Analysis of xx-top500-155-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 57.....4.1....3......8.......8....3..9.2.........4....6...5.1........9.8......2.. initial

Autosolve

position: 573.9284.1824.3.9.9468.532.4.85.973239.28.41.2..34..8962495817373..249.88.973.2.4 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # I2: 6,7 => SOL
* DIS # I2: 5 => CTR => I2: 6,7
* DIS # I2: 5,6 => CTR => I2: 7
* PRF # I2: 7 => SOL
* PRF # B6: 1,6 => SOL
* DIS # B6: 5 => CTR => B6: 1,6
* PRF # C6: 5,7 => SOL
* DIS # C6: 1 => CTR => C6: 5,7
* DIS # F6: 1,6 => CTR => F6: 7
* PRF # F6: 7 => SOL
* PRF # F6: 6,7 => SOL
* DIS # F6: 1 => CTR => F6: 6,7
* DIS # I2: 5,6 => CTR => I2: 7
* PRF # I2: 7 => SOL
* PRF # B6: 1 => SOL
* PRF # C6: 1,5 => SOL
* DIS # C6: 7 => CTR => C6: 1,5
* PRF # B6: 1,5 => SOL
* DIS # B6: 6 => CTR => B6: 1,5
* DIS # F6: 1,6 => CTR => F6: 7
* PRF # F6: 7 => SOL
* CNT  21 HDP CHAINS /  22 HYP OPENED

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

Pair Reduction

Pair Reduction

The following important HDP chains were detected:

* PRF # I2: 6,7 => SOL
* STA I2: 6,7
* CNT   1 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

57.....4.1....3......8.......8....3..9.2.........4....6...5.1........9.8......2.. initial
573.9284.1824.3.9.9468.532.4.85.973239.28.41.2..34..8962495817373..249.88.973.2.4 autosolve
573192846182463597946875321468519732397286415215347689624958173731624958859731264 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (18)
D1: 1,6
E2: 6,7
E3: 1,7
I1: 1,6
G2: 5,6
I3: 1,7
B4: 1,6
C5: 5,7
E4: 1,6
F5: 6,7
I5: 5,6
G6: 5,6
C8: 1,5
B9: 1,5
D8: 1,6
F9: 1,6
H8: 5,6
H9: 5,6

