Analysis of xx-top500-406-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: ..63...75.1..........2.....5.......2.....84......1........4.81.3..5.....2........ initial

Autosolve

position: 846391275.1285.34....2.4.815.84..1.21...2845.42..15.386...428133.15...242.41..5.. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # F9: 6,7 => CTR => F9: 3,9
* DIS # B5: 7,9 => CTR => B5: 3,6
* DIS # D6: 7,9 => CTR => D6: 6
* DIS # F4: 9 => CTR => F4: 3,7
* DIS # B4: 7 => CTR => B4: 6,9
* DIS # F9: 7,9 => CTR => F9: 3,6
* DIS # D6: 7,9 => CTR => D6: 6
* DIS # F9: 6,9 => CTR => F9: 3,7
* CNT   8 HDP CHAINS /  38 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 # F9: 6,7 => CTR => F9: 3,9
* PRF F9: 3,9 # F8: 9 => SOL
* STA F9: 3,9 + F8: 9
* CNT   2 HDP CHAINS /   4 HYP OPENED

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

Details

Positions

..63...75.1..........2.....5.......2.....84......1........4.81.3..5.....2........ initial
846391275.1285.34....2.4.815.84..1.21...2845.42..15.386...428133.15...242.41..5.. autosolve
846391275712856349935274681598437162163928457427615938659742813381569724274183596 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (13)
A2: 7,9
A3: 7,9
B3: 3,5
C3: 3,5
F2: 6,7
E3: 6,7
I2: 6,9
G3: 6,9
C6: 7,9
E4: 3,7
H4: 6,9
D7: 7,9
H9: 6,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
B3,C3: 3.. / B3 = 3  => 12 pairs (_) / C3 = 3  => 22 pairs (_)
B5,C5: 3.. / B5 = 3  => 22 pairs (_) / C5 = 3  => 12 pairs (_)
E4,F4: 3.. / E4 = 3  => 13 pairs (_) / F4 = 3  =>  0 pairs (X)
E9,F9: 3.. / E9 = 3  =>  0 pairs (X) / F9 = 3  => 13 pairs (_)
B3,B5: 3.. / B3 = 3  => 12 pairs (_) / B5 = 3  => 22 pairs (_)
C3,C5: 3.. / C3 = 3  => 22 pairs (_) / C5 = 3  => 12 pairs (_)
E4,E9: 3.. / E4 = 3  => 13 pairs (_) / E9 = 3  =>  0 pairs (X)
F4,F9: 3.. / F4 = 3  =>  0 pairs (X) / F9 = 3  => 13 pairs (_)
B3,C3: 5.. / B3 = 5  => 22 pairs (_) / C3 = 5  => 12 pairs (_)
B7,C7: 5.. / B7 = 5  => 12 pairs (_) / C7 = 5  => 22 pairs (_)
B3,B7: 5.. / B3 = 5  => 22 pairs (_) / B7 = 5  => 12 pairs (_)
C3,C7: 5.. / C3 = 5  => 12 pairs (_) / C7 = 5  => 22 pairs (_)
F2,E3: 6.. / F2 = 6  => 14 pairs (_) / E3 = 6  => 16 pairs (_)
I2,G3: 6.. / I2 = 6  => 16 pairs (_) / G3 = 6  => 14 pairs (_)
B4,B5: 6.. / B4 = 6  => 26 pairs (_) / B5 = 6  => 17 pairs (_)
D5,D6: 6.. / D5 = 6  =>  0 pairs (X) / D6 = 6  => 15 pairs (_)
F2,I2: 6.. / F2 = 6  => 14 pairs (_) / I2 = 6  => 16 pairs (_)
E3,G3: 6.. / E3 = 6  => 16 pairs (_) / G3 = 6  => 14 pairs (_)
B4,H4: 6.. / B4 = 6  => 26 pairs (_) / H4 = 6  => 17 pairs (_)
D6,G6: 6.. / D6 = 6  => 15 pairs (_) / G6 = 6  =>  0 pairs (X)
H4,H9: 6.. / H4 = 6  => 17 pairs (_) / H9 = 6  => 26 pairs (_)
A2,A3: 7.. / A2 = 7  => 14 pairs (_) / A3 = 7  => 16 pairs (_)
F2,E3: 7.. / F2 = 7  => 16 pairs (_) / E3 = 7  => 14 pairs (_)
I5,G6: 7.. / I5 = 7  => 22 pairs (_) / G6 = 7  => 19 pairs (_)
G8,I9: 7.. / G8 = 7  => 22 pairs (_) / I9 = 7  => 19 pairs (_)
A2,F2: 7.. / A2 = 7  => 14 pairs (_) / F2 = 7  => 16 pairs (_)
A3,E3: 7.. / A3 = 7  => 16 pairs (_) / E3 = 7  => 14 pairs (_)
G6,G8: 7.. / G6 = 7  => 19 pairs (_) / G8 = 7  => 22 pairs (_)
I5,I9: 7.. / I5 = 7  => 22 pairs (_) / I9 = 7  => 19 pairs (_)
B8,B9: 8.. / B8 = 8  => 16 pairs (_) / B9 = 8  => 14 pairs (_)
E8,E9: 8.. / E8 = 8  => 14 pairs (_) / E9 = 8  => 16 pairs (_)
B8,E8: 8.. / B8 = 8  => 16 pairs (_) / E8 = 8  => 14 pairs (_)
