Analysis of xx-top500-022-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: .89...7.....2.1............51.3...6.....9.4..2........1......2.3...7.......4..... initial

Autosolve

position: 6895347127352.1...4219.7...517348269863792451294615...1.685..2.3.217....9.842.1.. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # G2: 6,8 => SOL
* DIS # G2: 9 => CTR => G2: 6,8
* DIS # I2: 6,8 => CTR => I2: 4
* PRF # I2: 4 => SOL
* DIS # G3: 6,8 => CTR => G3: 3,5
* DIS # I3: 6,8 => CTR => I3: 3,5
* DIS # G3: 3,8 => CTR => G3: 5,6
* DIS # H6: 3,8 => CTR => H6: 7
* PRF # H6: 7 => SOL
* DIS # H6: 3,8 => CTR => H6: 7
* PRF # H6: 7 => SOL
* PRF # I6: 3,8 => SOL
* DIS # I6: 7 => CTR => I6: 3,8
* DIS # G3: 3,8 => CTR => G3: 5,6
* DIS # I8: 4,5 => CTR => I8: 6,8
* PRF # I9: 5,7 => SOL
* DIS # I9: 3,6 => CTR => I9: 5,7
* DIS # G8: 6,9 => CTR => G8: 5,8
* DIS # I9: 3,6 => CTR => I9: 5,7
* PRF # I9: 5,7 => SOL
* DIS # I9: 3,7 => CTR => I9: 5,6
* DIS # H6: 8 => CTR => H6: 3,7
* CNT  22 HDP CHAINS /  31 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 # G2: 6,8 => SOL
* STA G2: 6,8
* CNT   1 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

.89...7.....2.1............51.3...6.....9.4..2........1......2.3...7.......4..... initial
6895347127352.1...4219.7...517348269863792451294615...1.685..2.3.217....9.842.1.. autosolve
689534712735281694421967583517348269863792451294615378146853927352179846978426135 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (15)
E2: 6,8
E3: 6,8
H2: 4,9
H3: 3,8
G6: 3,8
B7: 4,7
B8: 4,5
B9: 5,7
F7: 3,9
F8: 6,9
F9: 3,6
G7: 3,9
I7: 4,7
H8: 4,9
H9: 3,7

