Analysis of zz-www.sudokuoftheday.co.uk-20060513-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: 1........2....961.6...1...3..5.4.....1..758....9.2..4.57....2...4...67..9...8715. initial
Autosolve
position: 1...6....2...3961.6...1...3..5.4....41..758....9.2..4.57..9.2...4..567..9...8715. autosolve
Pair Reduction Variants
Pair Reduction Analysis
The following important HDP chains were detected:
* DIS # B1: 5,8 => CTR => B1: 3,9 * DIS # B3: 5,8 => CTR => B3: 9 * DIS # D4: 1,6,8 => CTR => D4: 3,9 * DIS # C7: 3,8 => CTR => C7: 1,6 * PRF # C7: 1,6 => SOL * DIS # H8: 9 => CTR => H8: 3,8 * DIS # H8: 8,9 => CTR => H8: 3 * PRF # H8: 3 => SOL * DIS # I7: 8 => CTR => I7: 4,6 * CNT 9 HDP CHAINS / 20 HYP OPENED
See Appendix: Full HDP Chains for full list of HDP chains.
Pair Reduction
The following important HDP chains were detected:
* DIS # B1: 5,8 => CTR => B1: 3,9 * DIS B1: 3,9 # B3: 5,8 => CTR => B3: 9 * PRF B1: 3,9 + B3: 9 => SOL * STA B1: 3,9 + B3: 9 * CNT 3 HDP CHAINS / 2 HYP OPENED
See Appendix: Full HDP Chains for full list of HDP chains.
Details
Positions
| 1........2....961.6...1...3..5.4.....1..758....9.2..4.57....2...4...67..9...8715. | initial |
| 1...6....2...3961.6...1...3..5.4....41..758....9.2..4.57..9.2...4..567..9...8715. | autosolve |
| 137864925254739618698512473725948361416375892389621547571493286842156739963287154 | solved |
Classification
level: medium
Pairing Analysis
-------------------------------------------------- * PAIRS (8) B2: 5,8 G4: 3,9 G6: 3,5 A8: 3,8 C8: 1,2 D8: 1,2 I8: 8,9 I9: 4,6 -------------------------------------------------- * CONSTRAINT PAIRS (AUTO SOLVE) I4,I6: 1.. / I4 = 1 => 9 pairs (_) / I6 = 1 => 0 pairs (X) C7,C8: 1.. / C7 = 1 => 0 pairs (*) / C8 = 1 => 0 pairs (X) C8,D8: 1.. / C8 = 1 => 7 pairs (_) / D8 = 1 => 0 pairs (*) F1,F3: 2.. / F1 = 2 => 10 pairs (_) / F3 = 2 => 9 pairs (_) B4,C5: 2.. / B4 = 2 => 10 pairs (_) / C5 = 2 => 0 pairs (X) D8,D9: 2.. / D8 = 2 => 7 pairs (_) / D9 = 2 => 0 pairs (*) F3,H3: 2.. / F3 = 2 => 9 pairs (_) / H3 = 2 => 10 pairs (_) C8,D8: 2.. / C8 = 2 => 0 pairs (*) / D8 = 2 => 0 pairs (X) B4,B9: 2.. / B4 = 2 => 10 pairs (_) / B9 = 2 => 0 pairs (X) B1,C1: 3.. / B1 = 3 => 0 pairs (*) / C1 = 3 => 0 pairs (X) G4,G6: 3.. / G4 = 3 => 10 pairs (_) / G6 = 3 => 0 pairs (X) H7,H8: 3.. / H7 = 3 => 0 pairs (X) / H8 = 3 => 0 pairs (_) C5,D5: 3.. / C5 = 3 => 0 pairs (X) / D5 = 3 => 0 pairs (_) A8,H8: 3.. / A8 = 3 => 0 pairs (X) / H8 = 3 => 0 pairs (_) G1,G3: 4.. / G1 = 4 => 10 pairs (_) / G3 = 4 => 11 pairs (_) I7,I9: 4.. / I7 = 4 => 0 pairs (X) / I9 = 4 => 9 pairs (_) C2,D2: 