Analysis of xx-top500-115-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 4.1.........8...2.........36..5.4....7.....8.....1.7...2.3...........4.1......9.. initial

Autosolve

position: 4.16..897...84.12.2.81.7.436825743191759..284.4.2187...243.1..8...7..4.1.1.4..9.2 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # F1: 3,5 => CTR => F1: 2
* DIS # F2: 3 => CTR => F2: 5,9
* DIS # B3: 5,9 => CTR => B3: 6
* PRF # B3: 6 => SOL
* DIS # E8: 5,9 => CTR => E8: 2,6,8
* DIS # B3: 9 => CTR => B3: 5,6
* DIS # A2: 3,9 => CTR => A2: 5,7
* DIS # A8: 3,9 => CTR => A8: 5,8
* DIS # H7: 5,6 => CTR => H7: 7
* DIS # E8: 5,6 => CTR => E8: 2,8,9
* DIS # F8: 5,6 => CTR => F8: 2,9
* DIS # E9: 5,6 => CTR => E9: 8
* DIS # H7: 5,6 => CTR => H7: 7
* DIS # E7: 9 => CTR => E7: 5,6
* CNT  14 HDP CHAINS /  43 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: 3,5 => CTR => F1: 2
* DIS F1: 2 # F2: 3 => CTR => F2: 5,9
* DIS F1: 2 + F2: 5,9 # A2: 3,9 => CTR => A2: 7
* PRF F1: 2 + F2: 5,9 + A2: 7 => SOL
* STA F1: 2 + F2: 5,9 + A2: 7
* CNT   4 HDP CHAINS /  13 HYP OPENED

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

Details

Positions

4.1.........8...2.........36..5.4....7.....8.....1.7...2.3...........4.1......9.. initial
4.16..897...84.12.2.81.7.436825743191759..284.4.2187...243.1..8...7..4.1.1.4..9.2 autosolve
451632897793845126268197543682574319175963284349218765924351678836729451517486932 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (12)
B1: 3,5
E3: 5,9
I2: 5,6
G3: 5,6
A6: 3,9
C6: 3,9
E5: 3,6
F5: 3,6
H6: 5,6
I6: 5,6
F9: 5,6
G7: 5,6

