Analysis of zz-www.sudokuoftheday.co.uk-20060531-absurd-base.sdk
Contents
Sudoku from http://www.sudokuoftheday.co.uk/cgi-bin/sudoku1280.cgi?ACTION=archive2&USER=&MONTH=May&YEAR=2006
level: medium
position: .9..3..68..89..5.3........74...79.82.374.....9..31...46..........31.....5.....891 initial
Autosolve
position: .9..3..68..89..5.33.....9.74.1.79382.374....99..31...4619....35..3195..65....3891 autosolve
Pair Reduction Variants
Pair Reduction Analysis
The following important HDP chains were detected:
* DIS # E5: 2,8 => CTR => E5: 5,6 * DIS # A8: 7 => CTR => A8: 2,8 * DIS # E5: 2,8 => CTR => E5: 5,6 * DIS # B9: 2,4 => CTR => B9: 7 * PRF # E9: 2,4 => SOL * DIS # C1: 2,4 => CTR => C1: 5 * DIS # C3: 2,4 => CTR => C3: 5,6 * CNT 7 HDP CHAINS / 24 HYP OPENED
See Appendix: Full HDP Chains for full list of HDP chains.
Pair Reduction
The following important HDP chains were detected:
* DIS # E5: 2,8 => CTR => E5: 5,6 * DIS E5: 5,6 # A8: 7 => CTR => A8: 2,8 * PRF E5: 5,6 + A8: 2,8 # B6: 5,6 => SOL * STA E5: 5,6 + A8: 2,8 + B6: 5,6 * CNT 3 HDP CHAINS / 11 HYP OPENED
See Appendix: Full HDP Chains for full list of HDP chains.
Details
Positions
| .9..3..68..89..5.3........74...79.82.374.....9..31...46..........31.....5.....891 | initial |
| .9..3..68..89..5.33.....9.74.1.79382.374....99..31...4619....35..3195..65....3891 | autosolve |
| 195237468728946513346851927461579382837462159952318674619784235283195746574623891 | solved |
Classification
level: medium
Pairing Analysis
-------------------------------------------------- * PAIRS (8) B4: 5,6 A5: 2,8 D4: 5,6 G5: 1,6 H5: 1,5 G6: 6,7 H6: 5,7 C9: 2,4 -------------------------------------------------- * CONSTRAINT PAIRS (AUTO SOLVE) A1,A2: 1.. / A1 = 1 => 0 pairs (*) / A2 = 1 => 0 pairs (X) G5,H5: 1.. / G5 = 1 => 0 pairs (*) / H5 = 1 => 0 pairs (X) F3,H3: 1.. / F3 = 1 => 9 pairs (_) / H3 = 1 => 0 pairs (X) G1,G5: 1.. / G1 = 1 => 0 pairs (X) / G5 = 1 => 0 pairs (_) D4,E5: 5.. / D4 = 5 => 0 pairs (*) / E5 = 5 => 0 pairs (X) H5,H6: 5.. / H5 = 5 => 0 pairs (*) / H6 = 5 => 0 pairs (X) C1,D1: 5.. / C1 = 5 => 10 pairs (_) / D1 = 5 => 0 pairs (X) B4,D4: 5.. / B4 = 5 => 0 pairs (X) / D4 = 5 => 0 pairs (_) E5,H5: 5.. / E5 = 5 => 0 pairs (X) / H5 = 5 => 0 pairs (_) E3,E5: 5.. / E3 = 5 => 0 pairs (*) / E5 = 5 => 0 pairs (X) G5,G6: 6.. / G5 = 6 => 0 pairs (X) / G6 = 6 => 0 pairs (_) D9,E9: 6.. / D9 = 6 => 0 pairs (*) / E9 = 6 => 0 pairs (X) B4,D4: 6.. / B4 = 6 => 0 pairs (*) / D4 = 6 => 0 pairs (X) C3,C6: 6.. / C3 = 6 => 9 pairs (_) / C6 = 6 => 0 pairs (X) G6,H6: 7.. / G6 = 7 => 0 pairs (X) / H6 = 7 => 0 pairs (_) B9,D9: 7.. / B9 = 7 => 13 pairs (_) / D9 = 7 => 0 pairs (X) H6,H8: 7.. / H6 = 7 => 0 pairs (*) / H8 = 7 => 0 pairs (X) A5,B6: 8.. / A5 = 8 => 11 pairs (_) / B6 = 8 => 11 pairs (_) A8,B8: 8.. / A8 = 8 => 11 pairs (_) / B8 = 8 => 11 