Analysis of xx-top500-127-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: ..3.5.......8..4...7............8.73.2.....5.9..1.....8.....1..4....6.......7.... initial

Autosolve

position: .83754.195198..4.7.74.1.3851465.8.73728....519351.78..8.72.51..451.867.23.2.715.8 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # E5: 3,6 => CTR => E5: 4,9
* DIS # D5: 6,9 => CTR => D5: 3,4
* PRF # D5: 3,4 => SOL
* PRF # H6: 2,6 => SOL
* DIS # H6: 4 => CTR => H6: 2,6
* DIS # D5: 3,9 => CTR => D5: 4,6
* PRF # E5: 3,9 => SOL
* PRF # H6: 2,6 => SOL
* DIS # H6: 4 => CTR => H6: 2,6
* DIS # D5: 6,9 => CTR => D5: 3,4
* PRF # D5: 3,4 => SOL
* PRF # E5: 6,9 => SOL
* DIS # H6: 4,6 => CTR => H6: 2
* PRF # H6: 2 => SOL
* DIS # H7: 6,9 => CTR => H7: 3,4
* PRF # H9: 4 => SOL
* PRF # E7: 4 => SOL
* DIS # D5: 3,9 => CTR => D5: 4,6
* DIS # E7: 3 => CTR => E7: 4,9
* PRF # H9: 4,9 => SOL
* DIS # H9: 6 => CTR => H9: 4,9
* PRF # D5: 4,9 => SOL
* DIS # H7: 4,6 => CTR => H7: 3,9
* DIS # H7: 4,6 => CTR => H7: 3,9
* 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 # E5: 3,6 => CTR => E5: 4,9
* DIS E5: 4,9 # D5: 6,9 => CTR => D5: 3,4
* PRF E5: 4,9 + D5: 3,4 => SOL
* STA E5: 4,9 + D5: 3,4
* CNT   3 HDP CHAINS /   2 HYP OPENED

