Analysis of xx-top500-123-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: .3.....2.....1.4..6..7......5.3.2.........8.1.........1.4.5.......4...3.8........ initial

Autosolve

position: 43.5.812.58.21.4.3612734985.51382.4.32694.8.1.481..3.21.48532..2.54.1.388.362.514 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # I4: 6,7 => CTR => I4: 9
* PRF # I4: 9 => SOL
* PRF # I7: 6,7 => SOL
* DIS # I7: 9 => CTR => I7: 6,7
* DIS # H7: 6,7 => CTR => H7: 9
* PRF # H7: 9 => SOL
* PRF # I4: 7,9 => SOL
* DIS # I4: 6 => CTR => I4: 7,9
* DIS # H6: 7,9 => CTR => H6: 5
* PRF # H6: 5 => SOL
* DIS # F6: 5,7 => CTR => F6: 6
* PRF # F6: 6 => SOL
* PRF # F6: 6,7 => SOL
* DIS # F6: 5 => CTR => F6: 6,7
* DIS # I4: 6,7 => CTR => I4: 9
* PRF # I4: 9 => SOL
* PRF # H6: 5,7 => SOL
* DIS # H6: 9 => CTR => H6: 5,7
* PRF # B8: 6,7 => SOL
* DIS # B8: 9 => CTR => B8: 6,7
* DIS # H7: 6,7 => CTR => H7: 9
* PRF # H7: 9 => SOL
* PRF # I7: 6,7 => SOL
* DIS # I7: 9 => CTR => I7: 6,7
* DIS # B8: 7,9 => CTR => B8: 6
* PRF # B8: 6 => SOL
* DIS # B8: 7,9 => CTR => B8: 6
* PRF # B8: 6 => SOL
* DIS # H7: 6,7 => CTR => H7: 9
* PRF # H7: 9 => SOL
* PRF # I7: 6,7 => SOL
* DIS # I7: 9 => CTR => I7: 6,7
* PRF # B8: 6,7 => SOL
* DIS # B8: 9 => CTR => B8: 6,7
* CNT  34 HDP CHAINS /  34 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 # I4: 6,7 => CTR => I4: 9
* PRF I4: 9 => SOL
* STA I4: 9
* CNT   2 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

.3.....2.....1.4..6..7......5.3.2.........8.1.........1.4.5.......4...3.8........ initial
43.5.812.58.21.4.3612734985.51382.4.32694.8.1.481..3.21.48532..2.54.1.388.362.514 autosolve
439568127587219463612734985751382649326945871948176352174853296265491738893627514 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (17)
C1: 7,9
C2: 7,9
E1: 6,9
F2: 6,9
I1: 6,7
H2: 6,7
A4: 7,9
A6: 7,9
F5: 5,7
E6: 6,7
G4: 6,7
H5: 5,7
B7: 6,7
B9: 7,9
E8: 7,9
F9: 7,9
G8: 6,7

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
F5,F6: 5.. / F5 = 5  =>  0 pairs (*) / F6 = 5  =>  0 pairs (X)
H5,H6: 5.. / H5 = 5  =>  0 pairs (X) / H6 = 5  =>  0 pairs (_)
F5,H5: 5.. / F5 = 5  =>  0 pairs (*) / H5 = 5  =>  0 pairs (X)
F6,H6: 5.. / F6 = 5  =>  0 pairs (X) / H6 = 5  =>  0 pairs (_)
E1,F2: 6.. / E1 = 6  =>  0 pairs (*) / F2 = 6  =>  0 pairs (X)
I1,H2: 6.. / I1 = 6  =>  0 pairs (X) / H2 = 6  =>  0 pairs (_)
E6,F6: 6.. / E6 = 6  =>  0 pairs (X) / F6 = 6  =>  0 pairs (_)
G4,I4: 6.. / G4 = 6  =>  0 pairs (*) / I4 = 6  =>  0 pairs (X)
B7,B8: 6.. / B7 = 6  =>  0 pairs (X) / B8 = 6  =>  0 pairs (_)
E1,I1: 6.. / E1 = 6  =>  0 pairs (*) / I1 = 6  =>  0 pairs (X)
