Analysis of xx-top500-139-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 2......36.7.4............5.1..5........2..7..3.5..........36....4....8......1.... initial

Autosolve

position: 25.1.7.369734651...1632..5712754.36..6.2.37153.56712.47.2.36541641.528.353..146.. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # C5: 4,8 => SOL
* DIS # C5: 9 => CTR => C5: 4,8
* PRF # C5: 4,8 => SOL
* DIS # C5: 9 => CTR => C5: 4,8
* PRF # C5: 8,9 => SOL
* DIS # C5: 4 => CTR => C5: 8,9
* PRF # C5: 8,9 => SOL
* DIS # C5: 4 => CTR => C5: 8,9
* PRF # D9: 8,9 => SOL
* DIS # D9: 7 => CTR => D9: 8,9
* PRF # C5: 8,9 => SOL
* DIS # C5: 4 => CTR => C5: 8,9
* PRF # D9: 8,9 => SOL
* DIS # D9: 7 => CTR => D9: 8,9
* DIS # D9: 7,9 => CTR => D9: 8
* PRF # D9: 8 => SOL
* PRF # H9: 7,9 => SOL
* DIS # H9: 2 => CTR => H9: 7,9
* DIS # H9: 2,9 => CTR => H9: 7
* PRF # H9: 7 => SOL
* CNT  20 HDP CHAINS /  20 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 # C5: 4,8 => SOL
* STA C5: 4,8
* CNT   1 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

