Analysis of xx-top500-384-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: .61...8.....39..............89..1...5.......3.......2.2..43.......2...6.......1.. initial

Autosolve

position: 961..283....39.6.1...16.29.389.214.65......131....3.2821.436.89...21.36.6.....1.2 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # B8: 4,7 => CTR => B8: 5,9
* DIS # E6: 4 => CTR => E6: 5,7
* PRF # D5: 8 => SOL
* CNT   3 HDP CHAINS /  39 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 # B8: 4,7 => CTR => B8: 5,9
* DIS B8: 5,9 # E6: 4 => CTR => E6: 5,7
* PRF B8: 5,9 + E6: 5,7 # D5: 8 => SOL
* STA B8: 5,9 + E6: 5,7 + D5: 8
* CNT   3 HDP CHAINS /  26 HYP OPENED

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

Details

Positions

.61...8.....39..............89..1...5.......3.......2.2..43.......2...6.......1.. initial
961..283....39.6.1...16.29.389.214.65......131....3.2821.436.89...21.36.6.....1.2 autosolve
961572834852394671743168295389721456526849713174653928217436589498215367635987142 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (9)
D1: 5,7
B6: 4,7
D4: 5,7
D6: 6,9
H4: 5,7
G5: 7,9
C7: 5,7
D9: 8,9
G7: 5,7