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

Details

Positions

..3.5.......8..4...7............8.73.2.....5.9..1.....8.....1..4....6.......7.... initial
.83754.195198..4.7.74.1.3851465.8.73728....519351.78..8.72.51..451.867.23.2.715.8 autosolve
683754219519832467274619385146528973728493651935167824897245136451386792362971548 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (20)
A1: 2,6
A3: 2,6
E2: 3,6
F2: 2,3
D3: 6,9
F3: 2,9
G1: 2,6
H2: 2,6
E4: 2,9
F5: 3,9
E6: 2,6
G4: 2,9
G5: 6,9
I6: 4,6
B7: 6,9
B9: 6,9
D8: 3,9
D9: 4,9
I7: 4,6
H8: 3,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
A1,A3: 2.. / A1 = 2  =>  0 pairs (X) / A3 = 2  =>  0 pairs (_)
F2,F3: 2.. / F2 = 2  =>  0 pairs (*) / F3 = 2  =>  0 pairs (X)
G1,H2: 2.. / G1 = 2  =>  0 pairs (*) / H2 = 2  =>  0 pairs (X)
E4,E6: 2.. / E4 = 2  =>  0 pairs (*) / E6 = 2  =>  0 pairs (X)
G4,H6: 2.. / G4 = 2  =>  0 pairs (X) / H6 = 2  =>  0 pairs (_)
A1,G1: 2.. / A1 = 2  =>  0 pairs (X) / G1 = 2  =>  0 pairs (_)
F2,H2: 2.. / F2 = 2  =>  0 pairs (*) / H2 = 2  =>  0 pairs (X)
A3,F3: 2.. / A3 = 2  =>  0 pairs (*) / F3 = 2  =>  0 pairs (X)
E4,G4: 2.. / E4 = 2  =>  0 pairs (*) / G4 = 2  =>  0 pairs (X)
E6,H6: 2.. / E6 = 2  =>  0 pairs (X) / H6 = 2  =>  0 pairs (_)
G1,G4: 2.. / G1 = 2  =>  0 pairs (*) / G4 = 2  =>  0 pairs (X)
H2,H6: 2.. / H2 = 2  =>  0 pairs (X) / H6 = 2  =>  0 pairs (_)
E2,F2: 3.. / E2 = 3  =>  0 pairs (*) / F2 = 3  =>  0 pairs (X)
E7,D8: 3.. / E7 = 3  =>  0 pairs (X) / D8 = 3  => 20 pairs (_)
H7,H8: 3.. / H7 = 3  => 20 pairs (_) / H8 = 3  =>  0 pairs (X)
E7,H7: 3.. / E7 = 3  =>  0 pairs (X) / H7 = 3  => 20 pairs (_)
D8,H8: 3.. / D8 = 3  => 20 pairs (_) / H8 = 3  =>  0 pairs (X)
D5,D8: 3.. / D5 = 3  =>  0 pairs (X) / D8 = 3  => 20 pairs (_)
F2,F5: 3.. / F2 = 3  =>  0 pairs (X) / F5 = 3  =>  0 pairs (_)
D5,E5: 4.. / D5 = 4  =>  0 pairs (*) / E5 = 4  =>  0 pairs (X)
H6,I6: 4.. / H6 = 4  =>  0 pairs (X) / I6 = 4  =>  0 pairs (_)
E7,D9: 4.. / E7 = 4  =>  0 pairs (*) / D9 = 4  =>  0 pairs (X)
D9,H9: 4.. / D9 = 4  => 21 pairs (_) / H9 = 4  =>  0 pairs (*)
D5,D9: 4.. / D5 = 4  =>  0 pairs (*) / D9 = 4  =>  0 pairs (X)
E5,E7: 4.. / E5 = 4  => 21 pairs (_) / E7 = 4  =>  0 pairs (*)
I6,I7: 4.. / I6 = 4  =>  0 pairs (*) / I7 = 4  =>  0 pairs (X)
A1,A3: 6.. / A1 = 6  =>  0 pairs (*) / A3 = 6  =>  0 pairs (X)
E2,D3: 6.. / E2 = 6  =>  0 pairs (X) / D3 = 6  =>  0 pairs (_)
G1,H2: 6.. / G1 = 6  =>  0 pairs (X) / H2 = 6  =>  0 pairs (_)
B7,B9: 6.. / B7 = 6  =>  0 pairs (X) / B9 = 6  =>  0 pairs (_)
A1,G1: 6.. / A1 = 6  =>  0 pairs (*) / G1 = 6  =>  0 pairs (X)
E2,H2: 6.. / E2 = 6  =>  0 pairs (X) / H2 = 6  =>  0 pairs (_)
A3,D3: 6.. / A3 = 6  =>  0 pairs (X) / D3 = 6  =>  0 pairs (_)
B9,H9: 6.. / B9 = 6  =>  0 pairs (*) / H9 = 6  =>  0 pairs (X)
D3,D5: 6.. / D3 = 6  =>  0 pairs (*) / D5 = 6  =>  0 pairs (X)
G1,G5: 6.. / G1 = 6  =>  0 pairs (X) / G5 = 6  =>  0 pairs (_)
I6,I7: 6.. / I6 = 6  =>  0 pairs (X) / I7 = 6  =>  0 pairs (_)
D3,F3: 9.. / D3 = 9  =>  0 pairs (X) / F3 = 9  =>  0 pairs (_)
G4,G5: 9.. / G4 = 9  =>  0 pairs (*) / G5 = 9  =>  0 pairs (X)
B7,B9: 9.. / B7 = 9  =>  0 pairs (*) / B9 = 9  =>  0 pairs (X)
E4,G4: 9.. / E4 = 9  =>  0 pairs (X) / G4 = 9  =>  0 pairs (_)
D8,H8: 9.. / D8 = 9  =>  0 pairs (X) / H8 = 9  => 20 pairs (_)
F3,F5: 9.. / F3 = 9  =>  0 pairs (*) / F5 = 9  =>  0 pairs (X)
* DURATION: 0:01:12.919026  START: 07:06:00.858171  END: 07:07:13.777197 2017-05-04
* CP COUNT: (43)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,A3,B7,B9,D3,D8,D9,E2,E4,E6,F2,F3,F5,G1,G4,G5,H2,H8,I6,I7)
* .83754.195198..4.7.74.1.3851465.8.73728....519351.78..8.72.51..451.867.23.2.715.8
* PAIR E2: 3,6 COL E
E5: 3,6,4,9                              # reduction candidate for 3,6
E5: 3,6 => CTR
