Analysis of xx-top500-030-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: .7..3.4..8......9..........6..8.9.....1...5.3...2......53.7..........1.........8. initial

Autosolve

position: .7..3.4588.....39.3...8..7.632859714981...523547213869.53.7894...8...13....3...8. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # B3: 1,2 => SOL
* DIS # F1: 6 => CTR => F1: 1,2
* PRF # B3: 1,2 => SOL
* DIS # D1: 1 => CTR => D1: 6,9
* PRF # B3: 2,6 => SOL
* PRF # E2: 4,6 => SOL
* DIS # E2: 2 => CTR => E2: 4,6
* DIS # E8: 4,6 => CTR => E8: 2,9
* DIS # E9: 4,6 => CTR => E9: 2,9
* PRF # E9: 2,9 => SOL
* DIS # B9: 6,9 => CTR => B9: 1,2
* DIS # B9: 6,9 => CTR => B9: 1,2
* PRF # E9: 6,9 => SOL
* DIS # F9: 1,6 => CTR => F9: 2,4,5
* PRF # F9: 2,4,5 => SOL
* PRF # D1: 1,6 => SOL
* DIS # D2: 1,6 => CTR => D2: 4,5,7
* DIS # B9: 2,6 => CTR => B9: 1,9
* DIS # E9: 2,6 => CTR => E9: 4,9
* DIS # F9: 2,6 => CTR => F9: 1,4,5
* CNT  20 HDP CHAINS /  48 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 # B3: 1,2 => SOL
* STA B3: 1,2
* CNT   1 HDP CHAINS /   2 HYP OPENED

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

Details

Positions

.7..3.4..8......9..........6..8.9.....1...5.3...2......53.7..........1.........8. initial
.7..3.4588.....39.3...8..7.632859714981...523547213869.53.7894...8...13....3...8. autosolve
179632458865741392324985671632859714981467523547213869253178946498526137716394285 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (15)
A1: 1,2
C1: 6,9
C2: 4,5
C3: 4,5
G3: 2,6
E5: 4,6
A7: 1,2
A8: 4,7
A9: 4,7
C9: 6,9
D7: 1,6
I7: 2,6
I8: 5,7
G9: 2,6
I9: 5,7

