Analysis of xx-top500-051-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 6...7.3..1...9.....2.......7.3.........5...2........8.4.....7.....2..4.....8.5... initial

Autosolve

position: 6...7.3..1...9.....2..5....783.2....9..583.27...7.49834.....7.....2.74.....845... autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # A8: 3,8 => CTR => A8: 5
* DIS # D3: 1,4 => CTR => D3: 3,6
* DIS # I1: 1,4 => CTR => I1: 2,5,9
* DIS # G4: 1,6 => CTR => G4: 5
* DIS # G9: 1,6 => CTR => G9: 2
* CNT   5 HDP CHAINS /  24 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 # A8: 3,8 => CTR => A8: 5
* DIS A8: 5 # H1: 9 => CTR => H1: 1,4
* PRF A8: 5 + H1: 1,4 # C6: 1,6 => SOL
* STA A8: 5 + H1: 1,4 + C6: 1,6
* CNT   3 HDP CHAINS /   7 HYP OPENED

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

Details

Positions

6...7.3..1...9.....2.......7.3.........5...2........8.4.....7.....2..4.....8.5... initial
6...7.3..1...9.....2..5....783.2....9..583.27...7.49834.....7.....2.74.....845... autosolve
695478312134692875827351694783129546946583127251764983412936758568217439379845261 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (8)
A3: 3,8
D1: 1,4
A6: 2,5
E6: 1,6
G5: 1,6
C7: 2,8
A9: 2,3
I7: 2,8