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
F7,F9: 3.. / F7 = 3  =>  0 pairs (*) / F9 = 3  =>  0 pairs (X)
F7,G7: 3.. / F7 = 3  =>  0 pairs (*) / G7 = 3  =>  0 pairs (X)
H2,I2: 4.. / H2 = 4  =>  0 pairs (X) / I2 = 4  =>  0 pairs (_)
B7,B8: 4.. / B7 = 4  =>  0 pairs (*) / B8 = 4  =>  0 pairs (X)
B7,I7: 4.. / B7 = 4  =>  0 pairs (*) / I7 = 4  =>  0 pairs (X)
H2,H8: 4.. / H2 = 4  =>  0 pairs (X) / H8 = 4  =>  0 pairs (_)
G3,I3: 5.. / G3 = 5  => 15 pairs (_) / I3 = 5  =>  0 pairs (X)
B8,B9: 5.. / B8 = 5  =>  0 pairs (*) / B9 = 5  =>  0 pairs (X)
B9,I9: 5.. / B9 = 5  =>  0 pairs (X) / I9 = 5  =>  0 pairs (_)
G3,G8: 5.. / G3 = 5  => 15 pairs (_) / G8 = 5  =>  0 pairs (X)
E2,E3: 6.. / E2 = 6  =>  0 pairs (X) / E3 = 6  => 15 pairs (_)
F8,F9: 6.. / F8 = 6  =>  0 pairs (X) / F9 = 6  =>  0 pairs (_)
F9,I9: 6.. / F9 = 6  =>  0 pairs (*) / I9 = 6  =>  0 pairs (X)
H6,I6: 7.. / H6 = 7  =>  0 pairs (*) / I6 = 7  =>  0 pairs (X)
B7,B9: 7.. / B7 = 7  =>  0 pairs (X) / B9 = 7  =>  0 pairs (_)
B7,I7: 7.. / B7 = 7  =>  0 pairs (X) / I7 = 7  =>  0 pairs (_)
H6,H9: 7.. / H6 = 7  =>  0 pairs (*) / H9 = 7  =>  0 pairs (X)
E2,E3: 8.. / E2 = 8  => 15 pairs (_) / E3 = 8  =>  0 pairs (X)
G8,I8: 8.. / G8 = 8  =>  0 pairs (*) / I8 = 8  =>  0 pairs (X)
H3,H6: 8.. / H3 = 8  => 17 pairs (_) / H6 = 8  =>  0 pairs (X)
G2,H2: 9.. / G2 = 9  =>  0 pairs (X) / H2 = 9  =>  0 pairs (_)
F7,F8: 9.. / F7 = 9  =>  0 pairs (X) / F8 = 9  =>  0 pairs (_)
F7,G7: 9.. / F7 = 9  =>  0 pairs (X) / G7 = 9  =>  0 pairs (_)
H2,H8: 9.. / H2 = 9  =>  0 pairs (*) / H8 = 9  =>  0 pairs (X)
* DURATION: 0:00:56.689682  START: 03:20:09.781589  END: 03:21:06.471271 2017-05-04
* CP COUNT: (24)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B7,B8,B9,E2,E3,F7,F8,F9,G6,G7,H2,H3,H8,H9,I7)
* 6895347127352.1...4219.7...517348269863792451294615...1.685..2.3.217....9.842.1..
* PAIR E2: 6,8 ROW 2
G2: 6,8,9                                # reduction candidate for 6,8
G2: 6,8 => SOLVED
* 689534712735281694421967583517348269863792451294615378146853927352179846978426135
G2: 9 => CTR
* 689534712735261948421987635517348269863792451294615...1.685932.3.2176.9.9.8423176
I2: 6,8,4                                # reduction candidate for 6,8
I2: 6,8 => CTR
* 689534712735261948421987635517348269863792451294615...1.685932.3.2176.9.9.8423176
I2: 4 => SOLVED
* 689534712735281694421967583517348269863792451294615378146853927352179846978426135
* PAIR E3: 6,8 ROW 3
G3: 6,8,3,5                              # reduction candidate for 6,8
G3: 6,8 => CTR
* 6895347127352.1..44219.7.35517348269863792451294615.8.1.685..2.3.217.5.895842.1.6
G3: 3,5                                  # 16 pairs
I3: 6,8,3,5                              # reduction candidate for 6,8
I3: 6,8 => CTR
* 6895347127352.1...4219.753.517348269863792451294615.8717685..2434217..9595842.173
I3: 3,5                                  # 16 pairs
* PAIR H3: 3,8 BLK 3
G3: 3,8,5,6                              # reduction candidate for 3,8
G3: 3,8 => CTR
* 6895347127352.1694421967..5517348269863792451294615..31.685..2.3.217.5.895842.1.6
G3: 5,6                                  # 16 pairs
I3: 3,8,5,6                              # reduction candidate for 3,8
I3: 3,8                                  # 16 pairs
* PAIR H3: 3,8 COL H
H6: 3,8,7                                # reduction candidate for 3,8
H6: 3,8 => CTR
* 68953471273526194842198763.517348269863792451294615..7176859324342176.9.958423176
H6: 7 => SOLVED
* 689534712735281694421967583517348269863792451294615378146853927352179846978426135
* PAIR G6: 3,8 BLK 6
H6: 3,8,7                                # reduction candidate for 3,8
H6: 3,8 => CTR
* 68953471273526194842198763.517348269863792451294615..7176859324342176.9.958423176
H6: 7 => SOLVED
* 689534712735281694421967583517348269863792451294615378146853927352179846978426135
I6: 3,8,7                                # reduction candidate for 3,8
I6: 3,8 => SOLVED
* 689534712735281694421967583517348269863792451294615378146853927352179846978426135
I6: 7 => CTR
* 68953471273526194842198763.517348269863792451294615..7176859324342176.9.958423176
* PAIR G6: 3,8 COL G
G3: 3,8,5,6                              # reduction candidate for 3,8
G3: 3,8 => CTR
* 6895347127352.1694421967..5517348269863792451294615..31.685..2.3.217.5.895842.1.6
G3: 5,6                                  # 16 pairs
* PAIR B8: 4,5 ROW 8
I8: 4,5,6,8                              # reduction candidate for 4,5
I8: 4,5 => CTR
* 6895347127352.1...4219.75..5173482698637924512946153..1.6853.2.3.217.8..9.842.1.6
I8: 6,8                                  # 16 pairs
* PAIR B9: 5,7 ROW 9
I9: 5,7,3,6                              # reduction candidate for 5,7
I9: 5,7 => SOLVED
* 689534712735281694421967583517348269863792451294615378146853927352179846978426135
I9: 3,6 => CTR
* 68953471273526194842198763.517348269863792451294615..7176859324342176.9.958423176
* PAIR F8: 6,9 ROW 8
G8: 6,9,5,8                              # reduction candidate for 6,9
G8: 6,9 => CTR
* 6895347127352.1.944219.758.517348269863792451294615...1.685..2.35217.648978426135
G8: 5,8                                  # 17 pairs
* PAIR F9: 3,6 ROW 9
I9: 3,6,5,7                              # reduction candidate for 3,6
I9: 3,6 => CTR
* 68953471273526194842198763.517348269863792451294615..7176859324342176.9.958423176
I9: 5,7 => SOLVED
* 689534712735281694421967583517348269863792451294615378146853927352179846978426135
* PAIR H9: 3,7 BLK 9
I9: 3,7,5,6                              # reduction candidate for 3,7
I9: 3,7 => CTR
* 6895347127352.1...4219.7...517348269863792451294615...1768539243.217....9584261..
I9: 5,6                                  # 16 pairs
* PAIR H9: 3,7 COL H
H6: 3,7,8                                # reduction candidate for 3,7
H6: 8 => CTR
* 6895347127352.1...4219.7...517348269863792451294615.8717685..2434217..9.95842.17.
H6: 3,7                                  # 17 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-022-base-pr-000.dot
* REASONING
* PRF # G2: 6,8 => SOL
* DIS # G2: 9 => CTR => G2: 6,8
* DIS # I2: 6,8 => CTR => I2: 4
* PRF # I2: 4 => SOL
* DIS # G3: 6,8 => CTR => G3: 3,5
* DIS # I3: 6,8 => CTR => I3: 3,5
* DIS # G3: 3,8 => CTR => G3: 5,6
* DIS # H6: 3,8 => CTR => H6: 7
* PRF # H6: 7 => SOL
* DIS # H6: 3,8 => CTR => H6: 7
* PRF # H6: 7 => SOL
* PRF # I6: 3,8 => SOL
* DIS # I6: 7 => CTR => I6: 3,8
* DIS # G3: 3,8 => CTR => G3: 5,6
* DIS # I8: 4,5 => CTR => I8: 6,8
* PRF # I9: 5,7 => SOL
* DIS # I9: 3,6 => CTR => I9: 5,7
* DIS # G8: 6,9 => CTR => G8: 5,8
* DIS # I9: 3,6 => CTR => I9: 5,7
* PRF # I9: 5,7 => SOL
* DIS # I9: 3,7 => CTR => I9: 5,6
* DIS # H6: 8 => CTR => H6: 3,7
* CNT  22 HDP CHAINS /  31 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B7,B8,B9,E2,E3,F7,F8,F9,G6,G7,H2,H3,H8,H9,I7)
* 6895347127352.1...4219.7...517348269863792451294615...1.685..2.3.217....9.842.1..
* PAIR E2: 6,8 ROW 2
G2: 6,8,9                                # reduction candidate for 6,8
G2: 6,8 => SOLVED
* 689534712735281694421967583517348269863792451294615378146853927352179846978426135
* DURATION: 0:00:02.344359  START: 03:21:53.745460  END: 03:21:56.089819 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-022-base-pr-001.dot
* REASONING
* PRF # G2: 6,8 => SOL
* STA G2: 6,8
* CNT   1 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 022

