Analysis of xx-top500-372-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: .7....85.....12......3.....7......12.4.9.................67.4..3.....6....1...... initial

Autosolve

position: 172469853...7129..6943..1277.9.46.1224.9.17...162.7...92.67.4313.71246..461.9327. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # B2: 5,8 => CTR => B2: 3
* PRF # B2: 3 => SOL
* PRF # C2: 5,8 => SOL
* DIS # C2: 3 => CTR => C2: 5,8
* DIS # E6: 5,8 => CTR => E6: 3
* PRF # E6: 3 => SOL
* PRF # B4: 3,5 => SOL
* DIS # B4: 8 => CTR => B4: 3,5
* DIS # C2: 3,5 => CTR => C2: 8
* PRF # C2: 8 => SOL
* PRF # B4: 5,8 => SOL
* DIS # B4: 3 => CTR => B4: 5,8
* DIS # E6: 5,8 => CTR => E6: 3
* PRF # E6: 3 => SOL
* DIS # E6: 5,8 => CTR => E6: 3
* PRF # E6: 3 => SOL
* PRF # B4: 5,8 => SOL
* DIS # B4: 3 => CTR => B4: 5,8
* PRF # E6: 3,5 => SOL
* DIS # E6: 8 => CTR => E6: 3,5
* PRF # B4: 3,5 => SOL
* DIS # B4: 8 => CTR => B4: 3,5
* PRF # E6: 3,5 => SOL
* DIS # E6: 8 => CTR => E6: 3,5
* PRF # C2: 5,8 => SOL
* DIS # C2: 3 => CTR => C2: 5,8
* DIS # I8: 9 => CTR => I8: 5,8
* DIS # B2: 5,8 => CTR => B2: 3
* PRF # B2: 3 => SOL
* PRF # B4: 5,8 => SOL
* DIS # B4: 3 => CTR => B4: 5,8
* DIS # I8: 8,9 => CTR => I8: 5
* PRF # I8: 5 => SOL
* DIS # I8: 9 => CTR => I8: 5,8
* CNT  34 HDP CHAINS /  36 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 # B2: 5,8 => CTR => B2: 3
* PRF B2: 3 => SOL
* STA B2: 3
* CNT   2 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

.7....85.....12......3.....7......12.4.9.................67.4..3.....6....1...... initial
172469853...7129..6943..1277.9.46.1224.9.17...162.7...92.67.4313.71246..461.9327. autosolve
172469853538712964694385127759846312243951786816237549925678431387124695461593278 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (21)
A2: 5,8
E3: 5,8
F3: 5,8
H2: 4,6
I2: 4,6
C5: 3,5
A6: 5,8
D4: 5,8
E5: 3,5
G4: 3,5
H5: 6,8
I5: 6,8
G6: 3,5
H6: 4,9
I6: 4,9
C7: 5,8
B8: 5,8
F7: 5,8
D9: 5,8
H8: 8,9
I9: 5,8

