Analysis of xx-top500-395-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 24......6...51.8............3.8..9..4......1....3.....1....2.....5...3......4.... initial

Autosolve

position: 24...31563..51.8..51.42.739.318.49..48.2...13.523.14..1.4.32....25...3..8.3.452.. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # D8: 7,9 => CTR => D8: 1,6
* DIS # A6: 6,7 => CTR => A6: 9
* DIS # A8: 9 => CTR => A8: 6,7
* PRF # E5: 7,9 => SOL
* PRF # C5: 6 => SOL
* PRF # E5: 7,9 => SOL
* CNT   6 HDP CHAINS /  32 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 # D8: 7,9 => CTR => D8: 1,6
* DIS D8: 1,6 # A6: 6,7 => CTR => A6: 9
* DIS D8: 1,6 + A6: 9 # E4: 6,7 => CTR => E4: 5
* DIS D8: 1,6 + A6: 9 + E4: 5 # H4: 2 => CTR => H4: 6,7
* PRF D8: 1,6 + A6: 9 + E4: 5 + H4: 6,7 # E5: 7,9 => SOL
* STA D8: 1,6 + A6: 9 + E4: 5 + H4: 6,7 + E5: 7,9
* CNT   5 HDP CHAINS /  20 HYP OPENED

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

Details

Positions

24......6...51.8............3.8..9..4......1....3.....1....2.....5...3......4.... initial
24...31563..51.8..51.42.739.318.49..48.2...13.523.14..1.4.32....25...3..8.3.452.. autosolve
247983156369517824518426739731854962486279513952361478194732685625198347873645291 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (11)
C3: 6,8
D1: 7,9
F3: 6,8
H2: 2,4
I2: 2,4
A4: 6,7
F5: 7,9
G5: 5,6
I6: 7,8
G7: 5,6
I9: 1,7

