Analysis of xx-top500-095-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: ...76.2..4..8.....15............1.4..3....8...2..........2....36......1.....8.... initial

Autosolve

position: 3897642514.2815...15...24.88...21.4..314..826.246.81...1.24..83648..3.122.318.5.4 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # H2: 6,7 => CTR => H2: 3,9
* DIS # B4: 9 => CTR => B4: 6,7
* DIS # C4: 5 => CTR => C4: 6,7
* DIS # H2: 6,7 => CTR => H2: 3,9
* DIS # H9: 9 => CTR => H9: 6,7
* DIS # F9: 7,9 => CTR => F9: 6
* DIS # A7: 9 => CTR => A7: 5,7
* DIS # C4: 5,7 => CTR => C4: 6
* DIS # A7: 5 => CTR => A7: 7,9
* DIS # F9: 7,9 => CTR => F9: 6
* DIS # B4: 6 => CTR => B4: 7,9
* DIS # G7: 7,9 => CTR => G7: 6
* CNT  12 HDP CHAINS /  49 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 # H2: 6,7 => CTR => H2: 3,9
* DIS H2: 3,9 # B4: 9 => CTR => B4: 6,7
* PRF H2: 3,9 + B4: 6,7 # G2: 6,7 => SOL
* STA H2: 3,9 + B4: 6,7 + G2: 6,7
* CNT   3 HDP CHAINS /   7 HYP OPENED