F2,H2: 6.. / F2 = 6  =>  0 pairs (X) / H2 = 6  =>  0 pairs (_)
B8,G8: 6.. / B8 = 6  =>  0 pairs (*) / G8 = 6  =>  0 pairs (X)
E1,E6: 6.. / E1 = 6  =>  0 pairs (*) / E6 = 6  =>  0 pairs (X)
F2,F6: 6.. / F2 = 6  =>  0 pairs (X) / F6 = 6  =>  0 pairs (_)
G4,G8: 6.. / G4 = 6  =>  0 pairs (*) / G8 = 6  =>  0 pairs (X)
H2,H7: 6.. / H2 = 6  =>  0 pairs (*) / H7 = 6  =>  0 pairs (X)
C1,C2: 7.. / C1 = 7  =>  0 pairs (X) / C2 = 7  =>  0 pairs (_)
I1,H2: 7.. / I1 = 7  =>  0 pairs (*) / H2 = 7  =>  0 pairs (X)
A4,A6: 7.. / A4 = 7  =>  0 pairs (*) / A6 = 7  =>  0 pairs (X)
E8,F9: 7.. / E8 = 7  =>  0 pairs (X) / F9 = 7  =>  0 pairs (_)
C1,I1: 7.. / C1 = 7  =>  0 pairs (X) / I1 = 7  =>  0 pairs (_)
C2,H2: 7.. / C2 = 7  =>  0 pairs (*) / H2 = 7  =>  0 pairs (X)
F5,H5: 7.. / F5 = 7  =>  0 pairs (X) / H5 = 7  =>  0 pairs (_)
B9,F9: 7.. / B9 = 7  =>  0 pairs (X) / F9 = 7  =>  0 pairs (_)
E6,E8: 7.. / E6 = 7  =>  0 pairs (*) / E8 = 7  =>  0 pairs (X)
G4,G8: 7.. / G4 = 7  =>  0 pairs (X) / G8 = 7  =>  0 pairs (_)
C1,C2: 9.. / C1 = 9  =>  0 pairs (*) / C2 = 9  =>  0 pairs (X)
E1,F2: 9.. / E1 = 9  =>  0 pairs (X) / F2 = 9  =>  0 pairs (_)
A4,A6: 9.. / A4 = 9  =>  0 pairs (X) / A6 = 9  =>  0 pairs (_)
I4,H6: 9.. / I4 = 9  =>  0 pairs (*) / H6 = 9  =>  0 pairs (X)
B8,B9: 9.. / B8 = 9  =>  0 pairs (X) / B9 = 9  =>  0 pairs (_)
E8,F9: 9.. / E8 = 9  =>  0 pairs (*) / F9 = 9  =>  0 pairs (X)
H7,I7: 9.. / H7 = 9  =>  0 pairs (*) / I7 = 9  =>  0 pairs (X)
C1,E1: 9.. / C1 = 9  =>  0 pairs (*) / E1 = 9  =>  0 pairs (X)
C2,F2: 9.. / C2 = 9  =>  0 pairs (X) / F2 = 9  =>  0 pairs (_)
A4,I4: 9.. / A4 = 9  =>  0 pairs (X) / I4 = 9  =>  0 pairs (_)
A6,H6: 9.. / A6 = 9  =>  0 pairs (*) / H6 = 9  =>  0 pairs (X)
B8,E8: 9.. / B8 = 9  =>  0 pairs (X) / E8 = 9  =>  0 pairs (_)
B9,F9: 9.. / B9 = 9  =>  0 pairs (*) / F9 = 9  =>  0 pairs (X)
E1,E8: 9.. / E1 = 9  =>  0 pairs (X) / E8 = 9  =>  0 pairs (_)
F2,F9: 9.. / F2 = 9  =>  0 pairs (*) / F9 = 9  =>  0 pairs (X)
H6,H7: 9.. / H6 = 9  =>  0 pairs (X) / H7 = 9  =>  0 pairs (_)
I4,I7: 9.. / I4 = 9  =>  0 pairs (*) / I7 = 9  =>  0 pairs (X)
* DURATION: 0:01:11.494633  START: 06:58:09.022313  END: 06:59:20.516946 2017-05-04
* CP COUNT: (43)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A4,A6,B7,B9,C1,C2,E1,E6,E8,F2,F5,F9,G4,G8,H2,H5,I1)
* 43.5.812.58.21.4.3612734985.51382.4.32694.8.1.481..3.21.48532..2.54.1.388.362.514
* PAIR I1: 6,7 COL I
I4: 6,7,9                                # reduction candidate for 6,7
I4: 6,7 => CTR
* 43.598126589216473612734985951382.4.32694.8.17481653921.48532.92.5471638873629514
I4: 9 => SOLVED
* 439568127587219463612734985751382649326945871948176352174853296265491738893627514
