Analysis of zz-www.sudokuoftheday.co.uk-20060817-absurd-base.sdk
Contents
Sudoku from http://www.sudokuoftheday.co.uk/cgi-bin/sudoku1280.cgi?ACTION=archive2&USER=&MONTH=Aug&YEAR=2006
level: medium
position: ....579.8...3...7.6.........8.7.....2...9...49.5...8.......14.97.45....6...6.3.1. initial
Autosolve
position: ....57968...3...7.6..9...4..8.7...9.2...9...49.5...8......714.97145.9..6...643.1. autosolve
Pair Reduction Variants
Pair Reduction Analysis
The following important HDP chains were detected:
* PRF # F2: 2,8 => SOL * PRF # C3: 2,8 => SOL * DIS # G4: 3,5 => CTR => G4: 1,2,6 * DIS # G5: 3,5 => CTR => G5: 1,6,7 * DIS # G4: 2,3 => CTR => G4: 1,5,6 * DIS # I6: 2,3 => CTR => I6: 1,7 * DIS # H8: 8 => CTR => H8: 2,3 * DIS # A2: 1,4 => CTR => A2: 5,8 * DIS # H7: 5 => CTR => H7: 2,8 * DIS # H8: 3 => CTR => H8: 2,8 * DIS # H8: 8 => CTR => H8: 2,3 * DIS # G4: 2,3 => CTR => G4: 1,5,6 * CNT 12 HDP CHAINS / 35 HYP OPENED
See Appendix: Full HDP Chains for full list of HDP chains.
Pair Reduction
The following important HDP chains were detected:
* PRF # F2: 2,8 => SOL * STA F2: 2,8 * CNT 1 HDP CHAINS / 2 HYP OPENED
See Appendix: Full HDP Chains for full list of HDP chains.
Details
Positions
| ....579.8...3...7.6.........8.7.....2...9...49.5...8.......14.97.45....6...6.3.1. | initial |
| ....57968...3...7.6..9...4..8.7...9.2...9...49.5...8......714.97145.9..6...643.1. | autosolve |
| 123457968549368271678912543481735692237896154965124837356271489714589326892643715 | solved |
Classification
level: medium
Pairing Analysis
-------------------------------------------------- * PAIRS (9) F3: 2,8 D5: 1,8 H5: 3,5 H6: 2,3 A7: 3,5 A9: 5,8 D7: 2,8 E8: 2,8 G8: 2,3 -------------------------------------------------- * CONSTRAINT PAIRS (AUTO SOLVE) D7,E8: 2.. / D7 = 2 => 23 pairs (_) / E8 = 2 => 0 pairs (X) G3,I3: 3.. / G3 = 3 => 0 pairs (X) / I3 = 3 => 9 pairs (_) E4,E6: 3.. / E4 = 3 => 11 pairs (_) / E6 = 3 => 13 pairs (_) G8,H8: 3.. / G8 = 3 => 9 pairs (_) / H8 = 3 => 0 pairs (X) D1,F2: 4.. / D1 = 4 => 15 pairs (_) / F2 = 4 => 16 pairs (_) A4,B6: 4.. / A4 = 4 => 11 pairs (_) / B6 = 4 => 0 pairs (X) A4,F4: 4.. / A4 = 4 => 11 pairs (_) / F4 = 4 => 0 pairs (X) D1,D6: 4.. / D1 = 4 => 15 pairs (_) / D6 = 4 => 16 pairs (_) F4,F5: 5.. / F4 = 5 => 12 pairs (_) / F5 = 5 => 0 pairs (X) H5,H7: 5.. / H5 = 5 => 20 pairs (_) / H7 = 5 => 0 pairs (X) E2,F2: 6.. / E2 = 6 => 9 pairs (_) / F2 = 6 => 19 pairs (_) G4,G5: 6.. / G4 = 6 => 10 pairs (_) / G5 = 6 => 0 pairs (X) B7,C7: 6.. / B7 = 6 => 12 pairs (_) / C7 = 6 => 10 pairs (_) B3,C3: 7.. / B3 = 7 => 0 pairs (*) / C3 = 7 => 0 pairs (X) G5,I6: 7.. / G5 = 7 => 22 pairs (_) / I6 = 7 => 23 pairs (_) G9,I9: 7.. / G9 = 7 => 23 pairs (_) / I9 = 7 => 22 pairs (_) B6,I6: 7.. / B6 = 7 => 22 pairs (_) / I6 = 7 => 23 pairs (_) C3,C5: 7.. / C3 = 7 => 12 pairs (_) / C5 = 7 => 0 pairs (*) G5,G9: 7.. / G5 = 7 => 22 pairs (_) / G9 = 7 => 23 pairs (_) I6,I9: 7.. / I6 = 7 => 23 pairs (_) / I9 = 7 => 22 pairs (_) D5,F5: 8.. / D5 = 8 => 23 pairs (_) / F5 = 8 => 0 pairs (X) A9,C9: 8.. / A9 = 8 => 9 pairs (_) / C9 = 8 => 0 pairs (X) D7,E8: 8.. / D7 = 8 => 0 pairs (X) / E8 = 8 => 23 pairs (_) H7,H8: 8.. / H7 = 8 => 