4.. / C2 = 4 => 9 pairs (_) / D2 = 4 => 0 pairs (X) D9,I9: 4.. / D9 = 4 => 0 pairs (X) / I9 = 4 => 9 pairs (_) G6,I6: 5.. / G6 = 5 => 10 pairs (_) / I6 = 5 => 0 pairs (X) A4,A6: 7.. / A4 = 7 => 19 pairs (_) / A6 = 7 => 9 pairs (_) A6,I6: 7.. / A6 = 7 => 9 pairs (_) / I6 = 7 => 19 pairs (_) C7,A8: 8.. / C7 = 8 => 0 pairs (X) / A8 = 8 => 0 pairs (_) B1,B3: 9.. / B1 = 9 => 0 pairs (X) / B3 = 9 => 9 pairs (_) D4,D5: 9.. / D4 = 9 => 11 pairs (_) / D5 = 9 => 0 pairs (X) H8,I8: 9.. / H8 = 9 => 0 pairs (X) / I8 = 9 => 9 pairs (_) * DURATION: 0:00:28.069234 START: 23:07:20.636491 END: 23:07:48.705725 2019-04-30 * CP COUNT: (25) * SOLUTION FOUND -------------------------------------------------- * PREPARE PR GRAPH * PAIR REDUCTION .. * LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A8,B2,C8,D8,G4,G6,I8,I9) * 1...6....2...3961.6...1...3..5.4....41..758....9.2..4.57..9.2...4..567..9...8715. * PAIR B2: 5,8 BLK 1 B1: 5,8,3,9 # reduction candidate for 5,8 B1: 5,8 => CTR * 1.3.6....2...3961.69..1...3.2594.3..41637589238962154757..932..84..56739932487156 B1: 3,9 # 9 pairs B3: 5,8,9 # reduction candidate for 5,8 B3: 5,8 => CTR * 193.6....2...3961.6...1...3.2594.3..41637589238962154757..932..84..56739932487156 B3: 9 # 9 pairs * PAIR B2: 5,8 ROW 2 D2: 5,8,4,7 # reduction candidate for 5,8 D2: 5,8 # 11 pairs I2: 5,8,7 # reduction candidate for 5,8 I2: 5,8 # 11 pairs * PAIR G4: 3,9 ROW 4 D4: 3,9,1,6,8 # reduction candidate for 3,9 D4: 1,6,8 => CTR * 13..6....2...3961.69..1...3.25.4....4139758...69.2..4.57..9.2..34..567..9..387154 D4: 3,9 # 11 pairs * PAIR A8: 3,8 BLK 7 C7: 3,8,1,6 # reduction candidate for 3,8 C7: 3,8 => CTR * 1...6....2...3961.6...1...3..5.4....413.758....9.2..4.578.9.2...412567..9..387154 C7: 1,6 => SOLVED * 137864925254739618698512473725948361416375892389621547571493286842156739963287154 * PAIR A8: 3,8 ROW 8 H8: 3,8,9 # reduction candidate for 3,8 H8: 9 => CTR * 1...6....2...3961.6...1...3..5.4....413.758....9.2..4.578.9.2363412567989..387154 H8: 3,8 # 9 pairs * PAIR A8: 3,8 COL A A4: 3,8,7 # reduction candidate for 3,8 A4: 3,8 # 9 pairs A6: 3,8,7 # reduction candidate for 3,8 A6: 3,8 # 19 pairs * PAIR I8: 8,9 BLK 9 H8: 8,9,3 # reduction candidate for 8,9 H8: 8,9 => CTR * 1...6....2...3961.6...1...3..5.4....413.758....9.2..4.578.9.2363412567..9..387154 H8: 3 => SOLVED * 137864925254739618698512473725948361416375892389621547571493286842156739963287154 * PAIR I8: 8,9 COL I I1: 8,9,2,5,7 # reduction candidate for 8,9 I1: 8,9 # 16 pairs I1: 2,5,7 # 8 pairs * PAIR I9: 4,6 BLK 9 I7: 4,6,8 # reduction candidate for 4,6 I7: 8 => CTR * 1...6....25..3961769..1...3..5.4..7.41.37589.7.9.2.34.57..9.26884..567399...87154 I7: 4,6 # 11 pairs * INCONCLUSIVE * SAVE PR GRAPH zz-www.sudokuoftheday.co.uk-20060513-absurd-base-pr-000.dot * REASONING * DIS # B1: 5,8 => CTR => B1: 3,9 * DIS # B3: 5,8 => CTR => B3: 9 * DIS # D4: 1,6,8 => CTR => D4: 3,9 * DIS # C7: 3,8 => CTR => C7: 1,6 * PRF # C7: 1,6 => SOL * DIS # H8: 9 => CTR => H8: 3,8 * DIS # H8: 8,9 => CTR => H8: 3 * PRF # H8: 3 => SOL * DIS # I7: 8 => CTR => I7: 4,6 * CNT 9 HDP CHAINS / 20 HYP OPENED -------------------------------------------------- * PREPARE PR GRAPH * PAIR REDUCTION .. * LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A8,B2,C8,D8,G4,G6,I8,I9) * 1...6....2...3961.6...1...3..5.4....41..758....9.2..4.57..9.2...4..567..9...8715. * PAIR B2: 5,8 BLK 1 B1: 5,8,3,9 # reduction candidate for 5,8 B1: 5,8 => CTR * 1.3.6....2...3961.69..1...3.2594.3..41637589238962154757..932..84..56739932487156 B3: 5,8,9 # reduction candidate for 5,8 B3: 5,8 => CTR * 193.6....2...3961.6...1...3.2594.3..41637589238962154757..932..84..56739932487156 B3: 9 => SOLVED * 137864925254739618698512473725948361416375892389621547571493286842156739963287154 * DURATION: 0:00:02.383038 START: 23:08:01.826111 END: 23:08:04.209149 2019-04-30 * SOLUTION FOUND * SAVE PR GRAPH zz-www.sudokuoftheday.co.uk-20060513-absurd-base-pr-001.dot * REASONING * DIS # B1: 5,8 => CTR => B1: 3,9 * DIS B1: 3,9 # B3: 5,8 => CTR => B3: 9 * PRF B1: 3,9 + B3: 9 => SOL * STA B1: 3,9 + B3: 9 * CNT 3 HDP CHAINS / 2 HYP OPENED
Header Info
http://www.sudokuoftheday.co.uk/cgi-bin/sudoku1280.cgi?ACTION=archive2&USER=&MONTH=May&YEAR=2006, 20060513, absurd
Solution
position: 137864925254739618698512473725948361416375892389621547571493286842156739963287154 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 # B1: 5,8 => CTR => B1: 3,9 * INC # B1: 3,9 => UNS * DIS # B3: 5,8 => CTR => B3: 9 * INC # B3: 9 => UNS * INC # D2: 5,8 => UNS * INC # I2: 5,8 => UNS * INC # D4: 3,9 => UNS * DIS # D4: 1,6,8 => CTR => D4: 3,9 * DIS # C7: 3,8 => CTR => C7: 1,6 * PRF # C7: 1,6 => SOL * INC # H8: 3,8 => UNS * DIS # H8: 9 => CTR => H8: 3,8 * INC # A4: 3,8 => UNS * INC # A6: 3,8 => UNS * DIS # H8: 8,9 => CTR => H8: 3 * PRF # H8: 3 => SOL * INC # I1: 8,9 => UNS * INC # I1: 2,5,7 => UNS * INC # I7: 4,6 => UNS * DIS # I7: 8 => CTR => I7: 4,6 * CNT 20 HDP CHAINS / 20 HYP OPENED
A2. Pair Reduction
Full list of HDP chains traversed:
* DIS # B1: 5,8 => CTR => B1: 3,9 * DIS B1: 3,9 # B3: 5,8 => CTR => B3: 9 * PRF B1: 3,9 + B3: 9 => SOL * STA B1: 3,9 + B3: 9 * CNT 3 HDP CHAINS / 2 HYP OPENED