Analysis of xx-top500-113-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: ....35.8.2.1...............7..2......8.....3......6...6..1..2...5..8..........4.7 initial

Autosolve

position: ....351822.1..........21...7..2......82....3......6.2.6..1..2.8.5..82....2....4.7 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # C1: 4,9 => CTR => C1: 6,7
* DIS # A5: 4,9 => CTR => A5: 5
* PRF # A5: 5 => SOL
* PRF # A6: 4,9 => SOL
* DIS # A8: 4,9 => CTR => A8: 1
* PRF # A8: 1 => SOL
* PRF # F7: 3,9 => SOL
* DIS # F7: 4,7 => CTR => F7: 3,9
* DIS # D9: 3,9 => CTR => D9: 5,6
* PRF # D9: 5,6 => SOL
* PRF # A9: 3,9 => SOL
* DIS # A9: 1,8 => CTR => A9: 3,9
* DIS # C9: 3,9 => CTR => C9: 8
* DIS # H9: 5,9 => CTR => H9: 1,6
* DIS # E7: 5,9 => CTR => E7: 4,7
* CNT  15 HDP CHAINS /  25 HYP OPENED

See Appendix: Full HDP Chains for full list of HDP chains.

Pair Reduction

Pair Reduction

The following important HDP chains were detected:

* DIS # C1: 4,9 => CTR => C1: 6,7
* DIS C1: 6,7 # A5: 4,9 => CTR => A5: 5
* PRF C1: 6,7 + A5: 5 => SOL
* STA C1: 6,7 + A5: 5
* CNT   3 HDP CHAINS /   7 HYP OPENED

See Appendix: Full HDP Chains for full list of HDP chains.

