Analysis of xx-top500-298-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: .1.7.........5.4..........34..3.....2.....5.....1...8.5...2.6...3.....7......4... initial

Autosolve

position: .1.7.........5.4..........34..3.....2.....5.....1...8.5...2.6...3.....7.1....4... autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # D8: 8,9 => CTR => D8: 5,6
* DIS # E8: 8,9 => CTR => E8: 1,6
* DIS # B7: 8,9 => CTR => B7: 4,7
* PRF # I7: 8,9 => SOL
* DIS # D2: 8,9 => CTR => D2: 2,6
* DIS # D3: 8,9 => CTR => D3: 2,4,6
* DIS # D5: 8,9 => CTR => D5: 4,6
* CNT   7 HDP CHAINS /  17 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 # D8: 8,9 => CTR => D8: 5,6
* DIS D8: 5,6 # E8: 8,9 => CTR => E8: 1,6
* DIS D8: 5,6 + E8: 1,6 # B7: 8,9 => CTR => B7: 4,7
* PRF D8: 5,6 + E8: 1,6 + B7: 4,7 # I7: 8,9 => SOL
* STA D8: 5,6 + E8: 1,6 + B7: 4,7 + I7: 8,9
* CNT   4 HDP CHAINS /   7 HYP OPENED

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

Details

Positions

.1.7.........5.4..........34..3.....2.....5.....1...8.5...2.6...3.....7......4... initial
.1.7.........5.4..........34..3.....2.....5.....1...8.5...2.6...3.....7.1....4... autosolve
614739852398251467752468193461385729283697541975142386547923618839516274126874935 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (5)
F4: 2,5
F6: 2,5
D7: 8,9
F7: 3,7
E9: 3,7