23 pairs (_) / H8 = 8 => 0 pairs (X) D7,H7: 8.. / D7 = 8 => 0 pairs (X) / H7 = 8 => 23 pairs (_) E8,H8: 8.. / E8 = 8 => 23 pairs (_) / H8 = 8 => 0 pairs (X) A2,A9: 8.. / A2 = 8 => 0 pairs (X) / A9 = 8 => 9 pairs (_) D5,D7: 8.. / D5 = 8 => 23 pairs (_) / D7 = 8 => 0 pairs (X) B2,C2: 9.. / B2 = 9 => 9 pairs (_) / C2 = 9 => 10 pairs (_) B9,C9: 9.. / B9 = 9 => 10 pairs (_) / C9 = 9 => 9 pairs (_) B2,B9: 9.. / B2 = 9 => 9 pairs (_) / B9 = 9 => 10 pairs (_) C2,C9: 9.. / C2 = 9 => 10 pairs (_) / C9 = 9 => 9 pairs (_) * DURATION: 0:00:34.415233 START: 01:51:04.647248 END: 01:51:39.062481 2019-05-01 * CP COUNT: (32) * SOLUTION FOUND -------------------------------------------------- * PREPARE PR GRAPH * PAIR REDUCTION .. * LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A7,A9,D5,D7,E8,F3,G8,H5,H6) * ....57968...3...7.6..9...4..8.7...9.2...9...49.5...8......714.97145.9..6...643.1. * PAIR F3: 2,8 BLK 2 E2: 2,8,1,6 # reduction candidate for 2,8 E2: 2,8 # 20 pairs F2: 2,8,4,6 # reduction candidate for 2,8 F2: 2,8 => SOLVED * 123457968549368271678912543481735692237896154965124837356271489714589326892643715 F2: 4,6 # 10 pairs E3: 2,8,1 # reduction candidate for 2,8 E3: 2,8 # 17 pairs * PAIR F3: 2,8 ROW 3 C3: 2,8,1,7 # reduction candidate for 2,8 C3: 2,8 => SOLVED * 123457968549368271678912543481735692237896154965124837356271489714589326892643715 C3: 1,7 # 12 pairs * PAIR H5: 3,5 BLK 6 G4: 3,5,1,2,6 # reduction candidate for 3,5 G4: 3,5 => CTR * ....57968...3...7.6..9...4..8.7...912.18956349.5...8.7....714.97145.9..6...64371. G4: 1,2,6 # 9 pairs I4: 3,5,1,2 # reduction candidate for 3,5 I4: 3,5 # 15 pairs G5: 3,5,1,6,7 # reduction candidate for 3,5 G5: 3,5 => CTR * ....57968...3...726.79.8.43.837..6912.189...49.5...827..6271489714589236...643715 G5: 1,6,7 # 9 pairs * PAIR H6: 2,3 BLK 6 G4: 2,3,1,5,6 # reduction candidate for 2,3 G4: 2,3 => CTR * ....57968...3...7.6..9...4..8.7...912.18956349.5...8.7....714.97145.9..6...64371. G4: 1,5,6 # 9 pairs I4: 2,3,1,5 # reduction candidate for 2,3 I4: 2,3 # 26 pairs I6: 2,3,1,7 # reduction candidate for 2,3 I6: 2,3 => CTR * ....57968...3...7.6.79...4.48.7..6912.189.754975...8....6271489714589..6...643517 I6: 1,7 # 10 pairs * PAIR H6: 2,3 ROW 6 E6: 2,3,1,6 # reduction candidate for 2,3 E6: 2,3 # 13 pairs E6: 1,6 # 12 pairs * PAIR H6: 2,3 COL H H8: 2,3,8 # reduction candidate for 2,3 H8: 8 => CTR * ...457968.493.62756579821434817356922..1987549752648315..8714297145293868..643517 H8: 2,3 # 23 pairs * PAIR A7: 3,5 BLK 7 B7: 3,5,2,6 # reduction candidate for 3,5 B7: 3,5 # 21 pairs B7: 2,6 # 10 pairs * PAIR A9: 5,8 COL A A2: 5,8,1,4 # reduction candidate for 5,8 A2: 1,4 => CTR * 34215796819836457265792814.48.7.5.9.2..896.549654.28375.6271489714589326829643715 A2: 5,8 # 12 pairs * PAIR D7: 2,8 ROW 7 H7: 2,8,5 # reduction candidate for 2,8 H7: 5 => CTR * ....57968...3...7.6..9...43.8.7...9.2..1985349.5...8.....871459714529386...643.1. H7: 2,8 # 20 pairs * PAIR E8: 2,8 ROW 8 H8: 2,8,3 # reduction candidate for 2,8 H8: 3 => CTR * .2.457968.49368.726.8912.4348372569127.896.54965134827..6271489714589236892643715 H8: 2,8 # 9 pairs * PAIR E8: 2,8 COL E E2: 2,8,1,6 # reduction candidate for 