Analysis of xx-top500-047-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 4.....6......7..5......1......43.2...17.......5.....3.8..6..3.....2............1. initial

Autosolve

position: 4315..6.7....7.15.7.5..1......435271317...5..2541.7.3.87.61.3.51..25.7..5..7...1. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # B2: 6,9 => CTR => B2: 2,8
* PRF # G3: 8,9 => SOL
* DIS # H3: 8,9 => CTR => H3: 2,4
* DIS # F1: 8,9 => CTR => F1: 2
* DIS # H8: 8,9 => CTR => H8: 4,6
* DIS # E5: 8,9 => CTR => E5: 2,6
* PRF # F5: 8,9 => SOL
* DIS # I5: 8,9 => CTR => I5: 4,6
* DIS # I5: 8,9 => CTR => I5: 4,6
* PRF # I6: 8,9 => SOL
* PRF # E6: 6 => SOL
* PRF # G3: 8,9 => SOL
* DIS # C9: 2,9 => CTR => C9: 3,6
* PRF # H7: 2,9 => SOL
* PRF # F8: 4,9 => SOL
* DIS # F9: 4,9 => CTR => F9: 3,8
* DIS # H7: 2 => CTR => H7: 4,9
* CNT  17 HDP CHAINS /  52 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 # B2: 6,9 => CTR => B2: 2,8
* PRF B2: 2,8 # G3: 8,9 => SOL
* STA B2: 2,8 + G3: 8,9
* CNT   2 HDP CHAINS /   5 HYP OPENED