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
C4,C5: 1.. / C4 = 1  =>  0 pairs (*) / C5 = 1  =>  0 pairs (X)
E8,F8: 1.. / E8 = 1  =>  5 pairs (_) / F8 = 1  =>  0 pairs (X)
H7,I7: 1.. / H7 = 1  =>  0 pairs (*) / I7 = 1  =>  0 pairs (X)
E3,E8: 1.. / E3 = 1  =>  0 pairs (X) / E8 = 1  =>  5 pairs (_)
G3,G4: 1.. / G3 = 1  =>  6 pairs (_) / G4 = 1  =>  0 pairs (X)
D2,D3: 2.. / D2 = 2  =>  5 pairs (_) / D3 = 2  =>  0 pairs (X)
F4,F6: 2.. / F4 = 2  =>  3 pairs (_) / F6 = 2  =>  3 pairs (_)
H5,G6: 3.. / H5 = 3  =>  0 pairs (X) / G6 = 3  =>  0 pairs (_)
F7,E9: 3.. / F7 = 3  =>  0 pairs (*) / E9 = 3  =>  0 pairs (X)
C5,H5: 3.. / C5 = 3  =>  0 pairs (*) / H5 = 3  =>  0 pairs (X)
F7,H7: 3.. / F7 = 3  =>  0 pairs (*) / H7 = 3  =>  0 pairs (X)
E1,E9: 3.. / E1 = 3  =>  0 pairs (*) / E9 = 3  =>  0 pairs (X)
G6,G9: 3.. / G6 = 3  =>  0 pairs (*) / G9 = 3  =>  0 pairs (X)
C1,E1: 4.. / C1 = 4  =>  0 pairs (*) / E1 = 4  =>  0 pairs (X)
E6,I6: 4.. / E6 = 4  =>  0 pairs (*) / I6 = 4  =>  0 pairs (X)
C8,I8: 4.. / C8 = 4  =>  0 pairs (X) / I8 = 4  =>  0 pairs (_)
B3,B7: 4.. / B3 = 4  =>  0 pairs (X) / B7 = 4  =>  0 pairs (_)
D3,D5: 4.. / D3 = 4  =>  0 pairs (*) / D5 = 4  =>  0 pairs (X)
H5,H7: 4.. / H5 = 4  =>  0 pairs (*) / H7 = 4  =>  0 pairs (X)
F4,F6: 5.. / F4 = 5  =>  3 pairs (_) / F6 = 5  =>  3 pairs (_)
D8,D9: 5.. / D8 = 5  =>  5 pairs (_) / D9 = 5  =>  0 pairs (X)
D8,I8: 5.. / D8 = 5  =>  5 pairs (_) / I8 = 5  =>  0 pairs (X)
I2,G3: 7.. / I2 = 7  =>  5 pairs (_) / G3 = 7  =>  0 pairs (X)
F7,E9: 7.. / F7 = 7  =>  0 pairs (X) / E9 = 7  =>  0 pairs (_)
F5,F7: 7.. / F5 = 7  =>  0 pairs (*) / F7 = 7  =>  0 pairs (X)
* DURATION: 0:00:37.504709  START: 13:09:31.152105  END: 13:10:08.656814 2017-05-04
* CP COUNT: (25)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (D7,E9,F4,F6,F7)
* .1.7.........5.4..........34..3.....2.....5.....1...8.5...2.6...3.....7.1....4...
* PAIR D7: 8,9 BLK 8
D8: 8,9,5,6                              # reduction candidate for 8,9
D8: 8,9 => CTR
* .1.74........5.4...4......34..3.....2..4..5.....1...845...2.641.34...2751..534.98
D8: 5,6                                  #  6 pairs
E8: 8,9,1,6                              # reduction candidate for 8,9
E8: 8,9 => CTR
* .1.7.........5.4......1...34..3..1..2.1...53....1...8.5...23641.34..1.7.1...74...
E8: 1,6                                  #  6 pairs
F8: 8,9,1,6                              # reduction candidate for 8,9
F8: 8,9                                  #  8 pairs
D9: 8,9,5,6                              # reduction candidate for 8,9
D9: 8,9                                  # 11 pairs
* PAIR D7: 8,9 ROW 7
B7: 8,9,4,7                              # reduction candidate for 8,9
B7: 8,9 => CTR
* .1.74........5.4...4......34..3.....2..4..5.....1...845...23641.34....7.1...74...
B7: 4,7                                  #  6 pairs
C7: 8,9,4,7                              # reduction candidate for 8,9
C7: 8,9                                  #  8 pairs
I7: 8,9,1,4                              # reduction candidate for 8,9
I7: 8,9 => SOLVED
* 614739852398251467752468193461385729283697541975142386547923618839516274126874935
I7: 1,4                                  #  6 pairs
* PAIR D7: 8,9 COL D
D2: 8,9,2,6                              # reduction candidate for 8,9
D2: 8,9 => CTR
* .1.74........5.4...4.2....34..3.....2..4..5.....1...845...23641.34....7.1...74...
D2: 2,6                                  #  6 pairs
D3: 8,9,2,4,6                            # reduction candidate for 8,9
D3: 8,9 => CTR
* .1.74.......25.4...4......34..3.....2..4..5.....1...845...23641.34....7.12..74...
D3: 2,4,6                                #  5 pairs
D5: 8,9,4,6                              # reduction candidate for 8,9
D5: 8,9 => CTR
* .1473..523.82514.7...4..1.34.13..72.2.3..7541...14238.547.23618836519.741..674.35
D5: 4,6                                  #  6 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-298-base-pr-000.dot
* REASONING
* DIS # D8: 8,9 => CTR => D8: 5,6
* DIS # E8: 8,9 => CTR => E8: 1,6
* DIS # B7: 8,9 => CTR => B7: 4,7
* PRF # I7: 8,9 => SOL
* DIS # D2: 8,9 => CTR => D2: 2,6
* DIS # D3: 8,9 => CTR => D3: 2,4,6
* DIS # D5: 8,9 => CTR => D5: 4,6
* CNT   7 HDP CHAINS /  17 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (D7,E9,F4,F6,F7)
* .1.7.........5.4..........34..3.....2.....5.....1...8.5...2.6...3.....7.1....4...
* PAIR D7: 8,9 BLK 8
D8: 8,9,5,6                              # reduction candidate for 8,9
D8: 8,9 => CTR
* .1.74........5.4...4......34..3.....2..4..5.....1...845...2.641.34...2751..534.98
E8: 8,9,1,6                              # reduction candidate for 8,9
E8: 8,9 => CTR
* .1.7.........5.4......1...34..3..1..2.1...53....1...8.5...23641.34..1.7.1...74...
F8: 8,9,1,6                              # reduction candidate for 8,9
F8: 8,9                                  #  8 pairs
D9: 8,9,5,6                              # reduction candidate for 8,9
D9: 8,9                                  # 11 pairs
* PAIR D7: 8,9 ROW 7
B7: 8,9,4,7                              # reduction candidate for 8,9
B7: 8,9 => CTR
* .1.74........5.4...4......34..3.....2..4..5.....1...845...23641.34....7.1...74...
C7: 8,9,4,7                              # reduction candidate for 8,9
C7: 8,9                                  # 10 pairs
I7: 8,9,1,4                              # reduction candidate for 8,9
I7: 8,9 => SOLVED
* 614739852398251467752468193461385729283697541975142386547923618839516274126874935
* DURATION: 0:00:07.137687  START: 13:10:20.966712  END: 13:10:28.104399 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-298-base-pr-001.dot
* REASONING
* DIS # D8: 8,9 => CTR => D8: 5,6
* DIS D8: 5,6 # E8: 8,9 => CTR => E8: 1,6
* DIS D8: 5,6 + E8: 1,6 # B7: 8,9 => CTR => B7: 4,7
* PRF D8: 5,6 + E8: 1,6 + B7: 4,7 # I7: 8,9 => SOL
* STA D8: 5,6 + E8: 1,6 + B7: 4,7 + I7: 8,9
* CNT   4 HDP CHAINS /   7 HYP OPENED