solution: 689534712735281694421967583517348269863792451294615378146853927352179846978426135
info: 1313     FNBTHY   S8.f     42959

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

Solution

position: 689534712735281694421967583517348269863792451294615378146853927352179846978426135 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 # G2: 6,8 => SOL
* DIS # G2: 9 => CTR => G2: 6,8
* DIS # I2: 6,8 => CTR => I2: 4
* PRF # I2: 4 => SOL
* DIS # G3: 6,8 => CTR => G3: 3,5
* INC # G3: 3,5 => UNS
* DIS # I3: 6,8 => CTR => I3: 3,5
* INC # I3: 3,5 => UNS
* DIS # G3: 3,8 => CTR => G3: 5,6
* INC # G3: 5,6 => UNS
* INC # I3: 3,8 => UNS
* DIS # H6: 3,8 => CTR => H6: 7
* PRF # H6: 7 => SOL
* DIS # H6: 3,8 => CTR => H6: 7
* PRF # H6: 7 => SOL
* PRF # I6: 3,8 => SOL
* DIS # I6: 7 => CTR => I6: 3,8
* DIS # G3: 3,8 => CTR => G3: 5,6
* INC # G3: 5,6 => UNS
* DIS # I8: 4,5 => CTR => I8: 6,8
* INC # I8: 6,8 => UNS
* PRF # I9: 5,7 => SOL
* DIS # I9: 3,6 => CTR => I9: 5,7
* DIS # G8: 6,9 => CTR => G8: 5,8
* INC # G8: 5,8 => UNS
* DIS # I9: 3,6 => CTR => I9: 5,7
* PRF # I9: 5,7 => SOL
* DIS # I9: 3,7 => CTR => I9: 5,6
* INC # I9: 5,6 => UNS
* INC # H6: 3,7 => UNS
* DIS # H6: 8 => CTR => H6: 3,7
* CNT  31 HDP CHAINS /  31 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* PRF # G2: 6,8 => SOL
* STA G2: 6,8
* CNT   1 HDP CHAINS /   1 HYP OPENED