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
B2,C2: 2.. / B2 = 2  => 12 pairs (_) / C2 = 2  =>  9 pairs (_)
B5,C5: 2.. / B5 = 2  =>  9 pairs (_) / C5 = 2  => 12 pairs (_)
B2,B5: 2.. / B2 = 2  => 12 pairs (_) / B5 = 2  =>  9 pairs (_)
C2,C5: 2.. / C2 = 2  =>  9 pairs (_) / C5 = 2  => 12 pairs (_)
B3,C3: 3.. / B3 = 3  =>  9 pairs (_) / C3 = 3  => 10 pairs (_)
B9,C9: 3.. / B9 = 3  => 10 pairs (_) / C9 = 3  =>  9 pairs (_)
B3,B9: 3.. / B3 = 3  =>  9 pairs (_) / B9 = 3  => 10 pairs (_)
C3,C9: 3.. / C3 = 3  => 10 pairs (_) / C9 = 3  =>  9 pairs (_)
I8,H9: 4.. / I8 = 4  => 20 pairs (_) / H9 = 4  => 11 pairs (_)
E1,I1: 4.. / E1 = 4  => 13 pairs (_) / I1 = 4  => 22 pairs (_)
H2,H9: 4.. / H2 = 4  => 20 pairs (_) / H9 = 4  => 11 pairs (_)
D4,E6: 5.. / D4 = 5  => 10 pairs (_) / E6 = 5  => 20 pairs (_)
H4,G6: 5.. / H4 = 5  => 20 pairs (_) / G6 = 5  => 10 pairs (_)
D4,H4: 5.. / D4 = 5  => 10 pairs (_) / H4 = 5  => 20 pairs (_)
E6,G6: 5.. / E6 = 5  => 20 pairs (_) / G6 = 5  => 10 pairs (_)
C7,G7: 5.. / C7 = 5  => 10 pairs (_) / G7 = 5  => 20 pairs (_)
D1,D4: 5.. / D1 = 5  => 20 pairs (_) / D4 = 5  => 10 pairs (_)
G6,G7: 5.. / G6 = 5  => 10 pairs (_) / G7 = 5  => 20 pairs (_)
C5,C6: 6.. / C5 = 6  => 16 pairs (_) / C6 = 6  =>  9 pairs (_)
D5,D6: 6.. / D5 = 6  =>  9 pairs (_) / D6 = 6  => 16 pairs (_)
C5,D5: 6.. / C5 = 6  => 16 pairs (_) / D5 = 6  =>  9 pairs (_)
C6,D6: 6.. / C6 = 6  =>  9 pairs (_) / D6 = 6  => 16 pairs (_)
D4,H4: 7.. / D4 = 7  => 20 pairs (_) / H4 = 7  => 10 pairs (_)
C7,G7: 7.. / C7 = 7  => 20 pairs (_) / G7 = 7  => 10 pairs (_)
D1,D4: 7.. / D1 = 7  => 10 pairs (_) / D4 = 7  => 20 pairs (_)
F2,F3: 8.. / F2 = 8  => 10 pairs (_) / F3 = 8  => 10 pairs (_)
D5,E5: 8.. / D5 = 8  =>  0 pairs (*) / E5 = 8  =>  0 pairs (X)
A8,C8: 8.. / A8 = 8  => 13 pairs (_) / C8 = 8  => 10 pairs (_)
D9,E9: 8.. / D9 = 8  => 11 pairs (_) / E9 = 8  =>  0 pairs (*)
D5,D9: 8.. / D5 = 8  =>  0 pairs (*) / D9 = 8  =>  0 pairs (X)
E5,E9: 8.. / E5 = 8  => 11 pairs (_) / E9 = 8  =>  0 pairs (*)
G5,G6: 9.. / G5 = 9  =>  9 pairs (_) / G6 = 9  => 16 pairs (_)
B8,B9: 9.. / B8 = 9  => 10 pairs (_) / B9 = 9  => 14 pairs (_)
D6,G6: 9.. / D6 = 9  =>  9 pairs (_) / G6 = 9  => 16 pairs (_)
B8,F8: 9.. / B8 = 9  => 10 pairs (_) / F8 = 9  => 14 pairs (_)
* DURATION: 0:01:03.069172  START: 15:58:09.729248  END: 15:59:12.798420 2017-05-04
* CP COUNT: (35)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B6,C7,D1,D4,D6,D9,G5,G7,H4)
* 961..283....39.6.1...16.29.389.214.65......131....3.2821.436.89...21.36.6.....1.2
* PAIR D1: 5,7 BLK 2
E1: 5,7,4                                # reduction candidate for 5,7
E1: 5,7                                  # 22 pairs
F2: 5,7,4,8                              # reduction candidate for 5,7
F2: 5,7                                  # 15 pairs
F3: 5,7,4,8                              # reduction candidate for 5,7
F3: 5,7                                  # 15 pairs
* PAIR D1: 5,7 ROW 1
I1: 5,7,4                                # reduction candidate for 5,7
I1: 4                                    # 22 pairs
I1: 5,7                                  # 13 pairs
* PAIR B6: 4,7 BLK 4
B5: 4,7,2                                # reduction candidate for 4,7
B5: 4,7                                  # 12 pairs
C5: 4,7,2,6                              # reduction candidate for 4,7
C5: 4,7                                  # 10 pairs
C6: 4,7,6                                # reduction candidate for 4,7
C6: 4,7                                  # 16 pairs
* PAIR B6: 4,7 ROW 6
E6: 4,7,5                                # reduction candidate for 4,7
E6: 5                                    # 20 pairs
E6: 4,7                                  # 10 pairs
* PAIR B6: 4,7 COL B
B2: 4,7,2,5                              # reduction candidate for 4,7
B2: 4,7                                  # 15 pairs
B3: 4,7,3,5                              # reduction candidate for 4,7
B3: 4,7                                  # 18 pairs
B8: 4,7,5,9                              # reduction candidate for 4,7
B8: 4,7 => CTR
* 961..283..5239.671.3.16.29.38972145652..84.131...53.2821.436.89...21936.6938..142
B8: 5,9                                  # 10 pairs
B9: 4,7,3,5,9                            # reduction candidate for 4,7
B9: 4,7                                  # 13 pairs
* PAIR D4: 5,7 BLK 5
E6: 5,7,4                                # reduction candidate for 5,7
E6: 4 => CTR
* 961752834...39.651.5316.2973895214765..687913176943528215436789...21.36563.87.1.2
E6: 5,7                                  # 13 pairs
* PAIR D6: 6,9 BLK 5
D5: 6,9,8                                # reduction candidate for 6,9
D5: 8 => SOLVED
* 961572834852394671743168295389721456526849713174653928217436589498215367635987142
D5: 6,9                                  # 11 pairs
* PAIR H4: 5,7 BLK 6
G6: 5,7,9                                # reduction candidate for 5,7
G6: 9                                    # 16 pairs
G6: 5,7                                  #  9 pairs
* PAIR H4: 5,7 COL H
H2: 5,7,4                                # reduction candidate for 5,7
H2: 5,7                                  # 11 pairs
H9: 5,7,4                                # reduction candidate for 5,7
H9: 5,7                                  # 20 pairs
* PAIR G5: 7,9 BLK 6
G6: 7,9,5                                # reduction candidate for 7,9
G6: 7,9                                  # 20 pairs
G6: 5                                    # 10 pairs
