Analysis of xx-top500-145-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: .4.....1..5.2.....6....3.....8...7........6.2.1..4....5...1....4.....3.....6..... initial

Autosolve

position: .42.6.5131532.4..668.15342.3685..741..4381652215746.3.53641.2..4.1...36582.6351.4 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # F1: 7,9 => CTR => F1: 8
* PRF # F1: 8 => SOL
* PRF # F1: 8,9 => SOL
* DIS # F1: 7 => CTR => F1: 8,9
* DIS # F1: 7,9 => CTR => F1: 8
* PRF # F1: 8 => SOL
* PRF # H2: 8 => SOL
* DIS # E8: 7,9 => CTR => E8: 2
* PRF # E8: 2 => SOL
* PRF # H2: 8,9 => SOL
* DIS # H2: 7 => CTR => H2: 8,9
* PRF # H2: 8 => SOL
* PRF # I7: 8 => SOL
* PRF # E8: 2,9 => SOL
* DIS # E8: 7 => CTR => E8: 2,9
* DIS # F8: 2,9 => CTR => F8: 7,8
* PRF # F8: 7,8 => SOL
* PRF # I7: 8,9 => SOL
* DIS # I7: 7 => CTR => I7: 8,9
* DIS # E8: 7,9 => CTR => E8: 2
* PRF # E8: 2 => SOL
* PRF # F8: 7,9 => SOL
* DIS # E8: 7,9 => CTR => E8: 2
* PRF # E8: 2 => SOL
* PRF # F8: 7,9 => SOL
* PRF # H7: 7,9 => SOL
* DIS # F1: 7,9 => CTR => F1: 8
* PRF # F1: 8 => SOL
* DIS # F8: 8,9 => CTR => F8: 2,7
* PRF # F8: 2,7 => SOL
* PRF # H7: 7,9 => SOL
* PRF # H2: 8 => SOL
* CNT  32 HDP CHAINS /  42 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 # F1: 7,9 => CTR => F1: 8
* PRF F1: 8 => SOL
* STA F1: 8
* CNT   2 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

.4.....1..5.2.....6....3.....8...7........6.2.1..4....5...1....4.....3.....6..... initial
.42.6.5131532.4..668.15342.3685..741..4381652215746.3.53641.2..4.1...36582.6351.4 autosolve
742968513153274986689153427368592741974381652215746839536419278491827365827635194 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (17)
A1: 7,9
C3: 7,9
D1: 8,9
E2: 7,9
G2: 8,9
I3: 7,9
A5: 7,9
B5: 7,9
E4: 2,9
F4: 2,9
G6: 8,9
I6: 8,9
B8: 7,9
C9: 7,9
F7: 7,9
D8: 8,9
H9: 7,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
E4,F4: 2.. / E4 = 2  =>  0 pairs (X) / F4 = 2  =>  0 pairs (_)
E8,F8: 2.. / E8 = 2  =>  0 pairs (*) / F8 = 2  =>  0 pairs (X)
E4,E8: 2.. / E4 = 2  =>  0 pairs (X) / E8 = 2  =>  0 pairs (_)
F4,F8: 2.. / F4 = 2  =>  0 pairs (*) / F8 = 2  =>  0 pairs (X)
A1,C3: 7.. / A1 = 7  =>  0 pairs (*) / C3 = 7  =>  0 pairs (X)
F1,E2: 7.. / F1 = 7  =>  0 pairs (X) / E2 = 7  =>  0 pairs (_)
H2,I3: 7.. / H2 = 7  =>  0 pairs (X) / I3 = 7  =>  0 pairs (_)
A5,B5: 7.. / A5 = 7  =>  0 pairs (X) / B5 = 7  =>  0 pairs (_)
B8,C9: 7.. / B8 = 7  =>  0 pairs (X) / C9 = 7  =>  0 pairs (_)
A1,F1: 7.. / A1 = 7  =>  0 pairs (*) / F1 = 7  =>  0 pairs (X)
E2,H2: 7.. / E2 = 7  =>  0 pairs (*) / H2 = 7  =>  0 pairs (X)
C3,I3: 7.. / C3 = 7  =>  0 pairs (X) / I3 = 7  =>  0 pairs (_)
C9,H9: 7.. / C9 = 7  =>  0 pairs (*) / H9 = 7  =>  0 pairs (X)
A1,A5: 7.. / A1 = 7  =>  0 pairs (*) / A5 = 7  =>  0 pairs (X)
