Analysis of zz-www.sudokuoftheday.co.uk-20060626-absurd-base.sdk
Contents
Sudoku from http://www.sudokuoftheday.co.uk/cgi-bin/sudoku1280.cgi?ACTION=archive2&USER=&MONTH=Jun&YEAR=2006
level: medium
position: 4.327.6.......3....7.6...5........9.35....42.6..13...89...1.8.....7.6...1........ initial
Autosolve
position: 4.32756.......3....7.6.1.5.7......9.35...742.6..13.5789...1.8.....7.6...1........ autosolve
Pair Reduction Variants
Pair Reduction Analysis
The following important HDP chains were detected:
* PRF # B2: 2,8 => SOL * DIS # C2: 2,8 => CTR => C2: 1,5,6,9 * DIS # B1: 9 => CTR => B1: 1,8 * DIS # I2: 1,9 => CTR => I2: 2,4,7 * DIS # B1: 8 => CTR => B1: 1,9 * DIS # I8: 1,9 => CTR => I8: 2,4,5 * DIS # E5: 8,9 => CTR => E5: 6 * DIS # C5: 1 => CTR => C5: 8,9 * DIS # D9: 8,9 => CTR => D9: 3,4,5 * DIS # I4: 1,3 => CTR => I4: 6 * DIS # I4: 3 => CTR => I4: 1,6 * DIS # F9: 2,4 => CTR => F9: 8,9 * DIS # C7: 2,4 => CTR => C7: 5,6,7 * DIS # I7: 2,4 => CTR => I7: 5,7 * DIS # F4: 2,4 => CTR => F4: 8 * CNT 15 HDP CHAINS / 42 HYP OPENED
See Appendix: Full HDP Chains for full list of HDP chains.
Pair Reduction
The following important HDP chains were detected:
* PRF # B2: 2,8 => SOL * STA B2: 2,8 * CNT 1 HDP CHAINS / 2 HYP OPENED
See Appendix: Full HDP Chains for full list of HDP chains.
Details
Positions
| 4.327.6.......3....7.6...5........9.35....42.6..13...89...1.8.....7.6...1........ | initial |
| 4.32756.......3....7.6.1.5.7......9.35...742.6..13.5789...1.8.....7.6...1........ | autosolve |
| 413275689526893147879641253741528396358967421692134578967412835235786914184359762 | solved |
Classification
level: medium
Pairing Analysis
-------------------------------------------------- * PAIRS (7) A3: 2,8 H1: 1,8 I1: 1,9 D5: 8,9 G4: 1,3 I5: 1,6 F7: 2,4 -------------------------------------------------- * CONSTRAINT PAIRS (AUTO SOLVE) C5,I5: 1.. / C5 = 1 => 0 pairs (X) / I5 = 1 => 12 pairs (_) G3,I3: 3.. / G3 = 3 => 0 pairs (X) / I3 = 3 => 12 pairs (_) G4,I4: 3.. / G4 = 3 => 12 pairs (_) / I4 = 3 => 0 pairs (X) D7,D9: 3.. / D7 = 3 => 10 pairs (_) / D9 = 3 => 9 pairs (_) B8,H8: 3.. / B8 = 3 => 10 pairs (_) / H8 = 3 => 12 pairs (_) G3,G4: 3.. / G3 = 3 => 0 pairs (X) / G4 = 3 => 12 pairs (_) I3,I4: 3.. / I3 = 3 => 12 pairs (_) / I4 = 3 => 0 pairs (X) E3,I3: 4.. / E3 = 4 => 12 pairs (_) / I3 = 4 => 0 pairs (X) A2,C2: 5.. / A2 = 5 => 8 pairs (_) / C2 = 5 => 12 pairs (_) D4,E4: 5.. / D4 = 5 => 10 pairs (_) / E4 = 5 => 0 pairs (X) A2,A8: 5.. / A2 = 5 => 8 pairs (_) / A8 = 5 => 12 pairs (_) B2,C2: 