Details

Positions

....35.8.2.1...............7..2......8.....3......6...6..1..2...5..8..........4.7 initial
....351822.1..........21...7..2......82....3......6.2.6..1..2.8.5..82....2....4.7 autosolve
976435182231897564845621379763258941582914736419376825697143258154782693328569417 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (7)
A1: 4,9
A3: 5,8
C3: 5,8
F4: 3,8
D6: 3,8
F9: 3,9
H7: 5,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
B4,B6: 1.. / B4 = 1  =>  0 pairs (X) / B6 = 1  =>  7 pairs (_)
A8,A9: 1.. / A8 = 1  =>  0 pairs (*) / A9 = 1  =>  0 pairs (X)
E5,I5: 1.. / E5 = 1  =>  7 pairs (_) / I5 = 1  =>  0 pairs (X)
A9,H9: 1.. / A9 = 1  =>  0 pairs (X) / H9 = 1  =>  0 pairs (_)
B2,B3: 3.. / B2 = 3  =>  7 pairs (_) / B3 = 3  => 10 pairs (_)
F4,D6: 3.. / F4 = 3  =>  0 pairs (X) / D6 = 3  =>  0 pairs (_)
G8,I8: 3.. / G8 = 3  =>  8 pairs (_) / I8 = 3  =>  9 pairs (_)
C4,F4: 3.. / C4 = 3  =>  0 pairs (*) / F4 = 3  =>  0 pairs (X)
C7,F7: 3.. / C7 = 3  =>  0 pairs (X) / F7 = 3  =>  0 pairs (_)
A6,A9: 3.. / A6 = 3  =>  0 pairs (X) / A9 = 3  =>  0 pairs (_)
D6,D9: 3.. / D6 = 3  =>  0 pairs (*) / D9 = 3  =>  0 pairs (X)
A3,C3: 5.. / A3 = 5  =>  0 pairs (X) / C3 = 5  =>  5 pairs (_)
G2,I2: 5.. / G2 = 5  =>  8 pairs (_) / I2 = 5  =>  9 pairs (_)
H7,H9: 5.. / H7 = 5  =>  6 pairs (_) / H9 = 5  =>  0 pairs (X)
E7,H7: 5.. / E7 = 5  =>  0 pairs (X) / H7 = 5  =>  6 pairs (_)
D5,D9: 5.. / D5 = 5  =>  0 pairs (X) / D9 = 5  =>  0 pairs (_)
B4,C4: 6.. / B4 = 6  =>  8 pairs (_) / C4 = 6  =>  0 pairs (X)
G5,I5: 6.. / G5 = 6  =>  0 pairs (X) / I5 = 6  =>  7 pairs (_)
C1,C4: 6.. / C1 = 6  =>  8 pairs (_) / C4 = 6  =>  0 pairs (X)
E2,E9: 6.. / E2 = 6  =>  8 pairs (_) / E9 = 6  =>  7 pairs (_)
H2,H3: 7.. / H2 = 7  =>  8 pairs (_) / H3 = 7  =>  7 pairs (_)
G5,G6: 7.. / G5 = 7  =>  8 pairs (_) / G6 = 7  =>  0 pairs (X)
E6,G6: 7.. / E6 = 7  =>  8 pairs (_) / G6 = 7  =>  0 pairs (X)
C8,D8: 7.. / C8 = 7  =>  8 pairs (_) / D8 = 7  =>  9 pairs (_)
A3,C3: 8.. / A3 = 8  =>  5 pairs (_) / C3 = 8  =>  0 pairs (X)
D2,F2: 8.. / D2 = 8  =>  0 pairs (*) / F2 = 8  =>  0 pairs (X)
F4,D6: 8.. / F4 = 8  =>  0 pairs (*) / D6 = 8  =>  0 pairs (X)
G4,G6: 8.. / G4 = 8  =>  0 pairs (X) / G6 = 8  =>  0 pairs (_)
A9,C9: 8.. / A9 = 8  =>  0 pairs (X) / C9 = 8  =>  5 pairs (_)
F4,G4: 8.. / F4 = 8  =>  0 pairs (*) / G4 = 8  =>  0 pairs (X)
D6,G6: 8.. / D6 = 8  =>  0 pairs (X) / G6 = 8  =>  0 pairs (_)
A3,A9: 8.. / A3 = 8  =>  5 pairs (_) / A9 = 8  =>  0 pairs (X)
C3,C9: 8.. / C3 = 8  =>  0 pairs (X) / C9 = 8  =>  5 pairs (_)
D2,D6: 8.. / D2 = 8  =>  0 pairs (*) / D6 = 8  =>  0 pairs (X)
F2,F4: 8.. / F2 = 8  =>  0 pairs (X) / F4 = 8  =>  0 pairs (_)
* DURATION: 0:00:58.360485  START: 06:37:33.786205  END: 06:38:32.146690 2017-05-04
* CP COUNT: (35)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,A3,C3,D6,F4,F9,H7)
* ....351822.1..........21...7..2......82....3......6.2.6..1..2.8.5..82....2....4.7
* PAIR A1: 4,9 BLK 1
B1: 4,9,6,7                              # reduction candidate for 4,9
B1: 4,9                                  # 10 pairs
C1: 4,9,6,7                              # reduction candidate for 4,9
C1: 4,9 => CTR
* ....351822.1..8.......21...7.62.38...825...3.3.58.6.2.6.31..2.8.57.82....283.94.7
C1: 6,7                                  #  8 pairs
B2: 4,9,3,6,7                            # reduction candidate for 4,9
B2: 4,9                                  # 14 pairs
B3: 4,9,3,6,7                            # reduction candidate for 4,9
B3: 4,9                                  # 11 pairs
* PAIR A1: 4,9 ROW 1
D1: 4,9,6,7                              # reduction candidate for 4,9
D1: 4,9                                  # 10 pairs
D1: 6,7                                  #  8 pairs
* PAIR A1: 4,9 COL A
A5: 4,9,5                                # reduction candidate for 4,9
A5: 4,9 => CTR
* ..6.351822.18.7...8.5.21.7.7632.8....82.147365..37682.6..143258154782...328..9417
A5: 5 => SOLVED
* 976435182231897564845621379763258941582914736419376825697143258154782693328569417
A6: 4,9,3,5                              # reduction candidate for 4,9