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

Details

Positions

4.....6......7..5......1......43.2...17.......5.....3.8..6..3.....2............1. initial
4315..6.7....7.15.7.5..1......435271317...5..2541.7.3.87.61.3.51..25.7..5..7...1. autosolve
431592687928376154765841923689435271317928546254167839872614395143259768596783412 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (9)
A2: 6,9
F2: 4,6
E3: 4,6
H1: 8,9
A4: 6,9
D5: 8,9
G6: 8,9
C7: 2,9
F7: 4,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
E1,F1: 2.. / E1 = 2  =>  0 pairs (X) / F1 = 2  => 10 pairs (_)
E5,F5: 2.. / E5 = 2  => 10 pairs (_) / F5 = 2  =>  0 pairs (X)
H7,I9: 2.. / H7 = 2  =>  0 pairs (X) / I9 = 2  => 11 pairs (_)
C7,H7: 2.. / C7 = 2  => 11 pairs (_) / H7 = 2  =>  0 pairs (X)
E1,E5: 2.. / E1 = 2  =>  0 pairs (X) / E5 = 2  => 10 pairs (_)
F1,F5: 2.. / F1 = 2  => 10 pairs (_) / F5 = 2  =>  0 pairs (X)
H3,H7: 2.. / H3 = 2  => 11 pairs (_) / H7 = 2  =>  0 pairs (X)
D2,D3: 3.. / D2 = 3  => 10 pairs (_) / D3 = 3  => 17 pairs (_)
I2,I3: 3.. / I2 = 3  => 17 pairs (_) / I3 = 3  => 10 pairs (_)
C8,C9: 3.. / C8 = 3  =>  9 pairs (_) / C9 = 3  => 14 pairs (_)
F8,F9: 3.. / F8 = 3  => 14 pairs (_) / F9 = 3  =>  9 pairs (_)
D2,I2: 3.. / D2 = 3  => 10 pairs (_) / I2 = 3  => 17 pairs (_)
D3,I3: 3.. / D3 = 3  => 17 pairs (_) / I3 = 3  => 10 pairs (_)
C8,F8: 3.. / C8 = 3  =>  9 pairs (_) / F8 = 3  => 14 pairs (_)
C9,F9: 3.. / C9 = 3  => 14 pairs (_) / F9 = 3  =>  9 pairs (_)
F2,E3: 4.. / F2 = 4  => 15 pairs (_) / E3 = 4  =>  0 pairs (*)
H5,I5: 4.. / H5 = 4  =>  0 pairs (*) / I5 = 4  =>  0 pairs (X)
B8,B9: 4.. / B8 = 4  =>  9 pairs (_) / B9 = 4  =>  0 pairs (X)
F2,I2: 4.. / F2 = 4  => 15 pairs (_) / I2 = 4  =>  0 pairs (*)
F7,H7: 4.. / F7 = 4  =>  0 pairs (*) / H7 = 4  =>  0 pairs (X)
E3,E9: 4.. / E3 = 4  =>  0 pairs (*) / E9 = 4  =>  0 pairs (X)
G3,G9: 4.. / G3 = 4  => 15 pairs (_) / G9 = 4  =>  0 pairs (*)
F2,E3: 6.. / F2 = 6  =>  0 pairs (*) / E3 = 6  =>  0 pairs (X)
B3,E3: 6.. / B3 = 6  =>  0 pairs (*) / E3 = 6  =>  0 pairs (X)
E6,I6: 6.. / E6 = 6  =>  0 pairs (*) / I6 = 6  =>  0 pairs (X)
A2,A4: 6.. / A2 = 6  => 16 pairs (_) / A4 = 6  => 10 pairs (_)
F2,F5: 6.. / F2 = 6  =>  0 pairs (*) / F5 = 6  =>  0 pairs (X)
H5,H8: 6.. / H5 = 6  =>  0 pairs (X) / H8 = 6  => 11 pairs (_)
B4,C4: 8.. / B4 = 8  => 11 pairs (_) / C4 = 8  => 10 pairs (_)
C2,C4: 8.. / C2 = 8  => 11 pairs (_) / C4 = 8  => 10 pairs (_)
A2,A4: 9.. / A2 = 9  => 10 pairs (_) / A4 = 9  => 16 pairs (_)
* DURATION: 0:00:49.354619  START: 04:16:12.656731  END: 04:17:02.011350 2017-05-04
* CP COUNT: (31)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A2,A4,C7,D5,E3,F2,F7,G6,H1)
* 4315..6.7....7.15.7.5..1......435271317...5..2541.7.3.87.61.3.51..25.7..5..7...1.
* PAIR A2: 6,9 BLK 1
B2: 6,9,2,8                              # reduction candidate for 6,9
B2: 6,9 => CTR
* 4315.26.7..2.7415.7.5.61......435271317..65..2541.7.3687.61934514.25.76.5..74..12
B2: 2,8                                  # 10 pairs
C2: 6,9,2,8                              # reduction candidate for 6,9
C2: 6,9                                  # 20 pairs
B3: 6,9,2,8                              # reduction candidate for 6,9
B3: 6,9                                  # 13 pairs
* PAIR H1: 8,9 BLK 3
I2: 8,9,2,3,4                            # reduction candidate for 8,9
I2: 8,9                                  # 17 pairs
G3: 8,9,4                                # reduction candidate for 8,9
G3: 8,9 => SOLVED
* 431592687928376154765841923689435271317928546254167839872614395143259768596783412
G3: 4                                    # 15 pairs
H3: 8,9,2,4                              # reduction candidate for 8,9
H3: 8,9 => CTR
* 4315..6.7....76154765..1......435271317...5..2541.7.3.8796143251..25.7..5..7...1.
H3: 2,4                                  # 10 pairs
I3: 8,9,2,3,4                            # reduction candidate for 8,9
I3: 8,9                                  # 17 pairs
* PAIR H1: 8,9 ROW 1
E1: 8,9,2                                # reduction candidate for 8,9
E1: 8,9                                  # 10 pairs
F1: 8,9,2                                # reduction candidate for 8,9
F1: 8,9 => CTR
* 43152.6.7928376154765.41.23689435271317..254.2541.7.3.872614395143259768596783412
F1: 2                                    # 10 pairs
* PAIR H1: 8,9 COL H
H5: 8,9,4,6                              # reduction candidate for 8,9
H5: 8,9                                  # 15 pairs
H8: 8,9,4,6                              # reduction candidate for 8,9
H8: 8,9 => CTR
* 4315..6.7....7.15.7.5..1......435271317...564254167.3.87.61.3.51..25.7..5..7...1.
H8: 4,6                                  # 10 pairs
* PAIR A4: 6,9 BLK 4
B4: 6,9,8                                # reduction candidate for 6,9
B4: 6,9                                  # 10 pairs
C4: 6,9,8                                # reduction candidate for 6,9
C4: 6,9                                  # 11 pairs
* PAIR D5: 8,9 BLK 5
E5: 8,9,2,6                              # reduction candidate for 8,9
E5: 8,9 => CTR
* 43152.6.7928376154765.41.23689435271317..2546254167.3.872614395143259768596783412
E5: 2,6                                  # 10 pairs
F5: 8,9,2,6                              # reduction candidate for 8,9
F5: 8,9 => SOLVED
* 431592687928376154765841923689435271317928546254167839872614395143259768596783412
F5: 2,6                                  # 10 pairs