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
B2,C2: 3.. / B2 = 3  =>  0 pairs (*) / C2 = 3  =>  0 pairs (X)
B4,C5: 3.. / B4 = 3  =>  0 pairs (X) / C5 = 3  =>  0 pairs (_)
E5,E6: 3.. / E5 = 3  =>  0 pairs (X) / E6 = 3  =>  0 pairs (_)
G4,G6: 3.. / G4 = 3  =>  0 pairs (*) / G6 = 3  =>  0 pairs (X)
B4,G4: 3.. / B4 = 3  =>  0 pairs (X) / G4 = 3  =>  0 pairs (_)
C5,E5: 3.. / C5 = 3  =>  0 pairs (*) / E5 = 3  =>  0 pairs (X)
E6,G6: 3.. / E6 = 3  =>  0 pairs (*) / G6 = 3  =>  0 pairs (X)
B2,B4: 3.. / B2 = 3  =>  0 pairs (*) / B4 = 3  =>  0 pairs (X)
C2,C5: 3.. / C2 = 3  =>  0 pairs (X) / C5 = 3  =>  0 pairs (_)
H2,I2: 4.. / H2 = 4  =>  0 pairs (X) / I2 = 4  => 15 pairs (_)
H6,I6: 4.. / H6 = 4  => 15 pairs (_) / I6 = 4  =>  0 pairs (X)
H2,H6: 4.. / H2 = 4  =>  0 pairs (X) / H6 = 4  => 15 pairs (_)
I2,I6: 4.. / I2 = 4  => 15 pairs (_) / I6 = 4  =>  0 pairs (X)
E3,F3: 5.. / E3 = 5  =>  0 pairs (X) / F3 = 5  =>  0 pairs (_)
G4,G6: 5.. / G4 = 5  =>  0 pairs (X) / G6 = 5  =>  0 pairs (_)
C7,B8: 5.. / C7 = 5  =>  0 pairs (*) / B8 = 5  =>  0 pairs (X)
F7,D9: 5.. / F7 = 5  =>  0 pairs (X) / D9 = 5  =>  0 pairs (_)
I8,I9: 5.. / I8 = 5  =>  0 pairs (*) / I9 = 5  =>  0 pairs (X)
C5,E5: 5.. / C5 = 5  =>  0 pairs (X) / E5 = 5  =>  0 pairs (_)
C7,F7: 5.. / C7 = 5  =>  0 pairs (*) / F7 = 5  =>  0 pairs (X)
B8,I8: 5.. / B8 = 5  =>  0 pairs (X) / I8 = 5  =>  0 pairs (_)
D9,I9: 5.. / D9 = 5  =>  0 pairs (*) / I9 = 5  =>  0 pairs (X)
A2,A6: 5.. / A2 = 5  =>  0 pairs (*) / A6 = 5  =>  0 pairs (X)
D4,D9: 5.. / D4 = 5  =>  0 pairs (X) / D9 = 5  =>  0 pairs (_)
F3,F7: 5.. / F3 = 5  =>  0 pairs (*) / F7 = 5  =>  0 pairs (X)
H2,I2: 6.. / H2 = 6  => 15 pairs (_) / I2 = 6  =>  0 pairs (X)
H5,I5: 6.. / H5 = 6  =>  0 pairs (X) / I5 = 6  => 15 pairs (_)
H2,H5: 6.. / H2 = 6  => 15 pairs (_) / H5 = 6  =>  0 pairs (X)
I2,I5: 6.. / I2 = 6  =>  0 pairs (X) / I5 = 6  => 15 pairs (_)
E3,F3: 8.. / E3 = 8  =>  0 pairs (*) / F3 = 8  =>  0 pairs (X)
B4,A6: 8.. / B4 = 8  =>  0 pairs (X) / A6 = 8  =>  0 pairs (_)
D4,E6: 8.. / D4 = 8  =>  0 pairs (*) / E6 = 8  =>  0 pairs (X)
H5,I5: 8.. / H5 = 8  => 15 pairs (_) / I5 = 8  =>  0 pairs (X)
C7,B8: 8.. / C7 = 8  =>  0 pairs (X) / B8 = 8  =>  0 pairs (_)
F7,D9: 8.. / F7 = 8  =>  0 pairs (*) / D9 = 8  =>  0 pairs (X)
B4,D4: 8.. / B4 = 8  =>  0 pairs (X) / D4 = 8  =>  0 pairs (_)
A6,E6: 8.. / A6 = 8  =>  0 pairs (*) / E6 = 8  =>  0 pairs (X)
C7,F7: 8.. / C7 = 8  =>  0 pairs (X) / F7 = 8  =>  0 pairs (_)
D9,I9: 8.. / D9 = 8  =>  0 pairs (X) / I9 = 8  =>  0 pairs (_)
A2,A6: 8.. / A2 = 8  =>  0 pairs (X) / A6 = 8  =>  0 pairs (_)
C2,C7: 8.. / C2 = 8  =>  0 pairs (*) / C7 = 8  =>  0 pairs (X)
D4,D9: 8.. / D4 = 8  =>  0 pairs (*) / D9 = 8  =>  0 pairs (X)
E3,E6: 8.. / E3 = 8  =>  0 pairs (*) / E6 = 8  =>  0 pairs (X)
F3,F7: 8.. / F3 = 8  =>  0 pairs (X) / F7 = 8  =>  0 pairs (_)
H5,H8: 8.. / H5 = 8  => 15 pairs (_) / H8 = 8  =>  0 pairs (X)
H6,I6: 9.. / H6 = 9  =>  0 pairs (X) / I6 = 9  => 15 pairs (_)
H8,I8: 9.. / H8 = 9  => 15 pairs (_) / I8 = 9  =>  0 pairs (X)
H6,H8: 9.. / H6 = 9  =>  0 pairs (X) / H8 = 9  => 15 pairs (_)
I6,I8: 9.. / I6 = 9  => 15 pairs (_) / I8 = 9  =>  0 pairs (X)
* DURATION: 0:01:39.477655  START: 15:34:34.245955  END: 15:36:13.723610 2017-05-04
* CP COUNT: (49)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A2,A6,B8,C5,C7,D4,D9,E3,E5,F3,F7,G4,G6,H2,H5,H6,H8,I2,I5,I6,I9)
* 172469853...7129..6943..1277.9.46.1224.9.17...162.7...92.67.4313.71246..461.9327.
* PAIR A2: 5,8 BLK 1