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
D8,D9: 1.. / D8 = 1  => 11 pairs (_) / D9 = 1  => 13 pairs (_)
I8,I9: 1.. / I8 = 1  => 13 pairs (_) / I9 = 1  => 11 pairs (_)
D8,I8: 1.. / D8 = 1  => 11 pairs (_) / I8 = 1  => 13 pairs (_)
D9,I9: 1.. / D9 = 1  => 13 pairs (_) / I9 = 1  => 11 pairs (_)
H2,I2: 2.. / H2 = 2  => 14 pairs (_) / I2 = 2  =>  9 pairs (_)
H4,I4: 2.. / H4 = 2  =>  9 pairs (_) / I4 = 2  => 14 pairs (_)
H2,H4: 2.. / H2 = 2  => 14 pairs (_) / H4 = 2  =>  9 pairs (_)
I2,I4: 2.. / I2 = 2  =>  9 pairs (_) / I4 = 2  => 14 pairs (_)
H2,I2: 4.. / H2 = 4  =>  9 pairs (_) / I2 = 4  => 14 pairs (_)
H8,I8: 4.. / H8 = 4  => 14 pairs (_) / I8 = 4  =>  9 pairs (_)
H2,H8: 4.. / H2 = 4  =>  9 pairs (_) / H8 = 4  => 14 pairs (_)
I2,I8: 4.. / I2 = 4  => 14 pairs (_) / I8 = 4  =>  9 pairs (_)
E4,E5: 5.. / E4 = 5  => 15 pairs (_) / E5 = 5  => 15 pairs (_)
I4,G5: 5.. / I4 = 5  => 15 pairs (_) / G5 = 5  => 15 pairs (_)
G7,I7: 5.. / G7 = 5  => 15 pairs (_) / I7 = 5  => 15 pairs (_)
E4,I4: 5.. / E4 = 5  => 15 pairs (_) / I4 = 5  => 15 pairs (_)
E5,G5: 5.. / E5 = 5  => 15 pairs (_) / G5 = 5  => 15 pairs (_)
G5,G7: 5.. / G5 = 5  => 15 pairs (_) / G7 = 5  => 15 pairs (_)
I4,I7: 5.. / I4 = 5  => 15 pairs (_) / I7 = 5  => 15 pairs (_)
F2,F3: 6.. / F2 = 6  => 19 pairs (_) / F3 = 6  => 12 pairs (_)
C3,F3: 6.. / C3 = 6  => 19 pairs (_) / F3 = 6  => 12 pairs (_)
G5,G7: 6.. / G5 = 6  => 15 pairs (_) / G7 = 6  => 15 pairs (_)
C1,C3: 8.. / C1 = 8  => 19 pairs (_) / C3 = 8  => 12 pairs (_)
E1,F3: 8.. / E1 = 8  => 12 pairs (_) / F3 = 8  => 19 pairs (_)
H6,I6: 8.. / H6 = 8  => 13 pairs (_) / I6 = 8  => 12 pairs (_)
E8,F8: 8.. / E8 = 8  => 19 pairs (_) / F8 = 8  => 12 pairs (_)
H7,I7: 8.. / H7 = 8  => 12 pairs (_) / I7 = 8  => 13 pairs (_)
C1,E1: 8.. / C1 = 8  => 19 pairs (_) / E1 = 8  => 12 pairs (_)
C3,F3: 8.. / C3 = 8  => 12 pairs (_) / F3 = 8  => 19 pairs (_)
E1,E8: 8.. / E1 = 8  => 12 pairs (_) / E8 = 8  => 19 pairs (_)
F3,F8: 8.. / F3 = 8  => 19 pairs (_) / F8 = 8  => 12 pairs (_)
H6,H7: 8.. / H6 = 8  => 13 pairs (_) / H7 = 8  => 12 pairs (_)
I6,I7: 8.. / I6 = 8  => 12 pairs (_) / I7 = 8  => 13 pairs (_)
C5,A6: 9.. / C5 = 9  =>  0 pairs (X) / A6 = 9  => 15 pairs (_)
A6,E6: 9.. / A6 = 9  => 15 pairs (_) / E6 = 9  =>  0 pairs (X)
A6,A8: 9.. / A6 = 9  => 15 pairs (_) / A8 = 9  =>  0 pairs (X)
* DURATION: 0:01:02.355479  START: 16:19:41.971051  END: 16:20:44.326530 2017-05-04
* CP COUNT: (36)
* CLUE FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A4,C3,D1,F3,F5,G5,G7,H2,I2,I6,I9)
* 24...31563..51.8..51.42.739.318.49..48.2...13.523.14..1.4.32....25...3..8.3.452..
* PAIR D1: 7,9 BLK 2
E1: 7,9,8                                # reduction candidate for 7,9
E1: 7,9                                  # 19 pairs
F2: 7,9,6                                # reduction candidate for 7,9
F2: 7,9                                  # 12 pairs
* PAIR D1: 7,9 ROW 1
C1: 7,9,8                                # reduction candidate for 7,9
C1: 8                                    # 19 pairs
C1: 7,9                                  # 12 pairs
* PAIR D1: 7,9 COL D
D7: 7,9,6                                # reduction candidate for 7,9
D7: 7,9                                  # 14 pairs
D8: 7,9,1,6                              # reduction candidate for 7,9
D8: 7,9 => CTR
* 24...31563..51.8.451.42.739.318.49.248.2..513.523.14.81.4632....25...3.18.31452.7
D8: 1,6                                  # 12 pairs
D9: 7,9,1,6                              # reduction candidate for 7,9
D9: 7,9                                  # 17 pairs
* PAIR A4: 6,7 BLK 4
C5: 6,7,9                                # reduction candidate for 6,7
C5: 6,7                                  # 15 pairs
A6: 6,7,9                                # reduction candidate for 6,7
A6: 6,7 => CTR
* 24.9.31563..51.8..51.42.739.318.49..4892.7.13.523914..1.4.32...925..83..8.3.452..
A6: 9                                    # 15 pairs
* PAIR A4: 6,7 ROW 4
E4: 6,7,5                                # reduction candidate for 6,7
E4: 6,7                                  # 15 pairs
H4: 6,7,2                                # reduction candidate for 6,7
H4: 6,7                                  # 14 pairs
* PAIR A4: 6,7 COL A
A8: 6,7,9                                # reduction candidate for 6,7
A8: 9 => CTR
* 24...315639.51.8..51.42.739.318.49..4892.7.13.523914..1.4.32...925..83..8.3.452..
A8: 6,7                                  # 15 pairs
* PAIR F5: 7,9 BLK 5
E5: 7,9,5,6                              # reduction candidate for 7,9
E5: 7,9 => SOLVED
* 247983156369517824518426739731854962486279513952361478194732685625198347873645291
E5: 5,6                                  # 18 pairs
E6: 7,9,6                                # reduction candidate for 7,9
E6: 7,9                                  # 20 pairs
* PAIR F5: 7,9 ROW 5
C5: 7,9,6                                # reduction candidate for 7,9
C5: 6 => SOLVED
* 247983156369517824518426739731854962486279513952361478194732685625198347873645291
