Analysis of xx-top500-382-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: .84....6....32.............7.....5.......23...6...4.....2....483...5.......1..... initial

Autosolve

position: 284..5.63...32.48..3.48..5272....5.44....23.6.6...482...2....4834.2586..8.614.235 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # E4: 1,9 => CTR => E4: 3,6
* DIS # B7: 7,9 => CTR => B7: 1,5
* CNT   2 HDP CHAINS /  26 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 # E4: 1,9 => CTR => E4: 3,6
* DIS E4: 3,6 # B7: 7,9 => CTR => B7: 1,5
* DIS E4: 3,6 + B7: 1,5 # C8: 1 => CTR => C8: 7,9
* PRF E4: 3,6 + B7: 1,5 + C8: 7,9 # F2: 7,9 => SOL
* STA E4: 3,6 + B7: 1,5 + C8: 7,9 + F2: 7,9
* CNT   4 HDP CHAINS /  31 HYP OPENED

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

Details

Positions

.84....6....32.............7.....5.......23...6...4.....2....483...5.......1..... initial
284..5.63...32.48..3.48..5272....5.44....23.6.6...482...2....4834.2586..8.614.235 autosolve
284915763651327489937486152728631594495872316163594827512763948349258671876149235 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (4)
D1: 7,9
H4: 1,9
B9: 7,9
F9: 7,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
E1,G1: 1.. / E1 = 1  => 11 pairs (_) / G1 = 1  => 15 pairs (_)
C4,C6: 3.. / C4 = 3  =>  6 pairs (_) / C6 = 3  =>  6 pairs (_)
E7,F7: 3.. / E7 = 3  => 15 pairs (_) / F7 = 3  =>  8 pairs (_)
C6,E6: 3.. / C6 = 3  =>  6 pairs (_) / E6 = 3  =>  6 pairs (_)
F4,F7: 3.. / F4 = 3  => 15 pairs (_) / F7 = 3  =>  8 pairs (_)
D5,D6: 5.. / D5 = 5  =>  6 pairs (_) / D6 = 5  =>  5 pairs (_)
A7,B7: 5.. / A7 = 5  =>  5 pairs (_) / B7 = 5  =>  8 pairs (_)
A2,A3: 6.. / A2 = 6  =>  5 pairs (_) / A3 = 6  =>  4 pairs (_)
F2,F3: 6.. / F2 = 6  =>  4 pairs (_) / F3 = 6  =>  5 pairs (_)
D4,E4: 6.. / D4 = 6  =>  8 pairs (_) / E4 = 6  =>  5 pairs (_)
D7,E7: 6.. / D7 = 6  =>  5 pairs (_) / E7 = 6  =>  8 pairs (_)
A2,F2: 6.. / A2 = 6  =>  5 pairs (_) / F2 = 6  =>  4 pairs (_)
A3,F3: 6.. / A3 = 6  =>  4 pairs (_) / F3 = 6  =>  5 pairs (_)
D4,D7: 6.. / D4 = 6  =>  8 pairs (_) / D7 = 6  =>  5 pairs (_)
E4,E7: 6.. / E4 = 6  =>  5 pairs (_) / E7 = 6  =>  8 pairs (_)
H5,I6: 7.. / H5 = 7  =>  7 pairs (_) / I6 = 7  => 10 pairs (_)
B9,F9: 7.. / B9 = 7  =>  9 pairs (_) / F9 = 7  => 10 pairs (_)
H5,H8: 7.. / H5 = 7  =>  7 pairs (_) / H8 = 7  => 10 pairs (_)
C4,C5: 8.. / C4 = 8  =>  9 pairs (_) / C5 = 8  =>  4 pairs (_)
D4,D5: 8.. / D4 = 8  =>  4 pairs (_) / D5 = 8  =>  9 pairs (_)
C4,D4: 8.. / C4 = 8  =>  9 pairs (_) / D4 = 8  =>  4 pairs (_)
C5,D5: 8.. / C5 = 8  =>  4 pairs (_) / D5 = 8  =>  9 pairs (_)
B9,F9: 9.. / B9 = 9  => 10 pairs (_) / F9 = 9  =>  9 pairs (_)
* DURATION: 0:00:35.347358  START: 15:55:01.340346  END: 15:55:36.687704 2017-05-04
* CP COUNT: (23)
* INCONCLUSIVE

