Analysis of xx-top500-119-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: .2..7....5.....1........8......2..731..5.................1..5.6.73....4....8..... initial

Autosolve

position: .2167835.58.3..1.773..158...58.216731.7563..836278..152..137586873.56.416158..73. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # C2: 4,9 => SOL
* DIS # C2: 6 => CTR => C2: 4,9
* DIS # C3: 4,9 => CTR => C3: 6
* PRF # C3: 6 => SOL
* DIS # F2: 4,9 => CTR => F2: 2
* PRF # F2: 2 => SOL
* PRF # D3: 4,9 => SOL
* DIS # D3: 2 => CTR => D3: 4,9
* PRF # C2: 4,9 => SOL
* DIS # C2: 6 => CTR => C2: 4,9
* PRF # I3: 4,9 => SOL
* DIS # I3: 2 => CTR => I3: 4,9
* DIS # G5: 4,9 => CTR => G5: 2
* PRF # G5: 2 => SOL
* PRF # D3: 4,9 => SOL
* DIS # D3: 2 => CTR => D3: 4,9
* DIS # F2: 4,9 => CTR => F2: 2
* PRF # F2: 2 => SOL
* PRF # F9: 4,9 => SOL
* DIS # F9: 2 => CTR => F9: 4,9
* PRF # G5: 2,9 => SOL
* DIS # G5: 4 => CTR => G5: 2,9
* DIS # H2: 2,9 => CTR => H2: 6
* PRF # H2: 6 => SOL
* PRF # H3: 2,9 => SOL
* DIS # H3: 6 => CTR => H3: 2,9
* DIS # G5: 4,9 => CTR => G5: 2
* PRF # G5: 2 => SOL
* PRF # C2: 4,9 => SOL
* DIS # C2: 6 => CTR => C2: 4,9
* DIS # C3: 4,9 => CTR => C3: 6
* PRF # C3: 6 => SOL
* PRF # F9: 4 => SOL
* PRF # D3: 2,9 => SOL
* DIS # D3: 4 => CTR => D3: 2,9
* PRF # F9: 4,9 => SOL
* DIS # F9: 2 => CTR => F9: 4,9
* PRF # G5: 2,9 => SOL
* DIS # G5: 4 => CTR => G5: 2,9
* PRF # F9: 4 => SOL
* DIS # I3: 2,9 => CTR => I3: 4
* PRF # I3: 4 => SOL
* CNT  42 HDP CHAINS /  44 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 # C2: 4,9 => SOL
* STA C2: 4,9
* CNT   1 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

.2..7....5.....1........8......2..731..5.................1..5.6.73....4....8..... initial
.2167835.58.3..1.773..158...58.216731.7563..836278..152..137586873.56.416158..73. autosolve
421678359589342167736915824958421673147563298362789415294137586873256941615894732 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (15)
A1: 4,9
E2: 4,9
I1: 4,9
A4: 4,9
B5: 4,9
D4: 4,9
F6: 4,9
H5: 2,9
G6: 4,9
B7: 4,9
C7: 4,9
D8: 2,9
E9: 4,9
G8: 2,9
I9: 2,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
F2,D3: 2.. / F2 = 2  =>  0 pairs (*) / D3 = 2  =>  0 pairs (X)
G5,H5: 2.. / G5 = 2  =>  0 pairs (*) / H5 = 2  =>  0 pairs (X)
D8,F9: 2.. / D8 = 2  =>  0 pairs (*) / F9 = 2  =>  0 pairs (X)
G8,I9: 2.. / G8 = 2  =>  0 pairs (X) / I9 = 2  =>  0 pairs (_)
F2,H2: 2.. / F2 = 2  =>  0 pairs (*) / H2 = 2  =>  0 pairs (X)
