Analysis of zz-www.sudokuoftheday.co.uk-20190202-absurd-base.sdk
Contents
Sudoku from http://www.sudokuoftheday.co.uk/cgi-bin/sudoku1280.cgi?ACTION=archive2&USER=&MONTH=Feb&YEAR=2019
level: medium
position: .2......6....63.........2.95..3..9.2.8...9.47.7...5.....7.8...1..4........15.286. initial
Autosolve
position: .2..9...6...263..86...5.2.95.63.7982.8.6.9547.7.8.5613257486391864931725..1572864 autosolve
Pair Reduction Variants
Pair Reduction Analysis
The following important HDP chains were detected:
* DIS # C1: 3,8 => CTR => C1: 5 * PRF # C1: 5 => SOL * PRF # A1: 3,4 => SOL * PRF # A1: 1,4 => SOL * DIS # A2: 1,4 => CTR => A2: 7,9 * PRF # A2: 7,9 => SOL * PRF # B2: 1,4 => SOL * DIS # B2: 9 => CTR => B2: 1,4 * DIS # H1: 5,7 => CTR => H1: 3 * PRF # H1: 3 => SOL * PRF # H1: 3,7 => SOL * DIS # H1: 5 => CTR => H1: 3,7 * PRF # B2: 1,4 => SOL * DIS # B2: 9 => CTR => B2: 1,4 * DIS # B3: 1,4 => CTR => B3: 3 * PRF # B3: 3 => SOL * DIS # A1: 1,3 => CTR => A1: 4,7 * DIS # A2: 4,9 => CTR => A2: 1,7 * CNT 18 HDP CHAINS / 22 HYP OPENED
See Appendix: Full HDP Chains for full list of HDP chains.
Pair Reduction
The following important HDP chains were detected:
* DIS # C1: 3,8 => CTR => C1: 5 * PRF C1: 5 => SOL * STA C1: 5 * CNT 2 HDP CHAINS / 1 HYP OPENED
See Appendix: Full HDP Chains for full list of HDP chains.
Details
Positions
| .2......6....63.........2.95..3..9.2.8...9.47.7...5.....7.8...1..4........15.286. | initial |
| .2..9...6...263..86...5.2.95.63.7982.8.6.9547.7.8.5613257486391864931725..1572864 | autosolve |
| 425798136719263458638154279546317982183629547972845613257486391864931725391572864 | solved |
Classification
level: medium
Pairing Analysis
-------------------------------------------------- * PAIRS (20) C2: 5,9 C3: 3,8 D1: 1,7 F1: 4,8 D3: 1,7 F3: 4,8 G1: 1,4 G2: 1,4 H2: 5,7 H3: 3,7 B4: 1,4 A5: 1,3 C5: 2,3 A6: 4,9 C6: 2,9 E4: 1,4 E5: 1,2 E6: 2,4 A9: 3,9 B9: 3,9 -------------------------------------------------- * CONSTRAINT PAIRS (AUTO SOLVE) D1,D3: 1.. / D1 = 1 => 0 pairs (X) / D3 = 1 => 0 pairs (_) G1,G2: 1.. / G1 = 1 => 0 pairs (*) / G2 = 1 => 0 pairs (X) B4,A5: 1.. / B4 = 1 => 0 pairs (X) / A5 = 1 => 0 pairs (_) E4,E5: 1.. / E4 = 1 => 0 pairs (*) / E5 = 1 => 0 pairs (X) B3,D3: 1.. / B3 = 1 => 0 pairs (X) / D3 = 1 => 0 pairs (_) B4,E4: 1.. / B4 = 1 => 0 pairs (X) / E4 = 1 => 0 pairs (_) A5,E5: 1.. / A5 = 1 => 0 pairs (*) / E5 = 1 => 0 pairs (X) C5,C6: 2.. / C5 = 2 => 0 pairs (X) / C6 = 2 => 0 pairs (_) E5,E6: 2.. / E5 = 2 => 0 pairs (*) / E6 = 2 => 0 pairs (X) C5,E5: 2.. / C5 = 2 => 0 pairs (X) / E5 = 2 => 0 pairs (_) C6,E6: 2.. / C6 = 2 => 0 pairs (*) / E6 = 2 => 0 pairs (X) H1,H3: 3.. / H1 = 3 => 0 pairs (*) / H3 = 3 => 0 pairs (X) A5,C5: 3.. / A5 = 3 => 0 pairs (X) / C5 = 3 => 0 pairs (_) A9,B9: 3.. / A9 = 3 => 0 pairs (*) / B9 = 3 => 0 pairs (X) B3,B9: 3.. / B3 = 3 => 0 pairs (*) / B9 = 3 => 0 pairs (X) F1,F3: 4.. / F1 = 4 => 0 pairs (X) / F3 = 4 => 19 pairs (_) G1,G2: 4.. / G1 = 4 => 18 pairs (_) / G2 = 4 => 0 pairs (*) B4,A6: 4.. / B4 = 4 => 0 pairs (*) / A6 = 4 => 0 pairs (X) E4,E6: 4.. / E4 = 4 => 0 pairs (X) / E6 = 4 => 0 pairs (_) B3,F3: 4.. / B3 = 4 => 0 pairs (X) / F3 = 4 => 19 pairs (_) B4,E4: 4.. / B4 = 4 => 0 pairs (*) / E4 = 4 => 0 pairs (X) A6,E6: 