Analysis of xx-top500-253-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 2...1..........4.3......5....53.7.........26..........82.....7....5...1.6..4..... initial

Autosolve

position: 243.157.651.7..4237.62..5.1965327148.3..5.26...2...35.824....753..5.2.1465147..32 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # F2: 8,9 => CTR => F2: 6
* DIS # F2: 8,9 => CTR => F2: 6
* PRF # D6: 8,9 => SOL
* PRF # E6: 6,8 => SOL
* DIS # F2: 8,9 => CTR => F2: 6
* CNT   5 HDP CHAINS /  23 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 # F2: 8,9 => CTR => F2: 6
* PRF F2: 6 # D6: 8,9 => SOL
* STA F2: 6 + D6: 8,9
* CNT   2 HDP CHAINS /   4 HYP OPENED

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

Details

Positions

2...1..........4.3......5....53.7.........26..........82.....7....5...1.6..4..... initial
243.157.651.7..4237.62..5.1965327148.3..5.26...2...35.824....753..5.2.1465147..32 autosolve
243815796518796423796243581965327148437158269182964357824631975379582614651479832 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (20)
C2: 8,9
B3: 8,9
D1: 8,9
E3: 3,4
F3: 3,4
H1: 8,9
H3: 8,9
A5: 1,4
C5: 7,8
A6: 1,4
B6: 7,8
I5: 7,9
I6: 7,9
B8: 7,9
C8: 7,9
E8: 6,8
F9: 8,9
G7: 6,9
G8: 6,8
G9: 8,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
A5,A6: 1.. / A5 = 1  => 20 pairs (_) / A6 = 1  => 18 pairs (_)
D7,F7: 1.. / D7 = 1  => 22 pairs (_) / F7 = 1  => 19 pairs (_)
E3,F3: 3.. / E3 = 3  => 20 pairs (_) / F3 = 3  => 18 pairs (_)
E7,F7: 3.. / E7 = 3  => 18 pairs (_) / F7 = 3  => 20 pairs (_)
E3,E7: 3.. / E3 = 3  => 20 pairs (_) / E7 = 3  => 18 pairs (_)
F3,F7: 3.. / F3 = 3  => 18 pairs (_) / F7 = 3  => 20 pairs (_)
E3,F3: 4.. / E3 = 4  => 18 pairs (_) / F3 = 4  => 20 pairs (_)
A5,A6: 4.. / A5 = 4  => 18 pairs (_) / A6 = 4  => 20 pairs (_)
A5,F5: 4.. / A5 = 4  => 18 pairs (_) / F5 = 4  => 20 pairs (_)
E3,E6: 4.. / E3 = 4  => 18 pairs (_) / E6 = 4  => 20 pairs (_)
E2,F2: 6.. / E2 = 6  =>  0 pairs (X) / F2 = 6  => 21 pairs (_)
G7,G8: 6.. / G7 = 6  => 18 pairs (_) / G8 = 6  => 19 pairs (_)
E8,G8: 6.. / E8 = 6  => 18 pairs (_) / G8 = 6  => 19 pairs (_)
D6,D7: 6.. / D6 = 6  => 21 pairs (_) / D7 = 6  => 17 pairs (_)
C5,B6: 7.. / C5 = 7  =>  0 pairs (*) / B6 = 7  =>  0 pairs (X)
I5,I6: 7.. / I5 = 7  =>  0 pairs (X) / I6 = 7  =>  0 pairs (_)
B8,C8: 7.. / B8 = 7  =>  0 pairs (*) / C8 = 7  =>  0 pairs (X)
C5,I5: 7.. / C5 = 7  =>  0 pairs (*) / I5 = 7  =>  0 pairs (X)
B6,I6: 7.. / B6 = 7  =>  0 pairs (X) / I6 = 7  =>  0 pairs (_)
B6,B8: 7.. / B6 = 7  =>  0 pairs (X) / B8 = 7  =>  0 pairs (_)
C5,C8: 7.. / C5 = 7  =>  0 pairs (*) / C8 = 7  =>  0 pairs (X)
C2,B3: 8.. / C2 = 8  =>  0 pairs (*) / B3 = 8  =>  0 pairs (X)
H1,H3: 8.. / H1 = 8  =>  0 pairs (X) / H3 = 8  =>  0 pairs (_)
C5,B6: 8.. / C5 = 8  =>  0 pairs (X) / B6 = 8  =>  0 pairs (_)
E8,F9: 8.. / E8 = 8  => 19 pairs (_) / F9 = 8  => 18 pairs (_)
G8,G9: 8.. / G8 = 8  => 18 pairs (_) / G9 = 8  => 19 pairs (_)
D1,H1: 8.. / D1 = 8  =>  0 pairs (*) / H1 = 8  =>  0 pairs (X)
B3,H3: 8.. / B3 = 8  =>  0 pairs (X) / H3 = 8  =>  0 pairs (_)
E8,G8: 8.. / E8 = 8  => 19 pairs (_) / G8 = 8  => 18 pairs (_)
F9,G9: 8.. / F9 = 8  => 18 pairs (_) / G9 = 8  => 19 pairs (_)
B3,B6: 8.. / B3 = 8  =>  0 pairs (X) / B6 = 8  =>  0 pairs (_)
C2,C5: 8.. / C2 = 8  =>  0 pairs (*) / C5 = 8  =>  0 pairs (X)
C2,B3: 9.. / C2 = 9  =>  0 pairs (X) / B3 = 9  =>  0 pairs (_)
H1,H3: 9.. / H1 = 9  =>  0 pairs (*) / H3 = 9  =>  0 pairs (X)
I5,I6: 9.. / I5 = 9  =>  0 pairs (*) / I6 = 9  =>  0 pairs (X)
B8,C8: 9.. / B8 = 9  =>  0 pairs (X) / C8 = 9  =>  0 pairs (_)
G7,G9: 9.. / G7 = 9  => 19 pairs (_) / G9 = 9  => 18 pairs (_)
D1,H1: 9.. / D1 = 9  =>  0 pairs (X) / H1 = 9  =>  0 pairs (_)
B3,H3: 9.. / B3 = 9  =>  0 pairs (*) / H3 = 9  =>  0 pairs (X)
F9,G9: 9.. / F9 = 9  => 19 pairs (_) / G9 = 9  => 18 pairs (_)
B3,B8: 9.. / B3 = 9  =>  0 pairs (*) / B8 = 9  =>  0 pairs (X)
C2,C8: 9.. / C2 = 9  =>  0 pairs (X) / C8 = 9  =>  0 pairs (_)
* DURATION: 0:01:15.425976  START: 11:25:54.914978  END: 11:27:10.340954 2017-05-04
* CP COUNT: (42)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A5,A6,B3,B6,B8,C2,C5,C8,D1,E3,E8,F3,F9,G7,G8,G9,H1,H3,I5,I6)
