Analysis of xx-top500-086-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: .1.53....46....2........8...7.....1.8....2..........6.2.....4.....67.......1..... initial

Autosolve

position: 9125386474687912..7..246891.7486..128.6.127.412.457.682.1.8.476.8.67412.64712..8. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # B5: 3,5 => SOL
* DIS # B5: 9 => CTR => B5: 3,5
* DIS # B7: 3,5 => CTR => B7: 9
* PRF # B7: 9 => SOL
* PRF # C8: 3,5 => SOL
* DIS # C8: 9 => CTR => C8: 3,5
* DIS # I8: 3,5 => CTR => I8: 9
* PRF # I8: 9 => SOL
* PRF # I9: 3,5 => SOL
* DIS # I9: 9 => CTR => I9: 3,5
* PRF # B5: 3,5 => SOL
* DIS # B5: 9 => CTR => B5: 3,5
* DIS # G4: 3,5 => CTR => G4: 9
* PRF # G4: 9 => SOL
* PRF # B5: 3,9 => SOL
* DIS # B5: 5 => CTR => B5: 3,9
* PRF # C8: 5 => SOL
* PRF # G4: 3,9 => SOL
* DIS # G4: 5 => CTR => G4: 3,9
* DIS # F7: 3,9 => CTR => F7: 5
* PRF # B5: 3,9 => SOL
* DIS # B5: 5 => CTR => B5: 3,9
* DIS # G4: 3,5 => CTR => G4: 9
* PRF # G4: 9 => SOL
* PRF # B5: 3,5 => SOL
* DIS # B5: 9 => CTR => B5: 3,5
* PRF # G4: 3,9 => SOL
* DIS # G4: 5 => CTR => G4: 3,9
* DIS # B7: 3,5 => CTR => B7: 9
* PRF # B7: 9 => SOL
* PRF # C8: 3,5 => SOL
* DIS # C8: 9 => CTR => C8: 3,5
* DIS # I8: 3,5 => CTR => I8: 9
* PRF # I8: 9 => SOL
* DIS # F7: 3,9 => CTR => F7: 5
* DIS # B7: 5 => CTR => B7: 3,9
* DIS # I8: 3,5 => CTR => I8: 9
* PRF # I8: 9 => SOL
* PRF # I9: 3,5 => SOL
* DIS # I9: 9 => CTR => I9: 3,5
* DIS # F9: 3,5 => CTR => F9: 9
* PRF # F9: 9 => SOL
* DIS # G4: 3,5 => CTR => G4: 9
* PRF # G4: 9 => SOL
* CNT  44 HDP CHAINS /  50 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 # B5: 3,5 => SOL
* STA B5: 3,5
* CNT   1 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

.1.53....46....2........8...7.....1.8....2..........6.2.....4.....67.......1..... initial
9125386474687912..7..246891.7486..128.6.127.412.457.682.1.8.476.8.67412.64712..8. autosolve
912538647468791235753246891574863912836912754129457368291385476385674129647129583 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (13)
B3: 3,5
C3: 3,5
H2: 3,5
I2: 3,5
A4: 3,5
C6: 3,9
F4: 3,9
D5: 3,9
H5: 3,5
G6: 3,9
A8: 3,5
D7: 3,9
G9: 3,5

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
B3,C3: 3.. / B3 = 3  => 16 pairs (_) / C3 = 3  =>  0 pairs (*)
H2,I2: 3.. / H2 = 3  =>  0 pairs (*) / I2 = 3  =>  0 pairs (X)
F4,D5: 3.. / F4 = 3  =>  0 pairs (*) / D5 = 3  =>  0 pairs (X)
C6,G6: 3.. / C6 = 3  =>  0 pairs (X) / G6 = 3  =>  0 pairs (_)
A4,A8: 3.. / A4 = 3  =>  0 pairs (X) / A8 = 3  =>  0 pairs (_)