Header Info

Top 500 Minimum 17 298

solution: 614739852398251467752468193461385729283697541975142386547923618839516274126874935
info: 2530     FNBHWXY  S8.f     15709

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

Solution

position: 614739852398251467752468193461385729283697541975142386547923618839516274126874935 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 # D8: 8,9 => CTR => D8: 5,6
* INC # D8: 5,6 => UNS
* DIS # E8: 8,9 => CTR => E8: 1,6
* INC # E8: 1,6 => UNS
* INC # F8: 8,9 => UNS
* INC # D9: 8,9 => UNS
* DIS # B7: 8,9 => CTR => B7: 4,7
* INC # B7: 4,7 => UNS
* INC # C7: 8,9 => UNS
* PRF # I7: 8,9 => SOL
* INC # I7: 1,4 => UNS
* DIS # D2: 8,9 => CTR => D2: 2,6
* INC # D2: 2,6 => UNS
* DIS # D3: 8,9 => CTR => D3: 2,4,6
* INC # D3: 2,4,6 => UNS
* DIS # D5: 8,9 => CTR => D5: 4,6
* INC # D5: 4,6 => UNS
* CNT  17 HDP CHAINS /  17 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # D8: 8,9 => CTR => D8: 5,6
* DIS D8: 5,6 # E8: 8,9 => CTR => E8: 1,6
* INC D8: 5,6 + E8: 1,6 # F8: 8,9 => UNS
* INC D8: 5,6 + E8: 1,6 # D9: 8,9 => UNS
* DIS D8: 5,6 + E8: 1,6 # B7: 8,9 => CTR => B7: 4,7
* INC D8: 5,6 + E8: 1,6 + B7: 4,7 # C7: 8,9 => UNS
* PRF D8: 5,6 + E8: 1,6 + B7: 4,7 # I7: 8,9 => SOL
* STA D8: 5,6 + E8: 1,6 + B7: 4,7 + I7: 8,9
* CNT   7 HDP CHAINS /   7 HYP OPENED