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
D1,E3: 1.. / D1 = 1  =>  0 pairs (*) / E3 = 1  =>  0 pairs (X)
I1,I3: 1.. / I1 = 1  =>  0 pairs (X) / I3 = 1  =>  0 pairs (_)
E4,F6: 1.. / E4 = 1  =>  0 pairs (*) / F6 = 1  =>  0 pairs (X)
C8,B9: 1.. / C8 = 1  =>  0 pairs (*) / B9 = 1  =>  0 pairs (X)
D8,F9: 1.. / D8 = 1  =>  0 pairs (X) / F9 = 1  =>  0 pairs (_)
D1,I1: 1.. / D1 = 1  =>  0 pairs (*) / I1 = 1  =>  0 pairs (X)
E3,I3: 1.. / E3 = 1  =>  0 pairs (X) / I3 = 1  =>  0 pairs (_)
B4,E4: 1.. / B4 = 1  =>  0 pairs (X) / E4 = 1  =>  0 pairs (_)
C8,D8: 1.. / C8 = 1  =>  0 pairs (*) / D8 = 1  =>  0 pairs (X)
B9,F9: 1.. / B9 = 1  =>  0 pairs (X) / F9 = 1  =>  0 pairs (_)
C6,C8: 1.. / C6 = 1  =>  0 pairs (X) / C8 = 1  =>  0 pairs (_)
D1,D8: 1.. / D1 = 1  =>  0 pairs (*) / D8 = 1  =>  0 pairs (X)
E3,E4: 1.. / E3 = 1  =>  0 pairs (X) / E4 = 1  =>  0 pairs (_)
F6,F9: 1.. / F6 = 1  =>  0 pairs (X) / F9 = 1  =>  0 pairs (_)
G2,I2: 5.. / G2 = 5  =>  0 pairs (*) / I2 = 5  =>  0 pairs (X)
I5,G6: 5.. / I5 = 5  =>  0 pairs (*) / G6 = 5  =>  0 pairs (X)
C8,B9: 5.. / C8 = 5  =>  0 pairs (X) / B9 = 5  =>  0 pairs (_)
H8,H9: 5.. / H8 = 5  =>  0 pairs (*) / H9 = 5  =>  0 pairs (X)
C5,I5: 5.. / C5 = 5  =>  0 pairs (X) / I5 = 5  =>  0 pairs (_)
C8,H8: 5.. / C8 = 5  =>  0 pairs (X) / H8 = 5  =>  0 pairs (_)
B9,H9: 5.. / B9 = 5  =>  0 pairs (*) / H9 = 5  =>  0 pairs (X)
B6,B9: 5.. / B6 = 5  =>  0 pairs (X) / B9 = 5  =>  0 pairs (_)
G2,G6: 5.. / G2 = 5  =>  0 pairs (*) / G6 = 5  =>  0 pairs (X)
I2,I5: 5.. / I2 = 5  =>  0 pairs (X) / I5 = 5  =>  0 pairs (_)
D1,E2: 6.. / D1 = 6  =>  0 pairs (X) / E2 = 6  =>  0 pairs (_)
B4,B6: 6.. / B4 = 6  =>  0 pairs (*) / B6 = 6  =>  0 pairs (X)
I5,G6: 6.. / I5 = 6  =>  0 pairs (X) / G6 = 6  =>  0 pairs (_)
D8,F9: 6.. / D8 = 6  =>  0 pairs (*) / F9 = 6  =>  0 pairs (X)
H8,H9: 6.. / H8 = 6  =>  0 pairs (X) / H9 = 6  =>  0 pairs (_)
D1,I1: 6.. / D1 = 6  =>  0 pairs (X) / I1 = 6  =>  0 pairs (_)
B4,E4: 6.. / B4 = 6  =>  0 pairs (*) / E4 = 6  =>  0 pairs (X)
F5,I5: 6.. / F5 = 6  =>  0 pairs (*) / I5 = 6  =>  0 pairs (X)
D8,H8: 6.. / D8 = 6  =>  0 pairs (*) / H8 = 6  =>  0 pairs (X)
F9,H9: 6.. / F9 = 6  =>  0 pairs (X) / H9 = 6  =>  0 pairs (_)
D1,D8: 6.. / D1 = 6  =>  0 pairs (X) / D8 = 6  =>  0 pairs (_)
E2,E4: 6.. / E2 = 6  =>  0 pairs (*) / E4 = 6  =>  0 pairs (X)
G2,G6: 6.. / G2 = 6  =>  0 pairs (X) / G6 = 6  =>  0 pairs (_)
E2,E3: 7.. / E2 = 7  =>  0 pairs (X) / E3 = 7  =>  0 pairs (_)
I2,I3: 7.. / I2 = 7  =>  0 pairs (*) / I3 = 7  =>  0 pairs (X)
C5,C6: 7.. / C5 = 7  =>  0 pairs (*) / C6 = 7  =>  0 pairs (X)
F5,F6: 7.. / F5 = 7  =>  0 pairs (X) / F6 = 7  =>  0 pairs (_)
E2,I2: 7.. / E2 = 7  =>  0 pairs (X) / I2 = 7  =>  0 pairs (_)
E3,I3: 7.. / E3 = 7  =>  0 pairs (*) / I3 = 7  =>  0 pairs (X)
C5,F5: 7.. / C5 = 7  =>  0 pairs (*) / F5 = 7  =>  0 pairs (X)
C6,F6: 7.. / C6 = 7  =>  0 pairs (X) / F6 = 7  =>  0 pairs (_)
* DURATION: 0:01:16.078644  START: 08:02:53.525109  END: 08:04:09.603753 2017-05-04
* CP COUNT: (45)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B4,B9,C5,C8,D1,D8,E2,E3,E4,F5,F9,G2,G6,H8,H9,I1,I3,I5)
* 573.9284.1824.3.9.9468.532.4.85.973239.28.41.2..34..8962495817373..249.88.973.2.4
* PAIR E2: 6,7 ROW 2
I2: 6,7,5                                # reduction candidate for 6,7
I2: 6,7 => SOLVED
* 573192846182463597946875321468519732397286415215347689624958173731624958859731264
I2: 5 => CTR
* 573.9284.18247369594681532741856973239528741.2..34..8962495817373..249.88.973.2.4
* PAIR G2: 5,6 BLK 3
I2: 5,6,7                                # reduction candidate for 5,6
I2: 5,6 => CTR
* 573.9284.182473.9.94681532741856973239.28741.2..34..8962495817373..249.88.973.2.4
I2: 7 => SOLVED
* 573192846182463597946875321468519732397286415215347689624958173731624958859731264
* PAIR B4: 1,6 BLK 4
B6: 1,6,5                                # reduction candidate for 1,6
