Analysis of xx-top500-076-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: .1.8...2........3........9....12.7..9...5....3.....4...2.5..6..4....3............ initial

Autosolve

position: .1983.5242..9.513.53.2.189....129753971354268352...419.2359.6414.5.139.219.4.23.5 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # C2: 6,7 => CTR => C2: 4,8
* PRF # F6: 6,7 => SOL
* DIS # F6: 8 => CTR => F6: 6,7
* DIS # C2: 6,7 => CTR => C2: 4,8
* DIS # E6: 6,7 => CTR => E6: 8
* PRF # E6: 8 => SOL
* PRF # F6: 6,7 => SOL
* DIS # F6: 8 => CTR => F6: 6,7
* DIS # C9: 7,8 => CTR => C9: 6
* PRF # C9: 6 => SOL
* PRF # C9: 6,8 => SOL
* DIS # C9: 7 => CTR => C9: 6,8
* PRF # E9: 7,8 => SOL
* DIS # E9: 6 => CTR => E9: 7,8
* DIS # F6: 7,8 => CTR => F6: 6
* PRF # F6: 6 => SOL
* PRF # E9: 6,7 => SOL
* DIS # E9: 8 => CTR => E9: 6,7
* DIS # C9: 7,8 => CTR => C9: 6
* PRF # C9: 6 => SOL
* PRF # E9: 7,8 => SOL
* DIS # E9: 6 => CTR => E9: 7,8
* CNT  22 HDP CHAINS /  34 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 # C2: 6,7 => CTR => C2: 4,8
* DIS C2: 4,8 # C3: 4 => CTR => C3: 6,7
* PRF C2: 4,8 + C3: 6,7 # F6: 6,7 => SOL
* STA C2: 4,8 + C3: 6,7 + F6: 6,7
* CNT   3 HDP CHAINS /   5 HYP OPENED

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

Details

Positions

.1.8...2........3........9....12.7..9...5....3.....4...2.5..6..4....3............ initial
.1983.5242..9.513.53.2.189....129753971354268352...419.2359.6414.5.139.219.4.23.5 autosolve
619837524248965137537241896864129753971354268352786419723598641485613972196472385 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (12)
A1: 6,7
F1: 6,7
I2: 6,7
I3: 6,7
A4: 6,8
D6: 6,7
A7: 7,8
B8: 6,8
F7: 7,8
D8: 6,7
H8: 7,8
H9: 7,8