2......36.7.4............5.1..5........2..7..3.5..........36....4....8......1.... initial
25.1.7.369734651...1632..5712754.36..6.2.37153.56712.47.2.36541641.528.353..146.. autosolve
254187936973465128816329457127548369468293715395671284782936541641752893539814672 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (20)
C1: 4,8
A3: 4,8
E1: 8,9
F3: 8,9
G1: 4,9
H2: 2,8
I2: 2,8
G3: 4,9
A5: 4,8
B6: 8,9
F4: 8,9
E5: 8,9
I4: 8,9
H6: 8,9
B7: 8,9
C9: 8,9
D7: 8,9
D8: 7,9
H8: 7,9
I9: 2,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
H2,I2: 2.. / H2 = 2  =>  0 pairs (*) / I2 = 2  =>  0 pairs (X)
H9,I9: 2.. / H9 = 2  =>  0 pairs (X) / I9 = 2  =>  0 pairs (_)
H2,H9: 2.. / H2 = 2  =>  0 pairs (*) / H9 = 2  =>  0 pairs (X)
I2,I9: 2.. / I2 = 2  =>  0 pairs (X) / I9 = 2  =>  0 pairs (_)
C1,A3: 4.. / C1 = 4  =>  0 pairs (*) / A3 = 4  =>  0 pairs (X)
G1,G3: 4.. / G1 = 4  =>  0 pairs (X) / G3 = 4  =>  0 pairs (_)
A5,C5: 4.. / A5 = 4  =>  0 pairs (*) / C5 = 4  =>  0 pairs (X)
C1,G1: 4.. / C1 = 4  =>  0 pairs (*) / G1 = 4  =>  0 pairs (X)
A3,G3: 4.. / A3 = 4  =>  0 pairs (X) / G3 = 4  =>  0 pairs (_)
A3,A5: 4.. / A3 = 4  =>  0 pairs (X) / A5 = 4  =>  0 pairs (_)
C1,C5: 4.. / C1 = 4  =>  0 pairs (*) / C5 = 4  =>  0 pairs (X)
D8,D9: 7.. / D8 = 7  =>  0 pairs (*) / D9 = 7  =>  0 pairs (X)
H8,H9: 7.. / H8 = 7  =>  0 pairs (X) / H9 = 7  =>  0 pairs (_)
D8,H8: 7.. / D8 = 7  =>  0 pairs (*) / H8 = 7  =>  0 pairs (X)
D9,H9: 7.. / D9 = 7  =>  0 pairs (X) / H9 = 7  =>  0 pairs (_)
C1,A3: 8.. / C1 = 8  =>  0 pairs (X) / A3 = 8  =>  0 pairs (_)
E1,F3: 8.. / E1 = 8  =>  0 pairs (*) / F3 = 8  =>  0 pairs (X)
H2,I2: 8.. / H2 = 8  =>  0 pairs (X) / I2 = 8  =>  0 pairs (_)
F4,E5: 8.. / F4 = 8  =>  0 pairs (*) / E5 = 8  =>  0 pairs (X)
I4,H6: 8.. / I4 = 8  =>  0 pairs (X) / H6 = 8  =>  0 pairs (_)
B7,C9: 8.. / B7 = 8  =>  0 pairs (*) / C9 = 8  =>  0 pairs (X)
D7,D9: 8.. / D7 = 8  =>  0 pairs (X) / D9 = 8  =>  0 pairs (_)
C1,E1: 8.. / C1 = 8  =>  0 pairs (X) / E1 = 8  =>  0 pairs (_)
A3,F3: 8.. / A3 = 8  =>  0 pairs (*) / F3 = 8  =>  0 pairs (X)
F4,I4: 8.. / F4 = 8  =>  0 pairs (*) / I4 = 8  =>  0 pairs (X)
B6,H6: 8.. / B6 = 8  =>  0 pairs (X) / H6 = 8  =>  0 pairs (_)
B7,D7: 8.. / B7 = 8  =>  0 pairs (*) / D7 = 8  =>  0 pairs (X)
C9,D9: 8.. / C9 = 8  =>  0 pairs (X) / D9 = 8  =>  0 pairs (_)
A3,A5: 8.. / A3 = 8  =>  0 pairs (*) / A5 = 8  =>  0 pairs (X)
B6,B7: 8.. / B6 = 8  =>  0 pairs (X) / B7 = 8  =>  0 pairs (_)
E1,E5: 8.. / E1 = 8  =>  0 pairs (*) / E5 = 8  =>  0 pairs (X)
F3,F4: 8.. / F3 = 8  =>  0 pairs (X) / F4 = 8  =>  0 pairs (_)
H2,H6: 8.. / H2 = 8  =>  0 pairs (X) / H6 = 8  =>  0 pairs (_)
I2,I4: 8.. / I2 = 8  =>  0 pairs (*) / I4 = 8  =>  0 pairs (X)
E1,F3: 9.. / E1 = 9  =>  0 pairs (X) / F3 = 9  =>  0 pairs (_)
G1,G3: 9.. / G1 = 9  =>  0 pairs (*) / G3 = 9  =>  0 pairs (X)
C5,B6: 9.. / C5 = 9  =>  0 pairs (X) / B6 = 9  =>  0 pairs (_)
F4,E5: 9.. / F4 = 9  =>  0 pairs (X) / E5 = 9  =>  0 pairs (_)
I4,H6: 9.. / I4 = 9  =>  0 pairs (*) / H6 = 9  =>  0 pairs (X)
B7,C9: 9.. / B7 = 9  =>  0 pairs (X) / C9 = 9  =>  0 pairs (_)
E1,G1: 9.. / E1 = 9  =>  0 pairs (X) / G1 = 9  =>  0 pairs (_)
F3,G3: 9.. / F3 = 9  =>  0 pairs (*) / G3 = 9  =>  0 pairs (X)
F4,I4: 9.. / F4 = 9  =>  0 pairs (X) / I4 = 9  =>  0 pairs (_)
C5,E5: 9.. / C5 = 9  =>  0 pairs (X) / E5 = 9  =>  0 pairs (_)
B6,H6: 9.. / B6 = 9  =>  0 pairs (*) / H6 = 9  =>  0 pairs (X)
B7,D7: 9.. / B7 = 9  =>  0 pairs (X) / D7 = 9  =>  0 pairs (_)
D8,H8: 9.. / D8 = 9  =>  0 pairs (X) / H8 = 9  =>  0 pairs (_)
B6,B7: 9.. / B6 = 9  =>  0 pairs (*) / B7 = 9  =>  0 pairs (X)
C5,C9: 9.. / C5 = 9  =>  0 pairs (X) / C9 = 9  =>  0 pairs (_)
E1,E5: 9.. / E1 = 9  =>  0 pairs (X) / E5 = 9  =>  0 pairs (_)
F3,F4: 9.. / F3 = 9  =>  0 pairs (*) / F4 = 9  =>  0 pairs (X)
I4,I9: 9.. / I4 = 9  =>  0 pairs (*) / I9 = 9  =>  0 pairs (X)
* DURATION: 0:01:28.309726  START: 07:29:26.878917  END: 07:30:55.188643 2017-05-04
* CP COUNT: (52)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A3,A5,B6,B7,C1,C9,D7,D8,E1,E5,F3,F4,G1,G3,H2,H6,H8,I2,I4,I9)
* 25.1.7.369734651...1632..5712754.36..6.2.37153.56712.47.2.36541641.528.353..146..
* PAIR C1: 4,8 COL C
C5: 4,8,9                                # reduction candidate for 4,8