pairs (_) B6,F6: 8.. / B6 = 8 => 11 pairs (_) / F6 = 8 => 11 pairs (_) A5,A8: 8.. / A5 = 8 => 11 pairs (_) / A8 = 8 => 11 pairs (_) B6,B8: 8.. / B6 = 8 => 11 pairs (_) / B8 = 8 => 11 pairs (_) D3,D7: 8.. / D3 = 8 => 9 pairs (_) / D7 = 8 => 12 pairs (_) * DURATION: 0:00:24.036562 START: 23:31:48.756535 END: 23:32:12.793097 2019-04-30 * CP COUNT: (23) * SOLUTION FOUND -------------------------------------------------- * PREPARE PR GRAPH * PAIR REDUCTION .. * LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A5,B4,C9,D4,G5,G6,H5,H6) * .9..3..68..89..5.33.....9.74.1.79382.374....99..31...4619....35..3195..65....3891 * PAIR B4: 5,6 BLK 4 B6: 5,6,2,8 # reduction candidate for 5,6 B6: 5,6 # 16 pairs C6: 5,6,2 # reduction candidate for 5,6 C6: 5,6 # 11 pairs * PAIR B4: 5,6 COL B B3: 5,6,2,4 # reduction candidate for 5,6 B3: 5,6 # 12 pairs B3: 2,4 # 10 pairs * PAIR A5: 2,8 BLK 4 B6: 2,8,5,6 # reduction candidate for 2,8 B6: 5,6 # 16 pairs B6: 2,8 # 11 pairs * PAIR A5: 2,8 ROW 5 E5: 2,8,5,6 # reduction candidate for 2,8 E5: 2,8 => CTR * .95.3..68..89..5.33..85.9.7461579382837426159952318674619.8..35.83195..65.46.3891 E5: 5,6 # 13 pairs F5: 2,8,6 # reduction candidate for 2,8 F5: 2,8 # 13 pairs * PAIR A5: 2,8 COL A A8: 2,8,7 # reduction candidate for 2,8 A8: 7 => CTR * .9..37.68.789.65.33....19.74.16793828374526.99..318..4619....35783195..65..763891 A8: 2,8 # 11 pairs * PAIR D4: 5,6 BLK 5 E5: 5,6,2,8 # reduction candidate for 5,6 E5: 2,8 => CTR * .95.3..68..89..5.33..85.9.7461579382837426159952318674619.8..35.83195..65.46.3891 E5: 5,6 # 13 pairs * PAIR D4: 5,6 COL D D3: 5,6,2,8 # reduction candidate for 5,6 D3: 5,6 # 18 pairs D3: 2,8 # 9 pairs * PAIR C9: 2,4 BLK 7 B8: 2,4,7,8 # reduction candidate for 2,4 B8: 2,4 # 14 pairs B9: 2,4,7 # reduction candidate for 2,4 B9: 2,4 => CTR * .9..3..68..89..5.33.6...9.7461579382.374.61599..31.674619...735..3195..65..763891 B9: 7 # 13 pairs * PAIR C9: 2,4 ROW 9 E9: 2,4,6 # reduction candidate for 2,4 E9: 2,4 => SOLVED * 195237468728946513346851927461579382837462159952318674619784235283195746574623891 E9: 6 # 11 pairs * PAIR C9: 2,4 COL C C1: 2,4,5 # reduction candidate for 2,4 C1: 2,4 => CTR * .9.53.1681.89.75.33.5...9.7451679382.3745.6199..31.754619....35..3195.7657.263891 C1: 5 # 10 pairs C3: 2,4,5,6 # reduction candidate for 2,4 C3: 2,4 => CTR * .9573.168..89..5.33.....9.7451679382.3745.6199.631.754619....35..3195.7657.263891 C3: 5,6 # 9 pairs * INCONCLUSIVE * SAVE PR GRAPH zz-www.sudokuoftheday.co.uk-20060531-absurd-base-pr-000.dot * REASONING * DIS # E5: 2,8 => CTR => E5: 5,6 * DIS # A8: 7 => CTR => A8: 2,8 * DIS # E5: 2,8 => CTR => E5: 5,6 * DIS # B9: 2,4 => CTR => B9: 7 * PRF # E9: 2,4 => SOL * DIS # C1: 2,4 => CTR => C1: 5 * DIS # C3: 2,4 => CTR => C3: 5,6 * CNT 7 HDP CHAINS / 24 HYP OPENED -------------------------------------------------- * PREPARE