D8,G8: 2.. / D8 = 2  =>  0 pairs (*) / G8 = 2  =>  0 pairs (X)
F9,I9: 2.. / F9 = 2  =>  0 pairs (X) / I9 = 2  =>  0 pairs (_)
D3,D8: 2.. / D3 = 2  =>  0 pairs (X) / D8 = 2  =>  0 pairs (_)
F2,F9: 2.. / F2 = 2  =>  0 pairs (*) / F9 = 2  =>  0 pairs (X)
G5,G8: 2.. / G5 = 2  =>  0 pairs (*) / G8 = 2  =>  0 pairs (X)
I3,I9: 2.. / I3 = 2  =>  0 pairs (X) / I9 = 2  =>  0 pairs (_)
I1,I3: 4.. / I1 = 4  =>  0 pairs (X) / I3 = 4  =>  0 pairs (_)
A4,B5: 4.. / A4 = 4  =>  0 pairs (X) / B5 = 4  =>  0 pairs (_)
D4,F6: 4.. / D4 = 4  =>  0 pairs (*) / F6 = 4  =>  0 pairs (X)
G5,G6: 4.. / G5 = 4  =>  0 pairs (X) / G6 = 4  =>  0 pairs (_)
B7,C7: 4.. / B7 = 4  =>  0 pairs (X) / C7 = 4  =>  0 pairs (_)
E9,F9: 4.. / E9 = 4  => 18 pairs (_) / F9 = 4  =>  0 pairs (*)
A1,I1: 4.. / A1 = 4  =>  0 pairs (*) / I1 = 4  =>  0 pairs (X)
A4,D4: 4.. / A4 = 4  =>  0 pairs (X) / D4 = 4  =>  0 pairs (_)
B5,G5: 4.. / B5 = 4  =>  0 pairs (*) / G5 = 4  =>  0 pairs (X)
F6,G6: 4.. / F6 = 4  =>  0 pairs (X) / G6 = 4  =>  0 pairs (_)
A1,A4: 4.. / A1 = 4  =>  0 pairs (*) / A4 = 4  =>  0 pairs (X)
B5,B7: 4.. / B5 = 4  =>  0 pairs (*) / B7 = 4  =>  0 pairs (X)
D3,D4: 4.. / D3 = 4  =>  0 pairs (X) / D4 = 4  =>  0 pairs (_)
E2,E9: 4.. / E2 = 4  =>  0 pairs (*) / E9 = 4  =>  0 pairs (X)
C2,C3: 6.. / C2 = 6  =>  0 pairs (X) / C3 = 6  =>  0 pairs (_)
H2,H3: 6.. / H2 = 6  =>  0 pairs (*) / H3 = 6  =>  0 pairs (X)
C2,H2: 6.. / C2 = 6  =>  0 pairs (X) / H2 = 6  =>  0 pairs (_)
C3,H3: 6.. / C3 = 6  =>  0 pairs (*) / H3 = 6  =>  0 pairs (X)
A4,B5: 9.. / A4 = 9  =>  0 pairs (*) / B5 = 9  =>  0 pairs (X)
D4,F6: 9.. / D4 = 9  =>  0 pairs (X) / F6 = 9  =>  0 pairs (_)
B7,C7: 9.. / B7 = 9  =>  0 pairs (*) / C7 = 9  =>  0 pairs (X)
G8,I9: 9.. / G8 = 9  =>  0 pairs (*) / I9 = 9  =>  0 pairs (X)
A1,I1: 9.. / A1 = 9  =>  0 pairs (X) / I1 = 9  =>  0 pairs (_)
A4,D4: 9.. / A4 = 9  =>  0 pairs (*) / D4 = 9  =>  0 pairs (X)
F6,G6: 9.. / F6 = 9  =>  0 pairs (*) / G6 = 9  =>  0 pairs (X)
D8,G8: 9.. / D8 = 9  =>  0 pairs (X) / G8 = 9  =>  0 pairs (_)
A1,A4: 9.. / A1 = 9  =>  0 pairs (X) / A4 = 9  =>  0 pairs (_)
B5,B7: 9.. / B5 = 9  =>  0 pairs (X) / B7 = 9  =>  0 pairs (_)
E2,E9: 9.. / E2 = 9  => 18 pairs (_) / E9 = 9  =>  0 pairs (*)
* DURATION: 0:01:04.127851  START: 06:50:55.572752  END: 06:51:59.700603 2017-05-04
* CP COUNT: (40)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,A4,B5,B7,C7,D4,D8,E2,E9,F6,G6,G8,H5,I1,I9)
* .2167835.58.3..1.773..158...58.216731.7563..836278..152..137586873.56.416158..73.