B5,B8: 7.. / B5 = 7  =>  0 pairs (*) / B8 = 7  =>  0 pairs (X)
C3,C9: 7.. / C3 = 7  =>  0 pairs (X) / C9 = 7  =>  0 pairs (_)
E2,E8: 7.. / E2 = 7  =>  0 pairs (*) / E8 = 7  =>  0 pairs (X)
I3,I7: 7.. / I3 = 7  =>  0 pairs (*) / I7 = 7  =>  0 pairs (X)
D1,F1: 8.. / D1 = 8  =>  0 pairs (X) / F1 = 8  =>  0 pairs (_)
G2,H2: 8.. / G2 = 8  => 16 pairs (_) / H2 = 8  =>  0 pairs (*)
G6,I6: 8.. / G6 = 8  =>  0 pairs (*) / I6 = 8  =>  0 pairs (X)
D8,F8: 8.. / D8 = 8  =>  0 pairs (*) / F8 = 8  =>  0 pairs (X)
H7,I7: 8.. / H7 = 8  => 16 pairs (_) / I7 = 8  =>  0 pairs (*)
D1,D8: 8.. / D1 = 8  =>  0 pairs (X) / D8 = 8  =>  0 pairs (_)
F1,F8: 8.. / F1 = 8  =>  0 pairs (*) / F8 = 8  =>  0 pairs (X)
G2,G6: 8.. / G2 = 8  => 16 pairs (_) / G6 = 8  =>  0 pairs (*)
H2,H7: 8.. / H2 = 8  =>  0 pairs (*) / H7 = 8  =>  0 pairs (X)
I6,I7: 8.. / I6 = 8  => 16 pairs (_) / I7 = 8  =>  0 pairs (*)
A1,C3: 9.. / A1 = 9  =>  0 pairs (X) / C3 = 9  =>  0 pairs (_)
A5,B5: 9.. / A5 = 9  =>  0 pairs (*) / B5 = 9  =>  0 pairs (X)
E4,F4: 9.. / E4 = 9  =>  0 pairs (*) / F4 = 9  =>  0 pairs (X)
G6,I6: 9.. / G6 = 9  => 16 pairs (_) / I6 = 9  =>  0 pairs (*)
B8,C9: 9.. / B8 = 9  =>  0 pairs (*) / C9 = 9  =>  0 pairs (X)
C3,I3: 9.. / C3 = 9  =>  0 pairs (*) / I3 = 9  =>  0 pairs (X)
C9,H9: 9.. / C9 = 9  =>  0 pairs (X) / H9 = 9  =>  0 pairs (_)
A1,A5: 9.. / A1 = 9  =>  0 pairs (X) / A5 = 9  =>  0 pairs (_)
B5,B8: 9.. / B5 = 9  =>  0 pairs (X) / B8 = 9  =>  0 pairs (_)
C3,C9: 9.. / C3 = 9  =>  0 pairs (*) / C9 = 9  =>  0 pairs (X)
D1,D8: 9.. / D1 = 9  =>  0 pairs (*) / D8 = 9  =>  0 pairs (X)
G2,G6: 9.. / G2 = 9  =>  0 pairs (*) / G6 = 9  =>  0 pairs (X)
* DURATION: 0:01:07.775160  START: 07:41:30.451670  END: 07:42:38.226830 2017-05-04
* CP COUNT: (40)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,A5,B5,B8,C3,C9,D1,D8,E2,E4,F4,F7,G2,G6,H9,I3,I6)
* .42.6.5131532.4..668.15342.3685..741..4381652215746.3.53641.2..4.1...36582.6351.4
* PAIR A1: 7,9 ROW 1
F1: 7,9,8                                # reduction candidate for 7,9
F1: 7,9 => CTR
* .4286.5131532.4..668.15342.3685..741..4381652215746.3.53641.2..4.19.8365829635174
F1: 8 => SOLVED
* 742968513153274986689153427368592741974381652215746839536419278491827365827635194
* PAIR D1: 8,9 BLK 2
F1: 8,9,7                                # reduction candidate for 8,9
F1: 8,9 => SOLVED
* 742968513153274986689153427368592741974381652215746839536419278491827365827635194
F1: 7 => CTR
* .42867513153294876687153429368529741..4381652215746.3.53641.2..4.1...36582.6351.4
* PAIR E2: 7,9 BLK 2
F1: 7,9,8                                # reduction candidate for 7,9
F1: 7,9 => CTR
* .4286.5131532.4..668.15342.3685..741..4381652215746.3.53641.2..4.19.8365829635174
