Analysis of xx-top500-413-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: ...35.9..6.....4....1......2..8......3.9............6.....46.1.39.......7........ initial

Autosolve

position: 84.3519.66.329.4.19.16.4.3.26.813.9443.96.1..1.94...635..74631939.1.....71.539... autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # B3: 5 => CTR => B3: 2,7
* DIS # B3: 2 => CTR => B3: 5,7
* PRF # H2: 8 => SOL
* DIS # H2: 5 => CTR => H2: 7,8
* DIS # C5: 8 => CTR => C5: 5,7
* PRF # F6: 2,7 => SOL
* PRF # G6: 5,7 => SOL
* CNT   7 HDP CHAINS /  39 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 # B3: 5 => CTR => B3: 2,7
* DIS B3: 2,7 # G3: 7,8 => CTR => G3: 2,5
* DIS B3: 2,7 + G3: 2,5 # I3: 7,8 => CTR => I3: 2,5
* PRF B3: 2,7 + G3: 2,5 + I3: 2,5 => SOL
* STA B3: 2,7 + G3: 2,5 + I3: 2,5
* CNT   4 HDP CHAINS /   4 HYP OPENED

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

Details

Positions

...35.9..6.....4....1......2..8......3.9............6.....46.1.39.......7........ initial
84.3519.66.329.4.19.16.4.3.26.813.9443.96.1..1.94...635..74631939.1.....71.539... autosolve
842351976653297481971684235265813794437965128189472563528746319394128657716539842 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (17)
C1: 2,7
B2: 5,7
F2: 7,8
E3: 7,8
H1: 2,7
C4: 5,7
B6: 7,8
E6: 2,7
G4: 5,7
B7: 2,8
C7: 2,8
C8: 4,6
C9: 4,6
E8: 2,8
F8: 2,8
I8: 5,7
I9: 2,8

