Analysis of xx-top500-082-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 7.48.....1.....5............3..562.......2..1..8......25.....9....41............. initial

Autosolve

position: 7.48.5.121.2.475..3.52.14..931756248.47.82..1.281.47..25367819487.41..2541.52.8.. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # E1: 6,9 => CTR => E1: 3
* PRF # E1: 3 => SOL
* PRF # G1: 6,9 => SOL
* DIS # G1: 3 => CTR => G1: 6,9
* DIS # E1: 6 => CTR => E1: 3,9
* DIS # E1: 6,9 => CTR => E1: 3
* PRF # E1: 3 => SOL
* DIS # H5: 3 => CTR => H5: 5,6
* PRF # H6: 3 => SOL
* DIS # G5: 6 => CTR => G5: 3,9
* PRF # I6: 6 => SOL
* DIS # E1: 6 => CTR => E1: 3,9
* PRF # G1: 3,6 => SOL
* DIS # G1: 9 => CTR => G1: 3,6
* DIS # G5: 3,6 => CTR => G5: 9
* PRF # G5: 9 => SOL
* CNT  16 HDP CHAINS /  30 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 # E1: 6,9 => CTR => E1: 3
* PRF E1: 3 => SOL
* STA E1: 3
* CNT   2 HDP CHAINS /   3 HYP OPENED

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

Details

Positions

7.48.....1.....5............3..562.......2..1..8......25.....9....41............. initial
7.48.5.121.2.475..3.52.14..931756248.47.82..1.281.47..25367819487.41..2541.52.8.. autosolve
794835612162947583385261479931756248647382951528194736253678194876419325419523867 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (12)
B1: 6,9
D2: 3,9
E3: 6,9
A5: 5,6
A6: 5,6
D5: 3,9
E6: 3,9
C8: 6,9
C9: 6,9
F8: 3,9
F9: 3,9
G8: 3,6