D5,D7: 3.. / D5 = 3  =>  0 pairs (X) / D7 = 3  =>  0 pairs (_)
H2,H5: 3.. / H2 = 3  =>  0 pairs (*) / H5 = 3  =>  0 pairs (X)
B3,C3: 5.. / B3 = 5  =>  0 pairs (*) / C3 = 5  =>  0 pairs (X)
H2,I2: 5.. / H2 = 5  =>  0 pairs (X) / I2 = 5  =>  0 pairs (_)
A4,B5: 5.. / A4 = 5  =>  0 pairs (*) / B5 = 5  =>  0 pairs (X)
G4,H5: 5.. / G4 = 5  =>  0 pairs (X) / H5 = 5  =>  0 pairs (_)
F7,F9: 5.. / F7 = 5  => 16 pairs (_) / F9 = 5  =>  0 pairs (X)
A4,G4: 5.. / A4 = 5  =>  0 pairs (*) / G4 = 5  =>  0 pairs (X)
B5,H5: 5.. / B5 = 5  =>  0 pairs (X) / H5 = 5  =>  0 pairs (_)
B7,F7: 5.. / B7 = 5  =>  0 pairs (X) / F7 = 5  => 16 pairs (_)
A4,A8: 5.. / A4 = 5  =>  0 pairs (*) / A8 = 5  =>  0 pairs (X)
C3,C8: 5.. / C3 = 5  => 16 pairs (_) / C8 = 5  =>  0 pairs (*)
G4,G9: 5.. / G4 = 5  =>  0 pairs (X) / G9 = 5  =>  0 pairs (_)
H2,H5: 5.. / H2 = 5  =>  0 pairs (X) / H5 = 5  =>  0 pairs (_)
B5,C6: 9.. / B5 = 9  =>  0 pairs (X) / C6 = 9  =>  0 pairs (_)
F4,D5: 9.. / F4 = 9  =>  0 pairs (X) / D5 = 9  =>  0 pairs (_)
G4,G6: 9.. / G4 = 9  =>  0 pairs (*) / G6 = 9  =>  0 pairs (X)
B7,C8: 9.. / B7 = 9  =>  0 pairs (*) / C8 = 9  =>  0 pairs (X)
I8,I9: 9.. / I8 = 9  =>  0 pairs (*) / I9 = 9  =>  0 pairs (X)
F4,G4: 9.. / F4 = 9  =>  0 pairs (X) / G4 = 9  =>  0 pairs (_)
B5,D5: 9.. / B5 = 9  =>  0 pairs (X) / D5 = 9  =>  0 pairs (_)
C6,G6: 9.. / C6 = 9  =>  0 pairs (*) / G6 = 9  =>  0 pairs (X)
C8,I8: 9.. / C8 = 9  =>  0 pairs (X) / I8 = 9  =>  0 pairs (_)
F9,I9: 9.. / F9 = 9  =>  0 pairs (*) / I9 = 9  =>  0 pairs (X)
B5,B7: 9.. / B5 = 9  =>  0 pairs (X) / B7 = 9  =>  0 pairs (_)
C6,C8: 9.. / C6 = 9  =>  0 pairs (*) / C8 = 9  =>  0 pairs (X)
D5,D7: 9.. / D5 = 9  =>  0 pairs (*) / D7 = 9  =>  0 pairs (X)
* DURATION: 0:00:54.399320  START: 05:43:19.936995  END: 05:44:14.336315 2017-05-04
* CP COUNT: (32)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A4,A8,B3,C3,C6,D5,D7,F4,G6,G9,H2,H5,I2)
* 9125386474687912..7..246891.7486..128.6.127.412.457.682.1.8.476.8.67412.64712..8.
* PAIR B3: 3,5 COL B
B5: 3,5,9                                # reduction candidate for 3,5
B5: 3,5 => SOLVED
* 912538647468791235753246891574863912836912754129457368291385476385674129647129583
B5: 9 => CTR
* 9125386474687912..7..24689157486..128963127541234579682.198.47638967412564712538.
B7: 3,5,9                                # reduction candidate for 3,5
B7: 3,5 => CTR
* 9125386474687912..7..246891.7486..128963127541234579682.198.47638967412564712538.