C5: 7,9                                  # 18 pairs
* PAIR F5: 7,9 COL F
F2: 7,9,6                                # reduction candidate for 7,9
F2: 7,9                                  # 12 pairs
F8: 7,9,8                                # reduction candidate for 7,9
F8: 7,9                                  # 19 pairs
* PAIR G5: 5,6 ROW 5
E5: 5,6,7,9                              # reduction candidate for 5,6
E5: 7,9 => SOLVED
* 247983156369517824518426739731854962486279513952361478194732685625198347873645291
E5: 5,6                                  # 18 pairs
* PAIR I6: 7,8 BLK 6
H6: 7,8,6                                # reduction candidate for 7,8
H6: 7,8                                  # 16 pairs
H6: 6                                    # 11 pairs
* PAIR I6: 7,8 COL I
I7: 7,8,5                                # reduction candidate for 7,8
I7: 7,8                                  # 15 pairs
I7: 5                                    # 15 pairs
* PAIR I9: 1,7 BLK 9
I8: 1,7,4                                # reduction candidate for 1,7
I8: 1,7                                  # 14 pairs
I8: 4                                    #  9 pairs
* PAIR I9: 1,7 ROW 9
D9: 1,7,6,9                              # reduction candidate for 1,7
D9: 1,7                                  # 14 pairs
D9: 6,9                                  # 12 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-395-base-pr-000.dot
* REASONING
* DIS # D8: 7,9 => CTR => D8: 1,6
* DIS # A6: 6,7 => CTR => A6: 9
* DIS # A8: 9 => CTR => A8: 6,7
* PRF # E5: 7,9 => SOL
* PRF # C5: 6 => SOL
* PRF # E5: 7,9 => SOL
* CNT   6 HDP CHAINS /  32 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A4,C3,D1,F3,F5,G5,G7,H2,I2,I6,I9)
* 24...31563..51.8..51.42.739.318.49..48.2...13.523.14..1.4.32....25...3..8.3.452..
* PAIR D1: 7,9 BLK 2
E1: 7,9,8                                # reduction candidate for 7,9
E1: 7,9                                  # 19 pairs
F2: 7,9,6                                # reduction candidate for 7,9
F2: 7,9                                  # 12 pairs
* PAIR D1: 7,9 ROW 1
C1: 7,9,8                                # reduction candidate for 7,9
C1: 8                                    # 19 pairs
C1: 7,9                                  # 12 pairs
* PAIR D1: 7,9 COL D
D7: 7,9,6                                # reduction candidate for 7,9
D7: 7,9                                  # 14 pairs
D8: 7,9,1,6                              # reduction candidate for 7,9
D8: 7,9 => CTR
* 24...31563..51.8.451.42.739.318.49.248.2..513.523.14.81.4632....25...3.18.31452.7
D9: 7,9,1,6                              # reduction candidate for 7,9
D9: 7,9                                  # 17 pairs
* PAIR RESTART
* PAIR D1: 7,9 BLK 2
E1: 7,9,8                                # reduction candidate for 7,9
E1: 7,9                                  # 19 pairs
F2: 7,9,6                                # reduction candidate for 7,9
F2: 7,9                                  # 13 pairs
* PAIR D1: 7,9 ROW 1
C1: 7,9,8                                # reduction candidate for 7,9
C1: 8                                    # 19 pairs
C1: 7,9                                  # 13 pairs
* PAIR D1: 7,9 COL D
D7: 7,9,6                                # reduction candidate for 7,9
D7: 7,9                                  # 14 pairs
D9: 7,9,1,6                              # reduction candidate for 7,9
D9: 7,9                                  # 17 pairs
* PAIR A4: 6,7 BLK 4
C5: 6,7,9                                # reduction candidate for 6,7
C5: 6,7                                  # 16 pairs
A6: 6,7,9                                # reduction candidate for 6,7
A6: 6,7 => CTR
* 24.9.31563..51.8..51.42.739.318.49..4892.7.13.523914..1.4.32...925..83..8.3.452..
* RESTART
* PAIR A4: 6,7 ROW 4
E4: 6,7,5                                # reduction candidate for 6,7
E4: 6,7 => CTR
* 24...31563.951.8.25164287396318749254872596139523614..1.4.325..725...3..8.3.452..
H4: 6,7,2                                # reduction candidate for 6,7
H4: 6,7                                  # 20 pairs
* RESTART
* PAIR A4: 6,7 ROW 4
H4: 6,7,2                                # reduction candidate for 6,7
H4: 2 => CTR
* 24...31563..51.8..51.42.7396318549274872695139523714681.4.326857256.83.18.3.452..
* PAIR RESTART
* PAIR F5: 7,9 BLK 5
E5: 7,9,6                                # reduction candidate for 7,9
E5: 7,9 => SOLVED
* 247983156369517824518426739731854962486279513952361478194732685625198347873645291
* DURATION: 0:00:20.479497  START: 16:21:15.199557  END: 16:21:35.679054 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-395-base-pr-001.dot
* REASONING
* DIS # D8: 7,9 => CTR => D8: 1,6
* DIS D8: 1,6 # A6: 6,7 => CTR => A6: 9
* DIS D8: 1,6 + A6: 9 # E4: 6,7 => CTR => E4: 5
* DIS D8: 1,6 + A6: 9 + E4: 5 # H4: 2 => CTR => H4: 6,7
* PRF D8: 1,6 + A6: 9 + E4: 5 + H4: 6,7 # E5: 7,9 => SOL
* STA D8: 1,6 + A6: 9 + E4: 5 + H4: 6,7 + E5: 7,9
* CNT   5 HDP CHAINS /  20 HYP OPENED