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

Details

Positions

...76.2..4..8.....15............1.4..3....8...2..........2....36......1.....8.... initial
3897642514.2815...15...24.88...21.4..314..826.246.81...1.24..83648..3.122.318.5.4 autosolve
389764251462815739157392468876921345931457826524638197715249683648573912293186574 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (11)
B2: 6,7
C3: 6,7
D3: 3,9
E3: 3,9
I2: 7,9
H3: 6,7
F5: 7,9
C7: 5,7
B9: 7,9
D8: 5,9
G8: 7,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
D3,E3: 3.. / D3 = 3  => 14 pairs (_) / E3 = 3  => 12 pairs (_)
G2,H2: 3.. / G2 = 3  => 12 pairs (_) / H2 = 3  => 14 pairs (_)
D4,E6: 3.. / D4 = 3  => 12 pairs (_) / E6 = 3  => 14 pairs (_)
G4,H6: 3.. / G4 = 3  => 14 pairs (_) / H6 = 3  => 12 pairs (_)
D4,G4: 3.. / D4 = 3  => 12 pairs (_) / G4 = 3  => 14 pairs (_)
E6,H6: 3.. / E6 = 3  => 14 pairs (_) / H6 = 3  => 12 pairs (_)
D3,D4: 3.. / D3 = 3  => 14 pairs (_) / D4 = 3  => 12 pairs (_)
E3,E6: 3.. / E3 = 3  => 12 pairs (_) / E6 = 3  => 14 pairs (_)
G2,G4: 3.. / G2 = 3  => 12 pairs (_) / G4 = 3  => 14 pairs (_)
H2,H6: 3.. / H2 = 3  => 14 pairs (_) / H6 = 3  => 12 pairs (_)
I4,I6: 5.. / I4 = 5  => 14 pairs (_) / I6 = 5  => 13 pairs (_)
A7,C7: 5.. / A7 = 5  =>  0 pairs (X) / C7 = 5  => 12 pairs (_)
D8,E8: 5.. / D8 = 5  => 12 pairs (_) / E8 = 5  => 15 pairs (_)
A5,E5: 5.. / A5 = 5  => 16 pairs (_) / E5 = 5  => 13 pairs (_)
C4,C7: 5.. / C4 = 5  =>  0 pairs (X) / C7 = 5  => 12 pairs (_)
D4,D8: 5.. / D4 = 5  => 15 pairs (_) / D8 = 5  => 12 pairs (_)
B2,C3: 6.. / B2 = 6  => 11 pairs (_) / C3 = 6  =>  0 pairs (X)
B4,C4: 6.. / B4 = 6  =>  0 pairs (X) / C4 = 6  => 11 pairs (_)
F7,F9: 6.. / F7 = 6  =>  0 pairs (X) / F9 = 6  => 13 pairs (_)
G7,H9: 6.. / G7 = 6  => 13 pairs (_) / H9 = 6  =>  0 pairs (X)
C3,H3: 6.. / C3 = 6  =>  0 pairs (X) / H3 = 6  => 11 pairs (_)
F7,G7: 6.. / F7 = 6  =>  0 pairs (X) / G7 = 6  => 13 pairs (_)
F9,H9: 6.. / F9 = 6  => 13 pairs (_) / H9 = 6  =>  0 pairs (X)
B2,B4: 6.. / B2 = 6  => 11 pairs (_) / B4 = 6  =>  0 pairs (X)
C3,C4: 6.. / C3 = 6  =>  0 pairs (X) / C4 = 6  => 11 pairs (_)
G2,G7: 6.. / G2 = 6  =>  0 pairs (X) / G7 = 6  => 13 pairs (_)
B2,C3: 7.. / B2 = 7  =>  0 pairs (X) / C3 = 7  => 11 pairs (_)
C3,H3: 7.. / C3 = 7  => 11 pairs (_) / H3 = 7  =>  0 pairs (X)
E8,G8: 7.. / E8 = 7  => 18 pairs (_) / G8 = 7  => 18 pairs (_)
D3,E3: 9.. / D3 = 9  => 12 pairs (_) / E3 = 9  => 14 pairs (_)
A7,B9: 9.. / A7 = 9  =>  0 pairs (X) / B9 = 9  => 19 pairs (_)
B4,B9: 9.. / B4 = 9  =>  0 pairs (X) / B9 = 9  => 19 pairs (_)
* DURATION: 0:00:55.596383  START: 06:01:21.516915  END: 06:02:17.113298 2017-05-04
* CP COUNT: (32)
* CLUE FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B2,B9,C3,C7,D3,D8,E3,F5,G8,H3,I2)
* 3897642514.2815...15...24.88...21.4..314..826.246.81...1.24..83648..3.122.318.5.4
* PAIR B2: 6,7 ROW 2
G2: 6,7,3,9                              # reduction candidate for 6,7
G2: 6,7                                  # 17 pairs
H2: 6,7,3,9                              # reduction candidate for 6,7
H2: 6,7 => CTR
* 3897642514.28153.915.9324.889632174..314..826.246.813..1.24.6836485.3.122.3186594
H2: 3,9                                  # 12 pairs
* PAIR B2: 6,7 COL B
B4: 6,7,9                                # reduction candidate for 6,7
B4: 9 => CTR
* 389764251462815937157..2468896.21.4..314..826.246.81..91524.683648..3.12273186594
B4: 6,7                                  # 19 pairs
* PAIR C3: 6,7 COL C
C4: 6,7,5                                # reduction candidate for 6,7
C4: 5 => CTR
* 389764251472815639156..2478865.21347731459826.246.81.551724..836485.3712293187564
C4: 6,7                                  # 12 pairs
* PAIR D3: 3,9 COL D
D4: 3,9,5                                # reduction candidate for 3,9
D4: 5                                    # 15 pairs
D4: 3,9                                  # 12 pairs
* PAIR E3: 3,9 COL E
E6: 3,9,5,7                              # reduction candidate for 3,9
E6: 3,9                                  # 15 pairs
E6: 5,7                                  # 14 pairs
* PAIR I2: 7,9 BLK 3
G2: 7,9,3,6                              # reduction candidate for 7,9
G2: 7,9                                  # 15 pairs
H2: 7,9,3,6                              # reduction candidate for 7,9
H2: 7,9                                  # 12 pairs
* PAIR I2: 7,9 COL I
I4: 7,9,5                                # reduction candidate for 7,9
I4: 7,9                                  # 13 pairs
I6: 7,9,5                                # reduction candidate for 7,9
I6: 7,9                                  # 14 pairs
* PAIR H3: 6,7 BLK 3
G2: 6,7,3,9                              # reduction candidate for 6,7
G2: 6,7                                  # 17 pairs
H2: 6,7,3,9                              # reduction candidate for 6,7
H2: 6,7 => CTR
* 3897642514.28153.915.9324.889632174..314..826.246.813..1.24.6836485.3.122.3186594
H2: 3,9                                  # 12 pairs
* PAIR H3: 6,7 COL H
H9: 6,7,9                                # reduction candidate for 6,7
H9: 9 => CTR
* 3897642514.2815...15...24.8896.21347.314..826.246.81...1.24.683648..37122.3186594
H9: 6,7                                  # 15 pairs
* PAIR F5: 7,9 BLK 5