E6: 8,9,6                                # reduction candidate for 8,9
E6: 8,9                                  # 14 pairs
* PAIR D5: 8,9 ROW 5
H5: 8,9,4,6                              # reduction candidate for 8,9
H5: 8,9                                  # 15 pairs
I5: 8,9,4,6                              # reduction candidate for 8,9
I5: 8,9 => CTR
* 43152.6.7928376154765.41.23689435271317.6254.2541.7.36872614395143259768596783412
I5: 4,6                                  # 10 pairs
* PAIR D5: 8,9 COL D
D2: 8,9,3                                # reduction candidate for 8,9
D2: 8,9                                  # 17 pairs
D3: 8,9,3                                # reduction candidate for 8,9
D3: 8,9                                  # 10 pairs
* PAIR G6: 8,9 BLK 6
H5: 8,9,4,6                              # reduction candidate for 8,9
H5: 8,9                                  # 15 pairs
I5: 8,9,4,6                              # reduction candidate for 8,9
I5: 8,9 => CTR
* 43152.6.7928376154765.41.23689435271317.6254.2541.7.36872614395143259768596783412
I5: 4,6                                  # 10 pairs
I6: 8,9,6                                # reduction candidate for 8,9
I6: 8,9 => SOLVED
* 431592687928376154765841923689435271317928546254167839872614395143259768596783412
I6: 6                                    # 14 pairs
* PAIR G6: 8,9 ROW 6
E6: 8,9,6                                # reduction candidate for 8,9
E6: 6 => SOLVED
* 431592687928376154765841923689435271317928546254167839872614395143259768596783412
E6: 8,9                                  # 14 pairs
* PAIR G6: 8,9 COL G
G3: 8,9,4                                # reduction candidate for 8,9
G3: 8,9 => SOLVED
* 431592687928376154765841923689435271317928546254167839872614395143259768596783412
G3: 4                                    # 15 pairs
G9: 8,9,4                                # reduction candidate for 8,9
G9: 8,9                                  # 15 pairs
* PAIR C7: 2,9 BLK 7
B9: 2,9,4,6                              # reduction candidate for 2,9
B9: 2,9                                  # 13 pairs
C9: 2,9,3,6                              # reduction candidate for 2,9
C9: 2,9 => CTR
* 4315.26.7....7415.7.5.6142....435271317.265.4254187936872619345143258769569743812
C9: 3,6                                  # 10 pairs
* PAIR C7: 2,9 ROW 7
H7: 2,9,4                                # reduction candidate for 2,9
H7: 2,9 => SOLVED
* 431592687928376154765841923689435271317928546254167839872614395143259768596783412
H7: 4                                    # 15 pairs
* PAIR C7: 2,9 COL C
C2: 2,9,6,8                              # reduction candidate for 2,9
C2: 2,9                                  # 14 pairs
C2: 6,8                                  # 10 pairs
* PAIR F7: 4,9 BLK 8
F8: 4,9,3,8                              # reduction candidate for 4,9
F8: 4,9 => SOLVED
* 431592687928376154765841923689435271317928546254167839872614395143259768596783412
F8: 3,8                                  # 10 pairs
E9: 4,9,8                                # reduction candidate for 4,9
E9: 4,9                                  # 13 pairs
F9: 4,9,3,8                              # reduction candidate for 4,9
F9: 4,9 => CTR
* 4315..6.7....76154765.41..36..435271317...54.2541.7.3.87.6143.51462537..5.378941.
F9: 3,8                                  # 10 pairs
* PAIR F7: 4,9 ROW 7
H7: 4,9,2                                # reduction candidate for 4,9
H7: 2 => CTR
* 4315..6.7....76154765..1......435271317...5..2541.7.3.87.6143251..25.7..5..7...1.
H7: 4,9                                  # 11 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-047-base-pr-000.dot
* REASONING
* DIS # B2: 6,9 => CTR => B2: 2,8
* PRF # G3: 8,9 => SOL
* DIS # H3: 8,9 => CTR => H3: 2,4
* DIS # F1: 8,9 => CTR => F1: 2
* DIS # H8: 8,9 => CTR => H8: 4,6
* DIS # E5: 8,9 => CTR => E5: 2,6
* PRF # F5: 8,9 => SOL
* DIS # I5: 8,9 => CTR => I5: 4,6
* DIS # I5: 8,9 => CTR => I5: 4,6
* PRF # I6: 8,9 => SOL
* PRF # E6: 6 => SOL
* PRF # G3: 8,9 => SOL
* DIS # C9: 2,9 => CTR => C9: 3,6
* PRF # H7: 2,9 => SOL
* PRF # F8: 4,9 => SOL
* DIS # F9: 4,9 => CTR => F9: 3,8
* DIS # H7: 2 => CTR => H7: 4,9
* CNT  17 HDP CHAINS /  52 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A2,A4,C7,D5,E3,F2,F7,G6,H1)
* 4315..6.7....7.15.7.5..1......435271317...5..2541.7.3.87.61.3.51..25.7..5..7...1.
* PAIR A2: 6,9 BLK 1
B2: 6,9,2,8                              # reduction candidate for 6,9
B2: 6,9 => CTR
* 4315.26.7..2.7415.7.5.61......435271317..65..2541.7.3687.61934514.25.76.5..74..12
C2: 6,9,2,8                              # reduction candidate for 6,9
C2: 6,9                                  # 20 pairs
B3: 6,9,2,8                              # reduction candidate for 6,9
B3: 6,9                                  # 13 pairs
* PAIR H1: 8,9 BLK 3
I2: 8,9,2,3,4                            # reduction candidate for 8,9
I2: 8,9                                  # 17 pairs
G3: 8,9,4                                # reduction candidate for 8,9
G3: 8,9 => SOLVED
* 431592687928376154765841923689435271317928546254167839872614395143259768596783412
* DURATION: 0:00:06.286330  START: 04:17:50.894435  END: 04:17:57.180765 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-047-base-pr-001.dot
* REASONING
* DIS # B2: 6,9 => CTR => B2: 2,8
* PRF B2: 2,8 # G3: 8,9 => SOL
* STA B2: 2,8 + G3: 8,9
* CNT   2 HDP CHAINS /   5 HYP OPENED

