Analysis of xx-top500-342-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 9..8...21.4..5...........6....9.2....7....3.......1...2.1..........3.4....6...... initial

Autosolve

position: 9..8...21.4..5...........64...9.2....7....3.....3.1...2.1.9........3.4..4.6...... autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # B6: 5,6 => CTR => B6: 2,8,9
* DIS # F1: 4,6 => CTR => F1: 3,7
* DIS # D3: 1,2 => CTR => D3: 7
* DIS # B3: 5,8 => CTR => B3: 1,2
* DIS # C1: 3 => CTR => C1: 5,7
* DIS # D9: 1,2 => CTR => D9: 5,7
* DIS # G9: 7,8,9 => CTR => G9: 1,2
* CNT   7 HDP CHAINS /  22 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 # B6: 5,6 => CTR => B6: 2,8,9
* DIS B6: 2,8,9 # F1: 4,6 => CTR => F1: 3,7
* PRF B6: 2,8,9 + F1: 3,7 # D2: 1,2 => SOL
* STA B6: 2,8,9 + F1: 3,7 + D2: 1,2
* CNT   3 HDP CHAINS /   8 HYP OPENED

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

Details

Positions

9..8...21.4..5...........6....9.2....7....3.......1...2.1..........3.4....6...... initial
9..8...21.4..5...........64...9.2....7....3.....3.1...2.1.9........3.4..4.6...... autosolve
965843721742156938318729564653982147179465382824371659231694875597238416486517293 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (5)
B1: 5,6
E1: 4,6
E3: 1,2
G1: 5,7
E9: 1,2