B2: 5,8,3                                # reduction candidate for 5,8
B2: 5,8 => CTR
* 172469853..37129..6943..1277398465122459317..8162573..92867.4313.71246..461.9327.
B2: 3 => SOLVED
* 172469853538712964694385127759846312243951786816237549925678431387124695461593278
C2: 5,8,3                                # reduction candidate for 5,8
C2: 5,8 => SOLVED
* 172469853538712964694385127759846312243951786816237549925678431387124695461593278
C2: 3 => CTR
* 172469853..37129..6943..1277398465122459317..8162573..92867.4313.71246..461.9327.
* PAIR E3: 5,8 COL E
E6: 5,8,3                                # reduction candidate for 5,8
E6: 5,8 => CTR
* 172469853..37129..6943..1277398465122459317..8162573..92867.4313.71246..461.9327.
E6: 3 => SOLVED
* 172469853538712964694385127759846312243951786816237549925678431387124695461593278
* PAIR C5: 3,5 BLK 4
B4: 3,5,8                                # reduction candidate for 3,5
B4: 3,5 => SOLVED
* 172469853538712964694385127759846312243951786816237549925678431387124695461593278
B4: 8 => CTR
* 172469853.3.7129..6943..12778954631224.9.17...162.7...92.67.4313.71246..461.9327.
* PAIR C5: 3,5 COL C
C2: 3,5,8                                # reduction candidate for 3,5
C2: 3,5 => CTR
* 172469853...7129..69435812778954631224.9.17...162.7...9286754313571246..461893275
C2: 8 => SOLVED
* 172469853538712964694385127759846312243951786816237549925678431387124695461593278
* PAIR A6: 5,8 BLK 4
B4: 5,8,3                                # reduction candidate for 5,8
B4: 5,8 => SOLVED
* 172469853538712964694385127759846312243951786816237549925678431387124695461593278
B4: 3 => CTR
* 172469853...7129..6943..1277398465122459317..8162573..92867.4313.71246..461.9327.
* PAIR A6: 5,8 ROW 6
E6: 5,8,3                                # reduction candidate for 5,8
E6: 5,8 => CTR
* 172469853..37129..6943..1277398465122459317..8162573..92867.4313.71246..461.9327.
E6: 3 => SOLVED
* 172469853538712964694385127759846312243951786816237549925678431387124695461593278
* PAIR D4: 5,8 BLK 5
E6: 5,8,3                                # reduction candidate for 5,8
E6: 5,8 => CTR
* 172469853..37129..6943..1277398465122459317..8162573..92867.4313.71246..461.9327.
E6: 3 => SOLVED
* 172469853538712964694385127759846312243951786816237549925678431387124695461593278
* PAIR D4: 5,8 ROW 4
B4: 5,8,3                                # reduction candidate for 5,8
B4: 5,8 => SOLVED
* 172469853538712964694385127759846312243951786816237549925678431387124695461593278
B4: 3 => CTR
* 172469853...7129..6943..1277398465122459317..8162573..92867.4313.71246..461.9327.
* PAIR E5: 3,5 BLK 5
E6: 3,5,8                                # reduction candidate for 3,5
E6: 3,5 => SOLVED
* 172469853538712964694385127759846312243951786816237549925678431387124695461593278
E6: 8 => CTR
* 172469853...7129..6943..1277.9.46.1224.9317...162873..92.67.4313.71246..461893275
* PAIR G4: 3,5 ROW 4
B4: 3,5,8                                # reduction candidate for 3,5
B4: 3,5 => SOLVED
* 172469853538712964694385127759846312243951786816237549925678431387124695461593278
B4: 8 => CTR
* 172469853.3.7129..6943..12778954631224.9.17...162.7...92.67.4313.71246..461.9327.
* PAIR G6: 3,5 ROW 6
E6: 3,5,8                                # reduction candidate for 3,5
E6: 3,5 => SOLVED
* 172469853538712964694385127759846312243951786816237549925678431387124695461593278
E6: 8 => CTR
* 172469853...7129..6943..1277.9.46.1224.9317...162873..92.67.4313.71246..461893275