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B9,D1,F9,H4)
* 284..5.63...32.48..3.48..5272....5.44....23.6.6...482...2....4834.2586..8.614.235
* PAIR D1: 7,9 BLK 2
E1: 7,9,1                                # reduction candidate for 7,9
E1: 7,9                                  # 15 pairs
F2: 7,9,1,6                              # reduction candidate for 7,9
F2: 7,9                                  # 13 pairs
F3: 7,9,1,6                              # reduction candidate for 7,9
F3: 7,9                                  # 12 pairs
* PAIR D1: 7,9 ROW 1
G1: 7,9,1                                # reduction candidate for 7,9
G1: 1                                    # 15 pairs
G1: 7,9                                  # 11 pairs
* PAIR D1: 7,9 COL D
D5: 7,9,5,8                              # reduction candidate for 7,9
D5: 7,9                                  #  6 pairs
D6: 7,9,5                                # reduction candidate for 7,9
D6: 7,9                                  #  6 pairs
D7: 7,9,6                                # reduction candidate for 7,9
D7: 7,9                                  #  8 pairs
* PAIR H4: 1,9 BLK 6
H5: 1,9,7                                # reduction candidate for 1,9
H5: 1,9                                  # 10 pairs
I6: 1,9,7                                # reduction candidate for 1,9
I6: 1,9                                  #  7 pairs
* PAIR H4: 1,9 ROW 4
C4: 1,9,3,8                              # reduction candidate for 1,9
C4: 1,9                                  # 15 pairs
E4: 1,9,3,6                              # reduction candidate for 1,9
E4: 1,9 => CTR
* 284..5.63...32.48..3.48..5272.6..5.44..8.23.6.6.5.482...2.63.4834.2586..8.614.235
E4: 3,6                                  #  5 pairs
F4: 1,9,3                                # reduction candidate for 1,9
F4: 1,9                                  #  8 pairs
* PAIR H4: 1,9 COL H
H8: 1,9,7                                # reduction candidate for 1,9
H8: 7                                    # 10 pairs
H8: 1,9                                  #  7 pairs
* PAIR B9: 7,9 BLK 7
B7: 7,9,1,5                              # reduction candidate for 7,9
B7: 7,9 => CTR
* 284.15.63...32.48113.486.5272...159441...2376.6...482.5.2...1483412586..8.614.235
B7: 1,5                                  #  5 pairs
C8: 7,9,1                                # reduction candidate for 7,9
C8: 7,9                                  #  9 pairs
* PAIR B9: 7,9 COL B
B2: 7,9,1,5                              # reduction candidate for 7,9
B2: 1,5                                  #  8 pairs
B2: 7,9                                  #  7 pairs
* PAIR F9: 7,9 BLK 8
D7: 7,9,6                                # reduction candidate for 7,9
D7: 7,9                                  #  8 pairs
E7: 7,9,3,6                              # reduction candidate for 7,9
E7: 7,9                                  #  6 pairs
F7: 7,9,3                                # reduction candidate for 7,9
F7: 7,9                                  # 15 pairs
* PAIR F9: 7,9 COL F
F2: 7,9,1,6                              # reduction candidate for 7,9
F2: 7,9                                  # 13 pairs
F3: 7,9,1,6                              # reduction candidate for 7,9
F3: 7,9                                  # 12 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-382-base-pr-000.dot
* REASONING
* DIS # E4: 1,9 => CTR => E4: 3,6
* DIS # B7: 7,9 => CTR => B7: 1,5
* CNT   2 HDP CHAINS /  26 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B9,D1,F9,H4)
* 284..5.63...32.48..3.48..5272....5.44....23.6.6...482...2....4834.2586..8.614.235
* PAIR D1: 7,9 BLK 2
E1: 7,9,1                                # reduction candidate for 7,9
E1: 7,9                                  # 15 pairs
F2: 7,9,1,6                              # reduction candidate for 7,9
F2: 7,9                                  # 13 pairs
F3: 7,9,1,6                              # reduction candidate for 7,9