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
A2,D2: 1.. / A2 = 1  =>  0 pairs (X) / D2 = 1  =>  9 pairs (_)
A5,H5: 1.. / A5 = 1  =>  9 pairs (_) / H5 = 1  =>  0 pairs (X)
D8,H8: 1.. / D8 = 1  =>  0 pairs (X) / H8 = 1  =>  9 pairs (_)
B3,B4: 1.. / B3 = 1  =>  9 pairs (_) / B4 = 1  =>  0 pairs (X)
E3,E9: 1.. / E3 = 1  =>  0 pairs (X) / E9 = 1  =>  9 pairs (_)
G4,G9: 1.. / G4 = 1  =>  9 pairs (_) / G9 = 1  =>  0 pairs (X)
C2,D2: 2.. / C2 = 2  =>  9 pairs (_) / D2 = 2  =>  0 pairs (X)
C5,I5: 2.. / C5 = 2  =>  0 pairs (X) / I5 = 2  =>  9 pairs (_)
D8,I8: 2.. / D8 = 2  =>  9 pairs (_) / I8 = 2  =>  0 pairs (X)
B3,B6: 2.. / B3 = 2  =>  0 pairs (X) / B6 = 2  =>  9 pairs (_)
E3,E9: 2.. / E3 = 2  =>  9 pairs (_) / E9 = 2  =>  0 pairs (X)
G6,G9: 2.. / G6 = 2  =>  0 pairs (X) / G9 = 2  =>  9 pairs (_)
F1,F3: 3.. / F1 = 3  =>  8 pairs (_) / F3 = 3  =>  0 pairs (X)
H2,I2: 3.. / H2 = 3  =>  5 pairs (_) / I2 = 3  =>  5 pairs (_)
A4,C4: 3.. / A4 = 3  =>  5 pairs (_) / C4 = 3  => 10 pairs (_)
B7,B9: 3.. / B7 = 3  =>  5 pairs (_) / B9 = 3  =>  6 pairs (_)
C1,F1: 3.. / C1 = 3  =>  0 pairs (X) / F1 = 3  =>  8 pairs (_)
A3,A4: 3.. / A3 = 3  => 10 pairs (_) / A4 = 3  =>  5 pairs (_)
E1,F1: 4.. / E1 = 4  =>  7 pairs (_) / F1 = 4  =>  0 pairs (X)
D7,F7: 4.. / D7 = 4  =>  6 pairs (_) / F7 = 4  =>  7 pairs (_)
D5,D7: 4.. / D5 = 4  =>  7 pairs (_) / D7 = 4  =>  6 pairs (_)
G1,G3: 5.. / G1 = 5  =>  7 pairs (_) / G3 = 5  => 10 pairs (_)
D5,F5: 5.. / D5 = 5  =>  6 pairs (_) / F5 = 5  =>  8 pairs (_)
B1,A2: 6.. / B1 = 6  =>  7 pairs (_) / A2 = 6  =>  0 pairs (X)
E4,E6: 7.. / E4 = 7  =>  5 pairs (_) / E6 = 7  =>  5 pairs (_)
A8,C8: 7.. / A8 = 7  =>  5 pairs (_) / C8 = 7  =>  8 pairs (_)
F2,F3: 9.. / F2 = 9  =>  0 pairs (X) / F3 = 9  =>  8 pairs (_)
F3,G3: 9.. / F3 = 9  =>  8 pairs (_) / G3 = 9  =>  0 pairs (X)
* DURATION: 0:00:39.379525  START: 14:25:38.852891  END: 14:26:18.232416 2017-05-04
* CP COUNT: (28)
* CLUE FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B1,E1,E3,E9,G1)
* 9..8...21.4..5...........64...9.2....7....3.....3.1...2.1.9........3.4..4.6......
* PAIR B1: 5,6 COL B
B4: 5,6,1,8                              # reduction candidate for 5,6
B4: 5,6                                  # 14 pairs
B6: 5,6,2,8,9                            # reduction candidate for 5,6
B6: 5,6 => CTR
* 9..8...2114.256....2.719.64.1.9.2....72...319..93.12..2.1694...7..13.4.24.65271..
B6: 2,8,9                                #  5 pairs
* PAIR E1: 4,6 BLK 2
F1: 4,6,3,7                              # reduction candidate for 4,6
F1: 4,6 => CTR
* 9.38..721.4..5.........3.64...9.2....7....3.....3.1...2.1.9........3.4..4.6......
F1: 3,7                                  #  7 pairs
* PAIR E1: 4,6 COL E
E4: 4,6,7,8                              # reduction candidate for 4,6
E4: 4,6                                  #  7 pairs
E5: 4,6,8                                # reduction candidate for 4,6
E5: 4,6                                  #  9 pairs
E6: 4,6,7,8                              # reduction candidate for 4,6
E6: 4,6                                  #  7 pairs
* PAIR E3: 1,2 BLK 2
D2: 1,2,6,7                              # reduction candidate for 1,2
D2: 1,2                                  #  8 pairs
D3: 1,2,7                                # reduction candidate for 1,2
D3: 1,2 => CTR
* 9..8...21142.5...........64.1.9.2....7....312.2.3.1...2.1.9........3.4..4.6......
D3: 7                                    #  8 pairs
* PAIR E3: 1,2 ROW 3
B3: 1,2,5,8                              # reduction candidate for 1,2
B3: 5,8 => CTR
* 9..8...21.4..5...........64.1.9.2....7....31..2.3.1...2.1.9.......13.4.24.6......
B3: 1,2                                  #  9 pairs
* PAIR G1: 5,7 BLK 3
G3: 5,7,8,9                              # reduction candidate for 5,7
G3: 5,7                                  # 13 pairs
G3: 8,9                                  # 11 pairs
* PAIR G1: 5,7 ROW 1
C1: 5,7,3                                # reduction candidate for 5,7
C1: 3 => CTR
* 963847521142659........396431.9.2....7....312.2.3.1...2.1.9........3.4..4.6......
C1: 5,7                                  #  8 pairs
* PAIR E9: 1,2 BLK 8
D8: 1,2,5,6                              # reduction candidate for 1,2
D8: 1,2                                  #  7 pairs
D9: 1,2,5,7                              # reduction candidate for 1,2
D9: 1,2 => CTR
* 9..8...21.4..5...........64...9.21..17....3.....3.12..2.1.9.6......3.4124.6......
D9: 5,7                                  #  7 pairs
* PAIR E9: 1,2 ROW 9
G9: 1,2,7,8,9                            # reduction candidate for 1,2
G9: 7,8,9 => CTR
* 9..8...21.4..5...........64...9.21..17....3.....3.12..2.1.9.6......3.4..4.6......
G9: 1,2                                  #  8 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-342-base-pr-000.dot
* REASONING
* DIS # B6: 5,6 => CTR => B6: 2,8,9
* DIS # F1: 4,6 => CTR => F1: 3,7
* DIS # D3: 1,2 => CTR => D3: 7
* DIS # B3: 5,8 => CTR => B3: 1,2
* DIS # C1: 3 => CTR => C1: 5,7
* DIS # D9: 1,2 => CTR => D9: 5,7
* DIS # G9: 7,8,9 => CTR => G9: 1,2
* CNT   7 HDP CHAINS /  22 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B1,E1,E3,E9,G1)
* 9..8...21.4..5...........64...9.2....7....3.....3.1...2.1.9........3.4..4.6......
* PAIR B1: 5,6 COL B
B4: 5,6,1,8                              # reduction candidate for 5,6
B4: 5,6                                  # 14 pairs
B6: 5,6,2,8,9                            # reduction candidate for 5,6
B6: 5,6 => CTR
* 9..8...2114.256....2.719.64.1.9.2....72...319..93.12..2.1694...7..13.4.24.65271..
* RESTART
* PAIR B1: 5,6 COL B
B4: 5,6,1,8                              # reduction candidate for 5,6
B4: 5,6                                  # 14 pairs
B4: 1,8                                  #  8 pairs
* PAIR RESTART
* PAIR B1: 5,6 COL B
B4: 5,6,1,8                              # reduction candidate for 5,6
B4: 5,6                                  # 14 pairs
B4: 1,8                                  #  8 pairs
* PAIR E1: 4,6 BLK 2
F1: 4,6,3,7                              # reduction candidate for 4,6
F1: 4,6 => CTR
* 9.38..721.4..5.........3.64...9.2....7....3.....3.1...2.1.9........3.4..4.6......
* PAIR E3: 1,2 BLK 2
D2: 1,2,6,7                              # reduction candidate for 1,2
D2: 1,2 => SOLVED
* 965843721742156938318729564653982147179465382824371659231694875597238416486517293
* DURATION: 0:00:09.521639  START: 14:26:34.574925  END: 14:26:44.096564 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-342-base-pr-001.dot
* REASONING
* DIS # B6: 5,6 => CTR => B6: 2,8,9
* DIS B6: 2,8,9 # F1: 4,6 => CTR => F1: 3,7
* PRF B6: 2,8,9 + F1: 3,7 # D2: 1,2 => SOL
* STA B6: 2,8,9 + F1: 3,7 + D2: 1,2
* CNT   3 HDP CHAINS /   8 HYP OPENED