4.. / A6 = 4 => 0 pairs (X) / E6 = 4 => 0 pairs (_) C1,C2: 5.. / C1 = 5 => 0 pairs (*) / C2 = 5 => 0 pairs (X) H1,H2: 5.. / H1 = 5 => 0 pairs (X) / H2 = 5 => 0 pairs (_) C1,H1: 5.. / C1 = 5 => 0 pairs (*) / H1 = 5 => 0 pairs (X) C2,H2: 5.. / C2 = 5 => 0 pairs (X) / H2 = 5 => 0 pairs (_) A1,A2: 7.. / A1 = 7 => 0 pairs (X) / A2 = 7 => 0 pairs (_) D1,D3: 7.. / D1 = 7 => 0 pairs (*) / D3 = 7 => 0 pairs (X) A2,H2: 7.. / A2 = 7 => 0 pairs (*) / H2 = 7 => 0 pairs (X) D3,H3: 7.. / D3 = 7 => 0 pairs (X) / H3 = 7 => 0 pairs (_) C1,C3: 8.. / C1 = 8 => 0 pairs (X) / C3 = 8 => 19 pairs (_) F1,F3: 8.. / F1 = 8 => 19 pairs (_) / F3 = 8 => 0 pairs (X) C1,F1: 8.. / C1 = 8 => 0 pairs (X) / F1 = 8 => 19 pairs (_) C3,F3: 8.. / C3 = 8 => 19 pairs (_) / F3 = 8 => 0 pairs (X) A6,C6: 9.. / A6 = 9 => 0 pairs (*) / C6 = 9 => 0 pairs (X) A9,B9: 9.. / A9 = 9 => 0 pairs (X) / B9 = 9 => 0 pairs (_) B2,B9: 9.. / B2 = 9 => 0 pairs (X) / B9 = 9 => 0 pairs (_) C2,C6: 9.. / C2 = 9 => 0 pairs (*) / C6 = 9 => 0 pairs (X) * DURATION: 0:00:45.920673 START: 03:24:27.395206 END: 03:25:13.315879 2019-05-01 * CP COUNT: (38) * SOLUTION FOUND -------------------------------------------------- * PREPARE PR GRAPH * PAIR REDUCTION .. * LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A5,A6,A9,B4,B9,C2,C3,C5,C6,D1,D3,E4,E5,E6,F1,F3,G1,G2,H2,H3) * .2..9...6...263..86...5.2.95.63.7982.8.6.9547.7.8.5613257486391864931725..1572864 * PAIR C3: 3,8 BLK 1 C1: 3,8,5 # reduction candidate for 3,8 C1: 3,8 => CTR * 723198456.952631786187542395463.7982.8.6.9547.79825613257486391864931725.31572864 C1: 5 => SOLVED * 425798136719263458638154279546317982183629547972845613257486391864931725391572864 * PAIR D1: 1,7 ROW 1 A1: 1,7,3,4 # reduction candidate for 1,7 A1: 3,4 => SOLVED * 425798136719263458638154279546317982183629547972845613257486391864931725391572864 A1: 1,7 # 20 pairs * PAIR G1: 1,4 ROW 1 A1: 1,4,3,7 # reduction candidate for 1,4 A1: 1,4 => SOLVED * 425798136719263458638154279546317982183629547972845613257486391864931725391572864 A1: 3,7 # 21 pairs * PAIR G2: 1,4 ROW 2 A2: 1,4,7,9 # reduction candidate for 1,4 A2: 1,4 => CTR * 72.19.4.6...26317861.7542395463179821836295479728.5613257486391864931725..1572864 A2: 7,9 => SOLVED * 425798136719263458638154279546317982183629547972845613257486391864931725391572864 B2: 1,4,9 # reduction candidate for 1,4 B2: 1,4 => SOLVED * 425798136719263458638154279546317982183629547972845613257486391864931725391572864 B2: 9 => CTR * 723198456495263.786..75.2395.63.7982.8.6.9547.79825613257486391864931725931572864 * PAIR H2: 5,7 BLK 3 H1: 5,7,3 # reduction candidate for 5,7 H1: 5,7 => CTR * .2..9...6.95263.786.87542395463179821836.9547.7.8.5613257486391864931725.31572864 H1: 3 => SOLVED * 425798136719263458638154279546317982183629547972845613257486391864931725391572864 * PAIR H3: 3,7 BLK 3 H1: 3,7,5 # reduction candidate for 3,7 H1: 3,7 => SOLVED * 425798136719263458638154279546317982183629547972845613257486391864931725391572864 H1: 5 => CTR * 723198456.952631786187542395463.7982.8.6.9547.79825613257486391864931725.31572864 * PAIR B4: 1,4 COL B B2: 1,4,9 # reduction candidate for 1,4 B2: 1,4 => SOLVED * 425798136719263458638154279546317982183629547972845613257486391864931725391572864 