Analysis of zz-www.sudokuoftheday.co.uk-20190213-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: 5.....9.6...27.3.5.9......1.7.5.3.....6...5..2.......37.13.5..2.6.......83.4....7 initial
Autosolve
position: 527134986618279345493.5...117.5.3...386...5..25......37413.5.92965....3.83249..57 autosolve
Pair Reduction Variants
Pair Reduction Analysis
The following important HDP chains were detected:
* PRF # D6: 6,8 => SOL * DIS # D6: 7,9 => CTR => D6: 6,8 * DIS # F6: 6,8 => CTR => F6: 1,7 * PRF # I4: 4,9 => SOL * DIS # I4: 8 => CTR => I4: 4,9 * DIS # D6: 7,9 => CTR => D6: 6,8 * PRF # D6: 6,8 => SOL * PRF # I4: 4,9 => SOL * DIS # I4: 8 => CTR => I4: 4,9 * DIS # F8: 7,8 => CTR => F8: 1,2 * PRF # F8: 1,2 => SOL * PRF # D6: 7,8 => SOL * PRF # G8: 4,8 => SOL * DIS # G8: 1 => CTR => G8: 4,8 * DIS # I4: 4,8 => CTR => I4: 9 * PRF # I4: 9 => SOL * CNT 16 HDP CHAINS / 26 HYP OPENED
See Appendix: Full HDP Chains for full list of HDP chains.
Pair Reduction
The following important HDP chains were detected:
* PRF # D6: 6,8 => SOL * STA D6: 6,8 * CNT 1 HDP CHAINS / 1 HYP OPENED
See Appendix: Full HDP Chains for full list of HDP chains.
Details
Positions
| 5.....9.6...27.3.5.9......1.7.5.3.....6...5..2.......37.13.5..2.6.......83.4....7 | initial |
| 527134986618279345493.5...117.5.3...386...5..25......37413.5.92965....3.83249..57 | autosolve |
| 527134986618279345493658271174563829386927514259841763741385692965712438832496157 | solved |
Classification
level: medium
Pairing Analysis
-------------------------------------------------- * PAIRS (15) D3: 6,8 F3: 6,8 G3: 2,7 H3: 2,7 C4: 4,9 C6: 4,9 D5: 7,9 H4: 2,6 I5: 4,9 E7: 6,8 D8: 7,8 F9: 1,6 G7: 6,8 I8: 4,8 G9: 1,6 -------------------------------------------------- * CONSTRAINT PAIRS (AUTO SOLVE) H5,H6: 1.. / H5 = 1 => 19 pairs (_) / H6 = 1 => 15 pairs (_) G8,G9: 1.. / G8 = 1 => 0 pairs (X) / G9 = 1 => 0 pairs (_) F9,G9: 1.. / F9 = 1 => 0 pairs (X) / G9 = 1 => 0 pairs (_) G3,H3: 2.. / G3 = 2 => 19 pairs (_) / H3 = 2 => 16 pairs (_) E8,F8: 2.. / E8 = 2 => 17 pairs (_) / F8 = 2 => 0 pairs (*) F5,F8: 2.. / F5 = 2 => 17 pairs (_) / F8 = 2 => 0 pairs (*) G3,G4: 2.. / G3 = 2 => 19 pairs (_) / G4 = 2 => 16 pairs (_) C4,C6: 4.. / C4 = 4 => 0 pairs (*) / C6 = 4 => 0 pairs (X) G8,I8: 4.. / G8 = 4 => 0 pairs (*) / I8 = 4 => 0 pairs (X) E5,I5: 4.. / E5 = 4 => 0 pairs (X) / I5 = 4 => 0 pairs (_) D3,F3: 6.. / D3 = 6 => 13 pairs (_) / F3 = 6 => 0 pairs (X) H4,H6: 6.. / H4 = 6 => 15 pairs (_) / H6 = 6 => 0 pairs (*) E7,F9: 6.. / E7 = 6 => 0 pairs (X) / F9 = 6 => 0 pairs (_) G7,G9: 6.. / G7 = 6 => 0 pairs (*) / G9 = 6 => 0 pairs (X) E4,H4: 6.. / E4 = 6 => 0 pairs (*) / H4 = 6 => 0 pairs (X) E7,G7: 6.. / E7 = 6 => 0 pairs (X) / G7 = 6 => 0 pairs (_) F9,G9: 6.. / F9 = 6 => 0 pairs (*) / G9 = 6 => 0 pairs (X) D3,D6: 6.. / D3 = 6 => 13 pairs (_) / D6 = 6 => 0 pairs (X) G3,H3: 7.. / G3 = 7 => 16 pairs (_) / H3 = 7 => 19 pairs (_) D8,F8: 7.. / D8 = 7 => 0 pairs (*) / F8 = 7 => 0 pairs (X) G3,G6: 7.. / G3 = 7 => 16 pairs (_) / G6 = 7 => 19 pairs (_) D3,F3: 8.. / D3 = 8 => 0 pairs (X) / F3 = 8 => 13 pairs (_) E7,G7: 8.. / E7 = 8 => 0 pairs (*) / G7 = 8 => 0 pairs (X) I4,I8: 8.. / I4 = 8 => 0 pairs (X) / I8 = 8 => 0 pairs (_) C4,C6: 9.. / C4 = 9 => 0 pairs (X) / C6 = 9 => 0 pairs (_) D5,D6: 9.. / D5 = 9 => 0 pairs (*) / D6 = 9 => 0 pairs (X) I4,I5: 9.. / I4 = 9 => 0 pairs (*) / I5 = 9 => 0 pairs (X) C4,I4: 9.. / C4 = 9 => 0 pairs (X) / I4 = 9 => 0 pairs (_) D5,I5: 9.. / D5 = 9 => 0 pairs (*) / I5 = 9 => 0 pairs (X) C6,D6: 9.. / C6 = 9 => 0 pairs (*) / D6 = 9 => 0 pairs (X) * DURATION: 0:00:36.096453 START: 03:42:11.265638 END: 03:42:47.362091 2019-05-01 * CP COUNT: (30) * SOLUTION FOUND -------------------------------------------------- * PREPARE PR GRAPH * PAIR REDUCTION .. * LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (C4,C6,D3,D5,D8,E7,F3,F9,G3,G7,G9,H3,H4,I5,I8) * 527134986618279345493.5...117.5.3...386...5..25......37413.5.92965....3.83249..57 * PAIR D3: 6,8 COL D D6: 6,8,7,9 # reduction candidate for 6,8 D6: 6,8 => SOLVED * 527134986618279345493658271174563829386927514259841763741385692965712438832496157 D6: 7,9 => CTR * 527134986618279345493658..117.5.3..8386.4251925.981.63741365.929658.7.3483249..57 * PAIR F3: 6,8 COL F F6: 6,8,1,7 # reduction candidate for 6,8 F6: 6,8 => CTR * 527134986618279345493.5...117.5.3.68386.4.51925.91...3741365892965....34832491657 F6: 1,7 # 16 pairs * PAIR H3: 2,7 COL H H5: 2,7,1 # reduction candidate for 2,7 H5: 1 # 19 pairs H5: 2,7 # 15 pairs * PAIR C4: 4,9 ROW 4 I4: 4,9,8 # reduction candidate for 4,9 I4: 4,9 => SOLVED * 527134986618279345493658271174563829386927514259841763741385692965712438832496157 I4: 8 => CTR * 5271349866182793454936582711795.34.838674.5.925498.7.374136589296581..3483249..57 * PAIR D5: 7,9 BLK 5 D6: 7,9,6,8 # reduction candidate for 7,9 D6: 7,9 => CTR * 527134986618279345493658..117.5.3..8386.4251925.981.63741365.929658.7.3483249..57 D6: 6,8 => SOLVED * 527134986618279345493658271174563829386927514259841763741385692965712438832496157 * PAIR H4: 2,6 ROW 4 E4: 2,6,4,8 # reduction candidate for 2,6 E4: 2,6 # 19 pairs E4: 4,8 # 16 pairs * PAIR I5: 4,9 BLK 6 I4: 4,9,8 # reduction candidate for 4,9 I4: 4,9 => SOLVED * 527134986618279345493658271174563829386927514259841763741385692965712438832496157 I4: 8 => CTR * 5271349866182793454936582711795.34.838674.5.925498.7.374136589296581..3483249..57 * PAIR E7: 6,8 COL E E4: 6,8,2,4 # reduction candidate for 6,8 E4: 6,8 # 19 pairs E6: 6,8,1,4 # reduction candidate for 6,8 E6: 6,8 # 19 pairs * PAIR D8: 7,8 BLK 8 F8: 7,8,1,2 # reduction candidate for 7,8 F8: 7,8 => CTR * 527134986618279345493.5...117.5.3..8386.4251925.918.637413.5.92965.2.134832491657 F8: 1,2 => SOLVED * 527134986618279345493658271174563829386927514259841763741385692965712438832496157 * PAIR D8: 7,8 COL D D6: 7,8,6,9 # reduction candidate for 7,8 D6: 7,8 => SOLVED * 527134986618279345493658271174563829386927514259841763741385692965712438832496157 D6: 6,9 # 16 pairs * PAIR F9: 1,6 COL F F6: 1,6,7,8 # reduction candidate for 1,6 F6: 7,8 # 16 pairs F6: 1,6 # 16 pairs * PAIR I8: 4,8 BLK 9 G8: 4,8,1 # reduction candidate for 4,8 G8: 4,8 => SOLVED * 527134986618279345493658271174563829386927514259841763741385692965712438832496157 G8: 1 => CTR * 527134986618279345493.5...117.5.3..8386.4.51925.918.63741365892965.82134832491657 * PAIR I8: 4,8 COL I I4: 4,8,9 # reduction candidate for 4,8 I4: 4,8 => CTR * 527134986618279345493658..11795.34.8386742519254981763741365.929658.7.3483249..57 I4: 9 => SOLVED * 527134986618279345493658271174563829386927514259841763741385692965712438832496157 * INCONCLUSIVE * SAVE PR GRAPH zz-www.sudokuoftheday.co.uk-20190213-absurd-base-pr-000.dot * REASONING * PRF # D6: 6,8 => SOL * DIS # D6: 7,9 => CTR => D6: 6,8 * DIS # F6: 6,8 => CTR => F6: 1,7 * PRF # I4: 4,9 => SOL * DIS # I4: 8 => CTR => I4: 4,9 * DIS # D6: 7,9 => CTR => D6: 6,8 * PRF # D6: 6,8 => SOL * PRF # I4: 4,9 => SOL * DIS # I4: 8 => CTR => I4: 4,9 * DIS # F8: 7,8 => CTR => F8: 1,2 * PRF # F8: 1,2 => SOL * PRF # D6: 7,8 => SOL * PRF # G8: 4,8 => SOL * DIS # G8: 1 => CTR => G8: 4,8 * DIS # I4: 4,8 => CTR => I4: 9 * PRF # I4: 9 => SOL * CNT 16 HDP CHAINS / 26 HYP OPENED -------------------------------------------------- * PREPARE PR GRAPH * PAIR REDUCTION .. * LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (C4,C6,D3,D5,D8,E7,F3,F9,G3,G7,G9,H3,H4,I5,I8) * 527134986618279345493.5...117.5.3...386...5..25......37413.5.92965....3.83249..57 * PAIR D3: 6,8 COL D D6: 6,8,7,9 # reduction candidate for 6,8 D6: 6,8 => SOLVED * 527134986618279345493658271174563829386927514259841763741385692965712438832496157 * DURATION: 0:00:01.496833 START: 03:43:07.527159 END: 03:43:09.023992 2019-05-01 * SOLUTION FOUND * SAVE PR GRAPH zz-www.sudokuoftheday.co.uk-20190213-absurd-base-pr-001.dot * REASONING * PRF # D6: 6,8 => SOL * STA D6: 6,8 * CNT 1 HDP CHAINS / 1 HYP OPENED
Header Info
http://www.sudokuoftheday.co.uk/cgi-bin/sudoku1280.cgi?ACTION=archive2&USER=&MONTH=Feb&YEAR=2019, 20190213, absurd
Solution
position: 527134986618279345493658271174563829386927514259841763741385692965712438832496157 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:
* PRF # D6: 6,8 => SOL * DIS # D6: 7,9 => CTR => D6: 6,8 * DIS # F6: 6,8 => CTR => F6: 1,7 * INC # F6: 1,7 => UNS * INC # H5: 2,7 => UNS * INC # H5: 1 => UNS * PRF # I4: 4,9 => SOL * DIS # I4: 8 => CTR => I4: 4,9 * DIS # D6: 7,9 => CTR => D6: 6,8 * PRF # D6: 6,8 => SOL * INC # E4: 2,6 => UNS * INC # E4: 4,8 => UNS * PRF # I4: 4,9 => SOL * DIS # I4: 8 => CTR => I4: 4,9 * INC # E4: 6,8 => UNS * INC # E6: 6,8 => UNS * DIS # F8: 7,8 => CTR => F8: 1,2 * PRF # F8: 1,2 => SOL * PRF # D6: 7,8 => SOL * INC # D6: 6,9 => UNS * INC # F6: 1,6 => UNS * INC # F6: 7,8 => UNS * PRF # G8: 4,8 => SOL * DIS # G8: 1 => CTR => G8: 4,8 * DIS # I4: 4,8 => CTR => I4: 9 * PRF # I4: 9 => SOL * CNT 26 HDP CHAINS / 26 HYP OPENED
A2. Pair Reduction
Full list of HDP chains traversed:
* PRF # D6: 6,8 => SOL * STA D6: 6,8 * CNT 1 HDP CHAINS / 1 HYP OPENED