F1: 8 => SOLVED
* 742968513153274986689153427368592741974381652215746839536419278491827365827635194
* PAIR E2: 7,9 ROW 2
H2: 7,9,8                                # reduction candidate for 7,9
H2: 8 => SOLVED
* 742968513153274986689153427368592741974381652215746839536419278491827365827635194
H2: 7,9                                  # 16 pairs
* PAIR E2: 7,9 COL E
E8: 7,9,2                                # reduction candidate for 7,9
E8: 7,9 => CTR
* .42.6.5131532.4..668.15342.368529741..4381652215746.3.5364172..471.92365829635174
E8: 2 => SOLVED
* 742968513153274986689153427368592741974381652215746839536419278491827365827635194
* PAIR G2: 8,9 BLK 3
H2: 8,9,7                                # reduction candidate for 8,9
H2: 8,9 => SOLVED
* 742968513153274986689153427368592741974381652215746839536419278491827365827635194
H2: 7 => CTR
* .42.6.5131532.48766871534293685..74179438165221574693853641.287471...3658296351.4
* PAIR I3: 7,9 BLK 3
H2: 7,9,8                                # reduction candidate for 7,9
H2: 8 => SOLVED
* 742968513153274986689153427368592741974381652215746839536419278491827365827635194
H2: 7,9                                  # 16 pairs
* PAIR I3: 7,9 COL I
I7: 7,9,8                                # reduction candidate for 7,9
I7: 8 => SOLVED
* 742968513153274986689153427368592741974381652215746839536419278491827365827635194
I7: 7,9                                  # 16 pairs
* PAIR E4: 2,9 COL E
E8: 2,9,7                                # reduction candidate for 2,9
E8: 2,9 => SOLVED
* 742968513153274986689153427368592741974381652215746839536419278491827365827635194
E8: 7 => CTR
* .42.6.5131532.4..668.15342.368529741..4381652215746.3.5364172..4.1...36582.6351.4
* PAIR F4: 2,9 COL F
F8: 2,9,7,8                              # reduction candidate for 2,9
F8: 2,9 => CTR
* .42.68513153274..668.1534273685..741..4381652215746.3.5364172..4718..3658296351.4
F8: 7,8 => SOLVED
* 742968513153274986689153427368592741974381652215746839536419278491827365827635194
* PAIR I6: 8,9 COL I
I7: 8,9,7                                # reduction candidate for 8,9
I7: 8,9 => SOLVED
* 742968513153274986689153427368592741974381652215746839536419278491827365827635194
I7: 7 => CTR
* .42.6.5131532.4..668.15342.3685..741..4381652215746.3853641.2874.1...365827635194
* PAIR B8: 7,9 ROW 8
E8: 7,9,2                                # reduction candidate for 7,9
E8: 7,9 => CTR
* .42.6.5131532.4..668.15342.368529741..4381652215746.3.5364172..471.92365829635174
E8: 2 => SOLVED
* 742968513153274986689153427368592741974381652215746839536419278491827365827635194
F8: 7,9,2,8                              # reduction candidate for 7,9
F8: 7,9 => SOLVED
* 742968513153274986689153427368592741974381652215746839536419278491827365827635194