B6: 1,6 => SOLVED
* 573192846182463597946875321468519732397286415215347689624958173731624958859731264
B6: 5 => CTR
* 573.9284.1824.3.9.9468.532.46851973239.28.41.2513476896249581737351249688197362.4
* PAIR C5: 5,7 BLK 4
C6: 5,7,1                                # reduction candidate for 5,7
C6: 5,7 => SOLVED
* 573192846182463597946875321468519732397286415215347689624958173731624958859731264
C6: 1 => CTR
* 573.9284.1824.3.9.9468.532.4.85.9732397286415251347689624958173735.249.88.973.2.4
* PAIR E4: 1,6 BLK 5
F6: 1,6,7                                # reduction candidate for 1,6
F6: 1,6 => CTR
* 573.9284.1824.3.9.9468.532.4.85.973239.2874162.734.5896249581737316249.88.973.2.4
F6: 7 => SOLVED
* 573192846182463597946875321468519732397286415215347689624958173731624958859731264
* PAIR F5: 6,7 BLK 5
F6: 6,7,1                                # reduction candidate for 6,7
F6: 6,7 => SOLVED
* 573192846182463597946875321468519732397286415215347689624958173731624958859731264
F6: 1 => CTR
* 573.9284.1824.3.9.9468.532.4.85.973239.287416267341589624958173731.249.88.973.2.4
* PAIR I5: 5,6 COL I
I2: 5,6,7                                # reduction candidate for 5,6
I2: 5,6 => CTR
* 573.9284.182473.9.94681532741856973239.28741.2..34..8962495817373..249.88.973.2.4
I2: 7 => SOLVED
* 573192846182463597946875321468519732397286415215347689624958173731624958859731264
* PAIR G6: 5,6 ROW 6
B6: 5,6,1                                # reduction candidate for 5,6
B6: 1 => SOLVED
* 573192846182463597946875321468519732397286415215347689624958173731624958859731264
B6: 5,6                                  # 21 pairs
* PAIR C8: 1,5 COL C
C6: 1,5,7                                # reduction candidate for 1,5
C6: 1,5 => SOLVED
* 573192846182463597946875321468519732397286415215347689624958173731624958859731264
C6: 7 => CTR
* 57319284618246359.9468.532.4.85.973239.28.41.2.734..89624958173731624958859731264
* PAIR B9: 1,5 COL B
B6: 1,5,6                                # reduction candidate for 1,5
B6: 1,5 => SOLVED
* 573192846182463597946875321468519732397286415215347689624958173731624958859731264
B6: 6 => CTR
* 573.9284.1824.3.9.9468.532.4.85.973239.28.41.26.34.58962495817373..249.8859731264
* PAIR F9: 1,6 COL F
F6: 1,6,7                                # reduction candidate for 1,6
F6: 1,6 => CTR
* 573.9284.1824.3.9.9468.532.4.85.973239.2874162.734.5896249581737316249.88.973.2.4
F6: 7 => SOLVED
* 573192846182463597946875321468519732397286415215347689624958173731624958859731264
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-155-base-pr-000.dot
* REASONING
* PRF # I2: 6,7 => SOL
* DIS # I2: 5 => CTR => I2: 6,7
* DIS # I2: 5,6 => CTR => I2: 7
* PRF # I2: 7 => SOL
* PRF # B6: 1,6 => SOL
* DIS # B6: 5 => CTR => B6: 1,6
* PRF # C6: 5,7 => SOL
* DIS # C6: 1 => CTR => C6: 5,7
* DIS # F6: 1,6 => CTR => F6: 7
* PRF # F6: 7 => SOL
* PRF # F6: 6,7 => SOL
* DIS # F6: 1 => CTR => F6: 6,7
* DIS # I2: 5,6 => CTR => I2: 7
* PRF # I2: 7 => SOL
* PRF # B6: 1 => SOL
* PRF # C6: 1,5 => SOL
* DIS # C6: 7 => CTR => C6: 1,5
* PRF # B6: 1,5 => SOL
* DIS # B6: 6 => CTR => B6: 1,5
* DIS # F6: 1,6 => CTR => F6: 7
* PRF # F6: 7 => SOL
* CNT  21 HDP CHAINS /  22 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B4,B9,C5,C8,D1,D8,E2,E3,E4,F5,F9,G2,G6,H8,H9,I1,I3,I5)
* 573.9284.1824.3.9.9468.532.4.85.973239.28.41.2..34..8962495817373..249.88.973.2.4
* PAIR E2: 6,7 ROW 2
I2: 6,7,5                                # reduction candidate for 6,7
I2: 6,7 => SOLVED
* 573192846182463597946875321468519732397286415215347689624958173731624958859731264
* DURATION: 0:00:01.947860  START: 08:04:34.885082  END: 08:04:36.832942 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-155-base-pr-001.dot
* REASONING
* PRF # I2: 6,7 => SOL
* STA I2: 6,7
* CNT   1 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 155