F3: 7,9                                  # 12 pairs
* PAIR D1: 7,9 ROW 1
G1: 7,9,1                                # reduction candidate for 7,9
G1: 1                                    # 15 pairs
G1: 7,9                                  # 11 pairs
* PAIR D1: 7,9 COL D
D5: 7,9,5,8                              # reduction candidate for 7,9
D5: 7,9                                  #  6 pairs
D6: 7,9,5                                # reduction candidate for 7,9
D6: 7,9                                  #  6 pairs
D7: 7,9,6                                # reduction candidate for 7,9
D7: 7,9                                  #  8 pairs
* PAIR H4: 1,9 BLK 6
H5: 1,9,7                                # reduction candidate for 1,9
H5: 1,9                                  # 10 pairs
I6: 1,9,7                                # reduction candidate for 1,9
I6: 1,9                                  #  7 pairs
* PAIR H4: 1,9 ROW 4
C4: 1,9,3,8                              # reduction candidate for 1,9
C4: 1,9                                  # 15 pairs
E4: 1,9,3,6                              # reduction candidate for 1,9
E4: 1,9 => CTR
* 284..5.63...32.48..3.48..5272.6..5.44..8.23.6.6.5.482...2.63.4834.2586..8.614.235
F4: 1,9,3                                # reduction candidate for 1,9
F4: 1,9                                  #  8 pairs
* PAIR H4: 1,9 COL H
H8: 1,9,7                                # reduction candidate for 1,9
H8: 7                                    # 11 pairs
H8: 1,9                                  #  8 pairs
* PAIR RESTART
* PAIR H4: 1,9 BLK 6
H5: 1,9,7                                # reduction candidate for 1,9
H5: 1,9                                  # 11 pairs
I6: 1,9,7                                # reduction candidate for 1,9
I6: 1,9                                  #  8 pairs
* PAIR H4: 1,9 ROW 4
C4: 1,9,3,8                              # reduction candidate for 1,9
C4: 1,9                                  # 15 pairs
F4: 1,9,3                                # reduction candidate for 1,9
F4: 1,9                                  #  8 pairs
* PAIR H4: 1,9 COL H
H8: 1,9,7                                # reduction candidate for 1,9
H8: 7                                    # 11 pairs
H8: 1,9                                  #  8 pairs
* PAIR B9: 7,9 BLK 7
B7: 7,9,1,5                              # reduction candidate for 7,9
B7: 7,9 => CTR
* 284.15.63...32.48113.486.5272...159441...2376.6...482.5.2...1483412586..8.614.235
C8: 7,9,1                                # reduction candidate for 7,9
C8: 7,9                                  # 10 pairs
* RESTART
* PAIR B9: 7,9 BLK 7
C8: 7,9,1                                # reduction candidate for 7,9
C8: 1 => CTR
* 284.15.63...32.48113.486.5272...159441...2376.6...482.952...1483412586..876149235
* PAIR B9: 7,9 COL B
B2: 7,9,1,5                              # reduction candidate for 7,9
B2: 1,5                                  # 21 pairs
B2: 7,9                                  # 14 pairs
* PAIR F9: 7,9 BLK 8
D7: 7,9,6                                # reduction candidate for 7,9
D7: 7,9                                  # 13 pairs
E7: 7,9,3,6                              # reduction candidate for 7,9
E7: 7,9                                  # 11 pairs
F7: 7,9,3                                # reduction candidate for 7,9
F7: 7,9                                  # 15 pairs
* PAIR F9: 7,9 COL F
F2: 7,9,1,6                              # reduction candidate for 7,9
F2: 7,9 => SOLVED
* 284915763651327489937486152728631594495872316163594827512763948349258671876149235
* DURATION: 0:00:28.623098  START: 15:55:59.144694  END: 15:56:27.767792 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-382-base-pr-001.dot
* REASONING
* DIS # E4: 1,9 => CTR => E4: 3,6
* DIS E4: 3,6 # B7: 7,9 => CTR => B7: 1,5
* DIS E4: 3,6 + B7: 1,5 # C8: 1 => CTR => C8: 7,9
* PRF E4: 3,6 + B7: 1,5 + C8: 7,9 # F2: 7,9 => SOL
* STA E4: 3,6 + B7: 1,5 + C8: 7,9 + F2: 7,9
* CNT   4 HDP CHAINS /  31 HYP OPENED

