Analysis of xx-top500-316-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: .......128...4...........6..9.2.....7.....4.....5.1....15..........3.9..6.2...... initial

Autosolve

position: .......128...4...........64.9.2.4...7.....4.....5.1...915......4...3.9..632...... autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # A3: 3,5 => CTR => A3: 1,2
* DIS # F1: 3,5 => CTR => F1: 6,7,8,9
* DIS # G1: 3,5 => CTR => G1: 7,8
* PRF # A4: 3,5 => SOL
* DIS # A4: 1 => CTR => A4: 3,5
* DIS # H6: 2,3 => CTR => H6: 7,8,9
* DIS # A3: 2,3 => CTR => A3: 1,5
* PRF # A3: 1,5 => SOL
* DIS # I8: 5 => CTR => I8: 1,6
* DIS # D2: 3,7 => CTR => D2: 1,6
* DIS # F8: 6 => CTR => F8: 2,5
* DIS # H5: 8,9 => CTR => H5: 2,5
* CNT  12 HDP CHAINS /  21 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 # A3: 3,5 => CTR => A3: 1,2
* DIS A3: 1,2 # F1: 3,5 => CTR => F1: 6,7,8,9
* DIS A3: 1,2 + F1: 6,7,8,9 # G1: 3,5 => CTR => G1: 7,8
* PRF A3: 1,2 + F1: 6,7,8,9 + G1: 7,8 # A4: 3,5 => SOL
* STA A3: 1,2 + F1: 6,7,8,9 + G1: 7,8 + A4: 3,5
* CNT   4 HDP CHAINS /   4 HYP OPENED

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

Details

Positions

.......128...4...........6..9.2.....7.....4.....5.1....15..........3.9..6.2...... initial
.......128...4...........64.9.2.4...7.....4.....5.1...915......4...3.9..632...... autosolve
349756812826143579157829364593264187761398425284571693915487236478632951632915748 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (6)
A1: 3,5
A6: 2,3
B8: 7,8
C8: 7,8
D8: 1,6
H8: 2,5