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
I2,I3: 1.. / I2 = 1  => 18 pairs (_) / I3 = 1  => 16 pairs (_)
A7,B9: 1.. / A7 = 1  =>  0 pairs (X) / B9 = 1  =>  0 pairs (_)
D7,F9: 1.. / D7 = 1  =>  0 pairs (*) / F9 = 1  =>  0 pairs (X)
A7,D7: 1.. / A7 = 1  =>  0 pairs (X) / D7 = 1  =>  0 pairs (_)
B9,F9: 1.. / B9 = 1  =>  0 pairs (*) / F9 = 1  =>  0 pairs (X)
A1,A7: 1.. / A1 = 1  =>  0 pairs (*) / A7 = 1  =>  0 pairs (X)
I7,G9: 2.. / I7 = 2  =>  0 pairs (X) / G9 = 2  =>  0 pairs (_)
A1,F1: 2.. / A1 = 2  =>  0 pairs (X) / F1 = 2  =>  0 pairs (_)
A7,I7: 2.. / A7 = 2  =>  0 pairs (*) / I7 = 2  =>  0 pairs (X)
A1,A7: 2.. / A1 = 2  =>  0 pairs (X) / A7 = 2  =>  0 pairs (_)
G3,G9: 2.. / G3 = 2  =>  0 pairs (X) / G9 = 2  =>  0 pairs (_)
C2,C3: 4.. / C2 = 4  => 16 pairs (_) / C3 = 4  => 13 pairs (_)
A8,A9: 4.. / A8 = 4  => 12 pairs (_) / A9 = 4  =>  0 pairs (X)
C2,C3: 5.. / C2 = 5  => 13 pairs (_) / C3 = 5  => 16 pairs (_)
I8,I9: 5.. / I8 = 5  =>  0 pairs (X) / I9 = 5  => 12 pairs (_)
F9,I9: 5.. / F9 = 5  =>  0 pairs (X) / I9 = 5  => 12 pairs (_)
I7,G9: 6.. / I7 = 6  =>  0 pairs (*) / G9 = 6  =>  0 pairs (X)
D7,I7: 6.. / D7 = 6  =>  0 pairs (X) / I7 = 6  =>  0 pairs (_)
C1,C9: 6.. / C1 = 6  => 16 pairs (_) / C9 = 6  =>  0 pairs (*)
G3,G9: 6.. / G3 = 6  =>  0 pairs (*) / G9 = 6  =>  0 pairs (X)
D2,F2: 7.. / D2 = 7  => 16 pairs (_) / F2 = 7  => 16 pairs (_)
D5,F5: 7.. / D5 = 7  => 16 pairs (_) / F5 = 7  => 16 pairs (_)
A8,A9: 7.. / A8 = 7  =>  0 pairs (X) / A9 = 7  => 12 pairs (_)
I8,I9: 7.. / I8 = 7  => 12 pairs (_) / I9 = 7  =>  0 pairs (X)
A8,I8: 7.. / A8 = 7  =>  0 pairs (X) / I8 = 7  => 12 pairs (_)
A9,I9: 7.. / A9 = 7  => 12 pairs (_) / I9 = 7  =>  0 pairs (X)
D2,D5: 7.. / D2 = 7  => 16 pairs (_) / D5 = 7  => 16 pairs (_)
F2,F5: 7.. / F2 = 7  => 16 pairs (_) / F5 = 7  => 16 pairs (_)
C1,B3: 9.. / C1 = 9  =>  0 pairs (*) / B3 = 9  =>  0 pairs (X)
D1,D3: 9.. / D1 = 9  => 16 pairs (_) / D3 = 9  =>  0 pairs (*)
E8,E9: 9.. / E8 = 9  => 16 pairs (_) / E9 = 9  =>  0 pairs (*)
C1,D1: 9.. / C1 = 9  =>  0 pairs (*) / D1 = 9  =>  0 pairs (X)
B3,D3: 9.. / B3 = 9  => 16 pairs (_) / D3 = 9  =>  0 pairs (*)
B8,E8: 9.. / B8 = 9  =>  0 pairs (*) / E8 = 9  =>  0 pairs (X)
C1,C9: 9.. / C1 = 9  =>  0 pairs (*) / C9 = 9  =>  0 pairs (X)
* DURATION: 0:01:02.557483  START: 03:39:32.644274  END: 03:40:35.201757 2017-05-04
* CP COUNT: (35)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,A7,A8,A9,C1,C2,C3,C9,D7,E5,G3,G9,I7,I8,I9)
* .7..3.4588.....39.3...8..7.632859714981...523547213869.53.7894...8...13....3...8.
* PAIR A1: 1,2 BLK 1
B2: 1,2,6                                # reduction candidate for 1,2
B2: 1,2                                  # 17 pairs
B3: 1,2,6,9                              # reduction candidate for 1,2
B3: 1,2 => SOLVED
* 179632458865741392324985671632859714981467523547213869253178946498526137716394285
B3: 6,9                                  # 17 pairs
* PAIR A1: 1,2 ROW 1
F1: 1,2,6                                # reduction candidate for 1,2
F1: 6 => CTR
* 27.1364588.....39.3..98..7.632859714981...523547213869153678942.68.9213....3...8.
F1: 1,2                                  # 17 pairs
* PAIR C1: 6,9 BLK 1
B3: 6,9,1,2                              # reduction candidate for 6,9
B3: 1,2 => SOLVED
* 179632458865741392324985671632859714981467523547213869253178946498526137716394285
B3: 6,9                                  # 17 pairs
* PAIR C1: 6,9 ROW 1
D1: 6,9,1                                # reduction candidate for 6,9
D1: 1 => CTR
* .791364588.....39.3..98..7.632859714981...523547213869153678942.68...13....3...8.
D1: 6,9                                  # 17 pairs
* PAIR C2: 4,5 ROW 2
D2: 4,5,1,6,7                            # reduction candidate for 4,5
D2: 4,5                                  # 18 pairs
F2: 4,5,1,2,6,7                          # reduction candidate for 4,5
F2: 4,5                                  # 18 pairs
* PAIR C3: 4,5 ROW 3
D3: 4,5,1,6,9                            # reduction candidate for 4,5
D3: 4,5                                  # 17 pairs
F3: 4,5,1,2,6                            # reduction candidate for 4,5
F3: 4,5                                  # 19 pairs
* PAIR G3: 2,6 BLK 3
I2: 2,6,1                                # reduction candidate for 2,6
I2: 2,6                                  # 16 pairs
I3: 2,6,1                                # reduction candidate for 2,6
I3: 2,6                                  # 18 pairs
* PAIR G3: 2,6 ROW 3
B3: 2,6,1,9                              # reduction candidate for 2,6
B3: 2,6 => SOLVED
* 179632458865741392324985671632859714981467523547213869253178946498526137716394285
B3: 1,9                                  # 16 pairs
F3: 2,6,1,4,5                            # reduction candidate for 2,6
F3: 2,6                                  # 19 pairs
* PAIR E5: 4,6 BLK 5
D5: 4,6,7                                # reduction candidate for 4,6
D5: 4,6                                  # 16 pairs
F5: 4,6,7                                # reduction candidate for 4,6