* 243.157.651.7..4237.62..5.1965327148.3..5.26...2...35.824....753..5.2.1465147..32
* PAIR C2: 8,9 ROW 2
E2: 8,9,6                                # reduction candidate for 8,9
E2: 8,9                                  # 21 pairs
F2: 8,9,6                                # reduction candidate for 8,9
F2: 8,9 => CTR
* 2439157865197684237862..591965327148.3815.26...2...35.824....753..582614651479832
F2: 6                                    # 21 pairs
* PAIR D1: 8,9 BLK 2
E2: 8,9,6                                # reduction candidate for 8,9
E2: 8,9                                  # 21 pairs
F2: 8,9,6                                # reduction candidate for 8,9
F2: 8,9 => CTR
* 2439157865197684237862..591965327148.3815.26...2...35.824....753..582614651479832
F2: 6                                    # 21 pairs
* PAIR D1: 8,9 COL D
D5: 8,9,1                                # reduction candidate for 8,9
D5: 8,9                                  # 24 pairs
D6: 8,9,1,6                              # reduction candidate for 8,9
D6: 8,9 => SOLVED
* 243815796518796423796243581965327148437158269182964357824631975379582614651479832
D6: 1,6                                  # 21 pairs
* PAIR A5: 1,4 ROW 5
F5: 1,4,8,9                              # reduction candidate for 1,4
F5: 1,4                                  # 24 pairs
F5: 8,9                                  # 19 pairs
* PAIR A6: 1,4 ROW 6
F6: 1,4,6,8,9                            # reduction candidate for 1,4
F6: 6,8,9                                # 25 pairs
F6: 1,4                                  # 19 pairs
* PAIR E8: 6,8 COL E
E2: 6,8,9                                # reduction candidate for 6,8
E2: 6,8                                  # 23 pairs
E6: 6,8,4,9                              # reduction candidate for 6,8
E6: 6,8 => SOLVED
* 243815796518796423796243581965327148437158269182964357824631975379582614651479832
E6: 4,9                                  # 21 pairs
* PAIR F9: 8,9 COL F
F2: 8,9,6                                # reduction candidate for 8,9
F2: 8,9 => CTR
* 2439157865197684237862..591965327148.3815.26...2...35.824....753..582614651479832
F2: 6                                    # 21 pairs
F5: 8,9,1,4                              # reduction candidate for 8,9
F5: 8,9                                  # 19 pairs
F6: 8,9,1,4,6                            # reduction candidate for 8,9
F6: 8,9                                  # 28 pairs
* PAIR G7: 6,9 ROW 7
D7: 6,9,1                                # reduction candidate for 6,9
D7: 6,9                                  # 19 pairs
E7: 6,9,3                                # reduction candidate for 6,9
E7: 6,9                                  # 20 pairs
F7: 6,9,1,3                              # reduction candidate for 6,9
F7: 6,9                                  # 24 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-253-base-pr-000.dot
* REASONING
* DIS # F2: 8,9 => CTR => F2: 6
* DIS # F2: 8,9 => CTR => F2: 6
* PRF # D6: 8,9 => SOL
* PRF # E6: 6,8 => SOL
* DIS # F2: 8,9 => CTR => F2: 6
* CNT   5 HDP CHAINS /  23 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A5,A6,B3,B6,B8,C2,C5,C8,D1,E3,E8,F3,F9,G7,G8,G9,H1,H3,I5,I6)
* 243.157.651.7..4237.62..5.1965327148.3..5.26...2...35.824....753..5.2.1465147..32
* PAIR C2: 8,9 ROW 2
E2: 8,9,6                                # reduction candidate for 8,9
E2: 8,9                                  # 21 pairs
F2: 8,9,6                                # reduction candidate for 8,9
F2: 8,9 => CTR
* 2439157865197684237862..591965327148.3815.26...2...35.824....753..582614651479832
* RESTART
* PAIR RESTART
* PAIR D1: 8,9 COL D
D5: 8,9,1                                # reduction candidate for 8,9
D5: 8,9                                  # 25 pairs
D6: 8,9,1,6                              # reduction candidate for 8,9
D6: 8,9 => SOLVED
* 243815796518796423796243581965327148437158269182964357824631975379582614651479832
* DURATION: 0:00:05.069310  START: 11:27:33.707905  END: 11:27:38.777215 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-253-base-pr-001.dot
* REASONING
* DIS # F2: 8,9 => CTR => F2: 6
* PRF F2: 6 # D6: 8,9 => SOL
* STA F2: 6 + D6: 8,9
* CNT   2 HDP CHAINS /   4 HYP OPENED