Header Info

Top 500 Minimum 17 395

solution: 247983156369517824518426739731854962486279513952361478194732685625198347873645291
info: 66841    FNBYK    S8.f     44969

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

Solution

position: 247983156369517824518426739731854962486279513952361478194732685625198347873645291 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: 7,9 => UNS
* INC # F2: 7,9 => UNS
* INC # C1: 7,9 => UNS
* INC # C1: 8 => UNS
* INC # D7: 7,9 => UNS
* DIS # D8: 7,9 => CTR => D8: 1,6
* INC # D8: 1,6 => UNS
* INC # D9: 7,9 => UNS
* INC # C5: 6,7 => UNS
* DIS # A6: 6,7 => CTR => A6: 9
* INC # A6: 9 => UNS
* INC # E4: 6,7 => UNS
* INC # H4: 6,7 => UNS
* INC # A8: 6,7 => UNS
* DIS # A8: 9 => CTR => A8: 6,7
* PRF # E5: 7,9 => SOL
* INC # E5: 5,6 => UNS
* INC # E6: 7,9 => UNS
* INC # C5: 7,9 => UNS
* PRF # C5: 6 => SOL
* INC # F2: 7,9 => UNS
* INC # F8: 7,9 => UNS
* INC # E5: 5,6 => UNS
* PRF # E5: 7,9 => SOL
* INC # H6: 7,8 => UNS
* INC # H6: 6 => UNS
* INC # I7: 7,8 => UNS
* INC # I7: 5 => UNS
* INC # I8: 1,7 => UNS
* INC # I8: 4 => UNS
* INC # D9: 1,7 => UNS
* INC # D9: 6,9 => UNS
* CNT  32 HDP CHAINS /  32 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # E1: 7,9 => UNS
* INC # F2: 7,9 => UNS
* INC # C1: 7,9 => UNS
* INC # C1: 8 => UNS
* INC # D7: 7,9 => UNS
* DIS # D8: 7,9 => CTR => D8: 1,6
* INC D8: 1,6 # D9: 7,9 => UNS
* INC D8: 1,6 # E1: 7,9 => UNS
* INC D8: 1,6 # F2: 7,9 => UNS
* INC D8: 1,6 # C1: 7,9 => UNS
* INC D8: 1,6 # C1: 8 => UNS
* INC D8: 1,6 # D7: 7,9 => UNS
* INC D8: 1,6 # D9: 7,9 => UNS
* INC D8: 1,6 # C5: 6,7 => UNS
* DIS D8: 1,6 # A6: 6,7 => CTR => A6: 9
* DIS D8: 1,6 + A6: 9 # E4: 6,7 => CTR => E4: 5
* INC D8: 1,6 + A6: 9 + E4: 5 # H4: 6,7 => UNS
* INC D8: 1,6 + A6: 9 + E4: 5 # H4: 6,7 => UNS
* DIS D8: 1,6 + A6: 9 + E4: 5 # H4: 2 => CTR => H4: 6,7
* PRF D8: 1,6 + A6: 9 + E4: 5 + H4: 6,7 # E5: 7,9 => SOL
* STA D8: 1,6 + A6: 9 + E4: 5 + H4: 6,7 + E5: 7,9
* CNT  20 HDP CHAINS /  20 HYP OPENED