B7: 9 => SOLVED
* 912538647468791235753246891574863912836912754129457368291385476385674129647129583
* PAIR C3: 3,5 COL C
C8: 3,5,9                                # reduction candidate for 3,5
C8: 3,5 => SOLVED
* 912538647468791235753246891574863912836912754129457368291385476385674129647129583
C8: 9 => CTR
* 9125386474687912..7.5246891.7486..128.6.127.41234579682.1.8.476389674125647125389
* PAIR I2: 3,5 COL I
I8: 3,5,9                                # reduction candidate for 3,5
I8: 3,5 => CTR
* 9125386474687912..7.5246891.7486..1289631275412345796825198347638967412564712..89
I8: 9 => SOLVED
* 912538647468791235753246891574863912836912754129457368291385476385674129647129583
I9: 3,5,9                                # reduction candidate for 3,5
I9: 3,5 => SOLVED
* 912538647468791235753246891574863912836912754129457368291385476385674129647129583
I9: 9 => CTR
* 9125386474687912..7.5246891.7486..1289631275412345796825198347638967412564712..89
* PAIR A4: 3,5 BLK 4
B5: 3,5,9                                # reduction candidate for 3,5
B5: 3,5 => SOLVED
* 912538647468791235753246891574863912836912754129457368291385476385674129647129583
B5: 9 => CTR
* 9125386474687912..7..24689157486..128963127541234579682.198.47638967412564712538.
* PAIR A4: 3,5 ROW 4
G4: 3,5,9                                # reduction candidate for 3,5
G4: 3,5 => CTR
* 9125386474687912..7..246891.74869.128963127541234579682.198.47638967412564712538.
G4: 9 => SOLVED
* 912538647468791235753246891574863912836912754129457368291385476385674129647129583
* PAIR C6: 3,9 BLK 4
B5: 3,9,5                                # reduction candidate for 3,9
B5: 3,9 => SOLVED
* 912538647468791235753246891574863912836912754129457368291385476385674129647129583
B5: 5 => CTR
* 9125386474687912..7..246891.7486..1285691273412.457.682.1.8.476.8.67412.64712..8.
* PAIR C6: 3,9 COL C
C8: 3,9,5                                # reduction candidate for 3,9
C8: 5 => SOLVED
* 912538647468791235753246891574863912836912754129457368291385476385674129647129583
C8: 3,9                                  # 16 pairs
* PAIR F4: 3,9 ROW 4
G4: 3,9,5                                # reduction candidate for 3,9
G4: 3,9 => SOLVED
* 912538647468791235753246891574863912836912754129457368291385476385674129647129583
G4: 5 => CTR
* 9125386474687912..7..246891.748695128.6.127.412.457.682.1.8.476.8.67412.64712..8.
* PAIR F4: 3,9 COL F
F7: 3,9,5                                # reduction candidate for 3,9
F7: 3,9 => CTR
* 9125386474687912..7..246891.7486..128.6.127.412.457.68251.8.476389674125647125389
F7: 5                                    # 16 pairs
F9: 3,9,5                                # reduction candidate for 3,9
F9: 3,9                                  # 16 pairs
* PAIR D5: 3,9 ROW 5
B5: 3,9,5                                # reduction candidate for 3,9
B5: 3,9 => SOLVED
* 912538647468791235753246891574863912836912754129457368291385476385674129647129583
B5: 5 => CTR
* 9125386474687912..7..246891.7486..1285691273412.457.682.1.8.476.8.67412.64712..8.
* PAIR H5: 3,5 BLK 6
G4: 3,5,9                                # reduction candidate for 3,5
G4: 3,5 => CTR
* 9125386474687912..7..246891.74869.128963127541234579682.198.47638967412564712538.
G4: 9 => SOLVED
* 912538647468791235753246891574863912836912754129457368291385476385674129647129583
* PAIR H5: 3,5 ROW 5
B5: 3,5,9                                # reduction candidate for 3,5
B5: 3,5 => SOLVED
* 912538647468791235753246891574863912836912754129457368291385476385674129647129583
B5: 9 => CTR
* 9125386474687912..7..24689157486..128963127541234579682.198.47638967412564712538.
* PAIR G6: 3,9 BLK 6
G4: 3,9,5                                # reduction candidate for 3,9
G4: 3,9 => SOLVED
* 912538647468791235753246891574863912836912754129457368291385476385674129647129583
G4: 5 => CTR
* 9125386474687912..7..246891.748695128.6.127.412.457.682.1.8.476.8.67412.64712..8.
* PAIR A8: 3,5 BLK 7
B7: 3,5,9                                # reduction candidate for 3,5
B7: 3,5 => CTR
* 9125386474687912..7..246891.7486..128963127541234579682.198.47638967412564712538.