B9,E9: 8.. / B9 = 8  => 14 pairs (_) / E9 = 8  => 16 pairs (_)
A2,A3: 9.. / A2 = 9  => 16 pairs (_) / A3 = 9  => 14 pairs (_)
I2,G3: 9.. / I2 = 9  => 14 pairs (_) / G3 = 9  => 16 pairs (_)
A2,I2: 9.. / A2 = 9  => 16 pairs (_) / I2 = 9  => 14 pairs (_)
A3,G3: 9.. / A3 = 9  => 14 pairs (_) / G3 = 9  => 16 pairs (_)
H4,H9: 9.. / H4 = 9  => 26 pairs (_) / H9 = 9  => 17 pairs (_)
* DURATION: 0:01:09.006371  START: 16:42:52.943019  END: 16:44:01.949390 2017-05-04
* CP COUNT: (38)
* CLUE FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A2,A3,B3,C3,C6,D7,E3,E4,F2,G3,H4,H9,I2)
* 846391275.1285.34....2.4.815.84..1.21...2845.42..15.386...428133.15...242.41..5..
* PAIR F2: 6,7 COL F
F8: 6,7,9                                # reduction candidate for 6,7
F8: 6,7                                  # 16 pairs
F9: 6,7,3,9                              # reduction candidate for 6,7
F9: 6,7 => CTR
* 846391275.128573467..26498159847316216..2845.42..15.386..7428133.1589624284136597
F9: 3,9                                  # 14 pairs
* PAIR E3: 6,7 COL E
E8: 6,7,8                                # reduction candidate for 6,7
E8: 6,7                                  # 16 pairs
E9: 6,7,3,8                              # reduction candidate for 6,7
E9: 6,7                                  # 16 pairs
* PAIR I2: 6,9 COL I
I5: 6,9,7                                # reduction candidate for 6,9
I5: 6,9                                  # 19 pairs
I9: 6,9,7                                # reduction candidate for 6,9
I9: 6,9                                  # 22 pairs
* PAIR G3: 6,9 COL G
G6: 6,9,7                                # reduction candidate for 6,9
G6: 6,9                                  # 22 pairs
G8: 6,9,7                                # reduction candidate for 6,9
G8: 6,9                                  # 19 pairs
* PAIR C6: 7,9 BLK 4
B4: 7,9,6                                # reduction candidate for 7,9
B4: 7,9                                  # 17 pairs
B5: 7,9,3,6                              # reduction candidate for 7,9
B5: 7,9 => CTR
* 84639127591285734..352.4.815684..1921936284574279156386597428133.15..724274183569
B5: 3,6                                  # 14 pairs
C5: 7,9,3                                # reduction candidate for 7,9
C5: 7,9                                  # 22 pairs
* PAIR C6: 7,9 ROW 6
D6: 7,9,6                                # reduction candidate for 7,9
D6: 7,9 => CTR
* 8463912759128573467..2649815684731.21..62845.42..156386...428133.15..7242.41..569
D6: 6                                    # 15 pairs
G6: 7,9,6                                # reduction candidate for 7,9
G6: 7,9                                  # 15 pairs
* PAIR C6: 7,9 COL C
C7: 7,9,5                                # reduction candidate for 7,9
C7: 5                                    # 22 pairs
C7: 7,9                                  # 12 pairs
* PAIR E4: 3,7 BLK 5
F4: 3,7,9                                # reduction candidate for 3,7
F4: 9 => CTR
* 8463912759128573467352649815784391621637284594296157386579428133915...242.41.3597
F4: 3,7                                  # 22 pairs
* PAIR E4: 3,7 COL E
E9: 3,7,6,8                              # reduction candidate for 3,7
E9: 3,7                                  # 16 pairs
E9: 6,8                                  # 14 pairs
* PAIR H4: 6,9 BLK 6