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
C2,D2: 1.. / C2 = 1  =>  0 pairs (X) / D2 = 1  =>  0 pairs (_)
C5,I5: 1.. / C5 = 1  =>  0 pairs (*) / I5 = 1  =>  0 pairs (X)
D8,I8: 1.. / D8 = 1  =>  0 pairs (X) / I8 = 1  =>  0 pairs (_)
A3,A4: 1.. / A3 = 1  =>  0 pairs (*) / A4 = 1  =>  0 pairs (X)
E3,E9: 1.. / E3 = 1  =>  0 pairs (X) / E9 = 1  =>  0 pairs (_)
G4,G9: 1.. / G4 = 1  =>  0 pairs (*) / G9 = 1  =>  0 pairs (X)
B2,F2: 2.. / B2 = 2  =>  0 pairs (*) / F2 = 2  =>  0 pairs (X)
B5,H5: 2.. / B5 = 2  =>  0 pairs (X) / H5 = 2  =>  0 pairs (_)
F8,H8: 2.. / F8 = 2  =>  0 pairs (*) / H8 = 2  =>  0 pairs (X)
A3,A6: 2.. / A3 = 2  =>  0 pairs (X) / A6 = 2  =>  0 pairs (_)
E3,E7: 2.. / E3 = 2  =>  0 pairs (*) / E7 = 2  =>  0 pairs (X)
G6,G7: 2.. / G6 = 2  =>  0 pairs (X) / G7 = 2  =>  0 pairs (_)
D5,F5: 3.. / D5 = 3  =>  6 pairs (_) / F5 = 3  =>  6 pairs (_)
B1,C1: 4.. / B1 = 4  =>  6 pairs (_) / C1 = 4  =>  6 pairs (_)
B6,C6: 4.. / B6 = 4  =>  6 pairs (_) / C6 = 4  =>  6 pairs (_)
D7,D9: 4.. / D7 = 4  =>  6 pairs (_) / D9 = 4  =>  6 pairs (_)
H7,H9: 4.. / H7 = 4  =>  6 pairs (_) / H9 = 4  =>  6 pairs (_)
D7,H7: 4.. / D7 = 4  =>  6 pairs (_) / H7 = 4  =>  6 pairs (_)
D9,H9: 4.. / D9 = 4  =>  6 pairs (_) / H9 = 4  =>  6 pairs (_)
B1,B6: 4.. / B1 = 4  =>  6 pairs (_) / B6 = 4  =>  6 pairs (_)
C1,C6: 4.. / C1 = 4  =>  6 pairs (_) / C6 = 4  =>  6 pairs (_)
A4,B5: 5.. / A4 = 5  =>  0 pairs (*) / B5 = 5  =>  0 pairs (X)
E4,E6: 7.. / E4 = 7  =>  6 pairs (_) / E6 = 7  =>  7 pairs (_)
B8,C8: 7.. / B8 = 7  =>  6 pairs (_) / C8 = 7  =>  4 pairs (_)
G1,G3: 8.. / G1 = 8  =>  6 pairs (_) / G3 = 8  =>  6 pairs (_)
B8,C8: 8.. / B8 = 8  =>  4 pairs (_) / C8 = 8  =>  6 pairs (_)
C1,C3: 9.. / C1 = 9  =>  6 pairs (_) / C3 = 9  =>  6 pairs (_)
H2,I2: 9.. / H2 = 9  =>  6 pairs (_) / I2 = 9  =>  6 pairs (_)
* DURATION: 0:00:40.333143  START: 13:47:58.503360  END: 13:48:38.836503 2017-05-04
* CP COUNT: (28)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,A6,B8,C8,D8,H8)
* .......128...4...........64.9.2.4...7.....4.....5.1...915......4...3.9..632......
* PAIR A1: 3,5 BLK 1
A3: 3,5,1,2                              # reduction candidate for 3,5
A3: 3,5 => CTR
* .......128...4...........6419.2.4...75....4212..5.1...915...2..4..132956632...1..
A3: 1,2                                  #  7 pairs
* PAIR A1: 3,5 ROW 1
F1: 3,5,6,7,8,9                          # reduction candidate for 3,5
F1: 3,5 => CTR
* 5....3.128...42...27.....6419.2.4...72.3..4.13..5.12..915.2....48713.92.632.5.1..
F1: 6,7,8,9                              #  6 pairs
G1: 3,5,7,8                              # reduction candidate for 3,5
G1: 3,5 => CTR
* 5.....31286..42...27....86419.2.4...72....4.13..5.12..915.2....48713.92.632.5.1..
G1: 7,8                                  #  7 pairs
* PAIR A1: 3,5 COL A
A4: 3,5,1                                # reduction candidate for 3,5
A4: 3,5 => SOLVED
* 349756812826143579157829364593264187761398425284571693915487236478632951632915748
A4: 1 => CTR
* .......128...4...........6419.2.4...75....421...5.1...915...2..4..132956632...1..
* PAIR A6: 2,3 ROW 6
G6: 2,3,6,7                              # reduction candidate for 2,3
G6: 2,3                                  #  7 pairs
H6: 2,3,7,8,9                            # reduction candidate for 2,3
H6: 2,3 => CTR
* .......1282..4........2..64.9.2.4...7.....42.2..5.1.3.915...2.34...32956632.1....
H6: 7,8,9                                #  6 pairs
* PAIR A6: 2,3 COL A
A3: 2,3,1,5                              # reduction candidate for 2,3
A3: 2,3 => CTR
* .......128...4...........6419.2.4...75....421...5.1...915...2..4..132956632...1..
A3: 1,5 => SOLVED
* 349756812826143579157829364593264187761398425284571693915487236478632951632915748
* PAIR D8: 1,6 ROW 8
I8: 1,6,5                                # reduction candidate for 1,6
I8: 5 => CTR
* .......128.1.4........1..6419.2.4...7.....4.....5.1...915......4..136925632......
I8: 1,6                                  #  8 pairs
* PAIR D8: 1,6 COL D
D2: 1,6,3,7                              # reduction candidate for 1,6
D2: 3,7 => CTR
* .......128.1.4...........6419.2.4...75....421...5.1...915...2..4..132956632...1..
D2: 1,6                                  #  7 pairs
* PAIR H8: 2,5 ROW 8
F8: 2,5,6                                # reduction candidate for 2,5
F8: 6 => CTR
* 5......128.1.425..27..15.6419.2.4...72....4513..5.12..915.2....487136925632.5.1..
F8: 2,5                                  #  8 pairs
* PAIR H8: 2,5 COL H
H5: 2,5,8,9                              # reduction candidate for 2,5
H5: 8,9 => CTR
* 5......128...42...27.....6419.2.4...72....4.53..5.1...915.2....487.3.92.632...15.
H5: 2,5                                  #  7 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-316-base-pr-000.dot
* REASONING
* DIS # A3: 3,5 => CTR => A3: 1,2
* DIS # F1: 3,5 => CTR => F1: 6,7,8,9
* DIS # G1: 3,5 => CTR => G1: 7,8
* PRF # A4: 3,5 => SOL
* DIS # A4: 1 => CTR => A4: 3,5
* DIS # H6: 2,3 => CTR => H6: 7,8,9
* DIS # A3: 2,3 => CTR => A3: 1,5
* PRF # A3: 1,5 => SOL
* DIS # I8: 5 => CTR => I8: 1,6
* DIS # D2: 3,7 => CTR => D2: 1,6
* DIS # F8: 6 => CTR => F8: 2,5
* DIS # H5: 8,9 => CTR => H5: 2,5
* CNT  12 HDP CHAINS /  21 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,A6,B8,C8,D8,H8)
* .......128...4...........64.9.2.4...7.....4.....5.1...915......4...3.9..632......
* PAIR A1: 3,5 BLK 1
A3: 3,5,1,2                              # reduction candidate for 3,5
A3: 3,5 => CTR
* .......128...4...........6419.2.4...75....4212..5.1...915...2..4..132956632...1..
* PAIR A1: 3,5 ROW 1
F1: 3,5,6,7,8,9                          # reduction candidate for 3,5
F1: 3,5 => CTR
* 5....3.128...42...27.....6419.2.4...72.3..4.13..5.12..915.2....48713.92.632.5.1..
G1: 3,5,7,8                              # reduction candidate for 3,5
G1: 3,5 => CTR
* 5.....31286..42...27....86419.2.4...72....4.13..5.12..915.2....48713.92.632.5.1..
* RESTART
* PAIR A1: 3,5 COL A
A4: 3,5,1                                # reduction candidate for 3,5
A4: 3,5 => SOLVED
* 349756812826143579157829364593264187761398425284571693915487236478632951632915748
* DURATION: 0:00:05.944936  START: 13:48:55.155335  END: 13:49:01.100271 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-316-base-pr-001.dot
* REASONING
* DIS # A3: 3,5 => CTR => A3: 1,2
* DIS A3: 1,2 # F1: 3,5 => CTR => F1: 6,7,8,9
* DIS A3: 1,2 + F1: 6,7,8,9 # G1: 3,5 => CTR => G1: 7,8
* PRF A3: 1,2 + F1: 6,7,8,9 + G1: 7,8 # A4: 3,5 => SOL
* STA A3: 1,2 + F1: 6,7,8,9 + G1: 7,8 + A4: 3,5
* CNT   4 HDP CHAINS /   4 HYP OPENED