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
E1,D2: 3.. / E1 = 3  =>  0 pairs (*) / D2 = 3  =>  0 pairs (X)
D5,E6: 3.. / D5 = 3  =>  0 pairs (*) / E6 = 3  =>  0 pairs (X)
F8,F9: 3.. / F8 = 3  => 12 pairs (_) / F9 = 3  =>  0 pairs (*)
E1,G1: 3.. / E1 = 3  =>  0 pairs (*) / G1 = 3  =>  0 pairs (X)
F8,G8: 3.. / F8 = 3  => 12 pairs (_) / G8 = 3  =>  0 pairs (*)
D2,D5: 3.. / D2 = 3  =>  0 pairs (X) / D5 = 3  =>  0 pairs (_)
E1,E6: 3.. / E1 = 3  =>  0 pairs (*) / E6 = 3  =>  0 pairs (X)
A5,A6: 5.. / A5 = 5  => 12 pairs (_) / A6 = 5  => 12 pairs (_)
H5,H6: 5.. / H5 = 5  => 12 pairs (_) / H6 = 5  => 12 pairs (_)
A5,H5: 5.. / A5 = 5  => 12 pairs (_) / H5 = 5  => 12 pairs (_)
A6,H6: 5.. / A6 = 5  => 12 pairs (_) / H6 = 5  => 12 pairs (_)
E1,E3: 6.. / E1 = 6  =>  0 pairs (X) / E3 = 6  => 15 pairs (_)
A5,A6: 6.. / A5 = 6  => 12 pairs (_) / A6 = 6  => 12 pairs (_)
C8,C9: 6.. / C8 = 6  =>  0 pairs (*) / C9 = 6  =>  0 pairs (X)
C8,G8: 6.. / C8 = 6  =>  0 pairs (*) / G8 = 6  =>  0 pairs (X)
H3,I3: 7.. / H3 = 7  => 15 pairs (_) / I3 = 7  => 14 pairs (_)
H9,I9: 7.. / H9 = 7  => 14 pairs (_) / I9 = 7  => 15 pairs (_)
H3,H9: 7.. / H3 = 7  => 15 pairs (_) / H9 = 7  => 14 pairs (_)
I3,I9: 7.. / I3 = 7  => 14 pairs (_) / I9 = 7  => 15 pairs (_)
B2,B3: 8.. / B2 = 8  => 16 pairs (_) / B3 = 8  => 14 pairs (_)
H2,H3: 8.. / H2 = 8  => 14 pairs (_) / H3 = 8  => 16 pairs (_)
B2,H2: 8.. / B2 = 8  => 16 pairs (_) / H2 = 8  => 14 pairs (_)
B3,H3: 8.. / B3 = 8  => 14 pairs (_) / H3 = 8  => 16 pairs (_)
D5,E6: 9.. / D5 = 9  =>  0 pairs (X) / E6 = 9  =>  0 pairs (_)
G5,I6: 9.. / G5 = 9  =>  0 pairs (*) / I6 = 9  =>  0 pairs (X)
C8,C9: 9.. / C8 = 9  => 12 pairs (_) / C9 = 9  =>  0 pairs (*)
F8,F9: 9.. / F8 = 9  =>  0 pairs (*) / F9 = 9  =>  0 pairs (X)
D5,G5: 9.. / D5 = 9  =>  0 pairs (X) / G5 = 9  =>  0 pairs (_)
E6,I6: 9.. / E6 = 9  =>  0 pairs (*) / I6 = 9  =>  0 pairs (X)
C8,F8: 9.. / C8 = 9  => 12 pairs (_) / F8 = 9  =>  0 pairs (*)
C9,F9: 9.. / C9 = 9  =>  0 pairs (*) / F9 = 9  =>  0 pairs (X)
D2,D5: 9.. / D2 = 9  =>  0 pairs (*) / D5 = 9  =>  0 pairs (X)
G1,G5: 9.. / G1 = 9  =>  0 pairs (X) / G5 = 9  =>  0 pairs (_)
* DURATION: 0:00:52.917606  START: 05:35:37.516276  END: 05:36:30.433882 2017-05-04
* CP COUNT: (33)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A5,A6,B1,C8,C9,D2,D5,E3,E6,F8,F9,G8)
* 7.48.5.121.2.475..3.52.14..931756248.47.82..1.281.47..25367819487.41..2541.52.8..
* PAIR B1: 6,9 BLK 1
B2: 6,9,8                                # reduction candidate for 6,9
B2: 6,9                                  # 14 pairs
B3: 6,9,8                                # reduction candidate for 6,9
B3: 6,9                                  # 16 pairs
* PAIR B1: 6,9 ROW 1
E1: 6,9,3                                # reduction candidate for 6,9
E1: 6,9 => CTR
* 7.48.53121.23475..3.52.14..931756248.479826.1.281.47..25367819487.41..2541.52.8..
E1: 3 => SOLVED
* 794835612162947583385261479931756248647382951528194736253678194876419325419523867
G1: 6,9,3                                # reduction candidate for 6,9
G1: 6,9 => SOLVED
* 794835612162947583385261479931756248647382951528194736253678194876419325419523867
G1: 3 => CTR
* 7.48.53121.23475..3.52.14..931756248.479826.1.281.47..25367819487.41..2541.52.8..
* PAIR D2: 3,9 BLK 2
E1: 3,9,6                                # reduction candidate for 3,9
E1: 6 => CTR
* 7.48653121.23475..3.52914..931756248.479826.1.281.47..25367819487.41..2541.52.8..
E1: 3,9                                  # 15 pairs
* PAIR D2: 3,9 ROW 2
I2: 3,9,6                                # reduction candidate for 3,9
I2: 6                                    # 20 pairs
I2: 3,9                                  # 15 pairs
* PAIR E3: 6,9 BLK 2
E1: 6,9,3                                # reduction candidate for 6,9
E1: 6,9 => CTR
* 7.48.53121.23475..3.52.14..931756248.479826.1.281.47..25367819487.41..2541.52.8..
E1: 3 => SOLVED
* 794835612162947583385261479931756248647382951528194736253678194876419325419523867
* PAIR E3: 6,9 ROW 3
B3: 6,9,8                                # reduction candidate for 6,9
B3: 6,9                                  # 16 pairs
I3: 6,9,7                                # reduction candidate for 6,9
I3: 6,9                                  # 15 pairs
* PAIR A5: 5,6 ROW 5
H5: 5,6,3                                # reduction candidate for 5,6
H5: 3 => CTR
* 7.48.5.121.2.475..3.52.14..931756248547.8263162813475925367819487641932541.52.8..
H5: 5,6                                  # 14 pairs
* PAIR A6: 5,6 ROW 6
H6: 5,6,3                                # reduction candidate for 5,6
H6: 3 => SOLVED
* 794835612162947583385261479931756248647382951528194736253678194876419325419523867
H6: 5,6                                  # 14 pairs
* PAIR D5: 3,9 ROW 5
G5: 3,9,6                                # reduction candidate for 3,9
G5: 6 => CTR
* 7.48.59121.2.475..3.52.14..931756248.479826316281347592536781948764193254195238..
G5: 3,9                                  # 14 pairs
* PAIR E6: 3,9 ROW 6
I6: 3,9,6                                # reduction candidate for 3,9
I6: 6 => SOLVED
* 794835612162947583385261479931756248647382951528194736253678194876419325419523867
I6: 3,9                                  # 14 pairs
* PAIR E6: 3,9 COL E
E1: 3,9,6                                # reduction candidate for 3,9
E1: 6 => CTR
* 7.48653121.23475..3.52914..931756248.479826.1.281.47..25367819487.41..2541.52.8..
E1: 3,9                                  # 15 pairs
* PAIR G8: 3,6 BLK 9
H9: 3,6,7                                # reduction candidate for 3,6
H9: 3,6                                  # 15 pairs
I9: 3,6,7                                # reduction candidate for 3,6
I9: 3,6                                  # 14 pairs
* PAIR G8: 3,6 COL G
G1: 3,6,9                                # reduction candidate for 3,6
G1: 3,6 => SOLVED
* 794835612162947583385261479931756248647382951528194736253678194876419325419523867
G1: 9 => CTR
* 7.48359121.29475..3.52.14..931756248.47.82..1.281.47..25367819487.41..2541.52.8..
G5: 3,6,9                                # reduction candidate for 3,6
G5: 3,6 => CTR
* 7.48.59121.2.475..3.52.14..931756248.47982..1.281347.925367819487.41..2541.52.8..
G5: 9 => SOLVED
* 794835612162947583385261479931756248647382951528194736253678194876419325419523867
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-082-base-pr-000.dot
* REASONING
* DIS # E1: 6,9 => CTR => E1: 3
* PRF # E1: 3 => SOL
* PRF # G1: 6,9 => SOL
* DIS # G1: 3 => CTR => G1: 6,9
* DIS # E1: 6 => CTR => E1: 3,9
* DIS # E1: 6,9 => CTR => E1: 3
* PRF # E1: 3 => SOL
* DIS # H5: 3 => CTR => H5: 5,6
* PRF # H6: 3 => SOL
* DIS # G5: 6 => CTR => G5: 3,9
* PRF # I6: 6 => SOL
* DIS # E1: 6 => CTR => E1: 3,9
* PRF # G1: 3,6 => SOL
* DIS # G1: 9 => CTR => G1: 3,6
* DIS # G5: 3,6 => CTR => G5: 9
* PRF # G5: 9 => SOL
* CNT  16 HDP CHAINS /  30 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A5,A6,B1,C8,C9,D2,D5,E3,E6,F8,F9,G8)
* 7.48.5.121.2.475..3.52.14..931756248.47.82..1.281.47..25367819487.41..2541.52.8..
* PAIR B1: 6,9 BLK 1
B2: 6,9,8                                # reduction candidate for 6,9
B2: 6,9                                  # 14 pairs
B3: 6,9,8                                # reduction candidate for 6,9
B3: 6,9                                  # 16 pairs
* PAIR B1: 6,9 ROW 1
E1: 6,9,3                                # reduction candidate for 6,9
E1: 6,9 => CTR
* 7.48.53121.23475..3.52.14..931756248.479826.1.281.47..25367819487.41..2541.52.8..
E1: 3 => SOLVED
* 794835612162947583385261479931756248647382951528194736253678194876419325419523867
* DURATION: 0:00:03.268536  START: 05:37:00.756206  END: 05:37:04.024742 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-082-base-pr-001.dot
* REASONING
* DIS # E1: 6,9 => CTR => E1: 3
* PRF E1: 3 => SOL
* STA E1: 3
* CNT   2 HDP CHAINS /   3 HYP OPENED