solution: 573192846182463597946875321468519732397286415215347689624958173731624958859731264
info: 1817     FNBWX    S8.f     33859

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

Solution

position: 573192846182463597946875321468519732397286415215347689624958173731624958859731264 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:

* PRF # I2: 6,7 => SOL
* DIS # I2: 5 => CTR => I2: 6,7
* DIS # I2: 5,6 => CTR => I2: 7
* PRF # I2: 7 => SOL
* PRF # B6: 1,6 => SOL
* DIS # B6: 5 => CTR => B6: 1,6
* PRF # C6: 5,7 => SOL
* DIS # C6: 1 => CTR => C6: 5,7
* DIS # F6: 1,6 => CTR => F6: 7
* PRF # F6: 7 => SOL
* PRF # F6: 6,7 => SOL
* DIS # F6: 1 => CTR => F6: 6,7
* DIS # I2: 5,6 => CTR => I2: 7
* PRF # I2: 7 => SOL
* INC # B6: 5,6 => UNS
* PRF # B6: 1 => SOL
* PRF # C6: 1,5 => SOL
* DIS # C6: 7 => CTR => C6: 1,5
* PRF # B6: 1,5 => SOL
* DIS # B6: 6 => CTR => B6: 1,5
* DIS # F6: 1,6 => CTR => F6: 7
* PRF # F6: 7 => SOL
* CNT  22 HDP CHAINS /  22 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* PRF # I2: 6,7 => SOL
* STA I2: 6,7
* CNT   1 HDP CHAINS /   1 HYP OPENED