Analysis of xx-top500-207-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: ....2..4.8.....1..1..9......26.5..........8...4.......9..8.1..........65...3..... initial

Autosolve

position: 69.12..488..5..19.1..98....326.58.19.19...8...48.19...9..861...481.9.365267345981 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # G3: 5,7 => CTR => G3: 2,6
* PRF # F5: 3,7 => SOL
* DIS # F5: 2 => CTR => F5: 3,7
* DIS # G3: 5,7 => CTR => G3: 2,6
* DIS # G6: 5,7 => CTR => G6: 2,6
* DIS # I3: 2,6 => CTR => I3: 3,7
* DIS # I6: 2,6 => CTR => I6: 3,7
* DIS # H5: 5,7 => CTR => H5: 2
* PRF # H5: 2 => SOL
* DIS # G6: 5,7 => CTR => G6: 2,6
* PRF # F5: 3,7 => SOL
* DIS # F5: 2 => CTR => F5: 3,7
* PRF # G7: 4,7 => SOL
* DIS # G7: 2 => CTR => G7: 4,7
* PRF # D6: 2,7 => SOL
* DIS # D6: 6 => CTR => D6: 2,7
* DIS # F5: 2,7 => CTR => F5: 3
* PRF # F5: 3 => SOL
* DIS # G7: 2,7 => CTR => G7: 4
* PRF # G7: 4 => SOL
* PRF # I7: 2,7 => SOL
* DIS # I7: 4 => CTR => I7: 2,7
* DIS # H3: 2,7 => CTR => H3: 3,5
* DIS # H6: 2,7 => CTR => H6: 3,5
* CNT  24 HDP CHAINS /  37 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 # G3: 5,7 => CTR => G3: 2,6
* PRF G3: 2,6 # H3: 3 => SOL
* STA G3: 2,6 + H3: 3
* CNT   2 HDP CHAINS /   4 HYP OPENED

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

Details

Positions

....2..4.8.....1..1..9......26.5..........8...4.......9..8.1..........65...3..... initial
69.12..488..5..19.1..98....326.58.19.19...8...48.19...9..861...481.9.365267345981 autosolve
693127548872534196154986237326458719519673824748219653935861472481792365267345981 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (23)
C1: 3,5
B2: 3,7
C2: 2,4
B3: 5,7
C3: 2,4
F1: 3,7
E2: 3,7
F2: 4,6
F3: 4,6
G1: 5,7
I2: 2,6
A5: 5,7
A6: 5,7
D4: 4,7
D5: 4,6
E5: 3,7
G4: 4,7
I5: 4,6
B7: 3,5
C7: 3,5
D8: 2,7
F8: 2,7
H7: 2,7