Header Info

Top 500 Minimum 17 253

solution: 243815796518796423796243581965327148437158269182964357824631975379582614651479832
info: 2076     FNBTWXY  S8.f     27267

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

Solution

position: 243815796518796423796243581965327148437158269182964357824631975379582614651479832 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 # E2: 8,9 => UNS
* DIS # F2: 8,9 => CTR => F2: 6
* INC # F2: 6 => UNS
* INC # E2: 8,9 => UNS
* DIS # F2: 8,9 => CTR => F2: 6
* INC # F2: 6 => UNS
* INC # D5: 8,9 => UNS
* PRF # D6: 8,9 => SOL
* INC # D6: 1,6 => UNS
* INC # F5: 1,4 => UNS
* INC # F5: 8,9 => UNS
* INC # F6: 1,4 => UNS
* INC # F6: 6,8,9 => UNS
* INC # E2: 6,8 => UNS
* PRF # E6: 6,8 => SOL
* INC # E6: 4,9 => UNS
* DIS # F2: 8,9 => CTR => F2: 6
* INC # F2: 6 => UNS
* INC # F5: 8,9 => UNS
* INC # F6: 8,9 => UNS
* INC # D7: 6,9 => UNS
* INC # E7: 6,9 => UNS
* INC # F7: 6,9 => UNS
* CNT  23 HDP CHAINS /  23 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # E2: 8,9 => UNS
* DIS # F2: 8,9 => CTR => F2: 6
* INC F2: 6 # D5: 8,9 => UNS
* PRF F2: 6 # D6: 8,9 => SOL
* STA F2: 6 + D6: 8,9
* CNT   4 HDP CHAINS /   4 HYP OPENED