* PAIR G5: 7,9 ROW 5
F5: 7,9,4                                # reduction candidate for 7,9
F5: 7,9                                  # 22 pairs
F5: 4                                    # 13 pairs
* PAIR C7: 5,7 BLK 7
B8: 5,7,4,9                              # reduction candidate for 5,7
B8: 5,7                                  # 17 pairs
C8: 5,7,4,8                              # reduction candidate for 5,7
C8: 5,7                                  # 19 pairs
B9: 5,7,3,4,9                            # reduction candidate for 5,7
B9: 5,7                                  # 15 pairs
C9: 5,7,3,4                              # reduction candidate for 5,7
C9: 5,7                                  # 17 pairs
* PAIR C7: 5,7 COL C
C2: 5,7,2,4,8                            # reduction candidate for 5,7
C2: 5,7                                  # 15 pairs
C3: 5,7,3,4,8                            # reduction candidate for 5,7
C3: 5,7                                  # 12 pairs
* PAIR D9: 8,9 COL D
D5: 8,9,6                                # reduction candidate for 8,9
D5: 8,9                                  # 16 pairs
D5: 6                                    #  9 pairs
* PAIR G7: 5,7 BLK 9
I8: 5,7,4                                # reduction candidate for 5,7
I8: 5,7                                  # 11 pairs
H9: 5,7,4                                # reduction candidate for 5,7
H9: 5,7                                  # 20 pairs
* PAIR G7: 5,7 COL G
G6: 5,7,9                                # reduction candidate for 5,7
G6: 9                                    # 16 pairs
G6: 5,7                                  #  9 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-384-base-pr-000.dot
* REASONING
* DIS # B8: 4,7 => CTR => B8: 5,9
* DIS # E6: 4 => CTR => E6: 5,7
* PRF # D5: 8 => SOL
* CNT   3 HDP CHAINS /  39 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B6,C7,D1,D4,D6,D9,G5,G7,H4)
* 961..283....39.6.1...16.29.389.214.65......131....3.2821.436.89...21.36.6.....1.2
* PAIR D1: 5,7 BLK 2
E1: 5,7,4                                # reduction candidate for 5,7
E1: 5,7                                  # 22 pairs
F2: 5,7,4,8                              # reduction candidate for 5,7
F2: 5,7                                  # 15 pairs
F3: 5,7,4,8                              # reduction candidate for 5,7
F3: 5,7                                  # 15 pairs
* PAIR D1: 5,7 ROW 1
I1: 5,7,4                                # reduction candidate for 5,7
I1: 4                                    # 22 pairs
I1: 5,7                                  # 13 pairs
* PAIR B6: 4,7 BLK 4
B5: 4,7,2                                # reduction candidate for 4,7
B5: 4,7                                  # 12 pairs
C5: 4,7,2,6                              # reduction candidate for 4,7
C5: 4,7                                  # 10 pairs
C6: 4,7,6                                # reduction candidate for 4,7
C6: 4,7                                  # 16 pairs
* PAIR B6: 4,7 ROW 6
E6: 4,7,5                                # reduction candidate for 4,7
E6: 5                                    # 20 pairs
E6: 4,7                                  # 10 pairs
* PAIR B6: 4,7 COL B
B2: 4,7,2,5                              # reduction candidate for 4,7
B2: 4,7                                  # 15 pairs
B3: 4,7,3,5                              # reduction candidate for 4,7
B3: 4,7                                  # 18 pairs
B8: 4,7,5,9                              # reduction candidate for 4,7
B8: 4,7 => CTR
* 961..283..5239.671.3.16.29.38972145652..84.131...53.2821.436.89...21936.6938..142
B9: 4,7,3,5,9                            # reduction candidate for 4,7
B9: 4,7                                  # 13 pairs
* PAIR RESTART
* PAIR B6: 4,7 BLK 4
B5: 4,7,2                                # reduction candidate for 4,7
B5: 4,7                                  # 12 pairs
C5: 4,7,2,6                              # reduction candidate for 4,7
C5: 4,7                                  # 11 pairs
C6: 4,7,6                                # reduction candidate for 4,7
C6: 4,7                                  # 17 pairs
* PAIR B6: 4,7 ROW 6
E6: 4,7,5                                # reduction candidate for 4,7
E6: 5                                    # 21 pairs
E6: 4,7                                  # 11 pairs
* PAIR B6: 4,7 COL B
B2: 4,7,2,5                              # reduction candidate for 4,7
B2: 4,7                                  # 15 pairs
B3: 4,7,3,5                              # reduction candidate for 4,7
B3: 4,7                                  # 18 pairs
B9: 4,7,3,5,9                            # reduction candidate for 4,7
B9: 4,7                                  # 13 pairs
* PAIR D4: 5,7 BLK 5
E6: 5,7,4                                # reduction candidate for 5,7
E6: 4 => CTR
* 961752834...39.651...16.29.3895214765.....9131..943528215436789.9.21.36.6..8.91.2
* PAIR D6: 6,9 BLK 5
D5: 6,9,8                                # reduction candidate for 6,9
D5: 8 => SOLVED
* 961572834852394671743168295389721456526849713174653928217436589498215367635987142
* DURATION: 0:00:27.530519  START: 15:59:52.175658  END: 16:00:19.706177 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-384-base-pr-001.dot
* REASONING
* DIS # B8: 4,7 => CTR => B8: 5,9
* DIS B8: 5,9 # E6: 4 => CTR => E6: 5,7
* PRF B8: 5,9 + E6: 5,7 # D5: 8 => SOL
* STA B8: 5,9 + E6: 5,7 + D5: 8
* CNT   3 HDP CHAINS /  26 HYP OPENED