* PAIR A1: 4,9 BLK 1
C2: 4,9,6                                # reduction candidate for 4,9
C2: 4,9 => SOLVED
* 421678359589342167736915824958421673147563298362789415294137586873256941615894732
C2: 6 => CTR
* 4216783595863941277392158649584216731475632.8362789415294137586873.56.416158..73.
C3: 4,9,6                                # reduction candidate for 4,9
C3: 4,9 => CTR
* 4216783595863941277392158649584216731475632.8362789415294137586873.56.416158..73.
C3: 6 => SOLVED
* 421678359589342167736915824958421673147563298362789415294137586873256941615894732
* PAIR E2: 4,9 BLK 2
F2: 4,9,2                                # reduction candidate for 4,9
F2: 4,9 => CTR
* .2167835.58.3..12773.21586..58421673147563298362789415294137586873956.416158..73.
F2: 2 => SOLVED
* 421678359589342167736915824958421673147563298362789415294137586873256941615894732
D3: 4,9,2                                # reduction candidate for 4,9
D3: 4,9 => SOLVED
* 421678359589342167736915824958421673147563298362789415294137586873256941615894732
D3: 2 => CTR
* .2167835.58.3..1.773.2158...58421673147563..83627894152941375868739562416158..73.
* PAIR E2: 4,9 ROW 2
C2: 4,9,6                                # reduction candidate for 4,9
C2: 4,9 => SOLVED
* 421678359589342167736915824958421673147563298362789415294137586873256941615894732
C2: 6 => CTR
* 4216783595863941277392158649584216731475632.8362789415294137586873.56.416158..73.
* PAIR I1: 4,9 BLK 3
I3: 4,9,2                                # reduction candidate for 4,9
I3: 4,9 => SOLVED
* 421678359589342167736915824958421673147563298362789415294137586873256941615894732
I3: 2 => CTR
* .2167835458.3..1.773..158.24589216731975634.836278..152..137586873.56.416158..73.
* PAIR B5: 4,9 ROW 5
G5: 4,9,2                                # reduction candidate for 4,9
G5: 4,9 => CTR
* .2167835.58.3..1.773..158...58.216731.7563.2836278..152..137586873.562416158.2739
G5: 2 => SOLVED
* 421678359589342167736915824958421673147563298362789415294137586873256941615894732
* PAIR D4: 4,9 COL D
D3: 4,9,2                                # reduction candidate for 4,9
D3: 4,9 => SOLVED
* 421678359589342167736915824958421673147563298362789415294137586873256941615894732
D3: 2 => CTR
* .2167835.58.3..1.773.2158...58421673147563..83627894152941375868739562416158..73.
* PAIR F6: 4,9 COL F
F2: 4,9,2                                # reduction candidate for 4,9
F2: 4,9 => CTR
* .2167835.58.3..12773.21586..58421673147563298362789415294137586873956.416158..73.
F2: 2 => SOLVED
* 421678359589342167736915824958421673147563298362789415294137586873256941615894732
F9: 4,9,2                                # reduction candidate for 4,9
F9: 4,9 => SOLVED
* 421678359589342167736915824958421673147563298362789415294137586873256941615894732
F9: 2 => CTR
* 92167835458.39412773..158...58.216731.7563..836278..152..137586873.56.41615842739
* PAIR H5: 2,9 BLK 6
G5: 2,9,4                                # reduction candidate for 2,9
G5: 2,9 => SOLVED
* 421678359589342167736915824958421673147563298362789415294137586873256941615894732
G5: 4 => CTR
* .2167835.58.3..1.773..158...58.216731.7563428362784915249137586873956.416158..73.
* PAIR H5: 2,9 COL H
H2: 2,9,6                                # reduction candidate for 2,9
H2: 2,9 => CTR
* 4216783595863941277392158649584216731475632.8362789415294137586873.56.416158..73.
H2: 6 => SOLVED
* 421678359589342167736915824958421673147563298362789415294137586873256941615894732
H3: 2,9,6                                # reduction candidate for 2,9
H3: 2,9 => SOLVED
* 421678359589342167736915824958421673147563298362789415294137586873256941615894732
H3: 6 => CTR
* 4216783595863941277392158649584216731475632.8362789415294137586873.56.416158..73.