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
E1,F1: 2.. / E1 = 2  =>  0 pairs (X) / F1 = 2  => 13 pairs (_)
E8,F8: 2.. / E8 = 2  => 13 pairs (_) / F8 = 2  =>  0 pairs (X)
E1,E8: 2.. / E1 = 2  =>  0 pairs (X) / E8 = 2  => 13 pairs (_)
F1,F8: 2.. / F1 = 2  => 13 pairs (_) / F8 = 2  =>  0 pairs (X)
A6,C6: 3.. / A6 = 3  => 11 pairs (_) / C6 = 3  =>  0 pairs (X)
E5,F5: 3.. / E5 = 3  => 15 pairs (_) / F5 = 3  => 13 pairs (_)
H8,H9: 3.. / H8 = 3  => 13 pairs (_) / H9 = 3  => 15 pairs (_)
E1,E5: 3.. / E1 = 3  => 13 pairs (_) / E5 = 3  => 15 pairs (_)
I2,G3: 5.. / I2 = 5  =>  0 pairs (X) / G3 = 5  =>  0 pairs (_)
H6,I6: 5.. / H6 = 5  =>  0 pairs (X) / I6 = 5  =>  0 pairs (_)
G3,G7: 5.. / G3 = 5  =>  0 pairs (*) / G7 = 5  =>  0 pairs (X)
I2,I6: 5.. / I2 = 5  =>  0 pairs (X) / I6 = 5  =>  0 pairs (_)
I2,G3: 6.. / I2 = 6  =>  0 pairs (*) / G3 = 6  =>  0 pairs (X)
E5,F5: 6.. / E5 = 6  => 13 pairs (_) / F5 = 6  => 15 pairs (_)
H6,I6: 6.. / H6 = 6  =>  0 pairs (*) / I6 = 6  =>  0 pairs (X)
B3,G3: 6.. / B3 = 6  =>  0 pairs (*) / G3 = 6  =>  0 pairs (X)
G3,G7: 6.. / G3 = 6  =>  0 pairs (X) / G7 = 6  =>  0 pairs (_)
I2,I6: 6.. / I2 = 6  =>  0 pairs (*) / I6 = 6  =>  0 pairs (X)
A2,C2: 7.. / A2 = 7  => 14 pairs (_) / C2 = 7  => 13 pairs (_)
H7,H9: 7.. / H7 = 7  => 13 pairs (_) / H9 = 7  =>  0 pairs (X)
A7,H7: 7.. / A7 = 7  =>  0 pairs (X) / H7 = 7  => 13 pairs (_)
C2,C9: 7.. / C2 = 7  => 13 pairs (_) / C9 = 7  => 14 pairs (_)
A8,A9: 8.. / A8 = 8  => 12 pairs (_) / A9 = 8  =>  0 pairs (X)
E8,E9: 8.. / E8 = 8  =>  0 pairs (X) / E9 = 8  => 12 pairs (_)
A8,E8: 8.. / A8 = 8  => 12 pairs (_) / E8 = 8  =>  0 pairs (X)
A9,E9: 8.. / A9 = 8  =>  0 pairs (X) / E9 = 8  => 12 pairs (_)
F2,E3: 9.. / F2 = 9  =>  0 pairs (X) / E3 = 9  => 16 pairs (_)
A6,C6: 9.. / A6 = 9  =>  0 pairs (X) / C6 = 9  => 11 pairs (_)
B3,E3: 9.. / B3 = 9  =>  0 pairs (X) / E3 = 9  => 16 pairs (_)
A7,E7: 9.. / A7 = 9  => 16 pairs (_) / E7 = 9  =>  0 pairs (X)
F2,F8: 9.. / F2 = 9  =>  0 pairs (X) / F8 = 9  => 16 pairs (_)
* DURATION: 0:00:57.532854  START: 06:41:41.601615  END: 06:42:39.134469 2017-05-04
* CP COUNT: (31)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A6,B1,C6,E3,E5,F5,F9,G3,G7,H6,I2,I6)
* 4.16..897...84.12.2.81.7.436825743191759..284.4.2187...243.1..8...7..4.1.1.4..9.2
* PAIR B1: 3,5 BLK 1
A2: 3,5,7,9                              # reduction candidate for 3,5
A2: 3,5                                  # 17 pairs
B2: 3,5,6,9                              # reduction candidate for 3,5
B2: 3,5                                  # 16 pairs
* PAIR B1: 3,5 ROW 1
E1: 3,5,2                                # reduction candidate for 3,5
E1: 3,5                                  # 13 pairs
F1: 3,5,2                                # reduction candidate for 3,5
F1: 3,5 => CTR
* 451623897...849125298157643682574319175936284.4.218756.243915685.97824318134659.2
F1: 2                                    # 13 pairs
* PAIR B1: 3,5 COL B
B8: 3,5,6,9                              # reduction candidate for 3,5
B8: 3,5                                  # 16 pairs
B8: 6,9                                  # 14 pairs
* PAIR E3: 5,9 BLK 2
F2: 5,9,3                                # reduction candidate for 5,9
F2: 3 => CTR
* 431652897.9.843125258197643682574319175936284349218756924361578...7294.1.1.4859.2
F2: 5,9                                  # 15 pairs
* PAIR E3: 5,9 ROW 3
B3: 5,9,6                                # reduction candidate for 5,9
B3: 5,9 => CTR
* 4.16..897...8491252981576436825743191759..284.4.218756.24391568..97..431.134..9.2
B3: 6 => SOLVED
* 451632897793845126268197543682574319175963284349218765924351678836729451517486932
* PAIR E3: 5,9 COL E
E7: 5,9,6                                # reduction candidate for 5,9
E7: 5,9                                  # 16 pairs
E8: 5,9,2,6,8                            # reduction candidate for 5,9
E8: 5,9 => CTR
* 451623897...849125298157643682574319175936284.4.2187565243.1..88..7.24.1.1.4859.2
E8: 2,6,8                                # 12 pairs
* PAIR I2: 5,6 ROW 2
B2: 5,6,3,9                              # reduction candidate for 5,6
B2: 5,6                                  # 15 pairs
B2: 3,9                                  # 13 pairs
* PAIR G3: 5,6 ROW 3
B3: 5,6,9                                # reduction candidate for 5,6
B3: 9 => CTR
* 4516..897..68491252981576436825743191759..284.4.218756.24391568.697..4.1.1.4..9.2
B3: 5,6                                  # 16 pairs
* PAIR A6: 3,9 COL A
A2: 3,9,5,7                              # reduction candidate for 3,9
A2: 3,9 => CTR
* 4.16..897..784912.2981576436825743191759..2849432187.6.24391568.3.7..4.1.1.4..9.2
A2: 5,7                                  # 13 pairs
A8: 3,9,5,8                              # reduction candidate for 3,9
A8: 3,9 => CTR
* 4.162.897...84912.298157643682574319175936284.4.2187.6.24391568.56782431813465972
A8: 5,8                                  # 13 pairs
* PAIR C6: 3,9 COL C
C2: 3,9,6,7                              # reduction candidate for 3,9
C2: 3,9                                  # 16 pairs
C8: 3,9,6                                # reduction candidate for 3,9