A6: 4,9 => SOLVED
* 976435182231897564845621379763258941582914736419376825697143258154782693328569417
A6: 3,5                                  #  8 pairs
A8: 4,9,1                                # reduction candidate for 4,9
A8: 4,9 => CTR
* ....351822.1..8...8.5.21...7..2.38..582....3.3..8.6.2.6.31..2.8.5..82...1283.94.7
A8: 1 => SOLVED
* 976435182231897564845621379763258941582914736419376825697143258154782693328569417
* PAIR F9: 3,9 BLK 8
F7: 3,9,4,7                              # reduction candidate for 3,9
F7: 3,9 => SOLVED
* 976435182231897564845621379763258941582914736419376825697143258154782693328569417
F7: 4,7 => CTR
* ....351822.1..8.......21...7..2.38...825...3.3..8.6.2.6.31..2.8.5..82....283.94.7
D9: 3,9,5,6                              # reduction candidate for 3,9
D9: 3,9 => CTR
* ....351822.1..........21...7..2......825...3......6.2.6..1..2.8.5..82....2....4.7
D9: 5,6 => SOLVED
* 976435182231897564845621379763258941582914736419376825697143258154782693328569417
* PAIR F9: 3,9 ROW 9
A9: 3,9,1,8                              # reduction candidate for 3,9
A9: 3,9 => SOLVED
* 976435182231897564845621379763258941582914736419376825697143258154782693328569417
A9: 1,8 => CTR
* ....351822.1..8.......21...7..2.38...825...3.3..8.6.2.6.31..2.8.5..82....283.94.7
C9: 3,9,8                                # reduction candidate for 3,9
C9: 3,9 => CTR
* ....351822.1......5.8.21...7..2......82....3.3..8.6.2.6..1..25815..82...82.3..417
C9: 8                                    #  5 pairs
* PAIR H7: 5,9 BLK 9
H9: 5,9,1,6                              # reduction candidate for 5,9
H9: 5,9 => CTR
* ....351822.1..8...8.5.21...7..2.38..582....3.3..8.6.2.6.315.298.5..82...128369457
H9: 1,6                                  #  9 pairs
* PAIR H7: 5,9 ROW 7
E7: 5,9,4,7                              # reduction candidate for 5,9
E7: 5,9 => CTR
* ....351822.1..8.......21...7..2.38...825...3.3..8.6.2.6.315.298.5..82...128369457
E7: 4,7                                  #  7 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-113-base-pr-000.dot
* REASONING
* DIS # C1: 4,9 => CTR => C1: 6,7
* DIS # A5: 4,9 => CTR => A5: 5
* PRF # A5: 5 => SOL
* PRF # A6: 4,9 => SOL
* DIS # A8: 4,9 => CTR => A8: 1
* PRF # A8: 1 => SOL
* PRF # F7: 3,9 => SOL
* DIS # F7: 4,7 => CTR => F7: 3,9
* DIS # D9: 3,9 => CTR => D9: 5,6
* PRF # D9: 5,6 => SOL
* PRF # A9: 3,9 => SOL
* DIS # A9: 1,8 => CTR => A9: 3,9
* DIS # C9: 3,9 => CTR => C9: 8
* DIS # H9: 5,9 => CTR => H9: 1,6
* DIS # E7: 5,9 => CTR => E7: 4,7
* CNT  15 HDP CHAINS /  25 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,A3,C3,D6,F4,F9,H7)
* ....351822.1..........21...7..2......82....3......6.2.6..1..2.8.5..82....2....4.7
* PAIR A1: 4,9 BLK 1
B1: 4,9,6,7                              # reduction candidate for 4,9
B1: 4,9                                  # 10 pairs
C1: 4,9,6,7                              # reduction candidate for 4,9
C1: 4,9 => CTR
* ....351822.1..8.......21...7.62.38...825...3.3.58.6.2.6.31..2.8.57.82....283.94.7
B2: 4,9,3,6,7                            # reduction candidate for 4,9
B2: 4,9                                  # 14 pairs
B3: 4,9,3,6,7                            # reduction candidate for 4,9
B3: 4,9                                  # 11 pairs
* PAIR A1: 4,9 ROW 1
D1: 4,9,6,7                              # reduction candidate for 4,9
D1: 6,7                                  # 10 pairs
D1: 4,9                                  # 10 pairs
* PAIR A1: 4,9 COL A
A5: 4,9,5                                # reduction candidate for 4,9
A5: 4,9 => CTR
* ..6.351822.18.7...8.5.21.7.7632.8....82.147365..37682.6..143258154782...328..9417
A5: 5 => SOLVED
* 976435182231897564845621379763258941582914736419376825697143258154782693328569417
* DURATION: 0:00:07.239964  START: 06:38:57.882252  END: 06:39:05.122216 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-113-base-pr-001.dot
* REASONING
* DIS # C1: 4,9 => CTR => C1: 6,7
* DIS C1: 6,7 # A5: 4,9 => CTR => A5: 5
* PRF C1: 6,7 + A5: 5 => SOL
* STA C1: 6,7 + A5: 5
* CNT   3 HDP CHAINS /   7 HYP OPENED