Header Info

Top 500 Minimum 17 384

solution: 961572834852394671743168295389721456526849713174653928217436589498215367635987142
info: 33592    FNBTXYO  S8.f     21752

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

Solution

position: 961572834852394671743168295389721456526849713174653928217436589498215367635987142 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: 5,7 => UNS
* INC # F2: 5,7 => UNS
* INC # F3: 5,7 => UNS
* INC # I1: 5,7 => UNS
* INC # I1: 4 => UNS
* INC # B5: 4,7 => UNS
* INC # C5: 4,7 => UNS
* INC # C6: 4,7 => UNS
* INC # E6: 4,7 => UNS
* INC # E6: 5 => UNS
* INC # B2: 4,7 => UNS
* INC # B3: 4,7 => UNS
* DIS # B8: 4,7 => CTR => B8: 5,9
* INC # B8: 5,9 => UNS
* INC # B9: 4,7 => UNS
* INC # E6: 5,7 => UNS
* DIS # E6: 4 => CTR => E6: 5,7
* INC # D5: 6,9 => UNS
* PRF # D5: 8 => SOL
* INC # G6: 5,7 => UNS
* INC # G6: 9 => UNS
* INC # H2: 5,7 => UNS
* INC # H9: 5,7 => UNS
* INC # G6: 7,9 => UNS
* INC # G6: 5 => UNS
* INC # F5: 7,9 => UNS
* INC # F5: 4 => UNS
* INC # B8: 5,7 => UNS
* INC # C8: 5,7 => UNS
* INC # B9: 5,7 => UNS
* INC # C9: 5,7 => UNS
* INC # C2: 5,7 => UNS
* INC # C3: 5,7 => UNS
* INC # D5: 8,9 => UNS
* INC # D5: 6 => UNS
* INC # I8: 5,7 => UNS
* INC # H9: 5,7 => UNS
* INC # G6: 5,7 => UNS
* INC # G6: 9 => UNS
* CNT  39 HDP CHAINS /  39 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # E1: 5,7 => UNS
* INC # F2: 5,7 => UNS
* INC # F3: 5,7 => UNS
* INC # I1: 5,7 => UNS
* INC # I1: 4 => UNS
* INC # B5: 4,7 => UNS
* INC # C5: 4,7 => UNS
* INC # C6: 4,7 => UNS
* INC # E6: 4,7 => UNS
* INC # E6: 5 => UNS
* INC # B2: 4,7 => UNS
* INC # B3: 4,7 => UNS
* DIS # B8: 4,7 => CTR => B8: 5,9
* INC B8: 5,9 # B9: 4,7 => UNS
* INC B8: 5,9 # B5: 4,7 => UNS
* INC B8: 5,9 # C5: 4,7 => UNS
* INC B8: 5,9 # C6: 4,7 => UNS
* INC B8: 5,9 # E6: 4,7 => UNS
* INC B8: 5,9 # E6: 5 => UNS
* INC B8: 5,9 # B2: 4,7 => UNS
* INC B8: 5,9 # B3: 4,7 => UNS
* INC B8: 5,9 # B9: 4,7 => UNS
* INC B8: 5,9 # E6: 5,7 => UNS
* DIS B8: 5,9 # E6: 4 => CTR => E6: 5,7
* INC B8: 5,9 + E6: 5,7 # D5: 6,9 => UNS
* PRF B8: 5,9 + E6: 5,7 # D5: 8 => SOL
* STA B8: 5,9 + E6: 5,7 + D5: 8
* CNT  26 HDP CHAINS /  26 HYP OPENED