E5: 7,9,5                                # reduction candidate for 7,9
E5: 7,9                                  # 16 pairs
E6: 7,9,3,5                              # reduction candidate for 7,9
E6: 7,9                                  # 14 pairs
* PAIR F5: 7,9 ROW 5
A5: 7,9,5                                # reduction candidate for 7,9
A5: 5                                    # 16 pairs
A5: 7,9                                  # 13 pairs
* PAIR F5: 7,9 COL F
F7: 7,9,6                                # reduction candidate for 7,9
F7: 7,9                                  # 13 pairs
F9: 7,9,6                                # reduction candidate for 7,9
F9: 7,9 => CTR
* 38976425147281563915639247886.92134..314..826.2463819..1.246.83648..3.12293187564
F9: 6                                    # 13 pairs
* PAIR C7: 5,7 BLK 7
A7: 5,7,9                                # reduction candidate for 5,7
A7: 9 => CTR
* 389764251462815937157..2468896.21345.314..826.246.81..91524.683648..3712273186594
A7: 5,7                                  # 19 pairs
* PAIR C7: 5,7 COL C
C4: 5,7,6                                # reduction candidate for 5,7
C4: 5,7 => CTR
* 389764251472815639156..247886..2134..314.98269246.81...1.24..83648..3.12293187564
C4: 6                                    # 11 pairs
* PAIR B9: 7,9 BLK 7
A7: 7,9,5                                # reduction candidate for 7,9
A7: 5 => CTR
* 389764251472815..9156..2478865.21.47.3145.826.246.819551724..836485.3712293187564
A7: 7,9                                  # 12 pairs
* PAIR B9: 7,9 ROW 9
F9: 7,9,6                                # reduction candidate for 7,9
F9: 7,9 => CTR
* 38976425147281563915639247886.92134..314..826.2463819..1.246.83648..3.12293187564
F9: 6                                    # 13 pairs
H9: 7,9,6                                # reduction candidate for 7,9
H9: 7,9                                  # 13 pairs
* PAIR B9: 7,9 COL B
B4: 7,9,6                                # reduction candidate for 7,9
B4: 6 => CTR
* 389764251472815639156..247886.921.4..314..826.246.819..1.24..83648..3.12293187564
B4: 7,9                                  # 11 pairs
* PAIR D8: 5,9 BLK 8
E8: 5,9,7                                # reduction candidate for 5,9
E8: 7                                    # 18 pairs
E8: 5,9                                  # 18 pairs
* PAIR D8: 5,9 COL D
D4: 5,9,3                                # reduction candidate for 5,9
D4: 5,9                                  # 14 pairs
D4: 3                                    # 12 pairs
* PAIR G8: 7,9 BLK 9
G7: 7,9,6                                # reduction candidate for 7,9
G7: 7,9 => CTR
* 38976425147281563915639247886.92134..314..826.2463819..1.246.83648..3.12293187564
G7: 6                                    # 13 pairs
H9: 7,9,6                                # reduction candidate for 7,9
H9: 7,9                                  # 13 pairs
* PAIR G8: 7,9 ROW 8
E8: 7,9,5                                # reduction candidate for 7,9
E8: 5                                    # 15 pairs
E8: 7,9                                  # 12 pairs
* PAIR G8: 7,9 COL G
G2: 7,9,3,6                              # reduction candidate for 7,9
G2: 7,9                                  # 15 pairs
G4: 7,9,3                                # reduction candidate for 7,9
G4: 7,9                                  # 12 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-095-base-pr-000.dot
* REASONING
* DIS # H2: 6,7 => CTR => H2: 3,9
* DIS # B4: 9 => CTR => B4: 6,7
* DIS # C4: 5 => CTR => C4: 6,7
* DIS # H2: 6,7 => CTR => H2: 3,9
* DIS # H9: 9 => CTR => H9: 6,7
* DIS # F9: 7,9 => CTR => F9: 6
* DIS # A7: 9 => CTR => A7: 5,7
* DIS # C4: 5,7 => CTR => C4: 6
* DIS # A7: 5 => CTR => A7: 7,9
* DIS # F9: 7,9 => CTR => F9: 6
* DIS # B4: 6 => CTR => B4: 7,9
* DIS # G7: 7,9 => CTR => G7: 6
* CNT  12 HDP CHAINS /  49 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B2,B9,C3,C7,D3,D8,E3,F5,G8,H3,I2)
* 3897642514.2815...15...24.88...21.4..314..826.246.81...1.24..83648..3.122.318.5.4
* PAIR B2: 6,7 ROW 2
G2: 6,7,3,9                              # reduction candidate for 6,7
G2: 6,7                                  # 17 pairs
H2: 6,7,3,9                              # reduction candidate for 6,7
H2: 6,7 => CTR
* 3897642514.28153.915.9324.889632174..314..826.246.813..1.24.6836485.3.122.3186594
* RESTART
* PAIR B2: 6,7 ROW 2
G2: 6,7,3,9                              # reduction candidate for 6,7
G2: 6,7                                  # 17 pairs
G2: 3,9                                  # 16 pairs
* PAIR B2: 6,7 COL B
B4: 6,7,9                                # reduction candidate for 6,7
B4: 9 => CTR
* 389764251462815937157..2468896.21.4..314..826.246.81..91524.683648..3.12273186594
* PAIR RESTART
* PAIR B2: 6,7 ROW 2
G2: 6,7,3                                # reduction candidate for 6,7
G2: 6,7 => SOLVED
* 389764251462815739157392468876921345931457826524638197715249683648573912293186574
* DURATION: 0:00:08.124482  START: 06:03:02.736914  END: 06:03:10.861396 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-095-base-pr-001.dot
* REASONING
* DIS # H2: 6,7 => CTR => H2: 3,9
* DIS H2: 3,9 # B4: 9 => CTR => B4: 6,7
* PRF H2: 3,9 + B4: 6,7 # G2: 6,7 => SOL
* STA H2: 3,9 + B4: 6,7 + G2: 6,7
* CNT   3 HDP CHAINS /   7 HYP OPENED