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
E2,E3: 4.. / E2 = 4  => 15 pairs (_) / E3 = 4  => 16 pairs (_)
B4,C4: 4.. / B4 = 4  => 14 pairs (_) / C4 = 4  => 16 pairs (_)
C3,E3: 4.. / C3 = 4  => 15 pairs (_) / E3 = 4  => 16 pairs (_)
B2,B4: 4.. / B2 = 4  => 16 pairs (_) / B4 = 4  => 14 pairs (_)
I2,I3: 6.. / I2 = 6  => 14 pairs (_) / I3 = 6  => 13 pairs (_)
B8,C9: 6.. / B8 = 6  =>  0 pairs (X) / C9 = 6  =>  0 pairs (_)
D8,E9: 6.. / D8 = 6  =>  0 pairs (*) / E9 = 6  =>  0 pairs (X)
A1,F1: 6.. / A1 = 6  =>  0 pairs (*) / F1 = 6  =>  0 pairs (X)
B8,D8: 6.. / B8 = 6  =>  0 pairs (X) / D8 = 6  =>  0 pairs (_)
C9,E9: 6.. / C9 = 6  =>  0 pairs (*) / E9 = 6  =>  0 pairs (X)
A1,A4: 6.. / A1 = 6  =>  0 pairs (*) / A4 = 6  =>  0 pairs (X)
D6,D8: 6.. / D6 = 6  =>  0 pairs (X) / D8 = 6  =>  0 pairs (_)
F1,F6: 6.. / F1 = 6  =>  0 pairs (X) / F6 = 6  =>  0 pairs (_)
I2,I3: 7.. / I2 = 7  => 13 pairs (_) / I3 = 7  => 14 pairs (_)
A7,C9: 7.. / A7 = 7  =>  0 pairs (*) / C9 = 7  =>  0 pairs (X)
H8,H9: 7.. / H8 = 7  =>  0 pairs (*) / H9 = 7  =>  0 pairs (X)
A1,F1: 7.. / A1 = 7  =>  0 pairs (X) / F1 = 7  =>  0 pairs (_)
A7,F7: 7.. / A7 = 7  =>  0 pairs (*) / F7 = 7  =>  0 pairs (X)
D8,H8: 7.. / D8 = 7  =>  0 pairs (X) / H8 = 7  =>  0 pairs (_)
A1,A7: 7.. / A1 = 7  =>  0 pairs (X) / A7 = 7  =>  0 pairs (_)
D6,D8: 7.. / D6 = 7  =>  0 pairs (*) / D8 = 7  =>  0 pairs (X)
B2,C2: 8.. / B2 = 8  =>  0 pairs (X) / C2 = 8  => 15 pairs (_)
E6,F6: 8.. / E6 = 8  =>  0 pairs (*) / F6 = 8  =>  0 pairs (X)
F7,E9: 8.. / F7 = 8  =>  0 pairs (*) / E9 = 8  =>  0 pairs (X)
H8,H9: 8.. / H8 = 8  =>  0 pairs (X) / H9 = 8  =>  0 pairs (_)
A7,F7: 8.. / A7 = 8  =>  0 pairs (X) / F7 = 8  =>  0 pairs (_)
B8,H8: 8.. / B8 = 8  =>  0 pairs (*) / H8 = 8  =>  0 pairs (X)
A4,A7: 8.. / A4 = 8  =>  0 pairs (*) / A7 = 8  =>  0 pairs (X)
E6,E9: 8.. / E6 = 8  =>  0 pairs (*) / E9 = 8  =>  0 pairs (X)
F6,F7: 8.. / F6 = 8  =>  0 pairs (X) / F7 = 8  =>  0 pairs (_)
* DURATION: 0:01:00.219722  START: 05:19:11.994610  END: 05:20:12.214332 2017-05-04
* CP COUNT: (30)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,A4,A7,B8,D6,D8,F1,F7,H8,H9,I2,I3)
* .1983.5242..9.513.53.2.189....129753971354268352...419.2359.6414.5.139.219.4.23.5
* PAIR A1: 6,7 BLK 1
C2: 6,7,4,8                              # reduction candidate for 6,7
C2: 6,7 => CTR
* .1983652428.94513.5342.189..4.129753971354268352...419.2359.64146571398219.462375
C2: 4,8                                  # 13 pairs
C3: 6,7,4                                # reduction candidate for 6,7
C3: 6,7                                  # 16 pairs
* PAIR F1: 6,7 BLK 2
E2: 6,7,4                                # reduction candidate for 6,7
E2: 6,7                                  # 16 pairs
E3: 6,7,4                                # reduction candidate for 6,7
E3: 6,7                                  # 15 pairs
* PAIR F1: 6,7 COL F
F6: 6,7,8                                # reduction candidate for 6,7
F6: 6,7 => SOLVED
* 619837524248965137537241896864129753971354268352786419723598641485613972196472385
F6: 8 => CTR
* .198365242..9.513.53.2.189.6..129753971354268352..8419823597641465.139.219.4.23.5
* PAIR I2: 6,7 ROW 2
C2: 6,7,4,8                              # reduction candidate for 6,7
C2: 6,7 => CTR
* .1983652428.94513.5342.189..4.129753971354268352...419.2359.64146571398219.462375
C2: 4,8                                  # 13 pairs
E2: 6,7,4                                # reduction candidate for 6,7
E2: 6,7                                  # 16 pairs
* PAIR I3: 6,7 ROW 3
C3: 6,7,4                                # reduction candidate for 6,7
C3: 6,7                                  # 16 pairs
E3: 6,7,4                                # reduction candidate for 6,7
E3: 6,7                                  # 15 pairs
* PAIR A4: 6,8 BLK 4
B4: 6,8,4                                # reduction candidate for 6,8
B4: 6,8                                  # 16 pairs
C4: 6,8,4                                # reduction candidate for 6,8
C4: 6,8                                  # 14 pairs
* PAIR D6: 6,7 BLK 5
E6: 6,7,8                                # reduction candidate for 6,7
E6: 6,7 => CTR
* .1983.5242..9.513.53.2.189....129753971354268352..8419823597641465.139.219.4.23.5
E6: 8 => SOLVED
* 619837524248965137537241896864129753971354268352786419723598641485613972196472385
F6: 6,7,8                                # reduction candidate for 6,7
F6: 6,7 => SOLVED