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
C2,C3: 2.. / C2 = 2  =>  0 pairs (*) / C3 = 2  =>  0 pairs (X)
F5,D6: 2.. / F5 = 2  =>  0 pairs (X) / D6 = 2  =>  0 pairs (_)
D8,F8: 2.. / D8 = 2  =>  0 pairs (X) / F8 = 2  =>  0 pairs (_)
C2,I2: 2.. / C2 = 2  =>  0 pairs (*) / I2 = 2  =>  0 pairs (X)
F5,H5: 2.. / F5 = 2  =>  0 pairs (X) / H5 = 2  =>  0 pairs (_)
D6,D8: 2.. / D6 = 2  =>  0 pairs (*) / D8 = 2  =>  0 pairs (X)
F5,F8: 2.. / F5 = 2  =>  0 pairs (X) / F8 = 2  =>  0 pairs (_)
C1,B2: 3.. / C1 = 3  =>  0 pairs (*) / B2 = 3  =>  0 pairs (X)
F1,E2: 3.. / F1 = 3  =>  0 pairs (X) / E2 = 3  =>  0 pairs (_)
H3,I3: 3.. / H3 = 3  => 23 pairs (_) / I3 = 3  => 23 pairs (_)
E5,F5: 3.. / E5 = 3  =>  0 pairs (X) / F5 = 3  =>  0 pairs (_)
H6,I6: 3.. / H6 = 3  => 23 pairs (_) / I6 = 3  => 23 pairs (_)
B7,C7: 3.. / B7 = 3  =>  0 pairs (*) / C7 = 3  =>  0 pairs (X)
C1,F1: 3.. / C1 = 3  =>  0 pairs (*) / F1 = 3  =>  0 pairs (X)
B2,E2: 3.. / B2 = 3  =>  0 pairs (X) / E2 = 3  =>  0 pairs (_)
B2,B7: 3.. / B2 = 3  =>  0 pairs (X) / B7 = 3  =>  0 pairs (_)
C1,C7: 3.. / C1 = 3  =>  0 pairs (*) / C7 = 3  =>  0 pairs (X)
E2,E5: 3.. / E2 = 3  =>  0 pairs (*) / E5 = 3  =>  0 pairs (X)
F1,F5: 3.. / F1 = 3  =>  0 pairs (X) / F5 = 3  =>  0 pairs (_)
H3,H6: 3.. / H3 = 3  => 23 pairs (_) / H6 = 3  => 23 pairs (_)
I3,I6: 3.. / I3 = 3  => 23 pairs (_) / I6 = 3  => 23 pairs (_)
C2,C3: 4.. / C2 = 4  => 19 pairs (_) / C3 = 4  =>  0 pairs (*)
F2,F3: 4.. / F2 = 4  =>  0 pairs (*) / F3 = 4  =>  0 pairs (X)
D4,D5: 4.. / D4 = 4  =>  0 pairs (*) / D5 = 4  =>  0 pairs (X)
G4,I5: 4.. / G4 = 4  =>  0 pairs (X) / I5 = 4  =>  0 pairs (_)
G7,I7: 4.. / G7 = 4  =>  0 pairs (*) / I7 = 4  =>  0 pairs (X)
C2,F2: 4.. / C2 = 4  => 19 pairs (_) / F2 = 4  =>  0 pairs (*)
C3,F3: 4.. / C3 = 4  =>  0 pairs (*) / F3 = 4  =>  0 pairs (X)
D4,G4: 4.. / D4 = 4  =>  0 pairs (*) / G4 = 4  =>  0 pairs (X)
D5,I5: 4.. / D5 = 4  =>  0 pairs (X) / I5 = 4  =>  0 pairs (_)
G4,G7: 4.. / G4 = 4  =>  0 pairs (X) / G7 = 4  =>  0 pairs (_)
I5,I7: 4.. / I5 = 4  =>  0 pairs (*) / I7 = 4  =>  0 pairs (X)
C1,B3: 5.. / C1 = 5  =>  0 pairs (X) / B3 = 5  =>  0 pairs (_)
A5,A6: 5.. / A5 = 5  => 25 pairs (_) / A6 = 5  =>  0 pairs (X)
B7,C7: 5.. / B7 = 5  =>  0 pairs (X) / C7 = 5  =>  0 pairs (_)
C1,G1: 5.. / C1 = 5  =>  0 pairs (X) / G1 = 5  =>  0 pairs (_)
A5,H5: 5.. / A5 = 5  => 25 pairs (_) / H5 = 5  =>  0 pairs (X)
B3,B7: 5.. / B3 = 5  =>  0 pairs (*) / B7 = 5  =>  0 pairs (X)
C1,C7: 5.. / C1 = 5  =>  0 pairs (X) / C7 = 5  =>  0 pairs (_)
F2,F3: 6.. / F2 = 6  => 19 pairs (_) / F3 = 6  =>  0 pairs (*)
D5,D6: 6.. / D5 = 6  =>  0 pairs (*) / D6 = 6  =>  0 pairs (X)
F2,I2: 6.. / F2 = 6  => 19 pairs (_) / I2 = 6  =>  0 pairs (*)
D5,I5: 6.. / D5 = 6  =>  0 pairs (*) / I5 = 6  =>  0 pairs (X)
G3,G6: 6.. / G3 = 6  => 20 pairs (_) / G6 = 6  =>  0 pairs (*)
B2,B3: 7.. / B2 = 7  =>  0 pairs (*) / B3 = 7  =>  0 pairs (X)
F1,E2: 7.. / F1 = 7  =>  0 pairs (*) / E2 = 7  =>  0 pairs (X)
A5,A6: 7.. / A5 = 7  =>  0 pairs (X) / A6 = 7  => 25 pairs (_)
D8,F8: 7.. / D8 = 7  =>  0 pairs (*) / F8 = 7  =>  0 pairs (X)
F1,G1: 7.. / F1 = 7  =>  0 pairs (*) / G1 = 7  =>  0 pairs (X)
B2,E2: 7.. / B2 = 7  =>  0 pairs (*) / E2 = 7  =>  0 pairs (X)
D4,G4: 7.. / D4 = 7  =>  0 pairs (X) / G4 = 7  =>  0 pairs (_)
E2,E5: 7.. / E2 = 7  =>  0 pairs (X) / E5 = 7  =>  0 pairs (_)
* DURATION: 0:01:57.683536  START: 09:52:27.259977  END: 09:54:24.943513 2017-05-04