* PAIR G6: 4,9 BLK 6
G5: 4,9,2                                # reduction candidate for 4,9
G5: 4,9 => CTR
* .2167835.58.3..1.773..158...58.216731.7563.2836278..152..137586873.562416158.2739
G5: 2 => SOLVED
* 421678359589342167736915824958421673147563298362789415294137586873256941615894732
* PAIR C7: 4,9 COL C
C2: 4,9,6                                # reduction candidate for 4,9
C2: 4,9 => SOLVED
* 421678359589342167736915824958421673147563298362789415294137586873256941615894732
C2: 6 => CTR
* 4216783595863941277392158649584216731475632.8362789415294137586873.56.416158..73.
C3: 4,9,6                                # reduction candidate for 4,9
C3: 4,9 => CTR
* 4216783595863941277392158649584216731475632.8362789415294137586873.56.416158..73.
C3: 6 => SOLVED
* 421678359589342167736915824958421673147563298362789415294137586873256941615894732
* PAIR D8: 2,9 BLK 8
F9: 2,9,4                                # reduction candidate for 2,9
F9: 4 => SOLVED
* 421678359589342167736915824958421673147563298362789415294137586873256941615894732
F9: 2,9                                  # 18 pairs
* PAIR D8: 2,9 COL D
D3: 2,9,4                                # reduction candidate for 2,9
D3: 2,9 => SOLVED
* 421678359589342167736915824958421673147563298362789415294137586873256941615894732
D3: 4 => CTR
* .2167835.58.3.21.773.4158..4589216731975634283627849152..137586873.56.416158..73.
* PAIR E9: 4,9 BLK 8
F9: 4,9,2                                # reduction candidate for 4,9
F9: 4,9 => SOLVED
* 421678359589342167736915824958421673147563298362789415294137586873256941615894732
F9: 2 => CTR
* 92167835458.39412773..158...58.216731.7563..836278..152..137586873.56.41615842739
* PAIR G8: 2,9 COL G
G5: 2,9,4                                # reduction candidate for 2,9
G5: 2,9 => SOLVED
* 421678359589342167736915824958421673147563298362789415294137586873256941615894732
G5: 4 => CTR
* .2167835.58.3..1.773..158...58.216731.7563428362784915249137586873956.416158..73.
* PAIR I9: 2,9 ROW 9
F9: 2,9,4                                # reduction candidate for 2,9
F9: 4 => SOLVED
* 421678359589342167736915824958421673147563298362789415294137586873256941615894732
F9: 2,9                                  # 18 pairs
* PAIR I9: 2,9 COL I
I3: 2,9,4                                # reduction candidate for 2,9
I3: 2,9 => CTR
* .2167835458.3..1.773..158..4589216731975634283627849152..137586873.56.416158..73.
I3: 4 => SOLVED
* 421678359589342167736915824958421673147563298362789415294137586873256941615894732
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-119-base-pr-000.dot
* REASONING
* PRF # C2: 4,9 => SOL
* DIS # C2: 6 => CTR => C2: 4,9
* DIS # C3: 4,9 => CTR => C3: 6
* PRF # C3: 6 => SOL
* DIS # F2: 4,9 => CTR => F2: 2
* PRF # F2: 2 => SOL
* PRF # D3: 4,9 => SOL
* DIS # D3: 2 => CTR => D3: 4,9
* PRF # C2: 4,9 => SOL
* DIS # C2: 6 => CTR => C2: 4,9
* PRF # I3: 4,9 => SOL
* DIS # I3: 2 => CTR => I3: 4,9
* DIS # G5: 4,9 => CTR => G5: 2
* PRF # G5: 2 => SOL
* PRF # D3: 4,9 => SOL
* DIS # D3: 2 => CTR => D3: 4,9
* DIS # F2: 4,9 => CTR => F2: 2
* PRF # F2: 2 => SOL
* PRF # F9: 4,9 => SOL
* DIS # F9: 2 => CTR => F9: 4,9
* PRF # G5: 2,9 => SOL
* DIS # G5: 4 => CTR => G5: 2,9
* DIS # H2: 2,9 => CTR => H2: 6
* PRF # H2: 6 => SOL
* PRF # H3: 2,9 => SOL
* DIS # H3: 6 => CTR => H3: 2,9
* DIS # G5: 4,9 => CTR => G5: 2
* PRF # G5: 2 => SOL
* PRF # C2: 4,9 => SOL
* DIS # C2: 6 => CTR => C2: 4,9
* DIS # C3: 4,9 => CTR => C3: 6
* PRF # C3: 6 => SOL
* PRF # F9: 4 => SOL
* PRF # D3: 2,9 => SOL
* DIS # D3: 4 => CTR => D3: 2,9
* PRF # F9: 4,9 => SOL
* DIS # F9: 2 => CTR => F9: 4,9
* PRF # G5: 2,9 => SOL
* DIS # G5: 4 => CTR => G5: 2,9
* PRF # F9: 4 => SOL
* DIS # I3: 2,9 => CTR => I3: 4
* PRF # I3: 4 => SOL
* CNT  42 HDP CHAINS /  44 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,A4,B5,B7,C7,D4,D8,E2,E9,F6,G6,G8,H5,I1,I9)
* .2167835.58.3..1.773..158...58.216731.7563..836278..152..137586873.56.416158..73.