PR GRAPH * PAIR REDUCTION .. * LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A5,B4,C9,D4,G5,G6,H5,H6) * .9..3..68..89..5.33.....9.74.1.79382.374....99..31...4619....35..3195..65....3891 * PAIR B4: 5,6 BLK 4 B6: 5,6,2,8 # reduction candidate for 5,6 B6: 5,6 # 16 pairs C6: 5,6,2 # reduction candidate for 5,6 C6: 5,6 # 11 pairs * PAIR B4: 5,6 COL B B3: 5,6,2,4 # reduction candidate for 5,6 B3: 5,6 # 12 pairs B3: 2,4 # 10 pairs * PAIR A5: 2,8 BLK 4 B6: 2,8,5,6 # reduction candidate for 2,8 B6: 5,6 # 16 pairs B6: 2,8 # 11 pairs * PAIR A5: 2,8 ROW 5 E5: 2,8,5,6 # reduction candidate for 2,8 E5: 2,8 => CTR * .95.3..68..89..5.33..85.9.7461579382837426159952318674619.8..35.83195..65.46.3891 * RESTART * PAIR A5: 2,8 COL A A8: 2,8,7 # reduction candidate for 2,8 A8: 7 => CTR * .9..37.68.789.65.33....19.74.16793828374526.99..318..4619....35783195..65..763891 * PAIR RESTART * PAIR A5: 2,8 BLK 4 B6: 2,8,5,6 # reduction candidate for 2,8 B6: 5,6 => SOLVED * 195237468728946513346851927461579382837462159952318674619784235283195746574623891 * DURATION: 0:00:07.483692 START: 23:32:26.423492 END: 23:32:33.907184 2019-04-30 * SOLUTION FOUND * SAVE PR GRAPH zz-www.sudokuoftheday.co.uk-20060531-absurd-base-pr-001.dot * REASONING * DIS # E5: 2,8 => CTR => E5: 5,6 * DIS E5: 5,6 # A8: 7 => CTR => A8: 2,8 * PRF E5: 5,6 + A8: 2,8 # B6: 5,6 => SOL * STA E5: 5,6 + A8: 2,8 + B6: 5,6 * CNT 3 HDP CHAINS / 11 HYP OPENED
Header Info
http://www.sudokuoftheday.co.uk/cgi-bin/sudoku1280.cgi?ACTION=archive2&USER=&MONTH=May&YEAR=2006, 20060531, absurd
Solution
position: 195237468728946513346851927461579382837462159952318674619784235283195746574623891 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 # B6: 5,6 => UNS * INC # C6: 5,6 => UNS * INC # B3: 5,6 => UNS * INC # B3: 2,4 => UNS * INC # B6: 2,8 => UNS * INC # B6: 5,6 => UNS * DIS # E5: 2,8 => CTR => E5: 5,6 * INC # E5: 5,6 => UNS * INC # F5: 2,8 => UNS * INC # A8: 2,8 => UNS * DIS # A8: 7 => CTR => A8: 2,8 * INC # E5: 5,6 => UNS * DIS # E5: 2,8 => CTR => E5: 5,6 * INC # D3: 5,6 => UNS * INC # D3: 2,8 => UNS * INC # B8: 2,4 => UNS * DIS # B9: 2,4 => CTR => B9: 7 * INC # B9: 7 => UNS * PRF # E9: 2,4 => SOL * INC # E9: 6 => UNS * DIS # C1: 2,4 => CTR => C1: 5 * INC # C1: 5 => UNS * DIS # C3: 2,4 => CTR => C3: 5,6 * INC # C3: 5,6 => UNS * CNT 24 HDP CHAINS / 24 HYP OPENED
A2. Pair Reduction
Full list of HDP chains traversed:
* INC # B6: 5,6 => UNS * INC # C6: 5,6 => UNS * INC # B3: 5,6 => UNS * INC # B3: 2,4 => UNS * INC # B6: 2,8 => UNS * INC # B6: 5,6 => UNS * DIS # E5: 2,8 => CTR => E5: 5,6 * INC E5: 5,6 # A8: 2,8 => UNS * DIS E5: 5,6 # A8: 7 => CTR => A8: 2,8 * INC E5: 5,6 + A8: 2,8 # B6: 2,8 => UNS * PRF E5: 5,6 + A8: 2,8 # B6: 5,6 => SOL * STA E5: 5,6 + A8: 2,8 + B6: 5,6 * CNT 11 HDP CHAINS / 11 HYP OPENED