Header Info

Top 500 Minimum 17 047

solution: 431592687928376154765841923689435271317928546254167839872614395143259768596783412
info: 1378     FNBHWXY  S8.f     30475

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

Solution

position: 431592687928376154765841923689435271317928546254167839872614395143259768596783412 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:

* DIS # B2: 6,9 => CTR => B2: 2,8
* INC # B2: 2,8 => UNS
* INC # C2: 6,9 => UNS
* INC # B3: 6,9 => UNS
* INC # I2: 8,9 => UNS
* PRF # G3: 8,9 => SOL
* INC # G3: 4 => UNS
* DIS # H3: 8,9 => CTR => H3: 2,4
* INC # H3: 2,4 => UNS
* INC # I3: 8,9 => UNS
* INC # E1: 8,9 => UNS
* DIS # F1: 8,9 => CTR => F1: 2
* INC # F1: 2 => UNS
* INC # H5: 8,9 => UNS
* DIS # H8: 8,9 => CTR => H8: 4,6
* INC # H8: 4,6 => UNS
* INC # B4: 6,9 => UNS
* INC # C4: 6,9 => UNS
* DIS # E5: 8,9 => CTR => E5: 2,6
* INC # E5: 2,6 => UNS
* PRF # F5: 8,9 => SOL
* INC # F5: 2,6 => UNS
* INC # E6: 8,9 => UNS
* INC # H5: 8,9 => UNS
* DIS # I5: 8,9 => CTR => I5: 4,6
* INC # I5: 4,6 => UNS
* INC # D2: 8,9 => UNS
* INC # D3: 8,9 => UNS
* INC # H5: 8,9 => UNS
* DIS # I5: 8,9 => CTR => I5: 4,6
* INC # I5: 4,6 => UNS
* PRF # I6: 8,9 => SOL
* INC # I6: 6 => UNS
* INC # E6: 8,9 => UNS
* PRF # E6: 6 => SOL
* PRF # G3: 8,9 => SOL
* INC # G3: 4 => UNS
* INC # G9: 8,9 => UNS
* INC # B9: 2,9 => UNS
* DIS # C9: 2,9 => CTR => C9: 3,6
* INC # C9: 3,6 => UNS
* PRF # H7: 2,9 => SOL
* INC # H7: 4 => UNS
* INC # C2: 2,9 => UNS
* INC # C2: 6,8 => UNS
* PRF # F8: 4,9 => SOL
* INC # F8: 3,8 => UNS
* INC # E9: 4,9 => UNS
* DIS # F9: 4,9 => CTR => F9: 3,8
* INC # F9: 3,8 => UNS
* INC # H7: 4,9 => UNS
* DIS # H7: 2 => CTR => H7: 4,9
* CNT  52 HDP CHAINS /  52 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # B2: 6,9 => CTR => B2: 2,8
* INC B2: 2,8 # C2: 6,9 => UNS
* INC B2: 2,8 # B3: 6,9 => UNS
* INC B2: 2,8 # I2: 8,9 => UNS
* PRF B2: 2,8 # G3: 8,9 => SOL
* STA B2: 2,8 + G3: 8,9
* CNT   5 HDP CHAINS /   5 HYP OPENED