,6 + C9: 5
* CNT   3 HDP CHAINS /   2 HYP OPENED