Analysis of xx-top500-143-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 46..3..........1...3.......2..1.5......8....6.4.....3.7.1...5.....2............4. initial

Autosolve

position: 462.31.858754.61.31395..6.42831654..917843256546...8317213.456.69425.31.35861..42 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # E6: 2,9 => CTR => E6: 7
* PRF # E6: 7 => SOL
* PRF # E3: 2,8 => SOL
* DIS # E3: 7 => CTR => E3: 2,8
* PRF # E3: 2,7 => SOL
* DIS # E3: 8 => CTR => E3: 2,7
* PRF # E6: 7,9 => SOL
* DIS # E6: 2 => CTR => E6: 7,9
* DIS # E6: 2,9 => CTR => E6: 7
* PRF # E6: 7 => 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 # E6: 2,9 => CTR => E6: 7
* PRF E6: 7 => SOL
* STA E6: 7
* CNT   2 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

46..3..........1...3.......2..1.5......8....6.4.....3.7.1...5.....2............4. initial
462.31.858754.61.31395..6.42831654..917843256546...8317213.456.69425.31.35861..42 autosolve
462731985875496123139528674283165497917843256546972831721384569694257318358619742 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (16)
D1: 7,9
E2: 2,9
F3: 2,8
G1: 7,9
H2: 2,9
H3: 2,7
D6: 7,9
F6: 2,9
H4: 7,9
I4: 7,9
E7: 8,9
F8: 7,8
F9: 7,9
I7: 8,9
I8: 7,8
G9: 7,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
H2,H3: 2.. / H2 = 2  =>  0 pairs (*) / H3 = 2  =>  0 pairs (X)
E6,F6: 2.. / E6 = 2  =>  0 pairs (X) / F6 = 2  =>  0 pairs (_)
E2,H2: 2.. / E2 = 2  =>  0 pairs (X) / H2 = 2  =>  0 pairs (_)
F3,F6: 2.. / F3 = 2  =>  0 pairs (X) / F6 = 2  =>  0 pairs (_)
D1,E3: 7.. / D1 = 7  =>  0 pairs (*) / E3 = 7  =>  0 pairs (X)
G1,H3: 7.. / G1 = 7  =>  0 pairs (X) / H3 = 7  =>  0 pairs (_)
D6,E6: 7.. / D6 = 7  =>  0 pairs (X) / E6 = 7  =>  0 pairs (_)
H4,I4: 7.. / H4 = 7  =>  0 pairs (X) / I4 = 7  =>  0 pairs (_)
F8,F9: 7.. / F8 = 7  =>  0 pairs (*) / F9 = 7  =>  0 pairs (X)
I8,G9: 7.. / I8 = 7  =>  0 pairs (X) / G9 = 7  =>  0 pairs (_)
D1,G1: 7.. / D1 = 7  =>  0 pairs (*) / G1 = 7  =>  0 pairs (X)
E3,H3: 7.. / E3 = 7  =>  0 pairs (X) / H3 = 7  =>  0 pairs (_)
F8,I8: 7.. / F8 = 7  =>  0 pairs (*) / I8 = 7  =>  0 pairs (X)
F9,G9: 7.. / F9 = 7  =>  0 pairs (X) / G9 = 7  =>  0 pairs (_)
D1,D6: 7.. / D1 = 7  =>  0 pairs (*) / D6 = 7  =>  0 pairs (X)
E3,E6: 7.. / E3 = 7  =>  0 pairs (X) / E6 = 7  =>  0 pairs (_)
G1,G9: 7.. / G1 = 7  =>  0 pairs (X) / G9 = 7  =>  0 pairs (_)
H3,H4: 7.. / H3 = 7  =>  0 pairs (*) / H4 = 7  =>  0 pairs (X)
I4,I8: 7.. / I4 = 7  =>  0 pairs (*) / I8 = 7  =>  0 pairs (X)
E3,F3: 8.. / E3 = 8  =>  0 pairs (X) / F3 = 8  =>  0 pairs (_)
E7,F8: 8.. / E7 = 8  =>  0 pairs (*) / F8 = 8  =>  0 pairs (X)
I7,I8: 8.. / I7 = 8  =>  0 pairs (X) / I8 = 8  =>  0 pairs (_)
E7,I7: 8.. / E7 = 8  =>  0 pairs (*) / I7 = 8  =>  0 pairs (X)
F8,I8: 8.. / F8 = 8  =>  0 pairs (X) / I8 = 8  =>  0 pairs (_)
E3,E7: 8.. / E3 = 8  =>  0 pairs (X) / E7 = 8  =>  0 pairs (_)
F3,F8: 8.. / F3 = 8  =>  0 pairs (*) / F8 = 8  =>  0 pairs (X)
D1,E2: 9.. / D1 = 9  =>  0 pairs (X) / E2 = 9  =>  0 pairs (_)
G1,H2: 9.. / G1 = 9  =>  0 pairs (*) / H2 = 9  =>  0 pairs (X)
H4,I4: 9.. / H4 = 9  =>  0 pairs (*) / I4 = 9  =>  0 pairs (X)
E7,F9: 9.. / E7 = 9  =>  0 pairs (X) / F9 = 9  =>  0 pairs (_)
I7,G9: 9.. / I7 = 9  =>  0 pairs (*) / G9 = 9  =>  0 pairs (X)
D1,G1: 9.. / D1 = 9  =>  0 pairs (X) / G1 = 9  =>  0 pairs (_)
E2,H2: 9.. / E2 = 9  =>  0 pairs (*) / H2 = 9  =>  0 pairs (X)
E7,I7: 9.. / E7 = 9  =>  0 pairs (X) / I7 = 9  =>  0 pairs (_)
F9,G9: 9.. / F9 = 9  =>  0 pairs (*) / G9 = 9  =>  0 pairs (X)
D1,D6: 9.. / D1 = 9  =>  0 pairs (X) / D6 = 9  =>  0 pairs (_)
F6,F9: 9.. / F6 = 9  =>  0 pairs (X) / F9 = 9  =>  0 pairs (_)
G1,G9: 9.. / G1 = 9  =>  0 pairs (*) / G9 = 9  =>  0 pairs (X)
H2,H4: 9.. / H2 = 9  =>  0 pairs (X) / H4 = 9  =>  0 pairs (_)
