Analysis of xx-top500-126-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 2..14.....7.....3...........8...3.....3.....7....6.1..6.5...2..1..7............8. initial

Autosolve

position: 239146758571289634864375912786.13.2..135..867.528671.36.5.382711.875.3.63.76.1.8. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # B8: 4,9 => CTR => B8: 2
* PRF # B8: 2 => SOL
* PRF # B9: 4,9 => SOL
* DIS # B9: 2 => CTR => B9: 4,9
* PRF # B8: 2,4 => SOL
* DIS # B8: 9 => CTR => B8: 2,4
* PRF # B9: 2,9 => SOL
* DIS # B9: 4 => CTR => B9: 2,9
* DIS # B8: 4,9 => CTR => B8: 2
* PRF # B8: 2 => SOL
* CNT  10 HDP CHAINS /  10 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 # B8: 4,9 => CTR => B8: 2
* PRF B8: 2 => SOL
* STA B8: 2
* CNT   2 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

2..14.....7.....3...........8...3.....3.....7....6.1..6.5...2..1..7............8. initial
239146758571289634864375912786.13.2..135..867.528671.36.5.382711.875.3.63.76.1.8. autosolve
239146758571289634864375912786413529413592867952867143645938271128754396397621485 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (15)
A5: 4,9
A6: 4,9
D4: 4,9
E5: 2,9
F5: 2,4
G4: 4,5
I4: 5,9
H6: 4,9
B7: 4,9
D7: 4,9
F8: 2,4
E9: 2,9
H8: 4,9
G9: 4,5
I9: 5,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
E5,F5: 2.. / E5 = 2  =>  0 pairs (X) / F5 = 2  =>  0 pairs (_)
B8,B9: 2.. / B8 = 2  =>  0 pairs (*) / B9 = 2  =>  0 pairs (X)
F8,E9: 2.. / F8 = 2  =>  0 pairs (X) / E9 = 2  =>  0 pairs (_)
B8,F8: 2.. / B8 = 2  =>  0 pairs (*) / F8 = 2  =>  0 pairs (X)
B9,E9: 2.. / B9 = 2  =>  0 pairs (X) / E9 = 2  =>  0 pairs (_)
E5,E9: 2.. / E5 = 2  =>  0 pairs (X) / E9 = 2  =>  0 pairs (_)
F5,F8: 2.. / F5 = 2  =>  0 pairs (*) / F8 = 2  =>  0 pairs (X)
A5,A6: 4.. / A5 = 4  =>  0 pairs (*) / A6 = 4  =>  0 pairs (X)
D4,F5: 4.. / D4 = 4  =>  0 pairs (*) / F5 = 4  =>  0 pairs (X)
G4,H6: 4.. / G4 = 4  =>  0 pairs (X) / H6 = 4  =>  0 pairs (_)
D7,F8: 4.. / D7 = 4  =>  0 pairs (X) / F8 = 4  =>  0 pairs (_)
H8,G9: 4.. / H8 = 4  =>  0 pairs (X) / G9 = 4  =>  0 pairs (_)
D4,G4: 4.. / D4 = 4  =>  0 pairs (*) / G4 = 4  =>  0 pairs (X)
A5,F5: 4.. / A5 = 4  =>  0 pairs (*) / F5 = 4  =>  0 pairs (X)
A6,H6: 4.. / A6 = 4  =>  0 pairs (X) / H6 = 4  =>  0 pairs (_)
B7,D7: 4.. / B7 = 4  =>  0 pairs (*) / D7 = 4  =>  0 pairs (X)
B9,G9: 4.. / B9 = 4  =>  0 pairs (X) / G9 = 4  =>  0 pairs (_)
D4,D7: 4.. / D4 = 4  =>  0 pairs (*) / D7 = 4  =>  0 pairs (X)
F5,F8: 4.. / F5 = 4  =>  0 pairs (X) / F8 = 4  =>  0 pairs (_)
G4,G9: 4.. / G4 = 4  =>  0 pairs (X) / G9 = 4  =>  0 pairs (_)
H6,H8: 4.. / H6 = 4  =>  0 pairs (*) / H8 = 4  =>  0 pairs (X)
G4,I4: 5.. / G4 = 5  =>  0 pairs (*) / I4 = 5  =>  0 pairs (X)
G9,I9: 5.. / G9 = 5  =>  0 pairs (X) / I9 = 5  =>  0 pairs (_)
G4,G9: 5.. / G4 = 5  =>  0 pairs (*) / G9 = 5  =>  0 pairs (X)
I4,I9: 5.. / I4 = 5  =>  0 pairs (X) / I9 = 5  =>  0 pairs (_)
A5,A6: 9.. / A5 = 9  =>  0 pairs (X) / A6 = 9  =>  0 pairs (_)
D4,E5: 9.. / D4 = 9  =>  0 pairs (X) / E5 = 9  =>  0 pairs (_)
I4,H6: 9.. / I4 = 9  =>  0 pairs (*) / H6 = 9  =>  0 pairs (X)
D7,E9: 9.. / D7 = 9  =>  0 pairs (*) / E9 = 9  =>  0 pairs (X)
H8,I9: 9.. / H8 = 9  =>  0 pairs (*) / I9 = 9  =>  0 pairs (X)
D4,I4: 9.. / D4 = 9  =>  0 pairs (X) / I4 = 9  =>  0 pairs (_)
A5,E5: 9.. / A5 = 9  =>  0 pairs (X) / E5 = 9  =>  0 pairs (_)
A6,H6: 9.. / A6 = 9  =>  0 pairs (*) / H6 = 9  =>  0 pairs (X)
B7,D7: 9.. / B7 = 9  =>  0 pairs (X) / D7 = 9  =>  0 pairs (_)
B8,H8: 9.. / B8 = 9  =>  0 pairs (X) / H8 = 9  =>  0 pairs (_)
D4,D7: 9.. / D4 = 9  =>  0 pairs (X) / D7 = 9  =>  0 pairs (_)
E5,E9: 9.. / E5 = 9  =>  0 pairs (*) / E9 = 9  =>  0 pairs (X)
H6,H8: 9.. / H6 = 9  =>  0 pairs (X) / H8 = 9  =>  0 pairs (_)