F8: 2,8                                  # 18 pairs
* PAIR F7: 7,9 BLK 8
E8: 7,9,2                                # reduction candidate for 7,9
E8: 7,9 => CTR
* .42.6.5131532.4..668.15342.368529741..4381652215746.3.5364172..471.92365829635174
E8: 2 => SOLVED
* 742968513153274986689153427368592741974381652215746839536419278491827365827635194
F8: 7,9,2,8                              # reduction candidate for 7,9
F8: 7,9 => SOLVED
* 742968513153274986689153427368592741974381652215746839536419278491827365827635194
F8: 2,8                                  # 18 pairs
* PAIR F7: 7,9 ROW 7
H7: 7,9,8                                # reduction candidate for 7,9
H7: 7,9 => SOLVED
* 742968513153274986689153427368592741974381652215746839536419278491827365827635194
H7: 8                                    # 16 pairs
I7: 7,9,8                                # reduction candidate for 7,9
I7: 7,9                                  # 16 pairs
* PAIR F7: 7,9 COL F
F1: 7,9,8                                # reduction candidate for 7,9
F1: 7,9 => CTR
* .4286.5131532.4..668.15342.3685..741..4381652215746.3.53641.2..4.19.8365829635174
F1: 8 => SOLVED
* 742968513153274986689153427368592741974381652215746839536419278491827365827635194
* PAIR D8: 8,9 BLK 8
F8: 8,9,2,7                              # reduction candidate for 8,9
F8: 8,9 => CTR
* .42.6.513153274..668.153427368592741..4381652215746.3.5364172..471.2.3658296351.4
F8: 2,7 => SOLVED
* 742968513153274986689153427368592741974381652215746839536419278491827365827635194
* PAIR H9: 7,9 BLK 9
H7: 7,9,8                                # reduction candidate for 7,9
H7: 7,9 => SOLVED
* 742968513153274986689153427368592741974381652215746839536419278491827365827635194
H7: 8                                    # 16 pairs
I7: 7,9,8                                # reduction candidate for 7,9
I7: 7,9                                  # 16 pairs
* PAIR H9: 7,9 COL H
H2: 7,9,8                                # reduction candidate for 7,9
H2: 8 => SOLVED
* 742968513153274986689153427368592741974381652215746839536419278491827365827635194
H2: 7,9                                  # 16 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-145-base-pr-000.dot
* REASONING
* DIS # F1: 7,9 => CTR => F1: 8
* PRF # F1: 8 => SOL
* PRF # F1: 8,9 => SOL
* DIS # F1: 7 => CTR => F1: 8,9
* DIS # F1: 7,9 => CTR => F1: 8
* PRF # F1: 8 => SOL
* PRF # H2: 8 => SOL
* DIS # E8: 7,9 => CTR => E8: 2
* PRF # E8: 2 => SOL
* PRF # H2: 8,9 => SOL
* DIS # H2: 7 => CTR => H2: 8,9
* PRF # H2: 8 => SOL
* PRF # I7: 8 => SOL
* PRF # E8: 2,9 => SOL
* DIS # E8: 7 => CTR => E8: 2,9
* DIS # F8: 2,9 => CTR => F8: 7,8
* PRF # F8: 7,8 => SOL
* PRF # I7: 8,9 => SOL