I5: 6,9,7                                # reduction candidate for 6,9
I5: 6,9                                  # 19 pairs
G6: 6,9,7                                # reduction candidate for 6,9
G6: 6,9                                  # 22 pairs
* PAIR H4: 6,9 ROW 4
B4: 6,9,7                                # reduction candidate for 6,9
B4: 7 => CTR
* 8463912759128573467352649815784391621637284594296157386579428133915...242.41.3597
B4: 6,9                                  # 22 pairs
* PAIR D7: 7,9 BLK 8
F8: 7,9,6                                # reduction candidate for 7,9
F8: 7,9                                  # 16 pairs
F9: 7,9,3,6                              # reduction candidate for 7,9
F9: 7,9 => CTR
* 846391275.128573467..2649815.84731.21...2845.42..15.386..7428133.1586.24284139567
F9: 3,6                                  # 14 pairs
* PAIR D7: 7,9 ROW 7
B7: 7,9,5                                # reduction candidate for 7,9
B7: 7,9                                  # 22 pairs
C7: 7,9,5                                # reduction candidate for 7,9
C7: 7,9                                  # 12 pairs
* PAIR D7: 7,9 COL D
D5: 7,9,6                                # reduction candidate for 7,9
D5: 7,9                                  # 15 pairs
D6: 7,9,6                                # reduction candidate for 7,9
D6: 7,9 => CTR
* 8463912759128573467..2649815684731.21..62845.42..156386...428133.15..7242.41..569
D6: 6                                    # 15 pairs
* PAIR H9: 6,9 BLK 9
G8: 6,9,7                                # reduction candidate for 6,9
G8: 6,9                                  # 19 pairs
I9: 6,9,7                                # reduction candidate for 6,9
I9: 6,9                                  # 22 pairs
* PAIR H9: 6,9 ROW 9
F9: 6,9,3,7                              # reduction candidate for 6,9
F9: 6,9 => CTR
* 846391275.128573467..2649815.84731.21...2845942.915.386..7428133.158..2428413.5.7
F9: 3,7                                  # 14 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-406-base-pr-000.dot
* REASONING
* DIS # F9: 6,7 => CTR => F9: 3,9
* DIS # B5: 7,9 => CTR => B5: 3,6
* DIS # D6: 7,9 => CTR => D6: 6
* DIS # F4: 9 => CTR => F4: 3,7
* DIS # B4: 7 => CTR => B4: 6,9
* DIS # F9: 7,9 => CTR => F9: 3,6
* DIS # D6: 7,9 => CTR => D6: 6
* DIS # F9: 6,9 => CTR => F9: 3,7
* CNT   8 HDP CHAINS /  38 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A2,A3,B3,C3,C6,D7,E3,E4,F2,G3,H4,H9,I2)
* 846391275.1285.34....2.4.815.84..1.21...2845.42..15.386...428133.15...242.41..5..
* PAIR F2: 6,7 COL F
F8: 6,7,9                                # reduction candidate for 6,7
F8: 6,7                                  # 16 pairs
F9: 6,7,3,9                              # reduction candidate for 6,7
F9: 6,7 => CTR
* 846391275.128573467..26498159847316216..2845.42..15.386..7428133.1589624284136597
* RESTART
* PAIR F2: 6,7 COL F
F8: 6,7,9                                # reduction candidate for 6,7
F8: 9 => SOLVED
* 846391275712856349935274681598437162163928457427615938659742813381569724274183596
* DURATION: 0:00:05.152052  START: 16:44:38.787998  END: 16:44:43.940050 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-406-base-pr-001.dot
* REASONING
* DIS # F9: 6,7 => CTR => F9: 3,9
* PRF F9: 3,9 # F8: 9 => SOL
* STA F9: 3,9 + F8: 9
* CNT   2 HDP CHAINS /   4 HYP OPENED