C5: 4,8 => SOLVED
* 254187936973465128816329457127548369468293715395671284782936541641752893539814672
C5: 9 => CTR
* 2541879369734651..81632..5712754.36..6.2.37153.56712.47.2.36541641.528.353..146..
* PAIR A5: 4,8 BLK 4
C5: 4,8,9                                # reduction candidate for 4,8
C5: 4,8 => SOLVED
* 254187936973465128816329457127548369468293715395671284782936541641752893539814672
C5: 9 => CTR
* 2541879369734651..81632..5712754.36..6.2.37153.56712.47.2.36541641.528.353..146..
* PAIR B6: 8,9 BLK 4
C5: 8,9,4                                # reduction candidate for 8,9
C5: 8,9 => SOLVED
* 254187936973465128816329457127548369468293715395671284782936541641752893539814672
C5: 4 => CTR
* 25.1.7.369734651...1632..5712754.36..64293715395671284782936541641752893539814672
* PAIR E5: 8,9 ROW 5
C5: 8,9,4                                # reduction candidate for 8,9
C5: 8,9 => SOLVED
* 254187936973465128816329457127548369468293715395671284782936541641752893539814672
C5: 4 => CTR
* 25.1.7.369734651...1632..5712754.36..64293715395671284782936541641752893539814672
* PAIR C9: 8,9 ROW 9
D9: 8,9,7                                # reduction candidate for 8,9
D9: 8,9 => SOLVED
* 254187936973465128816329457127548369468293715395671284782936541641752893539814672
D9: 7 => CTR
* 2541879369734651..81632..5712754.36..6.2.37153.56712.47.28365416419528735387146..
* PAIR C9: 8,9 COL C
C5: 8,9,4                                # reduction candidate for 8,9
C5: 8,9 => SOLVED
* 254187936973465128816329457127548369468293715395671284782936541641752893539814672
C5: 4 => CTR
* 25.1.7.369734651...1632..5712754.36..64293715395671284782936541641752893539814672
* PAIR D7: 8,9 BLK 8
D9: 8,9,7                                # reduction candidate for 8,9
D9: 8,9 => SOLVED
* 254187936973465128816329457127548369468293715395671284782936541641752893539814672
D9: 7 => CTR
* 2541879369734651..81632..5712754.36..6.2.37153.56712.47.28365416419528735387146..
* PAIR D8: 7,9 BLK 8
D9: 7,9,8                                # reduction candidate for 7,9
D9: 7,9 => CTR
* 2541879369734651..81632..5712754.36..6.2.37153.56712.47.2836541641.528.3538.146..
D9: 8 => SOLVED
* 254187936973465128816329457127548369468293715395671284782936541641752893539814672
* PAIR H8: 7,9 BLK 9
H9: 7,9,2                                # reduction candidate for 7,9
H9: 7,9 => SOLVED
* 254187936973465128816329457127548369468293715395671284782936541641752893539814672
H9: 2 => CTR
* 25.1.7.36973465182.1632..57127549368.69283715385671294792836541641952873538714629
* PAIR I9: 2,9 BLK 9
H9: 2,9,7                                # reduction candidate for 2,9
H9: 2,9 => CTR
* 2541879369734651..81632..5712754.36..6.2.37153.56712.47.28365416419528735387146..
H9: 7 => SOLVED
* 254187936973465128816329457127548369468293715395671284782936541641752893539814672
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-139-base-pr-000.dot
* REASONING
* PRF # C5: 4,8 => SOL
* DIS # C5: 9 => CTR => C5: 4,8
* PRF # C5: 4,8 => SOL
* DIS # C5: 9 => CTR => C5: 4,8
* PRF # C5: 8,9 => SOL
* DIS # C5: 4 => CTR => C5: 8,9
* PRF # C5: 8,9 => SOL
* DIS # C5: 4 => CTR => C5: 8,9
* PRF # D9: 8,9 => SOL
* DIS # D9: 7 => CTR => D9: 8,9
* PRF # C5: 8,9 => SOL
* DIS # C5: 4 => CTR => C5: 8,9
* PRF # D9: 8,9 => SOL
* DIS # D9: 7 => CTR => D9: 8,9
* DIS # D9: 7,9 => CTR => D9: 8
* PRF # D9: 8 => SOL
* PRF # H9: 7,9 => SOL
* DIS # H9: 2 => CTR => H9: 7,9
* DIS # H9: 2,9 => CTR => H9: 7
* PRF # H9: 7 => SOL
* CNT  20 HDP CHAINS /  20 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A3,A5,B6,B7,C1,C9,D7,D8,E1,E5,F3,F4,G1,G3,H2,H6,H8,I2,I4,I9)
* 25.1.7.369734651...1632..5712754.36..6.2.37153.56712.47.2.36541641.528.353..146..
* PAIR C1: 4,8 COL C
C5: 4,8,9                                # reduction candidate for 4,8
C5: 4,8 => SOLVED
* 254187936973465128816329457127548369468293715395671284782936541641752893539814672
* DURATION: 0:00:01.924636  START: 07:31:18.713514  END: 07:31:20.638150 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-139-base-pr-001.dot
* REASONING
* PRF # C5: 4,8 => SOL
* STA C5: 4,8
* CNT   1 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 139