* CP COUNT: (52)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A5,A6,B2,B3,B7,C1,C2,C3,C7,D4,D5,D8,E2,E5,F1,F2,F3,F8,G1,G4,H7,I2,I5)
* 69.12..488..5..19.1..98....326.58.19.19...8...48.19...9..861...481.9.365267345981
* PAIR B3: 5,7 ROW 3
G3: 5,7,2,6                              # reduction candidate for 5,7
G3: 5,7 => CTR
* 69.12..488..5..19.1..98....326.58.19.19...8...48.196..9..861274481.9.365267345981
G3: 2,6                                  # 25 pairs
H3: 5,7,2,3                              # reduction candidate for 5,7
H3: 5,7                                  # 25 pairs
* PAIR F1: 3,7 COL F
F5: 3,7,2                                # reduction candidate for 3,7
F5: 3,7 => SOLVED
* 693127548872534196154986237326458719519673824748219653935861472481792365267345981
F5: 2 => CTR
* 69.12374883.57.19.17.98....326758419.194328.6.48619...953861274481297365267345981
* PAIR G1: 5,7 BLK 3
G3: 5,7,2,6                              # reduction candidate for 5,7
G3: 5,7 => CTR
* 69.12..488..5..19.1..98....326.58.19.19...8...48.196..9..861274481.9.365267345981
G3: 2,6                                  # 25 pairs
H3: 5,7,2,3                              # reduction candidate for 5,7
H3: 5,7                                  # 25 pairs
* PAIR G1: 5,7 COL G
G6: 5,7,2,6                              # reduction candidate for 5,7
G6: 5,7 => CTR
* 69.1237488..5.61921.29846..326.58419.194..8.6.48619.239..861274481297365267345981
G6: 2,6                                  # 24 pairs
* PAIR I2: 2,6 BLK 3
G3: 2,6,5,7                              # reduction candidate for 2,6
G3: 2,6                                  # 25 pairs
I3: 2,6,3,7                              # reduction candidate for 2,6
I3: 2,6 => CTR
* 69.12..488..5..19.1..98..3.326.58.19.19...8.4.48.196.39..861427481.9.365267345981
I3: 3,7                                  # 24 pairs
* PAIR I2: 2,6 COL I
I6: 2,6,3,7                              # reduction candidate for 2,6
I6: 2,6 => CTR
* 69.12..488..5..19.1..98...3326458719.196.2854548719.3.9..861427481297365267345981
I6: 3,7                                  # 24 pairs
* PAIR A5: 5,7 ROW 5
H5: 5,7,2                                # reduction candidate for 5,7
H5: 5,7 => CTR
* 69.12374883.57.19.17.98....326758419.194328.6.48619...953861274481297365267345981
H5: 2 => SOLVED
* 693127548872534196154986237326458719519673824748219653935861472481792365267345981
* PAIR A6: 5,7 ROW 6
G6: 5,7,2,6                              # reduction candidate for 5,7
G6: 5,7 => CTR
* 69.1237488..5.61921.29846..326.58419.194..8.6.48619.239..861274481297365267345981
G6: 2,6                                  # 24 pairs
H6: 5,7,2,3                              # reduction candidate for 5,7
H6: 5,7                                  # 26 pairs
* PAIR E5: 3,7 BLK 5
F5: 3,7,2                                # reduction candidate for 3,7
F5: 3,7 => SOLVED
* 693127548872534196154986237326458719519673824748219653935861472481792365267345981
F5: 2 => CTR
* 69.12374883.57.19.17.98....326758419.194328.6.48619...953861274481297365267345981
* PAIR G4: 4,7 COL G
G7: 4,7,2                                # reduction candidate for 4,7
G7: 4,7 => SOLVED
* 693127548872534196154986237326458719519673824748219653935861472481792365267345981
G7: 2 => CTR
* 69.12374883.576192172984653326758419.194..8.6.48619...9..861274481297365267345981
* PAIR D8: 2,7 COL D
D6: 2,7,6                                # reduction candidate for 2,7
D6: 2,7 => SOLVED