I4,I9: 9.. / I4 = 9  =>  0 pairs (*) / I9 = 9  =>  0 pairs (X)
* DURATION: 0:01:05.446450  START: 07:04:26.659374  END: 07:05:32.105824 2017-05-04
* CP COUNT: (39)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A5,A6,B7,D4,D7,E5,E9,F5,F8,G4,G9,H6,H8,I4,I9)
* 239146758571289634864375912786.13.2..135..867.528671.36.5.382711.875.3.63.76.1.8.
* PAIR B7: 4,9 BLK 7
B8: 4,9,2                                # reduction candidate for 4,9
B8: 4,9 => CTR
* 239146758571289634864375912786.13.2..135..867.528671.36.5.382711.87523.6327691485
B8: 2 => SOLVED
* 239146758571289634864375912786413529413592867952867143645938271128754396397621485
B9: 4,9,2                                # reduction candidate for 4,9
B9: 4,9 => SOLVED
* 239146758571289634864375912786413529413592867952867143645938271128754396397621485
B9: 2 => CTR
* 239146758571289634864375912786.13.2..135..867.528671.36.5.382711.875.3.6327691485
* PAIR F8: 2,4 ROW 8
B8: 2,4,9                                # reduction candidate for 2,4
B8: 2,4 => SOLVED
* 239146758571289634864375912786413529413592867952867143645938271128754396397621485
B8: 9 => CTR
* 239146758571289634864375912786.13.2..135..867.528671.36.5.382711987523463.76.1.8.
* PAIR E9: 2,9 ROW 9
B9: 2,9,4                                # reduction candidate for 2,9
B9: 2,9 => SOLVED
* 239146758571289634864375912786413529413592867952867143645938271128754396397621485
B9: 4 => CTR
* 239146758571289634864375912786.13.2..135..867.528671.36.5.382711287543963476.1.8.
* PAIR H8: 4,9 ROW 8
B8: 4,9,2                                # reduction candidate for 4,9
B8: 4,9 => CTR
* 239146758571289634864375912786.13.2..135..867.528671.36.5.382711.87523.6327691485
B8: 2 => SOLVED
* 239146758571289634864375912786413529413592867952867143645938271128754396397621485
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-126-base-pr-000.dot
* REASONING
* DIS # B8: 4,9 => CTR => B8: 2
* PRF # B8: 2 => SOL
* PRF # B9: 4,9 => SOL
* DIS # B9: 2 => CTR => B9: 4,9
* PRF # B8: 2,4 => SOL
* DIS # B8: 9 => CTR => B8: 2,4
* PRF # B9: 2,9 => SOL
* DIS # B9: 4 => CTR => B9: 2,9
* DIS # B8: 4,9 => CTR => B8: 2
* PRF # B8: 2 => SOL
* CNT  10 HDP CHAINS /  10 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A5,A6,B7,D4,D7,E5,E9,F5,F8,G4,G9,H6,H8,I4,I9)
* 239146758571289634864375912786.13.2..135..867.528671.36.5.382711.875.3.63.76.1.8.
* PAIR B7: 4,9 BLK 7
B8: 4,9,2                                # reduction candidate for 4,9
B8: 4,9 => CTR
* 239146758571289634864375912786.13.2..135..867.528671.36.5.382711.87523.6327691485
B8: 2 => SOLVED
* 239146758571289634864375912786413529413592867952867143645938271128754396397621485
* DURATION: 0:00:01.824918  START: 07:05:44.372005  END: 07:05:46.196923 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-126-base-pr-001.dot
* REASONING
* DIS # B8: 4,9 => CTR => B8: 2
* PRF B8: 2 => SOL
* STA B8: 2
* CNT   2 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 126

solution: 239146758571289634864375912786413529413592867952867143645938271128754396397621485
info: 1808     FNWX     S8.f     44689

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

Solution

position: 239146758571289634864375912786413529413592867952867143645938271128754396397621485 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 # B8: 4,9 => CTR => B8: 2
* PRF # B8: 2 => SOL
* PRF # B9: 4,9 => SOL
* DIS # B9: 2 => CTR => B9: 4,9
* PRF # B8: 2,4 => SOL
* DIS # B8: 9 => CTR => B8: 2,4
* PRF # B9: 2,9 => SOL
* DIS # B9: 4 => CTR => B9: 2,9
* DIS # B8: 4,9 => CTR => B8: 2
* PRF # B8: 2 => SOL
* CNT  10 HDP CHAINS /  10 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # B8: 4,9 => CTR => B8: 2
* PRF B8: 2 => SOL
* STA B8: 2
* CNT   2 HDP CHAINS /   1 HYP OPENED