solution: 254187936973465128816329457127548369468293715395671284782936541641752893539814672
info: 1813     FNBWX    S8.f     26741

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

Solution

position: 254187936973465128816329457127548369468293715395671284782936541641752893539814672 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 # C5: 4,8 => SOL
* DIS # C5: 9 => CTR => C5: 4,8
* PRF # C5: 4,8 => SOL
* DIS # C5: 9 => CTR => C5: 4,8
* PRF # C5: 8,9 => SOL
* DIS # C5: 4 => CTR => C5: 8,9
* PRF # C5: 8,9 => SOL
* DIS # C5: 4 => CTR => C5: 8,9
* PRF # D9: 8,9 => SOL
* DIS # D9: 7 => CTR => D9: 8,9
* PRF # C5: 8,9 => SOL
* DIS # C5: 4 => CTR => C5: 8,9
* PRF # D9: 8,9 => SOL
* DIS # D9: 7 => CTR => D9: 8,9
* DIS # D9: 7,9 => CTR => D9: 8
* PRF # D9: 8 => SOL
* PRF # H9: 7,9 => SOL
* DIS # H9: 2 => CTR => H9: 7,9
* DIS # H9: 2,9 => CTR => H9: 7
* PRF # H9: 7 => SOL
* CNT  20 HDP CHAINS /  20 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* PRF # C5: 4,8 => SOL
* STA C5: 4,8
* CNT   1 HDP CHAINS /   1 HYP OPENED