Analysis of zz-www.sudokuoftheday.co.uk-20190408-absurd-base.sdk
Contents
Sudoku from http://www.sudokuoftheday.co.uk/cgi-bin/sudoku1280.cgi?ACTION=archive2&USER=&MONTH=Apr&YEAR=2019
level: medium
position: 4.83....6..2....5..37...18...65....23...7.4.....8...7...........4....9.7....16... initial
Autosolve
position: 4.83....6..2....5..37...18...65....23...7.4....48...7...........4.2..9.7....16... autosolve
Pair Reduction Variants
Pair Reduction Analysis
The following important HDP chains were detected:
* PRF # F1: 5,9 => SOL * DIS # E3: 5,9 => CTR => E3: 2,4,6 * DIS # B1: 5,9 => CTR => B1: 1 * DIS # E3: 4,9 => CTR => E3: 2,5,6 * DIS # G7: 3,8 => CTR => G7: 2,5,6 * CNT 5 HDP CHAINS / 18 HYP OPENED
See Appendix: Full HDP Chains for full list of HDP chains.
Pair Reduction
The following important HDP chains were detected:
* PRF # F1: 5,9 => SOL * STA F1: 5,9 * CNT 1 HDP CHAINS / 1 HYP OPENED
See Appendix: Full HDP Chains for full list of HDP chains.
Details
Positions
| 4.83....6..2....5..37...18...65....23...7.4.....8...7...........4....9.7....16... | initial |
| 4.83....6..2....5..37...18...65....23...7.4....48...7...........4.2..9.7....16... | autosolve |
| 418395726962187354537624189176543892385972461294861573821739645643258917759416238 | solved |
Classification
level: medium
Pairing Analysis
-------------------------------------------------- * PAIRS (6) E1: 5,9 G1: 2,7 H1: 2,9 G2: 3,7 I3: 4,9 G4: 3,8 -------------------------------------------------- * CONSTRAINT PAIRS (AUTO SOLVE) B1,F1: 1.. / B1 = 1 => 12 pairs (_) / F1 = 1 => 0 pairs (X) D2,D5: 1.. / D2 = 1 => 13 pairs (_) / D5 = 1 => 12 pairs (_) E3,F3: 2.. / E3 = 2 => 6 pairs (_) / F3 = 2 => 0 pairs (X) G1,H1: 2.. / G1 = 2 => 15 pairs (_) / H1 = 2 => 7 pairs (_) B5,F5: 2.. / B5 = 2 => 0 pairs (X) / F5 = 2 => 6 pairs (_) E3,E6: 2.. / E3 = 2 => 6 pairs (_) / E6 = 2 => 0 pairs (X) G2,I2: 3.. / G2 = 3 => 7 pairs (_) / I2 = 3 => 15 pairs (_) I2,I3: 4.. / I2 = 4 => 8 pairs (_) / I3 = 4 => 12 pairs (_) E4,F4: 4.. / E4 = 4 => 6 pairs (_) / F4 = 4 => 7 pairs (_) H7,H9: 4.. / H7 = 4 => 9 pairs (_) / H9 = 4 => 7 pairs (_) D9,H9: 4.. / D9 = 4 => 9 pairs (_) / H9 = 4 => 7 pairs (_) B1,A3: 5.. / B1 = 5 => 0 pairs (X) / A3 = 5 => 9 pairs (_) D5,E6: 6.. / D5 = 6 => 0 pairs (X) / E6 = 6 => 11 pairs (_) H5,G6: 6.. / H5 = 6 => 11 pairs (_) / G6 = 6 => 0 pairs (X) D5,H5: 6.. / D5 = 6 => 0 pairs (X) / H5 = 6 => 11 pairs (_) E6,G6: 6.. / E6 = 6 => 11 pairs (_) / G6 = 6 => 0 pairs (X) A8,H8: 6.. / A8 = 6 => 11 pairs (_) / H8 = 6 => 0 pairs (X) B2,B7: 6.. / B2 = 6 => 10 pairs (_) / B7 = 6 => 0 pairs (X) G6,G7: 6.. / G6 = 6 => 0 pairs (X) / G7 = 6 => 11 pairs (_) G1,G2: 7.. / G1 = 7 => 7 pairs (_) / G2 = 7 => 15 pairs (_) A4,B4: 7.. / A4 = 7 => 6 pairs (_) / B4 = 7 => 6 pairs (_) F1,G1: 7.. / F1 = 7 => 15 pairs (_) / G1 = 7 => 7 pairs (_) E2,F2: 8.. / E2 = 8 => 9 pairs (_) / F2 = 8 => 9 pairs (_) G4,I5: 8.. / G4 = 8 => 5 pairs (_) / I5 = 8 => 0 pairs (X) B5,I5: 8.. / B5 = 8 => 5 pairs (_) / I5 = 8 => 0 pairs (X) * DURATION: 0:00:19.468136 START: 05:09:01.419304 END: 05:09:20.887440 2019-05-01 * CP COUNT: (25) * CLUE FOUND -------------------------------------------------- * PREPARE PR GRAPH * PAIR REDUCTION .. * LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (E1,G1,G2,G4,H1,I3) * 