C8: 3,9                                  # 15 pairs
* PAIR H6: 5,6 COL H
H7: 5,6,7                                # reduction candidate for 5,6
H7: 5,6 => CTR
* 4516..8973.784912.2981576436825743191759..284.4.2187.6724391568...7..431.1.4..972
H7: 7                                    # 13 pairs
H8: 5,6,3                                # reduction candidate for 5,6
H8: 5,6                                  # 15 pairs
H9: 5,6,3,7                              # reduction candidate for 5,6
H9: 5,6                                  # 17 pairs
* PAIR F9: 5,6 BLK 8
E7: 5,6,9                                # reduction candidate for 5,6
E7: 5,6                                  # 16 pairs
E8: 5,6,2,8,9                            # reduction candidate for 5,6
E8: 5,6 => CTR
* 451623897...849125298157643682574319175936284.4.2187565243.1..88..7.24.1.1.4859.2
E8: 2,8,9                                # 12 pairs
F8: 5,6,2,9                              # reduction candidate for 5,6
F8: 5,6 => CTR
* 451632897...849125298157643682574319175963284.4.218756.243915688.972543151348.9.2
F8: 2,9                                  # 13 pairs
E9: 5,6,8                                # reduction candidate for 5,6
E9: 5,6 => CTR
* 451623897.3.84912.298157643682574319175936284.4.2187.6.24391568...782431813465972
E9: 8                                    # 12 pairs
* PAIR F9: 5,6 ROW 9
H9: 5,6,3,7                              # reduction candidate for 5,6
H9: 5,6                                  # 17 pairs
H9: 3,7                                  # 13 pairs
* PAIR G7: 5,6 BLK 9
H7: 5,6,7                                # reduction candidate for 5,6
H7: 5,6 => CTR
* 4516..8973.784912.2981576436825743191759..284.4.2187.6724391568...7..431.1.4..972
H7: 7                                    # 13 pairs
H8: 5,6,3                                # reduction candidate for 5,6
H8: 5,6                                  # 15 pairs
H9: 5,6,3,7                              # reduction candidate for 5,6
H9: 5,6                                  # 17 pairs
* PAIR G7: 5,6 ROW 7
E7: 5,6,9                                # reduction candidate for 5,6
E7: 9 => CTR
* 4516..897.3.84912.2981576436825743191759..284.4.2187.6.24391568...7..431.1.4..972
E7: 5,6                                  # 16 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-115-base-pr-000.dot
* REASONING
* DIS # F1: 3,5 => CTR => F1: 2
* DIS # F2: 3 => CTR => F2: 5,9
* DIS # B3: 5,9 => CTR => B3: 6
* PRF # B3: 6 => SOL
* DIS # E8: 5,9 => CTR => E8: 2,6,8
* DIS # B3: 9 => CTR => B3: 5,6
* DIS # A2: 3,9 => CTR => A2: 5,7
* DIS # A8: 3,9 => CTR => A8: 5,8
* DIS # H7: 5,6 => CTR => H7: 7
* DIS # E8: 5,6 => CTR => E8: 2,8,9
* DIS # F8: 5,6 => CTR => F8: 2,9
* DIS # E9: 5,6 => CTR => E9: 8
* DIS # H7: 5,6 => CTR => H7: 7
* DIS # E7: 9 => CTR => E7: 5,6
* CNT  14 HDP CHAINS /  43 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A6,B1,C6,E3,E5,F5,F9,G3,G7,H6,I2,I6)
* 4.16..897...84.12.2.81.7.436825743191759..284.4.2187...243.1..8...7..4.1.1.4..9.2
* PAIR B1: 3,5 BLK 1
A2: 3,5,7,9                              # reduction candidate for 3,5
A2: 3,5                                  # 17 pairs
B2: 3,5,6,9                              # reduction candidate for 3,5
B2: 3,5                                  # 16 pairs
* PAIR B1: 3,5 ROW 1
E1: 3,5,2                                # reduction candidate for 3,5
E1: 3,5                                  # 13 pairs
F1: 3,5,2                                # reduction candidate for 3,5
F1: 3,5 => CTR
* 451623897...849125298157643682574319175936284.4.218756.243915685.97824318134659.2
* RESTART
* PAIR B1: 3,5 COL B
B8: 3,5,6,9                              # reduction candidate for 3,5
B8: 3,5                                  # 17 pairs
B8: 6,9                                  # 15 pairs
* PAIR RESTART
* PAIR B1: 3,5 BLK 1
A2: 3,5,7,9                              # reduction candidate for 3,5
A2: 3,5                                  # 18 pairs
B2: 3,5,6,9                              # reduction candidate for 3,5
B2: 3,5                                  # 17 pairs
* PAIR B1: 3,5 COL B
B8: 3,5,6,9                              # reduction candidate for 3,5
B8: 3,5                                  # 17 pairs
B8: 6,9                                  # 15 pairs
* PAIR E3: 5,9 BLK 2
F2: 5,9,3                                # reduction candidate for 5,9
F2: 3 => CTR
* 4316528975978431262.8197.43682574319175936284.4.2187..9243615788..7294.1.1.4859.2
* PAIR A6: 3,9 COL A
A2: 3,9,7                                # reduction candidate for 3,9
A2: 3,9 => CTR
* 451632897..7849125298157643682574319175963284943218756.2439156883.72.4.1.1.48.9.2
A2: 7 => SOLVED
* 451632897793845126268197543682574319175963284349218765924351678836729451517486932
* DURATION: 0:00:15.834250  START: 06:43:21.895717  END: 06:43:37.729967 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-115-base-pr-001.dot
* REASONING
* DIS # F1: 3,5 => CTR => F1: 2
* DIS F1: 2 # F2: 3 => CTR => F2: 5,9
* DIS F1: 2 + F2: 5,9 # A2: 3,9 => CTR => A2: 7
* PRF F1: 2 + F2: 5,9 + A2: 7 => SOL
* STA F1: 2 + F2: 5,9 + A2: 7
* CNT   4 HDP CHAINS /  13 HYP OPENED