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
C1,B3: 2.. / C1 = 2  => 16 pairs (_) / B3 = 2  =>  0 pairs (X)
B7,C7: 2.. / B7 = 2  => 16 pairs (_) / C7 = 2  =>  0 pairs (X)
E8,F8: 2.. / E8 = 2  =>  0 pairs (*) / F8 = 2  =>  0 pairs (X)
C1,H1: 2.. / C1 = 2  => 16 pairs (_) / H1 = 2  =>  0 pairs (X)
B3,B7: 2.. / B3 = 2  =>  0 pairs (X) / B7 = 2  => 16 pairs (_)
C1,C7: 2.. / C1 = 2  => 16 pairs (_) / C7 = 2  =>  0 pairs (X)
E6,E8: 2.. / E6 = 2  => 17 pairs (_) / E8 = 2  =>  0 pairs (*)
C8,C9: 4.. / C8 = 4  => 17 pairs (_) / C9 = 4  => 20 pairs (_)
H8,H9: 4.. / H8 = 4  => 20 pairs (_) / H9 = 4  => 17 pairs (_)
C8,H8: 4.. / C8 = 4  => 17 pairs (_) / H8 = 4  => 20 pairs (_)
C9,H9: 4.. / C9 = 4  => 20 pairs (_) / H9 = 4  => 17 pairs (_)
B2,B3: 5.. / B2 = 5  => 18 pairs (_) / B3 = 5  =>  0 pairs (X)
C4,C5: 5.. / C4 = 5  => 17 pairs (_) / C5 = 5  => 18 pairs (_)
F5,F6: 5.. / F5 = 5  =>  0 pairs (*) / F6 = 5  =>  0 pairs (X)
B2,H2: 5.. / B2 = 5  => 18 pairs (_) / H2 = 5  =>  0 pairs (X)
C4,G4: 5.. / C4 = 5  => 17 pairs (_) / G4 = 5  => 18 pairs (_)
F6,G6: 5.. / F6 = 5  => 18 pairs (_) / G6 = 5  =>  0 pairs (*)
C8,C9: 6.. / C8 = 6  => 20 pairs (_) / C9 = 6  => 17 pairs (_)
G8,G9: 6.. / G8 = 6  => 17 pairs (_) / G9 = 6  => 20 pairs (_)
C8,G8: 6.. / C8 = 6  => 20 pairs (_) / G8 = 6  => 17 pairs (_)
C9,G9: 6.. / C9 = 6  => 17 pairs (_) / G9 = 6  => 20 pairs (_)
F2,E3: 7.. / F2 = 7  =>  0 pairs (*) / E3 = 7  =>  0 pairs (X)
C1,H1: 7.. / C1 = 7  =>  0 pairs (X) / H1 = 7  => 16 pairs (_)
C4,G4: 7.. / C4 = 7  => 18 pairs (_) / G4 = 7  => 17 pairs (_)
E3,E6: 7.. / E3 = 7  => 17 pairs (_) / E6 = 7  =>  0 pairs (*)
F2,E3: 8.. / F2 = 8  => 17 pairs (_) / E3 = 8  =>  0 pairs (*)
C5,B6: 8.. / C5 = 8  =>  0 pairs (X) / B6 = 8  => 16 pairs (_)
B7,C7: 8.. / B7 = 8  =>  0 pairs (X) / C7 = 8  => 16 pairs (_)
E8,F8: 8.. / E8 = 8  => 17 pairs (_) / F8 = 8  =>  0 pairs (*)
F2,H2: 8.. / F2 = 8  => 17 pairs (_) / H2 = 8  =>  0 pairs (*)
B6,G6: 8.. / B6 = 8  => 16 pairs (_) / G6 = 8  =>  0 pairs (X)
B6,B7: 8.. / B6 = 8  => 16 pairs (_) / B7 = 8  =>  0 pairs (X)
C5,C7: 8.. / C5 = 8  =>  0 pairs (X) / C7 = 8  => 16 pairs (_)
E3,E8: 8.. / E3 = 8  =>  0 pairs (*) / E8 = 8  =>  0 pairs (X)
F2,F8: 8.. / F2 = 8  => 17 pairs (_) / F8 = 8  =>  0 pairs (*)
* DURATION: 0:01:08.931361  START: 16:54:23.455963  END: 16:55:32.387324 2017-05-04
* CP COUNT: (35)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B2,B6,B7,C1,C4,C7,C8,C9,E3,E6,E8,F2,F8,G4,H1,I8,I9)
* 84.3519.66.329.4.19.16.4.3.26.813.9443.96.1..1.94...635..74631939.1.....71.539...
* PAIR C1: 2,7 BLK 1
B3: 2,7,5                                # reduction candidate for 2,7
B3: 5 => CTR
* 842351976673298451951674.3.26.813.9443.96.1..18942..6352874631939.182.4.7145396..
B3: 2,7                                  # 18 pairs
* PAIR B2: 5,7 BLK 1
B3: 5,7,2                                # reduction candidate for 5,7
B3: 2 => CTR
* 84.3519.665329.4.19216.4.3.26.813.9443.96.1..17942586358274631939.182...71.5392.8
B3: 5,7                                  # 16 pairs
* PAIR B2: 5,7 ROW 2
H2: 5,7,8                                # reduction candidate for 5,7
H2: 8 => SOLVED
* 842351976653297481971684235265813794437965128189472563528746319394128657716539842
H2: 5,7                                  # 17 pairs
* PAIR F2: 7,8 ROW 2
H2: 7,8,5                                # reduction candidate for 7,8
H2: 5 => CTR
* 842351976673298451951674.3.26.813.9443.96.1..18942..6352874631939.182.4.7145396..
H2: 7,8                                  # 18 pairs
* PAIR E3: 7,8 ROW 3
G3: 7,8,2,5                              # reduction candidate for 7,8
G3: 7,8                                  # 20 pairs
I3: 7,8,2,5                              # reduction candidate for 7,8
I3: 7,8                                  # 20 pairs
* PAIR H1: 2,7 BLK 3
G3: 2,7,5,8                              # reduction candidate for 2,7
G3: 2,7                                  # 20 pairs
I3: 2,7,5,8                              # reduction candidate for 2,7
I3: 2,7                                  # 20 pairs
* PAIR H1: 2,7 COL H
H5: 2,7,5,8                              # reduction candidate for 2,7
H5: 2,7                                  # 21 pairs
H5: 5,8                                  # 18 pairs
* PAIR C4: 5,7 BLK 4
C5: 5,7,8                                # reduction candidate for 5,7
C5: 8 => CTR
* 84735192665329847192167453826581379443896715217942586358274631939.182...71.539...