* PAIR A1: 4,9 BLK 1
C2: 4,9,6                                # reduction candidate for 4,9
C2: 4,9 => SOLVED
* 421678359589342167736915824958421673147563298362789415294137586873256941615894732
* DURATION: 0:00:01.884913  START: 06:52:49.058828  END: 06:52:50.943741 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-119-base-pr-001.dot
* REASONING
* PRF # C2: 4,9 => SOL
* STA C2: 4,9
* CNT   1 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 119

solution: 421678359589342167736915824958421673147563298362789415294137586873256941615894732
info: 1802     FNWX     S8.f     16629

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

Solution

position: 421678359589342167736915824958421673147563298362789415294137586873256941615894732 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:

* PRF # C2: 4,9 => SOL
* DIS # C2: 6 => CTR => C2: 4,9
* DIS # C3: 4,9 => CTR => C3: 6
* PRF # C3: 6 => SOL
* DIS # F2: 4,9 => CTR => F2: 2
* PRF # F2: 2 => SOL
* PRF # D3: 4,9 => SOL
* DIS # D3: 2 => CTR => D3: 4,9
* PRF # C2: 4,9 => SOL
* DIS # C2: 6 => CTR => C2: 4,9
* PRF # I3: 4,9 => SOL
* DIS # I3: 2 => CTR => I3: 4,9
* DIS # G5: 4,9 => CTR => G5: 2
* PRF # G5: 2 => SOL
* PRF # D3: 4,9 => SOL
* DIS # D3: 2 => CTR => D3: 4,9
* DIS # F2: 4,9 => CTR => F2: 2
* PRF # F2: 2 => SOL
* PRF # F9: 4,9 => SOL
* DIS # F9: 2 => CTR => F9: 4,9
* PRF # G5: 2,9 => SOL
* DIS # G5: 4 => CTR => G5: 2,9
* DIS # H2: 2,9 => CTR => H2: 6
* PRF # H2: 6 => SOL
* PRF # H3: 2,9 => SOL
* DIS # H3: 6 => CTR => H3: 2,9
* DIS # G5: 4,9 => CTR => G5: 2
* PRF # G5: 2 => SOL
* PRF # C2: 4,9 => SOL
* DIS # C2: 6 => CTR => C2: 4,9
* DIS # C3: 4,9 => CTR => C3: 6
* PRF # C3: 6 => SOL
* INC # F9: 2,9 => UNS
* PRF # F9: 4 => SOL
* PRF # D3: 2,9 => SOL
* DIS # D3: 4 => CTR => D3: 2,9
* PRF # F9: 4,9 => SOL
* DIS # F9: 2 => CTR => F9: 4,9
* PRF # G5: 2,9 => SOL
* DIS # G5: 4 => CTR => G5: 2,9
* INC # F9: 2,9 => UNS
* PRF # F9: 4 => SOL
* DIS # I3: 2,9 => CTR => I3: 4
* PRF # I3: 4 => SOL
* CNT  44 HDP CHAINS /  44 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* PRF # C2: 4,9 => SOL
* STA C2: 4,9
* CNT   1 HDP CHAINS /   1 HYP OPENED