6.. / B2 = 6 => 9 pairs (_) / C2 = 6 => 8 pairs (_) E4,E5: 6.. / E4 = 6 => 0 pairs (X) / E5 = 6 => 12 pairs (_) I4,I5: 6.. / I4 = 6 => 12 pairs (_) / I5 = 6 => 0 pairs (X) H7,H9: 6.. / H7 = 6 => 8 pairs (_) / H9 = 6 => 8 pairs (_) E4,I4: 6.. / E4 = 6 => 0 pairs (X) / I4 = 6 => 12 pairs (_) E5,I5: 6.. / E5 = 6 => 12 pairs (_) / I5 = 6 => 0 pairs (X) G2,I2: 7.. / G2 = 7 => 8 pairs (_) / I2 = 7 => 7 pairs (_) C7,C9: 7.. / C7 = 7 => 7 pairs (_) / C9 = 7 => 8 pairs (_) C7,I7: 7.. / C7 = 7 => 7 pairs (_) / I7 = 7 => 8 pairs (_) G2,G9: 7.. / G2 = 7 => 8 pairs (_) / G9 = 7 => 7 pairs (_) H1,H2: 8.. / H1 = 8 => 8 pairs (_) / H2 = 8 => 0 pairs (X) B1,H1: 8.. / B1 = 8 => 0 pairs (X) / H1 = 8 => 8 pairs (_) F4,F9: 8.. / F4 = 8 => 12 pairs (_) / F9 = 8 => 0 pairs (X) B1,I1: 9.. / B1 = 9 => 0 pairs (X) / I1 = 9 => 8 pairs (_) F6,F9: 9.. / F6 = 9 => 0 pairs (X) / F9 = 9 => 12 pairs (_) * DURATION: 0:00:25.825347 START: 00:06:59.246599 END: 00:07:25.071946 2019-05-01 * CP COUNT: (26) * CLUE FOUND -------------------------------------------------- * PREPARE PR GRAPH * PAIR REDUCTION .. * LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A3,D5,F7,G4,H1,I1,I5) * 4.32756.......3....7.6.1.5.7......9.35...742.6..13.5789...1.8.....7.6...1........ * PAIR A3: 2,8 BLK 1 A2: 2,8,5 # reduction candidate for 2,8 A2: 2,8 # 12 pairs B2: 2,8,1,6,9 # reduction candidate for 2,8 B2: 2,8 => SOLVED * 413275689526893147879641253741528396358967421692134578967412835235786914184359762 B2: 1,6,9 # 7 pairs C2: 2,8,1,5,6,9 # reduction candidate for 2,8 C2: 2,8 => CTR * 413275689562.93147879641.5.7214583963589674216941325789.7.1486223.7.691.1....9... C2: 1,5,6,9 # 7 pairs C3: 2,8,9 # reduction candidate for 2,8 C3: 2,8 # 14 pairs * PAIR A3: 2,8 COL A A8: 2,8,5 # reduction candidate for 2,8 A8: 5 # 12 pairs A8: 2,8 # 8 pairs * PAIR H1: 1,8 BLK 3 H2: 1,8,4 # reduction candidate for 1,8 H2: 4 # 14 pairs H2: 1,8 # 11 pairs * PAIR H1: 1,8 ROW 1 B1: 1,8,9 # reduction candidate for 1,8 B1: 9 => CTR * 493275681.16..3.4..7.6413597...681933519.74266.913.5789...1.8.....7.6.1.1....9... B1: 1,8 # 8 pairs * PAIR I1: 1,9 BLK 3 G2: 1,9,2,7 # reduction candidate for 1,9 G2: 1,9 # 12 pairs I2: 1,9,2,4,7 # reduction candidate for 1,9 I2: 1,9 => CTR * 413275689.....37418796413527....819335...742.69.13.5789...1.8.....7.6...1....92.. I2: 2,4,7 # 7 pairs * PAIR I1: 1,9 ROW 1 B1: 1,9,8 # reduction candidate for 1,9 B1: 8 => CTR * 483275619.....3.8.2796813547.....19335189742669.13.5789...1.8..8..7.69.11........ B1: 1,9 # 8 pairs * PAIR I1: 1,9 COL I I8: 1,9,2,4,5 # reduction candidate for 1,9 I8: 1,9 => CTR * 4.32756.......3....7.6.135.7..56.193351..74266..13.5789...1.8.....7.6...1........ I8: 2,4,5 # 7 pairs * PAIR D5: 8,9 BLK 5 E5: 8,9,6 # reduction candidate for 8,9 E5: 8,9 => CTR * 4.32756.......3....7.6.1.5.7..56..9.351..74266..13.5789...1.8.....7.6...1........ E5: 6 # 12 pairs * PAIR D5: 8,9 ROW 5 C5: 8,9,1 # reduction candidate for 8,9 C5: 1 => CTR * 4.32756.......3....7.6.1.5.7..56..9.351..74266..13.5789...1.8.....7.6...1........ C5: 8,9 # 12 pairs * PAIR D5: 8,9 COL D D2: 8,9,4 # reduction candidate for 8,9 D2: 8,9 # 9 pairs D9: 8,9,3,4,5 # reduction candidate for 8,9 D9: 8,9 => CTR * 4.32756.....4.3....7.6.13547..56.193351..74266..13.5789..31.8.....7.6...1........ D9: 3,4,5 # 7 pairs * PAIR G4: 1,3 BLK 6 I4: 1,3,6 # reduction candidate for 1,3 I4: 1,3 => CTR * 4.32756.......3....7.6.1.5.7..56..9.351..74266..13.5789...1.8.....7.6...1........ I4: 6 # 12 pairs * PAIR I5: 1,6 BLK 6 I4: 1,6,3 # reduction candidate for 1,6 I4: 3 => CTR * 4.32756.......3....7.6.135.7..56.193351..74266..13.5789...1.8.....7.6...1........ I4: 1,6 # 12 pairs * PAIR F7: 2,4 BLK 8 E8: 2,4,5,8,9 # reduction candidate for 2,4 E8: 2,4 # 11 pairs E9: 2,4,5,8,9 # reduction candidate for 2,4 E9: 2,4 # 10 pairs F9: 2,4,8,9 # reduction candidate for 2,4 F9: 2,4 => CTR * 4.32756.......3....7.6.1.5.7....8.9.3589674216..13.5789...1.8.....7.6...1........ F9: 8,9 # 8 pairs * PAIR F7: 2,4 ROW 7 B7: 2,4,3,6 # reduction candidate for 2,4 B7: 2,4 # 11 pairs C7: 2,4,5,6,7 # reduction candidate for 2,4 C7: 2,4 => CTR * 4.32756.95.69.37...796412537.1452396358.674216..13.5789..51.8.7..57961..1.73289.5 C7: 5,6,7 # 7 pairs I7: 2,4,5,7 # reduction candidate for 2,4 I7: 2,4 => CTR * 413275689.6.8931478796412537214583963589674216941325789375148.2...7.691.1..3.976. I7: 5,7 # 8 pairs * PAIR F7: 2,4 COL F F4: 2,4,8 # reduction candidate for 2,4 F4: 2,4 => CTR * 4.32756.9.96483.1..7.691.547.1....9.3598674216..1395789...1.8.....7.6...1....8... F4: 8 # 12 pairs F6: 2,4,9 # reduction candidate for 2,4 F6: 2,4 # 12 pairs * INCONCLUSIVE * SAVE PR GRAPH zz-www.sudokuoftheday.co.uk-20060626-absurd-base-pr-000.dot * REASONING * PRF # B2: 2,8 => SOL * DIS # C2: 2,8 => CTR => C2: 1,5,6,9 * DIS # B1: 9 => CTR => B1: 1,8 * DIS # I2: 1,9 => CTR => I2: 2,4,7 * DIS # B1: 8 => CTR => B1: 1,9 * DIS # I8: 1,9 => CTR => I8: 2,4,5 * DIS # E5: 8,9 => CTR => E5: 6 * DIS # C5: 1 => CTR => C5: 8,9 * DIS # D9: 8,9 => CTR => D9: 3,4,5 * DIS # I4: 1,3 => CTR => I4: 6 * DIS # I4: 3 => CTR => I4: 1,6 * DIS # F9: 2,4 => CTR => F9: 8,9 * DIS # C7: 2,4 => CTR => C7: 5,6,7 * DIS # I7: 2,4 => CTR => I7: 5,7 * DIS # F4: 2,4 => CTR => F4: 8 * CNT 15 HDP CHAINS / 42 HYP OPENED -------------------------------------------------- * PREPARE PR GRAPH * PAIR REDUCTION .. * LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A3,D5,F7,G4,H1,I1,I5) * 4.32756.......3....7.6.1.5.7......9.35...742.6..13.5789...1.8.....7.6...1........ * PAIR A3: 2,8 BLK 1 A2: 2,8,5 # reduction candidate for 2,8 A2: 2,8 # 12 pairs B2: 2,8,1,6,9 # reduction candidate for 2,8 B2: 2,8 => SOLVED * 413275689526893147879641253741528396358967421692134578967412835235786914184359762 * DURATION: 0:00:02.621260 START: 00:07:48.572530 END: 00:07:51.193790 2019-05-01 * SOLUTION FOUND * SAVE PR GRAPH zz-www.sudokuoftheday.co.uk-20060626-absurd-base-pr-001.dot * REASONING * PRF # B2: 2,8 => SOL * STA B2: 2,8 * CNT 1 HDP CHAINS / 2 HYP OPENED
Header Info
http://www.sudokuoftheday.co.uk/cgi-bin/sudoku1280.cgi?ACTION=archive2&USER=&MONTH=Jun&YEAR=2006, 20060626, absurd
Solution
position: 413275689526893147879641253741528396358967421692134578967412835235786914184359762 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 # A2: 2,8 => UNS * PRF # B2: 2,8 => SOL * INC # B2: 1,6,9 => UNS * DIS # C2: 2,8 => CTR => C2: 1,5,6,9 * INC # C2: 1,5,6,9 => UNS * INC # C3: 2,8 => UNS * INC # A8: 2,8 => UNS * INC # A8: 5 => UNS * INC # H2: 1,8 => UNS * INC # H2: 4 => UNS * INC # B1: 1,8 => UNS * DIS # B1: 9 => CTR => B1: 1,8 * INC # G2: 1,9 => UNS * DIS # I2: 1,9 => CTR => I2: 2,4,7 * INC # I2: 2,4,7 => UNS * INC # B1: 1,9 => UNS * DIS # B1: 8 => CTR => B1: 1,9 * DIS # I8: 1,9 => CTR => I8: 2,4,5 * INC # I8: 2,4,5 => UNS * DIS # E5: 8,9 => CTR => E5: 6 * INC # E5: 6 => UNS * INC # C5: 8,9 => UNS * DIS # C5: 1 => CTR => C5: 8,9 * INC # D2: 8,9 => UNS * DIS # D9: 8,9 => CTR => D9: 3,4,5 * INC # D9: 3,4,5 => UNS * DIS # I4: 1,3 => CTR => I4: 6 * INC # I4: 6 => UNS * INC # I4: 1,6 => UNS * DIS # I4: 3 => CTR => I4: 1,6 * INC # E8: 2,4 => UNS * INC # E9: 2,4 => UNS * DIS # F9: 2,4 => CTR => F9: 8,9 * INC # F9: 8,9 => UNS * INC # B7: 2,4 => UNS * DIS # C7: 2,4 => CTR => C7: 5,6,7 * INC # C7: 5,6,7 => UNS * DIS # I7: 2,4 => CTR => I7: 5,7 * INC # I7: 5,7 => UNS * DIS # F4: 2,4 => CTR => F4: 8 * INC # F4: 8 => UNS * INC # F6: 2,4 => UNS * CNT 42 HDP CHAINS / 42 HYP OPENED
A2. Pair Reduction
Full list of HDP chains traversed:
* INC # A2: 2,8 => UNS * PRF # B2: 2,8 => SOL * STA B2: 2,8 * CNT 2 HDP CHAINS / 2 HYP OPENED