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
F1,F2: 2.. / F1 = 2  =>  0 pairs (X) / F2 = 2  => 10 pairs (_)
A6,C6: 2.. / A6 = 2  => 10 pairs (_) / C6 = 2  =>  0 pairs (X)
F1,I1: 2.. / F1 = 2  =>  0 pairs (X) / I1 = 2  => 10 pairs (_)
C7,I7: 2.. / C7 = 2  => 10 pairs (_) / I7 = 2  =>  0 pairs (X)
A6,A9: 2.. / A6 = 2  => 10 pairs (_) / A9 = 2  =>  0 pairs (X)
G2,G9: 2.. / G2 = 2  =>  0 pairs (X) / G9 = 2  => 10 pairs (_)
B2,A3: 3.. / B2 = 3  => 10 pairs (_) / A3 = 3  =>  0 pairs (X)
D2,D3: 3.. / D2 = 3  =>  0 pairs (X) / D3 = 3  => 10 pairs (_)
E7,E8: 3.. / E7 = 3  =>  9 pairs (_) / E8 = 3  => 12 pairs (_)
B2,D2: 3.. / B2 = 3  => 10 pairs (_) / D2 = 3  =>  0 pairs (X)
A3,D3: 3.. / A3 = 3  =>  0 pairs (X) / D3 = 3  => 10 pairs (_)
B5,C5: 4.. / B5 = 4  => 10 pairs (_) / C5 = 4  =>  9 pairs (_)
H4,I4: 4.. / H4 = 4  =>  8 pairs (_) / I4 = 4  =>  8 pairs (_)
B7,H7: 5.. / B7 = 5  =>  0 pairs (X) / H7 = 5  =>  8 pairs (_)
A6,A8: 5.. / A6 = 5  =>  0 pairs (X) / A8 = 5  => 10 pairs (_)
G2,G4: 5.. / G2 = 5  =>  0 pairs (X) / G4 = 5  =>  8 pairs (_)
H2,H3: 7.. / H2 = 7  =>  8 pairs (_) / H3 = 7  =>  8 pairs (_)
B9,C9: 7.. / B9 = 7  =>  8 pairs (_) / C9 = 7  =>  0 pairs (X)
C3,H3: 7.. / C3 = 7  =>  8 pairs (_) / H3 = 7  =>  8 pairs (_)
B2,B9: 7.. / B2 = 7  =>  0 pairs (X) / B9 = 7  =>  8 pairs (_)
G2,G3: 8.. / G2 = 8  => 10 pairs (_) / G3 = 8  =>  0 pairs (X)
I7,I8: 8.. / I7 = 8  => 10 pairs (_) / I8 = 8  =>  0 pairs (X)
C1,F1: 8.. / C1 = 8  =>  0 pairs (X) / F1 = 8  => 10 pairs (_)
C7,I7: 8.. / C7 = 8  =>  0 pairs (X) / I7 = 8  => 10 pairs (_)
A3,A8: 8.. / A3 = 8  => 10 pairs (_) / A8 = 8  =>  0 pairs (X)
D4,F4: 9.. / D4 = 9  => 10 pairs (_) / F4 = 9  => 10 pairs (_)
D7,F7: 9.. / D7 = 9  => 10 pairs (_) / F7 = 9  => 10 pairs (_)
D4,D7: 9.. / D4 = 9  => 10 pairs (_) / D7 = 9  => 10 pairs (_)
F4,F7: 9.. / F4 = 9  => 10 pairs (_) / F7 = 9  => 10 pairs (_)
* DURATION: 0:00:44.412151  START: 04:24:28.800225  END: 04:25:13.212376 2017-05-04
* CP COUNT: (29)
* CLUE FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A3,A6,A9,C7,D1,E6,G5,I7)
* 6...7.3..1...9.....2..5....783.2....9..583.27...7.49834.....7.....2.74.....845...
* PAIR A3: 3,8 COL A
A8: 3,8,5                                # reduction candidate for 3,8
A8: 3,8 => CTR
* 6...7.3..1...9.....2..5....783.2....9..583.275.27.49834.8...7.23..2.74.82..845.3.
A8: 5                                    # 10 pairs
* PAIR D1: 1,4 BLK 2
D3: 1,4,3,6                              # reduction candidate for 1,4
D3: 1,4 => CTR
* 6...7.3..1..39....32..5....783.2....9..583.27...7.49834.....7..8..2.74..2..845...
D3: 3,6                                  # 10 pairs
* PAIR D1: 1,4 ROW 1
H1: 1,4,5,9                              # reduction candidate for 1,4
H1: 1,4                                  # 11 pairs
I1: 1,4,2,5,9                            # reduction candidate for 1,4
I1: 1,4 => CTR
* 6.8.723..1...9....32..5....783.2....9..583.27...7.49834.2...7.....2.74.....845...
I1: 2,5,9                                #  8 pairs
* PAIR A6: 2,5 BLK 4
C6: 2,5,1,6                              # reduction candidate for 2,5
C6: 1,6                                  # 12 pairs
C6: 2,5                                  # 10 pairs
* PAIR E6: 1,6 BLK 5
D4: 1,6,9                                # reduction candidate for 1,6
D4: 1,6                                  # 10 pairs
F4: 1,6,9                                # reduction candidate for 1,6
F4: 1,6                                  # 10 pairs
* PAIR E6: 1,6 ROW 6
B6: 1,6,5                                # reduction candidate for 1,6
B6: 1,6                                  # 10 pairs
C6: 1,6,2,5                              # reduction candidate for 1,6
C6: 1,6                                  # 12 pairs
* PAIR E6: 1,6 COL E
E7: 1,6,3                                # reduction candidate for 1,6
E7: 1,6                                  # 12 pairs
E8: 1,6,3                                # reduction candidate for 1,6
E8: 1,6                                  #  9 pairs
* PAIR G5: 1,6 BLK 6
G4: 1,6,5                                # reduction candidate for 1,6
G4: 1,6 => CTR
* 6...7.3..1...9.5...2..5.8..783.2....9..583.27...7.49834.....7..8..2.74.....8452..
G4: 5                                    #  8 pairs
H4: 1,6,4,5                              # reduction candidate for 1,6
H4: 1,6                                  #  9 pairs
I4: 1,6,4,5                              # reduction candidate for 1,6
I4: 1,6                                  #  9 pairs
* PAIR G5: 1,6 ROW 5
B5: 1,6,4                                # reduction candidate for 1,6
B5: 1,6                                  #  9 pairs
C5: 1,6,4                                # reduction candidate for 1,6
C5: 1,6                                  # 10 pairs
* PAIR G5: 1,6 COL G
G3: 1,6,8                                # reduction candidate for 1,6
G3: 1,6                                  # 10 pairs
G9: 1,6,2                                # reduction candidate for 1,6
G9: 1,6 => CTR
* 6...723..1...982..32..5.8..783.2.5..9..583.275.27.49834.....7..8..2.74.....845...
G9: 2                                    # 10 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-051-base-pr-000.dot
* REASONING
* DIS # A8: 3,8 => CTR => A8: 5
* DIS # D3: 1,4 => CTR => D3: 3,6
* DIS # I1: 1,4 => CTR => I1: 2,5,9
* DIS # G4: 1,6 => CTR => G4: 5
* DIS # G9: 1,6 => CTR => G9: 2
* CNT   5 HDP CHAINS /  24 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A3,A6,A9,C7,D1,E6,G5,I7)
* 6...7.3..1...9.....2..5....783.2....9..583.27...7.49834.....7.....2.74.....845...
* PAIR A3: 3,8 COL A
A8: 3,8,5                                # reduction candidate for 3,8
A8: 3,8 => CTR
* 6...7.3..1...9.....2..5....783.2....9..583.275.27.49834.8...7.23..2.74.82..845.3.
* PAIR RESTART
* PAIR D1: 1,4 ROW 1
H1: 1,4,9                                # reduction candidate for 1,4
H1: 9 => CTR
* 6..17839213.492865829356174783.2.5419..5836272..7149834.2.317585.82.743.37.8452..
* PAIR RESTART
* PAIR E6: 1,6 BLK 5
D4: 1,6,9                                # reduction candidate for 1,6
D4: 1,6                                  # 17 pairs
F4: 1,6,9                                # reduction candidate for 1,6
F4: 1,6                                  # 17 pairs
* PAIR E6: 1,6 ROW 6
B6: 1,6,5                                # reduction candidate for 1,6
B6: 1,6                                  # 16 pairs
C6: 1,6,5                                # reduction candidate for 1,6
C6: 1,6 => SOLVED
* 695478312134692875827351694783129546946583127251764983412936758568217439379845261
* DURATION: 0:00:10.798666  START: 04:25:33.324291  END: 04:25:44.122957 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-051-base-pr-001.dot
* REASONING
* DIS # A8: 3,8 => CTR => A8: 5
* DIS A8: 5 # H1: 9 => CTR => H1: 1,4
* PRF A8: 5 + H1: 1,4 # C6: 1,6 => SOL
* STA A8: 5 + H1: 1,4 + C6: 1,6
* CNT   3 HDP CHAINS /   7 HYP OPENED