* DIS # I7: 7 => CTR => I7: 8,9
* DIS # E8: 7,9 => CTR => E8: 2
* PRF # E8: 2 => SOL
* PRF # F8: 7,9 => SOL
* DIS # E8: 7,9 => CTR => E8: 2
* PRF # E8: 2 => SOL
* PRF # F8: 7,9 => SOL
* PRF # H7: 7,9 => SOL
* DIS # F1: 7,9 => CTR => F1: 8
* PRF # F1: 8 => SOL
* DIS # F8: 8,9 => CTR => F8: 2,7
* PRF # F8: 2,7 => SOL
* PRF # H7: 7,9 => SOL
* PRF # H2: 8 => SOL
* CNT  32 HDP CHAINS /  42 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,A5,B5,B8,C3,C9,D1,D8,E2,E4,F4,F7,G2,G6,H9,I3,I6)
* .42.6.5131532.4..668.15342.3685..741..4381652215746.3.53641.2..4.1...36582.6351.4
* PAIR A1: 7,9 ROW 1
F1: 7,9,8                                # reduction candidate for 7,9
F1: 7,9 => CTR
* .4286.5131532.4..668.15342.3685..741..4381652215746.3.53641.2..4.19.8365829635174
F1: 8 => SOLVED
* 742968513153274986689153427368592741974381652215746839536419278491827365827635194
* DURATION: 0:00:02.853795  START: 07:43:28.163567  END: 07:43:31.017362 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-145-base-pr-001.dot
* REASONING
* DIS # F1: 7,9 => CTR => F1: 8
* PRF F1: 8 => SOL
* STA F1: 8
* CNT   2 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 145

solution: 742968513153274986689153427368592741974381652215746839536419278491827365827635194
info: 1814     FNBWX    S8.f     46625

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

Solution

position: 742968513153274986689153427368592741974381652215746839536419278491827365827635194 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 # F1: 7,9 => CTR => F1: 8
* PRF # F1: 8 => SOL
* PRF # F1: 8,9 => SOL
* DIS # F1: 7 => CTR => F1: 8,9
* DIS # F1: 7,9 => CTR => F1: 8
* PRF # F1: 8 => SOL
* INC # H2: 7,9 => UNS
* PRF # H2: 8 => SOL
* DIS # E8: 7,9 => CTR => E8: 2
* PRF # E8: 2 => SOL
* PRF # H2: 8,9 => SOL
* DIS # H2: 7 => CTR => H2: 8,9
* INC # H2: 7,9 => UNS
* PRF # H2: 8 => SOL
* INC # I7: 7,9 => UNS
* PRF # I7: 8 => SOL
* PRF # E8: 2,9 => SOL
* DIS # E8: 7 => CTR => E8: 2,9
* DIS # F8: 2,9 => CTR => F8: 7,8
* PRF # F8: 7,8 => SOL
* PRF # I7: 8,9 => SOL
* DIS # I7: 7 => CTR => I7: 8,9
* DIS # E8: 7,9 => CTR => E8: 2
* PRF # E8: 2 => SOL
* PRF # F8: 7,9 => SOL
* INC # F8: 2,8 => UNS
* DIS # E8: 7,9 => CTR => E8: 2
* PRF # E8: 2 => SOL
* PRF # F8: 7,9 => SOL
* INC # F8: 2,8 => UNS
* PRF # H7: 7,9 => SOL
* INC # H7: 8 => UNS
* INC # I7: 7,9 => UNS
* DIS # F1: 7,9 => CTR => F1: 8
* PRF # F1: 8 => SOL
* DIS # F8: 8,9 => CTR => F8: 2,7
* PRF # F8: 2,7 => SOL
* PRF # H7: 7,9 => SOL
* INC # H7: 8 => UNS
* INC # I7: 7,9 => UNS
* INC # H2: 7,9 => UNS
* PRF # H2: 8 => SOL
* CNT  42 HDP CHAINS /  42 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # F1: 7,9 => CTR => F1: 8
* PRF F1: 8 => SOL
* STA F1: 8
* CNT   2 HDP CHAINS /   1 HYP OPENED