2,8 E2: 2,8 # 20 pairs E3: 2,8,1 # reduction candidate for 2,8 E3: 2,8 # 17 pairs * PAIR G8: 2,3 BLK 9 H8: 2,3,8 # reduction candidate for 2,3 H8: 8 => CTR * ...457968.493.62756579821434817356922..1987549752648315..8714297145293868..643517 H8: 2,3 # 23 pairs * PAIR G8: 2,3 COL G G3: 2,3,1,5 # reduction candidate for 2,3 G3: 2,3 # 12 pairs G4: 2,3,1,5,6 # reduction candidate for 2,3 G4: 2,3 => CTR * ....57968...3...7.6..9...4..8.7...912.18956349.5...8.7....714.97145.9..6...64371. G4: 1,5,6 # 9 pairs * INCONCLUSIVE * SAVE PR GRAPH zz-www.sudokuoftheday.co.uk-20060817-absurd-base-pr-000.dot * REASONING * PRF # F2: 2,8 => SOL * PRF # C3: 2,8 => SOL * DIS # G4: 3,5 => CTR => G4: 1,2,6 * DIS # G5: 3,5 => CTR => G5: 1,6,7 * DIS # G4: 2,3 => CTR => G4: 1,5,6 * DIS # I6: 2,3 => CTR => I6: 1,7 * DIS # H8: 8 => CTR => H8: 2,3 * DIS # A2: 1,4 => CTR => A2: 5,8 * DIS # H7: 5 => CTR => H7: 2,8 * DIS # H8: 3 => CTR => H8: 2,8 * DIS # H8: 8 => CTR => H8: 2,3 * DIS # G4: 2,3 => CTR => G4: 1,5,6 * CNT 12 HDP CHAINS / 35 HYP OPENED -------------------------------------------------- * PREPARE PR GRAPH * PAIR REDUCTION .. * LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A7,A9,D5,D7,E8,F3,G8,H5,H6) * ....57968...3...7.6..9...4..8.7...9.2...9...49.5...8......714.97145.9..6...643.1. * PAIR F3: 2,8 BLK 2 E2: 2,8,1,6 # reduction candidate for 2,8 E2: 2,8 # 20 pairs F2: 2,8,4,6 # reduction candidate for 2,8 F2: 2,8 => SOLVED * 123457968549368271678912543481735692237896154965124837356271489714589326892643715 * DURATION: 0:00:02.342330 START: 01:51:59.042000 END: 01:52:01.384330 2019-05-01 * SOLUTION FOUND * SAVE PR GRAPH zz-www.sudokuoftheday.co.uk-20060817-absurd-base-pr-001.dot * REASONING * PRF # F2: 2,8 => SOL * STA F2: 2,8 * CNT 1 HDP CHAINS / 2 HYP OPENED
Header Info
http://www.sudokuoftheday.co.uk/cgi-bin/sudoku1280.cgi?ACTION=archive2&USER=&MONTH=Aug&YEAR=2006, 20060817, absurd
Solution
position: 123457968549368271678912543481735692237896154965124837356271489714589326892643715 solved
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 # E2: 2,8 => UNS * PRF # F2: 2,8 => SOL * INC # F2: 4,6 => UNS * INC # E3: 2,8 => UNS * PRF # C3: 2,8 => SOL * INC # C3: 1,7 => UNS * DIS # G4: 3,5 => CTR => G4: 1,2,6 * INC # G4: 1,2,6 => UNS * INC # I4: 3,5 => UNS * DIS # G5: 3,5 => CTR => G5: 1,6,7 * INC # G5: 1,6,7 => UNS * DIS # G4: 2,3 => CTR => G4: 1,5,6 * INC # G4: 1,5,6 => UNS * INC # I4: 2,3 => UNS * DIS # I6: 2,3 => CTR => I6: 1,7 * INC # I6: 1,7 => UNS * INC # E6: 2,3 => UNS * INC # E6: 1,6 => UNS * INC # H8: 2,3 => UNS * DIS # H8: 8 => CTR => H8: 2,3 * INC # B7: 3,5 => UNS * INC # B7: 2,6 => UNS * INC # A2: 5,8 => UNS * DIS # A2: 1,4 => CTR => A2: 5,8 * INC # H7: 2,8 => UNS * DIS # H7: 5 => CTR => H7: 2,8 * INC # H8: 2,8 => UNS * DIS # H8: 3 => CTR => H8: 2,8 * INC # E2: 2,8 => UNS * INC # E3: 2,8 => UNS * INC # H8: 2,3 => UNS * DIS # H8: 8 => CTR => H8: 2,3 * INC # G3: 2,3 => UNS * DIS # G4: 2,3 => CTR => G4: 1,5,6 * INC # G4: 1,5,6 => UNS * CNT 35 HDP CHAINS / 35 HYP OPENED
A2. Pair Reduction
Full list of HDP chains traversed:
* INC # E2: 2,8 => UNS * PRF # F2: 2,8 => SOL * STA F2: 2,8 * CNT 2 HDP CHAINS / 2 HYP OPENED