* 693127548872534196154986237326458719519673824748219653935861472481792365267345981
D6: 6 => CTR
* 69.12374883.57.19.17.98.653326758419519432876.48619...9..861...481297365267345981
* PAIR F8: 2,7 COL F
F5: 2,7,3                                # reduction candidate for 2,7
F5: 2,7 => CTR
* 69.12374883.57.19.17.98....326758419.194328.6.48619...953861274481297365267345981
F5: 3 => SOLVED
* 693127548872534196154986237326458719519673824748219653935861472481792365267345981
* PAIR H7: 2,7 BLK 9
G7: 2,7,4                                # reduction candidate for 2,7
G7: 2,7 => CTR
* 69.12374883.576192172984653326758419519432876.48619...9..861..4481297365267345981
G7: 4 => SOLVED
* 693127548872534196154986237326458719519673824748219653935861472481792365267345981
I7: 2,7,4                                # reduction candidate for 2,7
I7: 2,7 => SOLVED
* 693127548872534196154986237326458719519673824748219653935861472481792365267345981
I7: 4 => CTR
* 69.12374883.576192172984653326758419519432876.48619...9..861..4481297365267345981
* PAIR H7: 2,7 COL H
H3: 2,7,3,5                              # reduction candidate for 2,7
H3: 2,7 => CTR
* 69.12374883.57.19.17.98.523326758419719432856548.19.3.9..861...481297365267345981
H3: 3,5                                  # 24 pairs
H5: 2,7,5                                # reduction candidate for 2,7
H5: 2,7                                  # 25 pairs
H6: 2,7,3,5                              # reduction candidate for 2,7
H6: 2,7 => CTR
* 69.12374883.57.19.17.98.53.326758419719432856548.19..39..861...481297365267345981
H6: 3,5                                  # 24 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-207-base-pr-000.dot
* REASONING
* DIS # G3: 5,7 => CTR => G3: 2,6
* PRF # F5: 3,7 => SOL
* DIS # F5: 2 => CTR => F5: 3,7
* DIS # G3: 5,7 => CTR => G3: 2,6
* DIS # G6: 5,7 => CTR => G6: 2,6
* DIS # I3: 2,6 => CTR => I3: 3,7
* DIS # I6: 2,6 => CTR => I6: 3,7
* DIS # H5: 5,7 => CTR => H5: 2
* PRF # H5: 2 => SOL
* DIS # G6: 5,7 => CTR => G6: 2,6
* PRF # F5: 3,7 => SOL
* DIS # F5: 2 => CTR => F5: 3,7
* PRF # G7: 4,7 => SOL
* DIS # G7: 2 => CTR => G7: 4,7
* PRF # D6: 2,7 => SOL
* DIS # D6: 6 => CTR => D6: 2,7
* DIS # F5: 2,7 => CTR => F5: 3
* PRF # F5: 3 => SOL
* DIS # G7: 2,7 => CTR => G7: 4
* PRF # G7: 4 => SOL
* PRF # I7: 2,7 => SOL
* DIS # I7: 4 => CTR => I7: 2,7
* DIS # H3: 2,7 => CTR => H3: 3,5
* DIS # H6: 2,7 => CTR => H6: 3,5
* CNT  24 HDP CHAINS /  37 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A5,A6,B2,B3,B7,C1,C2,C3,C7,D4,D5,D8,E2,E5,F1,F2,F3,F8,G1,G4,H7,I2,I5)
* 69.12..488..5..19.1..98....326.58.19.19...8...48.19...9..861...481.9.365267345981
* PAIR B3: 5,7 ROW 3
G3: 5,7,2,6                              # reduction candidate for 5,7
G3: 5,7 => CTR
* 69.12..488..5..19.1..98....326.58.19.19...8...48.196..9..861274481.9.365267345981
H3: 5,7,3                                # reduction candidate for 5,7
H3: 5,7                                  # 25 pairs
* RESTART
* PAIR B3: 5,7 ROW 3
H3: 5,7,3                                # reduction candidate for 5,7
H3: 3 => SOLVED
* 693127548872534196154986237326458719519673824748219653935861472481792365267345981
* DURATION: 0:00:06.094130  START: 09:55:14.818139  END: 09:55:20.912269 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-207-base-pr-001.dot
* REASONING
* DIS # G3: 5,7 => CTR => G3: 2,6
* PRF G3: 2,6 # H3: 3 => SOL
* STA G3: 2,6 + H3: 3
* CNT   2 HDP CHAINS /   4 HYP OPENED