Header Info

Top 500 Minimum 17 082

solution: 794835612162947583385261479931756248647382951528194736253678194876419325419523867
info: 1552     FNWXY    S8.f     37374

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

Solution

position: 794835612162947583385261479931756248647382951528194736253678194876419325419523867 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:

* INC # B2: 6,9 => UNS
* INC # B3: 6,9 => UNS
* DIS # E1: 6,9 => CTR => E1: 3
* PRF # E1: 3 => SOL
* PRF # G1: 6,9 => SOL
* DIS # G1: 3 => CTR => G1: 6,9
* INC # E1: 3,9 => UNS
* DIS # E1: 6 => CTR => E1: 3,9
* INC # I2: 3,9 => UNS
* INC # I2: 6 => UNS
* DIS # E1: 6,9 => CTR => E1: 3
* PRF # E1: 3 => SOL
* INC # B3: 6,9 => UNS
* INC # I3: 6,9 => UNS
* INC # H5: 5,6 => UNS
* DIS # H5: 3 => CTR => H5: 5,6
* INC # H6: 5,6 => UNS
* PRF # H6: 3 => SOL
* INC # G5: 3,9 => UNS
* DIS # G5: 6 => CTR => G5: 3,9
* INC # I6: 3,9 => UNS
* PRF # I6: 6 => SOL
* INC # E1: 3,9 => UNS
* DIS # E1: 6 => CTR => E1: 3,9
* INC # H9: 3,6 => UNS
* INC # I9: 3,6 => UNS
* PRF # G1: 3,6 => SOL
* DIS # G1: 9 => CTR => G1: 3,6
* DIS # G5: 3,6 => CTR => G5: 9
* PRF # G5: 9 => SOL
* CNT  30 HDP CHAINS /  30 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # B2: 6,9 => UNS
* INC # B3: 6,9 => UNS
* DIS # E1: 6,9 => CTR => E1: 3
* PRF E1: 3 => SOL
* STA E1: 3
* CNT   4 HDP CHAINS /   3 HYP OPENED