4.83....6..2....5..37...18...65....23...7.4....48...7...........4.2..9.7....16... * PAIR E1: 5,9 BLK 2 F1: 5,9,1,7 # reduction candidate for 5,9 F1: 5,9 => SOLVED * 418395726962187354537624189176543892385972461294861573821739645643258917759416238 F1: 1,7 # 7 pairs E3: 5,9,2,4,6 # reduction candidate for 5,9 E3: 5,9 => CTR * 4.83....6..2.6835..37..218...65....232..7.4.8..482.675........1.4.2..9.7....16..3 E3: 2,4,6 # 6 pairs F3: 5,9,2,4 # reduction candidate for 5,9 F3: 5,9 # 9 pairs * PAIR E1: 5,9 ROW 1 B1: 5,9,1 # reduction candidate for 5,9 B1: 5,9 => CTR * 4.83.1726.62...35..3762.18...65..89238.17246...486.57.......6..64.2..9.7....162.. B1: 1 # 12 pairs * PAIR E1: 5,9 COL E E7: 5,9,3,4,8 # reduction candidate for 5,9 E7: 5,9 # 9 pairs E7: 3,4,8 # 6 pairs * PAIR I3: 4,9 BLK 3 I2: 4,9,3 # reduction candidate for 4,9 I2: 3 # 15 pairs I2: 4,9 # 7 pairs * PAIR I3: 4,9 ROW 3 D3: 4,9,6 # reduction candidate for 4,9 D3: 4,9 # 16 pairs E3: 4,9,2,5,6 # reduction candidate for 4,9 E3: 4,9 => CTR * 4.83....6..2.6835..37..218...65....232..7.4.8..482.675........1.4.2..9.7....16..3 E3: 2,5,6 # 6 pairs F3: 4,9,2,5 # reduction candidate for 4,9 F3: 4,9 # 12 pairs * PAIR G4: 3,8 COL G G7: 3,8,2,5,6 # reduction candidate for 3,8 G7: 3,8 => CTR * 4.8357296..21..753537962184..65..8323..67.41...48..67.........1.412..9.7....165.8 G7: 2,5,6 # 6 pairs G9: 3,8,2,5 # reduction candidate for 3,8 G9: 3,8 # 20 pairs * INCONCLUSIVE * SAVE PR GRAPH zz-www.sudokuoftheday.co.uk-20190408-absurd-base-pr-000.dot * REASONING * PRF # F1: 5,9 => SOL * DIS # E3: 5,9 => CTR => E3: 2,4,6 * DIS # B1: 5,9 => CTR => B1: 1 * DIS # E3: 4,9 => CTR => E3: 2,5,6 * DIS # G7: 3,8 => CTR => G7: 2,5,6 * CNT 5 HDP CHAINS / 18 HYP OPENED -------------------------------------------------- * PREPARE PR GRAPH * PAIR REDUCTION .. * LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (E1,G1,G2,G4,H1,I3) * 4.83....6..2....5..37...18...65....23...7.4....48...7...........4.2..9.7....16... * PAIR E1: 5,9 BLK 2 F1: 5,9,1,7 # reduction candidate for 5,9 F1: 5,9 => SOLVED * 418395726962187354537624189176543892385972461294861573821739645643258917759416238 * DURATION: 0:00:01.718656 START: 05:09:29.219026 END: 05:09:30.937682 2019-05-01 * SOLUTION FOUND * SAVE PR GRAPH zz-www.sudokuoftheday.co.uk-20190408-absurd-base-pr-001.dot * REASONING * PRF # F1: 5,9 => SOL * STA F1: 5,9 * CNT 1 HDP CHAINS / 1 HYP OPENED
Header Info
http://www.sudokuoftheday.co.uk/cgi-bin/sudoku1280.cgi?ACTION=archive2&USER=&MONTH=Apr&YEAR=2019, 20190408, absurd
Solution
position: 418395726962187354537624189176543892385972461294861573821739645643258917759416238 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 # F1: 5,9 => SOL * INC # F1: 1,7 => UNS * DIS # E3: 5,9 => CTR => E3: 2,4,6 * INC # E3: 2,4,6 => UNS * INC # F3: 5,9 => UNS * DIS # B1: 5,9 => CTR => B1: 1 * INC # B1: 1 => UNS * INC # E7: 5,9 => UNS * INC # E7: 3,4,8 => UNS * INC # I2: 4,9 => UNS * INC # I2: 3 => UNS * INC # D3: 4,9 => UNS * DIS # E3: 4,9 => CTR => E3: 2,5,6 * INC # E3: 2,5,6 => UNS * INC # F3: 4,9 => UNS * DIS # G7: 3,8 => CTR => G7: 2,5,6 * INC # G7: 2,5,6 => UNS * INC # G9: 3,8 => UNS * CNT 18 HDP CHAINS / 18 HYP OPENED
A2. Pair Reduction
Full list of HDP chains traversed:
* PRF # F1: 5,9 => SOL * STA F1: 5,9 * CNT 1 HDP CHAINS / 1 HYP OPENED