* PAIR C7: 5,8 COL C
C2: 5,8,3                                # reduction candidate for 5,8
C2: 5,8 => SOLVED
* 172469853538712964694385127759846312243951786816237549925678431387124695461593278
C2: 3 => CTR
* 172469853..37129..6943..1277398465122459317..8162573..92867.4313.71246..461.9327.
* PAIR B8: 5,8 ROW 8
I8: 5,8,9                                # reduction candidate for 5,8
I8: 9 => CTR
* 172469853...7129..6943.812778954631224.9.17...162.7...92.67.431357124689461893275
I8: 5,8                                  # 15 pairs
* PAIR B8: 5,8 COL B
B2: 5,8,3                                # reduction candidate for 5,8
B2: 5,8 => CTR
* 172469853..37129..6943..1277398465122459317..8162573..92867.4313.71246..461.9327.
B2: 3 => SOLVED
* 172469853538712964694385127759846312243951786816237549925678431387124695461593278
B4: 5,8,3                                # reduction candidate for 5,8
B4: 5,8 => SOLVED
* 172469853538712964694385127759846312243951786816237549925678431387124695461593278
B4: 3 => CTR
* 172469853...7129..6943..1277398465122459317..8162573..92867.4313.71246..461.9327.
* PAIR H8: 8,9 BLK 9
I8: 8,9,5                                # reduction candidate for 8,9
I8: 8,9 => CTR
* 172469853...7129..6943..1277.954631224.9.17...162.7...92.67.4313571246..461.93275
I8: 5 => SOLVED
* 172469853538712964694385127759846312243951786816237549925678431387124695461593278
* PAIR I9: 5,8 BLK 9
I8: 5,8,9                                # reduction candidate for 5,8
I8: 9 => CTR
* 172469853...7129..6943.812778954631224.9.17...162.7...92.67.431357124689461893275
I8: 5,8                                  # 15 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-372-base-pr-000.dot
* REASONING
* DIS # B2: 5,8 => CTR => B2: 3
* PRF # B2: 3 => SOL
* PRF # C2: 5,8 => SOL
* DIS # C2: 3 => CTR => C2: 5,8
* DIS # E6: 5,8 => CTR => E6: 3
* PRF # E6: 3 => SOL
* PRF # B4: 3,5 => SOL
* DIS # B4: 8 => CTR => B4: 3,5
* DIS # C2: 3,5 => CTR => C2: 8
* PRF # C2: 8 => SOL
* PRF # B4: 5,8 => SOL
* DIS # B4: 3 => CTR => B4: 5,8
* DIS # E6: 5,8 => CTR => E6: 3
* PRF # E6: 3 => SOL
* DIS # E6: 5,8 => CTR => E6: 3
* PRF # E6: 3 => SOL
* PRF # B4: 5,8 => SOL
* DIS # B4: 3 => CTR => B4: 5,8
* PRF # E6: 3,5 => SOL
* DIS # E6: 8 => CTR => E6: 3,5
* PRF # B4: 3,5 => SOL
* DIS # B4: 8 => CTR => B4: 3,5
* PRF # E6: 3,5 => SOL
* DIS # E6: 8 => CTR => E6: 3,5
* PRF # C2: 5,8 => SOL
* DIS # C2: 3 => CTR => C2: 5,8
* DIS # I8: 9 => CTR => I8: 5,8
* DIS # B2: 5,8 => CTR => B2: 3
* PRF # B2: 3 => SOL
* PRF # B4: 5,8 => SOL
* DIS # B4: 3 => CTR => B4: 5,8
* DIS # I8: 8,9 => CTR => I8: 5
* PRF # I8: 5 => SOL
* DIS # I8: 9 => CTR => I8: 5,8
* CNT  34 HDP CHAINS /  36 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A2,A6,B8,C5,C7,D4,D9,E3,E5,F3,F7,G4,G6,H2,H5,H6,H8,I2,I5,I6,I9)
* 172469853...7129..6943..1277.9.46.1224.9.17...162.7...92.67.4313.71246..461.9327.
* PAIR A2: 5,8 BLK 1
B2: 5,8,3                                # reduction candidate for 5,8
B2: 5,8 => CTR
* 172469853..37129..6943..1277398465122459317..8162573..92867.4313.71246..461.9327.
B2: 3 => SOLVED
* 172469853538712964694385127759846312243951786816237549925678431387124695461593278
* DURATION: 0:00:01.804336  START: 15:37:00.579709  END: 15:37:02.384045 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-372-base-pr-001.dot
* REASONING
* DIS # B2: 5,8 => CTR => B2: 3
* PRF B2: 3 => SOL
* STA B2: 3
* CNT   2 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 372