I7: 6,7,9                                # reduction candidate for 6,7
I7: 6,7 => SOLVED
* 439568127587219463612734985751382649326945871948176352174853296265491738893627514
I7: 9 => CTR
* 43.598126589216473612734985951382.4.32694.8.17481653921.48532.92.5471638873629514
* PAIR H2: 6,7 COL H
H7: 6,7,9                                # reduction candidate for 6,7
H7: 6,7 => CTR
* 43.598126589216473612734985951382.4.32694.8517481653921.48532.92.5471638873629514
H7: 9 => SOLVED
* 439568127587219463612734985751382649326945871948176352174853296265491738893627514
* PAIR A4: 7,9 ROW 4
I4: 7,9,6                                # reduction candidate for 7,9
I4: 7,9 => SOLVED
* 439568127587219463612734985751382649326945871948176352174853296265491738893627514
I4: 6 => CTR
* 43.5.812.58.21.4.36127349859513827463269478517481653921.48532.92.5471638873629514
* PAIR A6: 7,9 ROW 6
H6: 7,9,5                                # reduction candidate for 7,9
H6: 7,9 => CTR
* 43.5.812.58.216473612734985.51382.4.3269478517481653921.48532692654.1.388.362.514
H6: 5 => SOLVED
* 439568127587219463612734985751382649326945871948176352174853296265491738893627514
* PAIR F5: 5,7 BLK 5
F6: 5,7,6                                # reduction candidate for 5,7
F6: 5,7 => CTR
* 43.5.812.58.216473612734985.51382.4.3269478517481653921.48532692654.1.388.362.514
F6: 6 => SOLVED
* 439568127587219463612734985751382649326945871948176352174853296265491738893627514
* PAIR E6: 6,7 BLK 5
F6: 6,7,5                                # reduction candidate for 6,7
F6: 6,7 => SOLVED
* 439568127587219463612734985751382649326945871948176352174853296265491738893627514
F6: 5 => CTR
* 43.5.812.58.216473612734985.51382.4.3269478517481653921.48532692654.1.388.362.514
* PAIR G4: 6,7 BLK 6
I4: 6,7,9                                # reduction candidate for 6,7
I4: 6,7 => CTR
* 43.598126589216473612734985951382.4.32694.8.17481653921.48532.92.5471638873629514
I4: 9 => SOLVED
* 439568127587219463612734985751382649326945871948176352174853296265491738893627514
* PAIR H5: 5,7 BLK 6
H6: 5,7,9                                # reduction candidate for 5,7
H6: 5,7 => SOLVED
* 439568127587219463612734985751382649326945871948176352174853296265491738893627514
H6: 9 => CTR
* 43.5.812.58.216473612734985951382.473269478517481653921748532692654.1.388.362.514
* PAIR B7: 6,7 BLK 7
B8: 6,7,9                                # reduction candidate for 6,7
B8: 6,7 => SOLVED
* 439568127587219463612734985751382649326945871948176352174853296265491738893627514
B8: 9 => CTR
* 43.598126589216473612734985.5138274932694.8.1.481..3.21648532..295471638873629514