* 619837524248965137537241896864129753971354268352786419723598641485613972196472385
F6: 8 => CTR
* .198365242..9.513.53.2.189.6..129753971354268352..8419823597641465.139.219.4.23.5
* PAIR A7: 7,8 BLK 7
C9: 7,8,6                                # reduction candidate for 7,8
C9: 7,8 => CTR
* .198365242..9.513.53.2.189.6..129753971354268352687419.2359.64146571398219.462375
C9: 6 => SOLVED
* 619837524248965137537241896864129753971354268352786419723598641485613972196472385
* PAIR B8: 6,8 BLK 7
C9: 6,8,7                                # reduction candidate for 6,8
C9: 6,8 => SOLVED
* 619837524248965137537241896864129753971354268352786419723598641485613972196472385
C9: 7 => CTR
* .1983.5242..9.513.53.2.189....129753971354268352...419.2359.6414657139821974.23.5
* PAIR B8: 6,8 COL B
B2: 6,8,4                                # reduction candidate for 6,8
B2: 6,8                                  # 14 pairs
B4: 6,8,4                                # reduction candidate for 6,8
B4: 6,8                                  # 16 pairs
* PAIR F7: 7,8 BLK 8
E9: 7,8,6                                # reduction candidate for 7,8
E9: 7,8 => SOLVED
* 619837524248965137537241896864129753971354268352786419723598641485613972196472385
E9: 6 => CTR
* .1983652428.9.513.53.2.189....129753971354268352.8.419.235986414.5713982198462375
* PAIR F7: 7,8 COL F
F6: 7,8,6                                # reduction candidate for 7,8
F6: 7,8 => CTR
* .198365242..9.513.53.2.189.6..129753971354268352...419823597641465.139.219.4.23.5
F6: 6 => SOLVED
* 619837524248965137537241896864129753971354268352786419723598641485613972196472385
* PAIR D8: 6,7 BLK 8
E9: 6,7,8                                # reduction candidate for 6,7
E9: 6,7 => SOLVED
* 619837524248965137537241896864129753971354268352786419723598641485613972196472385
E9: 8 => CTR
* .1983.5242..9.513.53.2.189....129753971354268352...419.2359.6414.561397219.4.23.5
* PAIR H9: 7,8 ROW 9
C9: 7,8,6                                # reduction candidate for 7,8
C9: 7,8 => CTR
* .198365242..9.513.53.2.189.6..129753971354268352687419.2359.64146571398219.462375
C9: 6 => SOLVED
* 619837524248965137537241896864129753971354268352786419723598641485613972196472385
E9: 7,8,6                                # reduction candidate for 7,8
E9: 7,8 => SOLVED
* 619837524248965137537241896864129753971354268352786419723598641485613972196472385
E9: 6 => CTR
* .1983652428.9.513.53.2.189....129753971354268352.8.419.235986414.5713982198462375
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-076-base-pr-000.dot
* REASONING
* DIS # C2: 6,7 => CTR => C2: 4,8
* PRF # F6: 6,7 => SOL
* DIS # F6: 8 => CTR => F6: 6,7
* DIS # C2: 6,7 => CTR => C2: 4,8
* DIS # E6: 6,7 => CTR => E6: 8
* PRF # E6: 8 => SOL
* PRF # F6: 6,7 => SOL
* DIS # F6: 8 => CTR => F6: 6,7
* DIS # C9: 7,8 => CTR => C9: 6
* PRF # C9: 6 => SOL
* PRF # C9: 6,8 => SOL
* DIS # C9: 7 => CTR => C9: 6,8
* PRF # E9: 7,8 => SOL
* DIS # E9: 6 => CTR => E9: 7,8
* DIS # F6: 7,8 => CTR => F6: 6
* PRF # F6: 6 => SOL
* PRF # E9: 6,7 => SOL
* DIS # E9: 8 => CTR => E9: 6,7
* DIS # C9: 7,8 => CTR => C9: 6
* PRF # C9: 6 => SOL
* PRF # E9: 7,8 => SOL
* DIS # E9: 6 => CTR => E9: 7,8
* CNT  22 HDP CHAINS /  34 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,A4,A7,B8,D6,D8,F1,F7,H8,H9,I2,I3)
* .1983.5242..9.513.53.2.189....129753971354268352...419.2359.6414.5.139.219.4.23.5
* PAIR A1: 6,7 BLK 1
C2: 6,7,4,8                              # reduction candidate for 6,7
C2: 6,7 => CTR
* .1983652428.94513.5342.189..4.129753971354268352...419.2359.64146571398219.462375
C3: 6,7,4                                # reduction candidate for 6,7
C3: 6,7                                  # 16 pairs
* RESTART
* PAIR A1: 6,7 BLK 1
C3: 6,7,4                                # reduction candidate for 6,7
C3: 4 => CTR
* 7198365242689.513.53.2.189....129753971354268352...419.2359.6414.5.139.219.4.23.5
* PAIR F1: 6,7 COL F
F6: 6,7,8                                # reduction candidate for 6,7
F6: 6,7 => SOLVED
* 619837524248965137537241896864129753971354268352786419723598641485613972196472385
* DURATION: 0:00:07.126240  START: 05:20:56.143238  END: 05:21:03.269478 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-076-base-pr-001.dot
* REASONING
* DIS # C2: 6,7 => CTR => C2: 4,8
* DIS C2: 4,8 # C3: 4 => CTR => C3: 6,7
* PRF C2: 4,8 + C3: 6,7 # F6: 6,7 => SOL
* STA C2: 4,8 + C3: 6,7 + F6: 6,7
* CNT   3 HDP CHAINS /   5 HYP OPENED