Header Info

Top 500 Minimum 17 406

solution: 846391275712856349935274681598437162163928457427615938659742813381569724274183596
info: 94803    FNBXK    S8.f     14147

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

Solution

position: 846391275712856349935274681598437162163928457427615938659742813381569724274183596 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 # F8: 6,7 => UNS
* DIS # F9: 6,7 => CTR => F9: 3,9
* INC # F9: 3,9 => UNS
* INC # E8: 6,7 => UNS
* INC # E9: 6,7 => UNS
* INC # I5: 6,9 => UNS
* INC # I9: 6,9 => UNS
* INC # G6: 6,9 => UNS
* INC # G8: 6,9 => UNS
* INC # B4: 7,9 => UNS
* DIS # B5: 7,9 => CTR => B5: 3,6
* INC # B5: 3,6 => UNS
* INC # C5: 7,9 => UNS
* DIS # D6: 7,9 => CTR => D6: 6
* INC # D6: 6 => UNS
* INC # G6: 7,9 => UNS
* INC # C7: 7,9 => UNS
* INC # C7: 5 => UNS
* INC # F4: 3,7 => UNS
* DIS # F4: 9 => CTR => F4: 3,7
* INC # E9: 3,7 => UNS
* INC # E9: 6,8 => UNS
* INC # I5: 6,9 => UNS
* INC # G6: 6,9 => UNS
* INC # B4: 6,9 => UNS
* DIS # B4: 7 => CTR => B4: 6,9
* INC # F8: 7,9 => UNS
* DIS # F9: 7,9 => CTR => F9: 3,6
* INC # F9: 3,6 => UNS
* INC # B7: 7,9 => UNS
* INC # C7: 7,9 => UNS
* INC # D5: 7,9 => UNS
* DIS # D6: 7,9 => CTR => D6: 6
* INC # D6: 6 => UNS
* INC # G8: 6,9 => UNS
* INC # I9: 6,9 => UNS
* DIS # F9: 6,9 => CTR => F9: 3,7
* INC # F9: 3,7 => UNS
* CNT  38 HDP CHAINS /  38 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # F8: 6,7 => UNS
* DIS # F9: 6,7 => CTR => F9: 3,9
* INC F9: 3,9 # F8: 6,7 => UNS
* PRF F9: 3,9 # F8: 9 => SOL
* STA F9: 3,9 + F8: 9
* CNT   4 HDP CHAINS /   4 HYP OPENED