Header Info

Top 500 Minimum 17 342

solution: 965843721742156938318729564653982147179465382824371659231694875597238416486517293
info: 3295     FNBTHWXY S8.f     39082

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

Solution

position: 965843721742156938318729564653982147179465382824371659231694875597238416486517293 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 # B4: 5,6 => UNS
* DIS # B6: 5,6 => CTR => B6: 2,8,9
* INC # B6: 2,8,9 => UNS
* DIS # F1: 4,6 => CTR => F1: 3,7
* INC # F1: 3,7 => UNS
* INC # E4: 4,6 => UNS
* INC # E5: 4,6 => UNS
* INC # E6: 4,6 => UNS
* INC # D2: 1,2 => UNS
* DIS # D3: 1,2 => CTR => D3: 7
* INC # D3: 7 => UNS
* INC # B3: 1,2 => UNS
* DIS # B3: 5,8 => CTR => B3: 1,2
* INC # G3: 5,7 => UNS
* INC # G3: 8,9 => UNS
* INC # C1: 5,7 => UNS
* DIS # C1: 3 => CTR => C1: 5,7
* INC # D8: 1,2 => UNS
* DIS # D9: 1,2 => CTR => D9: 5,7
* INC # D9: 5,7 => UNS
* INC # G9: 1,2 => UNS
* DIS # G9: 7,8,9 => CTR => G9: 1,2
* CNT  22 HDP CHAINS /  22 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # B4: 5,6 => UNS
* DIS # B6: 5,6 => CTR => B6: 2,8,9
* INC B6: 2,8,9 # B4: 5,6 => UNS
* INC B6: 2,8,9 # B4: 1,8 => UNS
* INC B6: 2,8,9 # B4: 5,6 => UNS
* INC B6: 2,8,9 # B4: 1,8 => UNS
* DIS B6: 2,8,9 # F1: 4,6 => CTR => F1: 3,7
* PRF B6: 2,8,9 + F1: 3,7 # D2: 1,2 => SOL
* STA B6: 2,8,9 + F1: 3,7 + D2: 1,2
* CNT   8 HDP CHAINS /   8 HYP OPENED