Header Info

Top 500 Minimum 17 076

solution: 619837524248965137537241896864129753971354268352786419723598641485613972196472385
info: 1498     FNBHWXY  S8.f     15759

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

Solution

position: 619837524248965137537241896864129753971354268352786419723598641485613972196472385 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 # C2: 6,7 => CTR => C2: 4,8
* INC # C2: 4,8 => UNS
* INC # C3: 6,7 => UNS
* INC # E2: 6,7 => UNS
* INC # E3: 6,7 => UNS
* PRF # F6: 6,7 => SOL
* DIS # F6: 8 => CTR => F6: 6,7
* DIS # C2: 6,7 => CTR => C2: 4,8
* INC # C2: 4,8 => UNS
* INC # E2: 6,7 => UNS
* INC # C3: 6,7 => UNS
* INC # E3: 6,7 => UNS
* INC # B4: 6,8 => UNS
* INC # C4: 6,8 => UNS
* DIS # E6: 6,7 => CTR => E6: 8
* PRF # E6: 8 => SOL
* PRF # F6: 6,7 => SOL
* DIS # F6: 8 => CTR => F6: 6,7
* DIS # C9: 7,8 => CTR => C9: 6
* PRF # C9: 6 => SOL
* PRF # C9: 6,8 => SOL
* DIS # C9: 7 => CTR => C9: 6,8
* INC # B2: 6,8 => UNS
* INC # B4: 6,8 => UNS
* PRF # E9: 7,8 => SOL
* DIS # E9: 6 => CTR => E9: 7,8
* DIS # F6: 7,8 => CTR => F6: 6
* PRF # F6: 6 => SOL
* PRF # E9: 6,7 => SOL
* DIS # E9: 8 => CTR => E9: 6,7
* DIS # C9: 7,8 => CTR => C9: 6
* PRF # C9: 6 => SOL
* PRF # E9: 7,8 => SOL
* DIS # E9: 6 => CTR => E9: 7,8
* CNT  34 HDP CHAINS /  34 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # C2: 6,7 => CTR => C2: 4,8
* INC C2: 4,8 # C3: 6,7 => UNS
* INC C2: 4,8 # C3: 6,7 => UNS
* DIS C2: 4,8 # C3: 4 => CTR => C3: 6,7
* PRF C2: 4,8 + C3: 6,7 # F6: 6,7 => SOL
* STA C2: 4,8 + C3: 6,7 + F6: 6,7
* CNT   5 HDP CHAINS /   5 HYP OPENED