Header Info

Top 500 Minimum 17 115

solution: 451632897793845126268197543682574319175963284349218765924351678836729451517486932
info: 1702     FNBTHWXY S8.f     31248

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

Solution

position: 451632897793845126268197543682574319175963284349218765924351678836729451517486932 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 # A2: 3,5 => UNS
* INC # B2: 3,5 => UNS
* INC # E1: 3,5 => UNS
* DIS # F1: 3,5 => CTR => F1: 2
* INC # F1: 2 => UNS
* INC # B8: 3,5 => UNS
* INC # B8: 6,9 => UNS
* INC # F2: 5,9 => UNS
* DIS # F2: 3 => CTR => F2: 5,9
* DIS # B3: 5,9 => CTR => B3: 6
* PRF # B3: 6 => SOL
* INC # E7: 5,9 => UNS
* DIS # E8: 5,9 => CTR => E8: 2,6,8
* INC # E8: 2,6,8 => UNS
* INC # B2: 5,6 => UNS
* INC # B2: 3,9 => UNS
* INC # B3: 5,6 => UNS
* DIS # B3: 9 => CTR => B3: 5,6
* DIS # A2: 3,9 => CTR => A2: 5,7
* INC # A2: 5,7 => UNS
* DIS # A8: 3,9 => CTR => A8: 5,8
* INC # A8: 5,8 => UNS
* INC # C2: 3,9 => UNS
* INC # C8: 3,9 => UNS
* DIS # H7: 5,6 => CTR => H7: 7
* INC # H7: 7 => UNS
* INC # H8: 5,6 => UNS
* INC # H9: 5,6 => UNS
* INC # E7: 5,6 => UNS
* DIS # E8: 5,6 => CTR => E8: 2,8,9
* INC # E8: 2,8,9 => UNS
* DIS # F8: 5,6 => CTR => F8: 2,9
* INC # F8: 2,9 => UNS
* DIS # E9: 5,6 => CTR => E9: 8
* INC # E9: 8 => UNS
* INC # H9: 5,6 => UNS
* INC # H9: 3,7 => UNS
* DIS # H7: 5,6 => CTR => H7: 7
* INC # H7: 7 => UNS
* INC # H8: 5,6 => UNS
* INC # H9: 5,6 => UNS
* INC # E7: 5,6 => UNS
* DIS # E7: 9 => CTR => E7: 5,6
* CNT  43 HDP CHAINS /  43 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # A2: 3,5 => UNS
* INC # B2: 3,5 => UNS
* INC # E1: 3,5 => UNS
* DIS # F1: 3,5 => CTR => F1: 2
* INC F1: 2 # B8: 3,5 => UNS
* INC F1: 2 # B8: 6,9 => UNS
* INC F1: 2 # A2: 3,5 => UNS
* INC F1: 2 # B2: 3,5 => UNS
* INC F1: 2 # B8: 3,5 => UNS
* INC F1: 2 # B8: 6,9 => UNS
* INC F1: 2 # F2: 5,9 => UNS
* DIS F1: 2 # F2: 3 => CTR => F2: 5,9
* DIS F1: 2 + F2: 5,9 # A2: 3,9 => CTR => A2: 7
* PRF F1: 2 + F2: 5,9 + A2: 7 => SOL
* STA F1: 2 + F2: 5,9 + A2: 7
* CNT  14 HDP CHAINS /  13 HYP OPENED