solution: 172469853538712964694385127759846312243951786816237549925678431387124695461593278
info: 6441     FNBTWY   S8.f     22299

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

Solution

position: 172469853538712964694385127759846312243951786816237549925678431387124695461593278 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:

* DIS # B2: 5,8 => CTR => B2: 3
* PRF # B2: 3 => SOL
* PRF # C2: 5,8 => SOL
* DIS # C2: 3 => CTR => C2: 5,8
* DIS # E6: 5,8 => CTR => E6: 3
* PRF # E6: 3 => SOL
* PRF # B4: 3,5 => SOL
* DIS # B4: 8 => CTR => B4: 3,5
* DIS # C2: 3,5 => CTR => C2: 8
* PRF # C2: 8 => SOL
* PRF # B4: 5,8 => SOL
* DIS # B4: 3 => CTR => B4: 5,8
* DIS # E6: 5,8 => CTR => E6: 3
* PRF # E6: 3 => SOL
* DIS # E6: 5,8 => CTR => E6: 3
* PRF # E6: 3 => SOL
* PRF # B4: 5,8 => SOL
* DIS # B4: 3 => CTR => B4: 5,8
* PRF # E6: 3,5 => SOL
* DIS # E6: 8 => CTR => E6: 3,5
* PRF # B4: 3,5 => SOL
* DIS # B4: 8 => CTR => B4: 3,5
* PRF # E6: 3,5 => SOL
* DIS # E6: 8 => CTR => E6: 3,5
* PRF # C2: 5,8 => SOL
* DIS # C2: 3 => CTR => C2: 5,8
* INC # I8: 5,8 => UNS
* DIS # I8: 9 => CTR => I8: 5,8
* DIS # B2: 5,8 => CTR => B2: 3
* PRF # B2: 3 => SOL
* PRF # B4: 5,8 => SOL
* DIS # B4: 3 => CTR => B4: 5,8
* DIS # I8: 8,9 => CTR => I8: 5
* PRF # I8: 5 => SOL
* INC # I8: 5,8 => UNS
* DIS # I8: 9 => CTR => I8: 5,8
* CNT  36 HDP CHAINS /  36 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # B2: 5,8 => CTR => B2: 3
* PRF B2: 3 => SOL
* STA B2: 3
* CNT   2 HDP CHAINS /   1 HYP OPENED