Header Info

Top 500 Minimum 17 207

solution: 693127548872534196154986237326458719519673824748219653935861472481792365267345981
info: 1910     FNBTHWY  S8.f     3217

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

Solution

position: 693127548872534196154986237326458719519673824748219653935861472481792365267345981 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 # G3: 5,7 => CTR => G3: 2,6
* INC # G3: 2,6 => UNS
* INC # H3: 5,7 => UNS
* PRF # F5: 3,7 => SOL
* DIS # F5: 2 => CTR => F5: 3,7
* DIS # G3: 5,7 => CTR => G3: 2,6
* INC # G3: 2,6 => UNS
* INC # H3: 5,7 => UNS
* DIS # G6: 5,7 => CTR => G6: 2,6
* INC # G6: 2,6 => UNS
* INC # G3: 2,6 => UNS
* DIS # I3: 2,6 => CTR => I3: 3,7
* INC # I3: 3,7 => UNS
* DIS # I6: 2,6 => CTR => I6: 3,7
* INC # I6: 3,7 => UNS
* DIS # H5: 5,7 => CTR => H5: 2
* PRF # H5: 2 => SOL
* DIS # G6: 5,7 => CTR => G6: 2,6
* INC # G6: 2,6 => UNS
* INC # H6: 5,7 => UNS
* PRF # F5: 3,7 => SOL
* DIS # F5: 2 => CTR => F5: 3,7
* PRF # G7: 4,7 => SOL
* DIS # G7: 2 => CTR => G7: 4,7
* PRF # D6: 2,7 => SOL
* DIS # D6: 6 => CTR => D6: 2,7
* DIS # F5: 2,7 => CTR => F5: 3
* PRF # F5: 3 => SOL
* DIS # G7: 2,7 => CTR => G7: 4
* PRF # G7: 4 => SOL
* PRF # I7: 2,7 => SOL
* DIS # I7: 4 => CTR => I7: 2,7
* DIS # H3: 2,7 => CTR => H3: 3,5
* INC # H3: 3,5 => UNS
* INC # H5: 2,7 => UNS
* DIS # H6: 2,7 => CTR => H6: 3,5
* INC # H6: 3,5 => UNS
* CNT  37 HDP CHAINS /  37 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # G3: 5,7 => CTR => G3: 2,6
* INC G3: 2,6 # H3: 5,7 => UNS
* INC G3: 2,6 # H3: 5,7 => UNS
* PRF G3: 2,6 # H3: 3 => SOL
* STA G3: 2,6 + H3: 3
* CNT   4 HDP CHAINS /   4 HYP OPENED