Header Info

Top 500 Minimum 17 316

solution: 349756812826143579157829364593264187761398425284571693915487236478632951632915748
info: 2899     FNBHWY   S8.f     12

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

Solution

position: 349756812826143579157829364593264187761398425284571693915487236478632951632915748 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 # A3: 3,5 => CTR => A3: 1,2
* INC # A3: 1,2 => UNS
* DIS # F1: 3,5 => CTR => F1: 6,7,8,9
* INC # F1: 6,7,8,9 => UNS
* DIS # G1: 3,5 => CTR => G1: 7,8
* INC # G1: 7,8 => UNS
* PRF # A4: 3,5 => SOL
* DIS # A4: 1 => CTR => A4: 3,5
* INC # G6: 2,3 => UNS
* DIS # H6: 2,3 => CTR => H6: 7,8,9
* INC # H6: 7,8,9 => UNS
* DIS # A3: 2,3 => CTR => A3: 1,5
* PRF # A3: 1,5 => SOL
* INC # I8: 1,6 => UNS
* DIS # I8: 5 => CTR => I8: 1,6
* INC # D2: 1,6 => UNS
* DIS # D2: 3,7 => CTR => D2: 1,6
* INC # F8: 2,5 => UNS
* DIS # F8: 6 => CTR => F8: 2,5
* INC # H5: 2,5 => UNS
* DIS # H5: 8,9 => CTR => H5: 2,5
* CNT  21 HDP CHAINS /  21 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # A3: 3,5 => CTR => A3: 1,2
* DIS A3: 1,2 # F1: 3,5 => CTR => F1: 6,7,8,9
* DIS A3: 1,2 + F1: 6,7,8,9 # G1: 3,5 => CTR => G1: 7,8
* PRF A3: 1,2 + F1: 6,7,8,9 + G1: 7,8 # A4: 3,5 => SOL
* STA A3: 1,2 + F1: 6,7,8,9 + G1: 7,8 + A4: 3,5
* CNT   4 HDP CHAINS /   4 HYP OPENED