I4,I7: 9.. / I4 = 9  =>  0 pairs (X) / I7 = 9  =>  0 pairs (_)
* DURATION: 0:01:11.719093  START: 07:37:34.232649  END: 07:38:45.951742 2017-05-04
* CP COUNT: (40)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (D1,D6,E2,E7,F3,F6,F8,F9,G1,G9,H2,H3,H4,I4,I7,I8)
* 462.31.858754.61.31395..6.42831654..917843256546...8317213.456.69425.31.35861..42
* PAIR E2: 2,9 COL E
E6: 2,9,7                                # reduction candidate for 2,9
E6: 2,9 => CTR
* 462.31.858754.61.3139578624283165479917843256546...8317213.456.69425.31.35861..42
E6: 7 => SOLVED
* 462731985875496123139528674283165497917843256546972831721384569694257318358619742
* PAIR F3: 2,8 BLK 2
E3: 2,8,7                                # reduction candidate for 2,8
E3: 2,8 => SOLVED
* 462731985875496123139528674283165497917843256546972831721384569694257318358619742
E3: 7 => CTR
* 462.31.858754.61.3139578624283165479917843256546...8317213.456.69425.31.35861..42
* PAIR H3: 2,7 ROW 3
E3: 2,7,8                                # reduction candidate for 2,7
E3: 2,7 => SOLVED
* 462731985875496123139528674283165497917843256546972831721384569694257318358619742
E3: 8 => CTR
* 46273198587549612313958.6.42831654..917843256546...8317213.456.69425.31.35861..42
* PAIR D6: 7,9 BLK 5
E6: 7,9,2                                # reduction candidate for 7,9
E6: 7,9 => SOLVED
* 462731985875496123139528674283165497917843256546972831721384569694257318358619742
E6: 2 => CTR
* 462.31.858754.61.3139578624283165479917843256546...8317213.456.69425.31.35861..42
* PAIR F6: 2,9 BLK 5
E6: 2,9,7                                # reduction candidate for 2,9
E6: 2,9 => CTR
* 462.31.858754.61.3139578624283165479917843256546...8317213.456.69425.31.35861..42
E6: 7 => SOLVED
* 462731985875496123139528674283165497917843256546972831721384569694257318358619742
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-143-base-pr-000.dot
* REASONING
* DIS # E6: 2,9 => CTR => E6: 7
* PRF # E6: 7 => SOL
* PRF # E3: 2,8 => SOL
* DIS # E3: 7 => CTR => E3: 2,8
* PRF # E3: 2,7 => SOL
* DIS # E3: 8 => CTR => E3: 2,7
* PRF # E6: 7,9 => SOL
* DIS # E6: 2 => CTR => E6: 7,9
* DIS # E6: 2,9 => CTR => E6: 7
* PRF # E6: 7 => SOL
* CNT  10 HDP CHAINS /  10 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (D1,D6,E2,E7,F3,F6,F8,F9,G1,G9,H2,H3,H4,I4,I7,I8)
* 462.31.858754.61.31395..6.42831654..917843256546...8317213.456.69425.31.35861..42
* PAIR E2: 2,9 COL E
E6: 2,9,7                                # reduction candidate for 2,9
E6: 2,9 => CTR
* 462.31.858754.61.3139578624283165479917843256546...8317213.456.69425.31.35861..42
E6: 7 => SOLVED
* 462731985875496123139528674283165497917843256546972831721384569694257318358619742
* DURATION: 0:00:02.973158  START: 07:38:59.049698  END: 07:39:02.022856 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-143-base-pr-001.dot
* REASONING
* DIS # E6: 2,9 => CTR => E6: 7
* PRF E6: 7 => SOL
* STA E6: 7
* CNT   2 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 143

solution: 462731985875496123139528674283165497917843256546972831721384569694257318358619742
info: 1814     FNBWY    S8.f     31740

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

Solution

position: 462731985875496123139528674283165497917843256546972831721384569694257318358619742 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 # E6: 2,9 => CTR => E6: 7
* PRF # E6: 7 => SOL
* PRF # E3: 2,8 => SOL
* DIS # E3: 7 => CTR => E3: 2,8
* PRF # E3: 2,7 => SOL
* DIS # E3: 8 => CTR => E3: 2,7
* PRF # E6: 7,9 => SOL
* DIS # E6: 2 => CTR => E6: 7,9
* DIS # E6: 2,9 => CTR => E6: 7
* PRF # E6: 7 => SOL
* CNT  10 HDP CHAINS /  10 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # E6: 2,9 => CTR => E6: 7
* PRF E6: 7 => SOL
* STA E6: 7
* CNT   2 HDP CHAINS /   1 HYP OPENED