F5: 4,6                                  # 16 pairs
* PAIR E5: 4,6 COL E
E2: 4,6,2                                # reduction candidate for 4,6
E2: 4,6 => SOLVED
* 179632458865741392324985671632859714981467523547213869253178946498526137716394285
E2: 2 => CTR
* 27..3.4588...2.39.3...8..7.632859714981...523547213869153678942.68.9213..29341685
E8: 4,6,2,9                              # reduction candidate for 4,6
E8: 4,6 => CTR
* 279.3.4588...2.39.3..98.672632859714981...523547213869153.7894..98..213...639.28.
E8: 2,9                                  # 16 pairs
E9: 4,6,2,9                              # reduction candidate for 4,6
E9: 4,6 => CTR
* 27..3.4588...2.39.3...8..7.632859714981...523547213869153678942.68.9213..29341685
E9: 2,9 => SOLVED
* 179632458865741392324985671632859714981467523547213869253178946498526137716394285
* PAIR A7: 1,2 BLK 7
B9: 1,2,6,9                              # reduction candidate for 1,2
B9: 6,9 => CTR
* .7..3.4588.....39.3...8..7.632859714981...523547213869153678942..8...13....3...8.
B9: 1,2                                  # 17 pairs
* PAIR C9: 6,9 BLK 7
B8: 6,9,2                                # reduction candidate for 6,9
B8: 6,9                                  # 17 pairs
B9: 6,9,1,2                              # reduction candidate for 6,9
B9: 6,9 => CTR
* .7..3.4588.....39.3...8..7.632859714981...523547213869153678942..8...13....3...8.
B9: 1,2                                  # 17 pairs
* PAIR C9: 6,9 ROW 9
E9: 6,9,2,4                              # reduction candidate for 6,9
E9: 6,9 => SOLVED
* 179632458865741392324985671632859714981467523547213869253178946498526137716394285
E9: 2,4                                  # 17 pairs
* PAIR D7: 1,6 BLK 8
F9: 1,6,2,4,5                            # reduction candidate for 1,6
F9: 1,6 => CTR
* 27..3.4588...2.39.3...8..7.632859714981.6.523547213869153678942468592137729341685
F9: 2,4,5 => SOLVED
* 179632458865741392324985671632859714981467523547213869253178946498526137716394285
* PAIR D7: 1,6 COL D
D1: 1,6,9                                # reduction candidate for 1,6
D1: 1,6 => SOLVED
* 179632458865741392324985671632859714981467523547213869253178946498526137716394285
D1: 9                                    # 16 pairs
D2: 1,6,4,5,7                            # reduction candidate for 1,6
D2: 1,6 => CTR
* .7.93.4588.5.4739.39458..7.632859714981764523547213869.531789467.849613541.3.5.87
D2: 4,5,7                                # 15 pairs
D3: 1,6,4,5,9                            # reduction candidate for 1,6
D3: 1,6                                  # 22 pairs
* PAIR I7: 2,6 COL I
I2: 2,6,1                                # reduction candidate for 2,6
I2: 2,6                                  # 16 pairs
I3: 2,6,1                                # reduction candidate for 2,6
I3: 2,6                                  # 18 pairs
* PAIR G9: 2,6 ROW 9
B9: 2,6,1,9                              # reduction candidate for 2,6
B9: 2,6 => CTR
* .7..3.4588.....39.3...8..7.632859714981...523547213869153678942.68.9213..29341685
B9: 1,9                                  # 16 pairs
E9: 2,6,4,9                              # reduction candidate for 2,6
E9: 2,6 => CTR
* .7693.4588.....39.39..8..7.632859714981...523547213869.53178946.68.9213..1936.28.
E9: 4,9                                  # 16 pairs
F9: 2,6,1,4,5                            # reduction candidate for 2,6
F9: 2,6 => CTR
* 17..324588.....39.3...8.67.632859714981...523547213869253178946..8.2.13771.3..285
F9: 1,4,5                                # 15 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-030-base-pr-000.dot
* REASONING
* PRF # B3: 1,2 => SOL
* DIS # F1: 6 => CTR => F1: 1,2
* PRF # B3: 1,2 => SOL
* DIS # D1: 1 => CTR => D1: 6,9
* PRF # B3: 2,6 => SOL
* PRF # E2: 4,6 => SOL
* DIS # E2: 2 => CTR => E2: 4,6
* DIS # E8: 4,6 => CTR => E8: 2,9
* DIS # E9: 4,6 => CTR => E9: 2,9
* PRF # E9: 2,9 => SOL
* DIS # B9: 6,9 => CTR => B9: 1,2
* DIS # B9: 6,9 => CTR => B9: 1,2
* PRF # E9: 6,9 => SOL
* DIS # F9: 1,6 => CTR => F9: 2,4,5
* PRF # F9: 2,4,5 => SOL
* PRF # D1: 1,6 => SOL
* DIS # D2: 1,6 => CTR => D2: 4,5,7
* DIS # B9: 2,6 => CTR => B9: 1,9
* DIS # E9: 2,6 => CTR => E9: 4,9
* DIS # F9: 2,6 => CTR => F9: 1,4,5
* CNT  20 HDP CHAINS /  48 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,A7,A8,A9,C1,C2,C3,C9,D7,E5,G3,G9,I7,I8,I9)
* .7..3.4588.....39.3...8..7.632859714981...523547213869.53.7894...8...13....3...8.
* PAIR A1: 1,2 BLK 1
B2: 1,2,6                                # reduction candidate for 1,2
B2: 1,2                                  # 17 pairs
B3: 1,2,6,9                              # reduction candidate for 1,2
B3: 1,2 => SOLVED
* 179632458865741392324985671632859714981467523547213869253178946498526137716394285
* DURATION: 0:00:03.077389  START: 03:41:23.416095  END: 03:41:26.493484 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-030-base-pr-001.dot
* REASONING
* PRF # B3: 1,2 => SOL
* STA B3: 1,2
* CNT   1 HDP CHAINS /   2 HYP OPENED