C5: 5,7                                  # 16 pairs
* PAIR B6: 7,8 BLK 4
C5: 7,8,5                                # reduction candidate for 7,8
C5: 5                                    # 18 pairs
C5: 7,8                                  # 17 pairs
* PAIR B6: 7,8 ROW 6
G6: 7,8,2,5                              # reduction candidate for 7,8
G6: 2,5                                  # 18 pairs
G6: 7,8                                  # 17 pairs
* PAIR E6: 2,7 BLK 5
F5: 2,7,5                                # reduction candidate for 2,7
F5: 2,7                                  # 18 pairs
F6: 2,7,5                                # reduction candidate for 2,7
F6: 2,7 => SOLVED
* 842351976653297481971684235265813794437965128189472563528746319394128657716539842
F6: 5                                    # 18 pairs
* PAIR E6: 2,7 ROW 6
G6: 2,7,5,8                              # reduction candidate for 2,7
G6: 5,8                                  # 19 pairs
G6: 2,7                                  # 18 pairs
* PAIR G4: 5,7 BLK 6
H5: 5,7,2,8                              # reduction candidate for 5,7
H5: 5,7                                  # 22 pairs
I5: 5,7,2,8                              # reduction candidate for 5,7
I5: 5,7                                  # 22 pairs
G6: 5,7,2,8                              # reduction candidate for 5,7
G6: 5,7 => SOLVED
* 842351976653297481971684235265813794437965128189472563528746319394128657716539842
G6: 2,8                                  # 19 pairs
* PAIR G4: 5,7 COL G
G3: 5,7,2,8                              # reduction candidate for 5,7
G3: 5,7                                  # 20 pairs
G8: 5,7,6                                # reduction candidate for 5,7
G8: 5,7                                  # 20 pairs
* PAIR I8: 5,7 BLK 9
G8: 5,7,6                                # reduction candidate for 5,7
G8: 5,7                                  # 20 pairs
H8: 5,7,4                                # reduction candidate for 5,7
H8: 5,7                                  # 17 pairs
* PAIR I8: 5,7 COL I
I3: 5,7,2,8                              # reduction candidate for 5,7
I3: 5,7                                  # 19 pairs
I5: 5,7,2,8                              # reduction candidate for 5,7
I5: 5,7                                  # 22 pairs
* PAIR I9: 2,8 BLK 9
G9: 2,8,6                                # reduction candidate for 2,8
G9: 2,8                                  # 17 pairs
H9: 2,8,4                                # reduction candidate for 2,8
H9: 2,8                                  # 20 pairs
* PAIR I9: 2,8 COL I
I3: 2,8,5,7                              # reduction candidate for 2,8
I3: 2,8                                  # 22 pairs
I5: 2,8,5,7                              # reduction candidate for 2,8
I5: 2,8                                  # 19 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-413-base-pr-000.dot
* REASONING
* DIS # B3: 5 => CTR => B3: 2,7
* DIS # B3: 2 => CTR => B3: 5,7
* PRF # H2: 8 => SOL
* DIS # H2: 5 => CTR => H2: 7,8
* DIS # C5: 8 => CTR => C5: 5,7
* PRF # F6: 2,7 => SOL
* PRF # G6: 5,7 => SOL
* CNT   7 HDP CHAINS /  39 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B2,B6,B7,C1,C4,C7,C8,C9,E3,E6,E8,F2,F8,G4,H1,I8,I9)
* 84.3519.66.329.4.19.16.4.3.26.813.9443.96.1..1.94...635..74631939.1.....71.539...
* PAIR C1: 2,7 BLK 1
B3: 2,7,5                                # reduction candidate for 2,7
B3: 5 => CTR
* 842351976673298451951674.3.26.813.9443.96.1..18942..6352874631939.182.4.7145396..
* PAIR E3: 7,8 ROW 3
G3: 7,8,2,5                              # reduction candidate for 7,8
G3: 7,8 => CTR
* 84.35192665329.4.19216.4.3526.813.9443.96.1..17942586358274631939.18...771.539...
I3: 7,8,2,5                              # reduction candidate for 7,8
I3: 7,8 => CTR
* 84.35192665329.4.19216.453.26581379443.96.1..1794258635827463193941826..716539248
I3: 2,5 => SOLVED
* 842351976653297481971684235265813794437965128189472563528746319394128657716539842
* DURATION: 0:00:05.426608  START: 16:56:14.130527  END: 16:56:19.557135 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-413-base-pr-001.dot
* REASONING
* DIS # B3: 5 => CTR => B3: 2,7
* DIS B3: 2,7 # G3: 7,8 => CTR => G3: 2,5
* DIS B3: 2,7 + G3: 2,5 # I3: 7,8 => CTR => I3: 2,5
* PRF B3: 2,7 + G3: 2,5 + I3: 2,5 => SOL
* STA B3: 2,7 + G3: 2,5 + I3: 2,5
* CNT   4 HDP CHAINS /   4 HYP OPENED