B7: 9 => SOLVED
* 912538647468791235753246891574863912836912754129457368291385476385674129647129583
C8: 3,5,9                                # reduction candidate for 3,5
C8: 3,5 => SOLVED
* 912538647468791235753246891574863912836912754129457368291385476385674129647129583
C8: 9 => CTR
* 9125386474687912..7.5246891.7486..128.6.127.41234579682.1.8.476389674125647125389
* PAIR A8: 3,5 ROW 8
I8: 3,5,9                                # reduction candidate for 3,5
I8: 3,5 => CTR
* 9125386474687912..7.5246891.7486..1289631275412345796825198347638967412564712..89
I8: 9 => SOLVED
* 912538647468791235753246891574863912836912754129457368291385476385674129647129583
* PAIR D7: 3,9 BLK 8
F7: 3,9,5                                # reduction candidate for 3,9
F7: 3,9 => CTR
* 9125386474687912..7..246891.7486..128.6.127.412.457.68251.8.476389674125647125389
F7: 5                                    # 16 pairs
F9: 3,9,5                                # reduction candidate for 3,9
F9: 3,9                                  # 16 pairs
* PAIR D7: 3,9 ROW 7
B7: 3,9,5                                # reduction candidate for 3,9
B7: 5 => CTR
* 9125386474687912..7..246891.7486..1289631275412345796825198347638967412564712538.
B7: 3,9                                  # 16 pairs
* PAIR G9: 3,5 BLK 9
I8: 3,5,9                                # reduction candidate for 3,5
I8: 3,5 => CTR
* 9125386474687912..7.5246891.7486..1289631275412345796825198347638967412564712..89
I8: 9 => SOLVED
* 912538647468791235753246891574863912836912754129457368291385476385674129647129583
I9: 3,5,9                                # reduction candidate for 3,5
I9: 3,5 => SOLVED
* 912538647468791235753246891574863912836912754129457368291385476385674129647129583
I9: 9 => CTR
* 9125386474687912..7.5246891.7486..1289631275412345796825198347638967412564712..89
* PAIR G9: 3,5 ROW 9
F9: 3,5,9                                # reduction candidate for 3,5
F9: 3,5 => CTR
* 9125386474687912..7.5246891.7486..1289631275412345796825198347638967412564712..89
F9: 9 => SOLVED
* 912538647468791235753246891574863912836912754129457368291385476385674129647129583
* PAIR G9: 3,5 COL G
G4: 3,5,9                                # reduction candidate for 3,5
G4: 3,5 => CTR
* 9125386474687912..7..246891.74869.128963127541234579682.198.47638967412564712538.
G4: 9 => SOLVED
* 912538647468791235753246891574863912836912754129457368291385476385674129647129583
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-086-base-pr-000.dot
* REASONING
* PRF # B5: 3,5 => SOL
* DIS # B5: 9 => CTR => B5: 3,5
* DIS # B7: 3,5 => CTR => B7: 9
* PRF # B7: 9 => SOL
* PRF # C8: 3,5 => SOL
* DIS # C8: 9 => CTR => C8: 3,5
* DIS # I8: 3,5 => CTR => I8: 9
* PRF # I8: 9 => SOL
* PRF # I9: 3,5 => SOL
* DIS # I9: 9 => CTR => I9: 3,5
* PRF # B5: 3,5 => SOL
* DIS # B5: 9 => CTR => B5: 3,5
* DIS # G4: 3,5 => CTR => G4: 9
* PRF # G4: 9 => SOL
* PRF # B5: 3,9 => SOL
* DIS # B5: 5 => CTR => B5: 3,9
* PRF # C8: 5 => SOL
* PRF # G4: 3,9 => SOL
* DIS # G4: 5 => CTR => G4: 3,9
* DIS # F7: 3,9 => CTR => F7: 5
* PRF # B5: 3,9 => SOL
* DIS # B5: 5 => CTR => B5: 3,9
* DIS # G4: 3,5 => CTR => G4: 9
* PRF # G4: 9 => SOL
* PRF # B5: 3,5 => SOL
* DIS # B5: 9 => CTR => B5: 3,5
* PRF # G4: 3,9 => SOL
* DIS # G4: 5 => CTR => G4: 3,9
* DIS # B7: 3,5 => CTR => B7: 9
* PRF # B7: 9 => SOL
* PRF # C8: 3,5 => SOL
* DIS # C8: 9 => CTR => C8: 3,5
* DIS # I8: 3,5 => CTR => I8: 9
* PRF # I8: 9 => SOL
* DIS # F7: 3,9 => CTR => F7: 5
* DIS # B7: 5 => CTR => B7: 3,9
* DIS # I8: 3,5 => CTR => I8: 9
* PRF # I8: 9 => SOL
* PRF # I9: 3,5 => SOL
* DIS # I9: 9 => CTR => I9: 3,5
* DIS # F9: 3,5 => CTR => F9: 9
* PRF # F9: 9 => SOL
* DIS # G4: 3,5 => CTR => G4: 9
* PRF # G4: 9 => SOL
* CNT  44 HDP CHAINS /  50 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A4,A8,B3,C3,C6,D5,D7,F4,G6,G9,H2,H5,I2)
* 9125386474687912..7..246891.7486..128.6.127.412.457.682.1.8.476.8.67412.64712..8.