Header Info

Top 500 Minimum 17 030

solution: 179632458865741392324985671632859714981467523547213869253178946498526137716394285
info: 1326     FNBTWXY  S8.f     22434

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

Solution

position: 179632458865741392324985671632859714981467523547213869253178946498526137716394285 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 # B2: 1,2 => UNS
* PRF # B3: 1,2 => SOL
* INC # B3: 6,9 => UNS
* INC # F1: 1,2 => UNS
* DIS # F1: 6 => CTR => F1: 1,2
* INC # B3: 6,9 => UNS
* PRF # B3: 1,2 => SOL
* INC # D1: 6,9 => UNS
* DIS # D1: 1 => CTR => D1: 6,9
* INC # D2: 4,5 => UNS
* INC # F2: 4,5 => UNS
* INC # D3: 4,5 => UNS
* INC # F3: 4,5 => UNS
* INC # I2: 2,6 => UNS
* INC # I3: 2,6 => UNS
* PRF # B3: 2,6 => SOL
* INC # B3: 1,9 => UNS
* INC # F3: 2,6 => UNS
* INC # D5: 4,6 => UNS
* INC # F5: 4,6 => UNS
* PRF # E2: 4,6 => SOL
* DIS # E2: 2 => CTR => E2: 4,6
* DIS # E8: 4,6 => CTR => E8: 2,9
* INC # E8: 2,9 => UNS
* DIS # E9: 4,6 => CTR => E9: 2,9
* PRF # E9: 2,9 => SOL
* INC # B9: 1,2 => UNS
* DIS # B9: 6,9 => CTR => B9: 1,2
* INC # B8: 6,9 => UNS
* DIS # B9: 6,9 => CTR => B9: 1,2
* INC # B9: 1,2 => UNS
* PRF # E9: 6,9 => SOL
* INC # E9: 2,4 => UNS
* DIS # F9: 1,6 => CTR => F9: 2,4,5
* PRF # F9: 2,4,5 => SOL
* PRF # D1: 1,6 => SOL
* INC # D1: 9 => UNS
* DIS # D2: 1,6 => CTR => D2: 4,5,7
* INC # D2: 4,5,7 => UNS
* INC # D3: 1,6 => UNS
* INC # I2: 2,6 => UNS
* INC # I3: 2,6 => UNS
* DIS # B9: 2,6 => CTR => B9: 1,9
* INC # B9: 1,9 => UNS
* DIS # E9: 2,6 => CTR => E9: 4,9
* INC # E9: 4,9 => UNS
* DIS # F9: 2,6 => CTR => F9: 1,4,5
* INC # F9: 1,4,5 => UNS
* CNT  48 HDP CHAINS /  48 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # B2: 1,2 => UNS
* PRF # B3: 1,2 => SOL
* STA B3: 1,2
* CNT   2 HDP CHAINS /   2 HYP OPENED