* PAIR B7: 6,7 ROW 7
H7: 6,7,9                                # reduction candidate for 6,7
H7: 6,7 => CTR
* 43.598126589216473612734985951382.4.32694.8517481653921.48532.92.5471638873629514
H7: 9 => SOLVED
* 439568127587219463612734985751382649326945871948176352174853296265491738893627514
I7: 6,7,9                                # reduction candidate for 6,7
I7: 6,7 => SOLVED
* 439568127587219463612734985751382649326945871948176352174853296265491738893627514
I7: 9 => CTR
* 43.598126589216473612734985951382.4.32694.8.17481653921.48532.92.5471638873629514
* PAIR B9: 7,9 BLK 7
B8: 7,9,6                                # reduction candidate for 7,9
B8: 7,9 => CTR
* 43.5.812.58.21.463612734985.513827463269478517481..3.21648532..2.54.16388.362.514
B8: 6 => SOLVED
* 439568127587219463612734985751382649326945871948176352174853296265491738893627514
* PAIR E8: 7,9 ROW 8
B8: 7,9,6                                # reduction candidate for 7,9
B8: 7,9 => CTR
* 43.5.812.58.21.463612734985.513827463269478517481..3.21648532..2.54.16388.362.514
B8: 6 => SOLVED
* 439568127587219463612734985751382649326945871948176352174853296265491738893627514
* PAIR G8: 6,7 BLK 9
H7: 6,7,9                                # reduction candidate for 6,7
H7: 6,7 => CTR
* 43.598126589216473612734985951382.4.32694.8517481653921.48532.92.5471638873629514
H7: 9 => SOLVED
* 439568127587219463612734985751382649326945871948176352174853296265491738893627514
I7: 6,7,9                                # reduction candidate for 6,7
I7: 6,7 => SOLVED
* 439568127587219463612734985751382649326945871948176352174853296265491738893627514
I7: 9 => CTR
* 43.598126589216473612734985951382.4.32694.8.17481653921.48532.92.5471638873629514
* PAIR G8: 6,7 ROW 8
B8: 6,7,9                                # reduction candidate for 6,7
B8: 6,7 => SOLVED
* 439568127587219463612734985751382649326945871948176352174853296265491738893627514
B8: 9 => CTR
* 43.598126589216473612734985.5138274932694.8.1.481..3.21648532..295471638873629514
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-123-base-pr-000.dot
* REASONING
* DIS # I4: 6,7 => CTR => I4: 9
* PRF # I4: 9 => SOL
* PRF # I7: 6,7 => SOL
* DIS # I7: 9 => CTR => I7: 6,7
* DIS # H7: 6,7 => CTR => H7: 9
* PRF # H7: 9 => SOL
* PRF # I4: 7,9 => SOL
* DIS # I4: 6 => CTR => I4: 7,9
* DIS # H6: 7,9 => CTR => H6: 5
* PRF # H6: 5 => SOL
* DIS # F6: 5,7 => CTR => F6: 6
* PRF # F6: 6 => SOL
* PRF # F6: 6,7 => SOL
* DIS # F6: 5 => CTR => F6: 6,7
* DIS # I4: 6,7 => CTR => I4: 9
* PRF # I4: 9 => SOL
* PRF # H6: 5,7 => SOL
* DIS # H6: 9 => CTR => H6: 5,7
* PRF # B8: 6,7 => SOL
* DIS # B8: 9 => CTR => B8: 6,7