B2: 9 => CTR * 723198456495263.786..75.2395.63.7982.8.6.9547.79825613257486391864931725931572864 B3: 1,4,3 # reduction candidate for 1,4 B3: 1,4 => CTR * 723198456495263.786..75.2395.63.7982.8.6.9547.79825613257486391864931725931572864 B3: 3 => SOLVED * 425798136719263458638154279546317982183629547972845613257486391864931725391572864 * PAIR A5: 1,3 COL A A1: 1,3,4,7 # reduction candidate for 1,3 A1: 1,3 => CTR * .2..9...67..263.586...5.2.95.63.7982.8.6.95474798.5613257486391864931725..1572864 A1: 4,7 # 21 pairs * PAIR A6: 4,9 COL A A2: 4,9,1,7 # reduction candidate for 4,9 A2: 4,9 => CTR * 72.19.4.6...26317861.7542395463179821836295479728.5613257486391864931725..1572864 A2: 1,7 # 21 pairs * INCONCLUSIVE * SAVE PR GRAPH zz-www.sudokuoftheday.co.uk-20190202-absurd-base-pr-000.dot * REASONING * DIS # C1: 3,8 => CTR => C1: 5 * PRF # C1: 5 => SOL * PRF # A1: 3,4 => SOL * PRF # A1: 1,4 => SOL * DIS # A2: 1,4 => CTR => A2: 7,9 * PRF # A2: 7,9 => SOL * PRF # B2: 1,4 => SOL * DIS # B2: 9 => CTR => B2: 1,4 * DIS # H1: 5,7 => CTR => H1: 3 * PRF # H1: 3 => SOL * PRF # H1: 3,7 => SOL * DIS # H1: 5 => CTR => H1: 3,7 * PRF # B2: 1,4 => SOL * DIS # B2: 9 => CTR => B2: 1,4 * DIS # B3: 1,4 => CTR => B3: 3 * PRF # B3: 3 => SOL * DIS # A1: 1,3 => CTR => A1: 4,7 * DIS # A2: 4,9 => CTR => A2: 1,7 * CNT 18 HDP CHAINS / 22 HYP OPENED -------------------------------------------------- * PREPARE PR GRAPH * PAIR REDUCTION .. * LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A5,A6,A9,B4,B9,C2,C3,C5,C6,D1,D3,E4,E5,E6,F1,F3,G1,G2,H2,H3) * .2..9...6...263..86...5.2.95.63.7982.8.6.9547.7.8.5613257486391864931725..1572864 * PAIR C3: 3,8 BLK 1 C1: 3,8,5 # reduction candidate for 3,8 C1: 3,8 => CTR * 723198456.952631786187542395463.7982.8.6.9547.79825613257486391864931725.31572864 C1: 5 => SOLVED * 425798136719263458638154279546317982183629547972845613257486391864931725391572864 * DURATION: 0:00:02.327791 START: 03:25:31.208675 END: 03:25:33.536466 2019-05-01 * SOLUTION FOUND * SAVE PR GRAPH zz-www.sudokuoftheday.co.uk-20190202-absurd-base-pr-001.dot * REASONING * DIS # C1: 3,8 => CTR => C1: 5 * PRF C1: 5 => SOL * STA C1: 5 * CNT 2 HDP CHAINS / 1 HYP OPENED
Header Info
http://www.sudokuoftheday.co.uk/cgi-bin/sudoku1280.cgi?ACTION=archive2&USER=&MONTH=Feb&YEAR=2019, 20190202, absurd
Solution
position: 425798136719263458638154279546317982183629547972845613257486391864931725391572864 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:
* DIS # C1: 3,8 => CTR => C1: 5 * PRF # C1: 5 => SOL * INC # A1: 1,7 => UNS * PRF # A1: 3,4 => SOL * PRF # A1: 1,4 => SOL * INC # A1: 3,7 => UNS * DIS # A2: 1,4 => CTR => A2: 7,9 * PRF # A2: 7,9 => SOL * PRF # B2: 1,4 => SOL * DIS # B2: 9 => CTR => B2: 1,4 * DIS # H1: 5,7 => CTR => H1: 3 * PRF # H1: 3 => SOL * PRF # H1: 3,7 => SOL * DIS # H1: 5 => CTR => H1: 3,7 * PRF # B2: 1,4 => SOL * DIS # B2: 9 => CTR => B2: 1,4 * DIS # B3: 1,4 => CTR => B3: 3 * PRF # B3: 3 => SOL * DIS # A1: 1,3 => CTR => A1: 4,7 * INC # A1: 4,7 => UNS * DIS # A2: 4,9 => CTR => A2: 1,7 * INC # A2: 1,7 => UNS * CNT 22 HDP CHAINS / 22 HYP OPENED
A2. Pair Reduction
Full list of HDP chains traversed:
* DIS # C1: 3,8 => CTR => C1: 5 * PRF C1: 5 => SOL * STA C1: 5 * CNT 2 HDP CHAINS / 1 HYP OPENED