Header Info

Top 500 Minimum 17 051

solution: 695478312134692875827351694783129546946583127251764983412936758568217439379845261
info: 1387     FNBTHXY  S8.f     34718

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

Solution

position: 695478312134692875827351694783129546946583127251764983412936758568217439379845261 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:

* DIS # A8: 3,8 => CTR => A8: 5
* INC # A8: 5 => UNS
* DIS # D3: 1,4 => CTR => D3: 3,6
* INC # D3: 3,6 => UNS
* INC # H1: 1,4 => UNS
* DIS # I1: 1,4 => CTR => I1: 2,5,9
* INC # I1: 2,5,9 => UNS
* INC # C6: 2,5 => UNS
* INC # C6: 1,6 => UNS
* INC # D4: 1,6 => UNS
* INC # F4: 1,6 => UNS
* INC # B6: 1,6 => UNS
* INC # C6: 1,6 => UNS
* INC # E7: 1,6 => UNS
* INC # E8: 1,6 => UNS
* DIS # G4: 1,6 => CTR => G4: 5
* INC # G4: 5 => UNS
* INC # H4: 1,6 => UNS
* INC # I4: 1,6 => UNS
* INC # B5: 1,6 => UNS
* INC # C5: 1,6 => UNS
* INC # G3: 1,6 => UNS
* DIS # G9: 1,6 => CTR => G9: 2
* INC # G9: 2 => UNS
* CNT  24 HDP CHAINS /  24 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # A8: 3,8 => CTR => A8: 5
* INC A8: 5 # H1: 1,4 => UNS
* DIS A8: 5 # H1: 9 => CTR => H1: 1,4
* INC A8: 5 + H1: 1,4 # D4: 1,6 => UNS
* INC A8: 5 + H1: 1,4 # F4: 1,6 => UNS
* INC A8: 5 + H1: 1,4 # B6: 1,6 => UNS
* PRF A8: 5 + H1: 1,4 # C6: 1,6 => SOL
* STA A8: 5 + H1: 1,4 + C6: 1,6
* CNT   7 HDP CHAINS /   7 HYP OPENED