Header Info

Top 500 Minimum 17 095

solution: 389764251462815739157392468876921345931457826524638197715249683648573912293186574
info: 1573     FNBTWXY  S8.f     11907

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

Solution

position: 389764251462815739157392468876921345931457826524638197715249683648573912293186574 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 # G2: 6,7 => UNS
* DIS # H2: 6,7 => CTR => H2: 3,9
* INC # H2: 3,9 => UNS
* INC # B4: 6,7 => UNS
* DIS # B4: 9 => CTR => B4: 6,7
* INC # C4: 6,7 => UNS
* DIS # C4: 5 => CTR => C4: 6,7
* INC # D4: 3,9 => UNS
* INC # D4: 5 => UNS
* INC # E6: 3,9 => UNS
* INC # E6: 5,7 => UNS
* INC # G2: 7,9 => UNS
* INC # H2: 7,9 => UNS
* INC # I4: 7,9 => UNS
* INC # I6: 7,9 => UNS
* INC # G2: 6,7 => UNS
* DIS # H2: 6,7 => CTR => H2: 3,9
* INC # H2: 3,9 => UNS
* INC # H9: 6,7 => UNS
* DIS # H9: 9 => CTR => H9: 6,7
* INC # E5: 7,9 => UNS
* INC # E6: 7,9 => UNS
* INC # A5: 7,9 => UNS
* INC # A5: 5 => UNS
* INC # F7: 7,9 => UNS
* DIS # F9: 7,9 => CTR => F9: 6
* INC # F9: 6 => UNS
* INC # A7: 5,7 => UNS
* DIS # A7: 9 => CTR => A7: 5,7
* DIS # C4: 5,7 => CTR => C4: 6
* INC # C4: 6 => UNS
* INC # A7: 7,9 => UNS
* DIS # A7: 5 => CTR => A7: 7,9
* DIS # F9: 7,9 => CTR => F9: 6
* INC # F9: 6 => UNS
* INC # H9: 7,9 => UNS
* INC # B4: 7,9 => UNS
* DIS # B4: 6 => CTR => B4: 7,9
* INC # E8: 5,9 => UNS
* INC # E8: 7 => UNS
* INC # D4: 5,9 => UNS
* INC # D4: 3 => UNS
* DIS # G7: 7,9 => CTR => G7: 6
* INC # G7: 6 => UNS
* INC # H9: 7,9 => UNS
* INC # E8: 7,9 => UNS
* INC # E8: 5 => UNS
* INC # G2: 7,9 => UNS
* INC # G4: 7,9 => UNS
* CNT  49 HDP CHAINS /  49 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # G2: 6,7 => UNS
* DIS # H2: 6,7 => CTR => H2: 3,9
* INC H2: 3,9 # G2: 6,7 => UNS
* INC H2: 3,9 # G2: 3,9 => UNS
* INC H2: 3,9 # B4: 6,7 => UNS
* DIS H2: 3,9 # B4: 9 => CTR => B4: 6,7
* PRF H2: 3,9 + B4: 6,7 # G2: 6,7 => SOL
* STA H2: 3,9 + B4: 6,7 + G2: 6,7
* CNT   7 HDP CHAINS /   7 HYP OPENED