* PAIR B3: 3,5 COL B
B5: 3,5,9                                # reduction candidate for 3,5
B5: 3,5 => SOLVED
* 912538647468791235753246891574863912836912754129457368291385476385674129647129583
* DURATION: 0:00:01.897773  START: 05:45:09.260163  END: 05:45:11.157936 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-086-base-pr-001.dot
* REASONING
* PRF # B5: 3,5 => SOL
* STA B5: 3,5
* CNT   1 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 086

solution: 912538647468791235753246891574863912836912754129457368291385476385674129647129583
info: 1559     FNBWXY   S8.f     15621

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

Solution

position: 912538647468791235753246891574863912836912754129457368291385476385674129647129583 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 # B5: 3,5 => SOL
* DIS # B5: 9 => CTR => B5: 3,5
* DIS # B7: 3,5 => CTR => B7: 9
* PRF # B7: 9 => SOL
* PRF # C8: 3,5 => SOL
* DIS # C8: 9 => CTR => C8: 3,5
* DIS # I8: 3,5 => CTR => I8: 9
* PRF # I8: 9 => SOL
* PRF # I9: 3,5 => SOL
* DIS # I9: 9 => CTR => I9: 3,5
* PRF # B5: 3,5 => SOL
* DIS # B5: 9 => CTR => B5: 3,5
* DIS # G4: 3,5 => CTR => G4: 9
* PRF # G4: 9 => SOL
* PRF # B5: 3,9 => SOL
* DIS # B5: 5 => CTR => B5: 3,9
* INC # C8: 3,9 => UNS
* PRF # C8: 5 => SOL
* PRF # G4: 3,9 => SOL
* DIS # G4: 5 => CTR => G4: 3,9
* DIS # F7: 3,9 => CTR => F7: 5
* INC # F7: 5 => UNS
* INC # F9: 3,9 => UNS
* PRF # B5: 3,9 => SOL
* DIS # B5: 5 => CTR => B5: 3,9
* DIS # G4: 3,5 => CTR => G4: 9
* PRF # G4: 9 => SOL
* PRF # B5: 3,5 => SOL
* DIS # B5: 9 => CTR => B5: 3,5
* PRF # G4: 3,9 => SOL
* DIS # G4: 5 => CTR => G4: 3,9
* DIS # B7: 3,5 => CTR => B7: 9
* PRF # B7: 9 => SOL
* PRF # C8: 3,5 => SOL
* DIS # C8: 9 => CTR => C8: 3,5
* DIS # I8: 3,5 => CTR => I8: 9
* PRF # I8: 9 => SOL
* DIS # F7: 3,9 => CTR => F7: 5
* INC # F7: 5 => UNS
* INC # F9: 3,9 => UNS
* INC # B7: 3,9 => UNS
* DIS # B7: 5 => CTR => B7: 3,9
* DIS # I8: 3,5 => CTR => I8: 9
* PRF # I8: 9 => SOL
* PRF # I9: 3,5 => SOL
* DIS # I9: 9 => CTR => I9: 3,5
* DIS # F9: 3,5 => CTR => F9: 9
* PRF # F9: 9 => SOL
* DIS # G4: 3,5 => CTR => G4: 9
* PRF # G4: 9 => SOL
* CNT  50 HDP CHAINS /  50 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* PRF # B5: 3,5 => SOL
* STA B5: 3,5
* CNT   1 HDP CHAINS /   1 HYP OPENED