Header Info

Top 500 Minimum 17 413

solution: 842351976653297481971684235265813794437965128189472563528746319394128657716539842
info: 95044    FNBXK    S8.f     42362

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

Solution

position: 842351976653297481971684235265813794437965128189472563528746319394128657716539842 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 # B3: 2,7 => UNS
* DIS # B3: 5 => CTR => B3: 2,7
* INC # B3: 5,7 => UNS
* DIS # B3: 2 => CTR => B3: 5,7
* INC # H2: 5,7 => UNS
* PRF # H2: 8 => SOL
* INC # H2: 7,8 => UNS
* DIS # H2: 5 => CTR => H2: 7,8
* INC # G3: 7,8 => UNS
* INC # I3: 7,8 => UNS
* INC # G3: 2,7 => UNS
* INC # I3: 2,7 => UNS
* INC # H5: 2,7 => UNS
* INC # H5: 5,8 => UNS
* INC # C5: 5,7 => UNS
* DIS # C5: 8 => CTR => C5: 5,7
* INC # C5: 7,8 => UNS
* INC # C5: 5 => UNS
* INC # G6: 7,8 => UNS
* INC # G6: 2,5 => UNS
* INC # F5: 2,7 => UNS
* PRF # F6: 2,7 => SOL
* INC # F6: 5 => UNS
* INC # G6: 2,7 => UNS
* INC # G6: 5,8 => UNS
* INC # H5: 5,7 => UNS
* INC # I5: 5,7 => UNS
* PRF # G6: 5,7 => SOL
* INC # G6: 2,8 => UNS
* INC # G3: 5,7 => UNS
* INC # G8: 5,7 => UNS
* INC # G8: 5,7 => UNS
* INC # H8: 5,7 => UNS
* INC # I3: 5,7 => UNS
* INC # I5: 5,7 => UNS
* INC # G9: 2,8 => UNS
* INC # H9: 2,8 => UNS
* INC # I3: 2,8 => UNS
* INC # I5: 2,8 => UNS
* CNT  39 HDP CHAINS /  39 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # B3: 2,7 => UNS
* DIS # B3: 5 => CTR => B3: 2,7
* DIS B3: 2,7 # G3: 7,8 => CTR => G3: 2,5
* DIS B3: 2,7 + G3: 2,5 # I3: 7,8 => CTR => I3: 2,5
* PRF B3: 2,7 + G3: 2,5 + I3: 2,5 => SOL
* STA B3: 2,7 + G3: 2,5 + I3: 2,5
* CNT   5 HDP CHAINS /   4 HYP OPENED