Header Info

Top 500 Minimum 17 113

solution: 976435182231897564845621379763258941582914736419376825697143258154782693328569417
info: 1686     FNBHWY   S8.f     4066

http://www.sfsudoku.com/su17ExtremeDiff500.txt from http://www.minimumsudoku.com/

Solution

position: 976435182231897564845621379763258941582914736419376825697143258154782693328569417 solved
Solution

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 # B1: 4,9 => UNS
* DIS # C1: 4,9 => CTR => C1: 6,7
* INC # C1: 6,7 => UNS
* INC # B2: 4,9 => UNS
* INC # B3: 4,9 => UNS
* INC # D1: 4,9 => UNS
* INC # D1: 6,7 => UNS
* DIS # A5: 4,9 => CTR => A5: 5
* PRF # A5: 5 => SOL
* PRF # A6: 4,9 => SOL
* INC # A6: 3,5 => UNS
* DIS # A8: 4,9 => CTR => A8: 1
* PRF # A8: 1 => SOL
* PRF # F7: 3,9 => SOL
* DIS # F7: 4,7 => CTR => F7: 3,9
* DIS # D9: 3,9 => CTR => D9: 5,6
* PRF # D9: 5,6 => SOL
* PRF # A9: 3,9 => SOL
* DIS # A9: 1,8 => CTR => A9: 3,9
* DIS # C9: 3,9 => CTR => C9: 8
* INC # C9: 8 => UNS
* DIS # H9: 5,9 => CTR => H9: 1,6
* INC # H9: 1,6 => UNS
* DIS # E7: 5,9 => CTR => E7: 4,7
* INC # E7: 4,7 => UNS
* CNT  25 HDP CHAINS /  25 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # B1: 4,9 => UNS
* DIS # C1: 4,9 => CTR => C1: 6,7
* INC C1: 6,7 # B2: 4,9 => UNS
* INC C1: 6,7 # B3: 4,9 => UNS
* INC C1: 6,7 # D1: 4,9 => UNS
* INC C1: 6,7 # D1: 6,7 => UNS
* DIS C1: 6,7 # A5: 4,9 => CTR => A5: 5
* PRF C1: 6,7 + A5: 5 => SOL
* STA C1: 6,7 + A5: 5
* CNT   8 HDP CHAINS /   7 HYP OPENED