* DIS # H7: 6,7 => CTR => H7: 9
* PRF # H7: 9 => SOL
* PRF # I7: 6,7 => SOL
* DIS # I7: 9 => CTR => I7: 6,7
* DIS # B8: 7,9 => CTR => B8: 6
* PRF # B8: 6 => SOL
* DIS # B8: 7,9 => CTR => B8: 6
* PRF # B8: 6 => SOL
* DIS # H7: 6,7 => CTR => H7: 9
* PRF # H7: 9 => SOL
* PRF # I7: 6,7 => SOL
* DIS # I7: 9 => CTR => I7: 6,7
* PRF # B8: 6,7 => SOL
* DIS # B8: 9 => CTR => B8: 6,7
* CNT  34 HDP CHAINS /  34 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A4,A6,B7,B9,C1,C2,E1,E6,E8,F2,F5,F9,G4,G8,H2,H5,I1)
* 43.5.812.58.21.4.3612734985.51382.4.32694.8.1.481..3.21.48532..2.54.1.388.362.514
* PAIR I1: 6,7 COL I
I4: 6,7,9                                # reduction candidate for 6,7
I4: 6,7 => CTR
* 43.598126589216473612734985951382.4.32694.8.17481653921.48532.92.5471638873629514
I4: 9 => SOLVED
* 439568127587219463612734985751382649326945871948176352174853296265491738893627514
* DURATION: 0:00:01.874621  START: 06:59:59.747723  END: 07:00:01.622344 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-123-base-pr-001.dot
* REASONING
* DIS # I4: 6,7 => CTR => I4: 9
* PRF I4: 9 => SOL
* STA I4: 9
* CNT   2 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 123

solution: 439568127587219463612734985751382649326945871948176352174853296265491738893627514
info: 1806     FNBWY    S8.f     17385

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

Solution

position: 439568127587219463612734985751382649326945871948176352174853296265491738893627514 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 # I4: 6,7 => CTR => I4: 9
* PRF # I4: 9 => SOL
* PRF # I7: 6,7 => SOL
* DIS # I7: 9 => CTR => I7: 6,7
* DIS # H7: 6,7 => CTR => H7: 9
* PRF # H7: 9 => SOL
* PRF # I4: 7,9 => SOL
* DIS # I4: 6 => CTR => I4: 7,9
* DIS # H6: 7,9 => CTR => H6: 5
* PRF # H6: 5 => SOL
* DIS # F6: 5,7 => CTR => F6: 6
* PRF # F6: 6 => SOL
* PRF # F6: 6,7 => SOL
* DIS # F6: 5 => CTR => F6: 6,7
* DIS # I4: 6,7 => CTR => I4: 9
* PRF # I4: 9 => SOL
* PRF # H6: 5,7 => SOL
* DIS # H6: 9 => CTR => H6: 5,7
* PRF # B8: 6,7 => SOL
* DIS # B8: 9 => CTR => B8: 6,7
* DIS # H7: 6,7 => CTR => H7: 9
* PRF # H7: 9 => SOL
* PRF # I7: 6,7 => SOL
* DIS # I7: 9 => CTR => I7: 6,7
* DIS # B8: 7,9 => CTR => B8: 6
* PRF # B8: 6 => SOL
* DIS # B8: 7,9 => CTR => B8: 6
* PRF # B8: 6 => SOL
* DIS # H7: 6,7 => CTR => H7: 9
* PRF # H7: 9 => SOL
* PRF # I7: 6,7 => SOL
* DIS # I7: 9 => CTR => I7: 6,7
* PRF # B8: 6,7 => SOL
* DIS # B8: 9 => CTR => B8: 6,7
* CNT  34 HDP CHAINS /  34 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # I4: 6,7 => CTR => I4: 9
* PRF I4: 9 => SOL
* STA I4: 9
* CNT   2 HDP CHAINS /   1 HYP OPENED