Header Info

Top 500 Minimum 17 382

solution: 284915763651327489937486152728631594495872316163594827512763948349258671876149235
info: 33318    FNBTXYO  S8.f     42956

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

Solution

position: 284915763651327489937486152728631594495872316163594827512763948349258671876149235 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 # E1: 7,9 => UNS
* INC # F2: 7,9 => UNS
* INC # F3: 7,9 => UNS
* INC # G1: 7,9 => UNS
* INC # G1: 1 => UNS
* INC # D5: 7,9 => UNS
* INC # D6: 7,9 => UNS
* INC # D7: 7,9 => UNS
* INC # H5: 1,9 => UNS
* INC # I6: 1,9 => UNS
* INC # C4: 1,9 => UNS
* DIS # E4: 1,9 => CTR => E4: 3,6
* INC # E4: 3,6 => UNS
* INC # F4: 1,9 => UNS
* INC # H8: 1,9 => UNS
* INC # H8: 7 => UNS
* DIS # B7: 7,9 => CTR => B7: 1,5
* INC # B7: 1,5 => UNS
* INC # C8: 7,9 => UNS
* INC # B2: 7,9 => UNS
* INC # B2: 1,5 => UNS
* INC # D7: 7,9 => UNS
* INC # E7: 7,9 => UNS
* INC # F7: 7,9 => UNS
* INC # F2: 7,9 => UNS
* INC # F3: 7,9 => UNS
* CNT  26 HDP CHAINS /  26 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # E1: 7,9 => UNS
* INC # F2: 7,9 => UNS
* INC # F3: 7,9 => UNS
* INC # G1: 7,9 => UNS
* INC # G1: 1 => UNS
* INC # D5: 7,9 => UNS
* INC # D6: 7,9 => UNS
* INC # D7: 7,9 => UNS
* INC # H5: 1,9 => UNS
* INC # I6: 1,9 => UNS
* INC # C4: 1,9 => UNS
* DIS # E4: 1,9 => CTR => E4: 3,6
* INC E4: 3,6 # F4: 1,9 => UNS
* INC E4: 3,6 # H8: 1,9 => UNS
* INC E4: 3,6 # H8: 7 => UNS
* INC E4: 3,6 # H5: 1,9 => UNS
* INC E4: 3,6 # I6: 1,9 => UNS
* INC E4: 3,6 # C4: 1,9 => UNS
* INC E4: 3,6 # F4: 1,9 => UNS
* INC E4: 3,6 # H8: 1,9 => UNS
* INC E4: 3,6 # H8: 7 => UNS
* DIS E4: 3,6 # B7: 7,9 => CTR => B7: 1,5
* INC E4: 3,6 + B7: 1,5 # C8: 7,9 => UNS
* INC E4: 3,6 + B7: 1,5 # C8: 7,9 => UNS
* DIS E4: 3,6 + B7: 1,5 # C8: 1 => CTR => C8: 7,9
* INC E4: 3,6 + B7: 1,5 + C8: 7,9 # B2: 7,9 => UNS
* INC E4: 3,6 + B7: 1,5 + C8: 7,9 # B2: 1,5 => UNS
* INC E4: 3,6 + B7: 1,5 + C8: 7,9 # D7: 7,9 => UNS
* INC E4: 3,6 + B7: 1,5 + C8: 7,9 # E7: 7,9 => UNS
* INC E4: 3,6 + B7: 1,5 + C8: 7,9 # F7: 7,9 => UNS
* PRF E4: 3,6 + B7: 1,5 + C8: 7,9 # F2: 7,9 => SOL
* STA E4: 3,6 + B7: 1,5 + C8: 7,9 + F2: 7,9
* CNT  31 HDP CHAINS /  31 HYP OPENED