* .83754.195198..4.7.746193851465982737284.395193512786.8.7245136451386792362971548
E5: 4,9                                  # 21 pairs
* PAIR D3: 6,9 COL D
D5: 6,9,3,4                              # reduction candidate for 6,9
D5: 6,9 => CTR
* .83754.195198..4.7.74.1.3851465.8.73728.43.519351.78..8.72.51..4513867923.2471568
D5: 3,4 => SOLVED
* 683754219519832467274619385146528973728493651935167824897245136451386792362971548
* PAIR H2: 2,6 COL H
H6: 2,6,4                                # reduction candidate for 2,6
H6: 2,6 => SOLVED
* 683754219519832467274619385146528973728493651935167824897245136451386792362971548
H6: 4 => CTR
* .83754.195198..427.74.123851465.8273728..9.519351.78..8.72.51..451.867.23.2.715.8
* PAIR F5: 3,9 BLK 5
D5: 3,9,4,6                              # reduction candidate for 3,9
D5: 3,9 => CTR
* .83754.195198..4.7.746193851465.8.73728.436519351678248.72.51464513867923.2.715.8
D5: 4,6                                  # 21 pairs
E5: 3,9,4,6                              # reduction candidate for 3,9
E5: 3,9 => SOLVED
* 683754219519832467274619385146528973728493651935167824897245136451386792362971548
E5: 4,6                                  # 21 pairs
* PAIR E6: 2,6 ROW 6
H6: 2,6,4                                # reduction candidate for 2,6
H6: 2,6 => SOLVED
* 683754219519832467274619385146528973728493651935167824897245136451386792362971548
H6: 4 => CTR
* .83754.195198..427.74.123851465.8273728..9.519351.78..8.72.51..451.867.23.2.715.8
* PAIR G5: 6,9 ROW 5
D5: 6,9,3,4                              # reduction candidate for 6,9
D5: 6,9 => CTR
* .83754.195198..4.7.74.1.3851465.8.73728.43.519351.78..8.72.51..4513867923.2471568
D5: 3,4 => SOLVED
* 683754219519832467274619385146528973728493651935167824897245136451386792362971548
E5: 6,9,3,4                              # reduction candidate for 6,9
E5: 6,9 => SOLVED
* 683754219519832467274619385146528973728493651935167824897245136451386792362971548
E5: 3,4                                  # 21 pairs
* PAIR I6: 4,6 BLK 6
H6: 4,6,2                                # reduction candidate for 4,6
H6: 4,6 => CTR
* .83754.195198..427.74.123851465.8273728..9.519351.78..8.72.51..451.867.23.2.715.8
H6: 2 => SOLVED
* 683754219519832467274619385146528973728493651935167824897245136451386792362971548
* PAIR B7: 6,9 ROW 7
H7: 6,9,3,4                              # reduction candidate for 6,9
H7: 6,9 => CTR
* .83754.195198..4.7.74.1.3851465.8.73728....519351.78..8.72351.44519867323.24715.8
H7: 3,4                                  # 21 pairs
* PAIR B9: 6,9 ROW 9
H9: 6,9,4                                # reduction candidate for 6,9
H9: 4 => SOLVED
* 683754219519832467274619385146528973728493651935167824897245136451386792362971548
H9: 6,9                                  # 21 pairs
* PAIR D8: 3,9 BLK 8
E7: 3,9,4                                # reduction candidate for 3,9
E7: 4 => SOLVED
* 683754219519832467274619385146528973728493651935167824897245136451386792362971548
E7: 3,9                                  # 21 pairs
* PAIR D8: 3,9 COL D
D5: 3,9,4,6                              # reduction candidate for 3,9
D5: 3,9 => CTR
* .83754.195198..4.7.746193851465.8.73728.436519351678248.72.51464513867923.2.715.8
D5: 4,6                                  # 21 pairs
* PAIR D9: 4,9 BLK 8
E7: 4,9,3                                # reduction candidate for 4,9
E7: 3 => CTR
* .83754.195198..4.7.74.1.3851465.8.73728.4..519351.78..8.72351..4519867323.24715.8
E7: 4,9                                  # 20 pairs
* PAIR D9: 4,9 ROW 9
H9: 4,9,6                                # reduction candidate for 4,9
H9: 4,9 => SOLVED
* 683754219519832467274619385146528973728493651935167824897245136451386792362971548
H9: 6 => CTR
* .837546195198634276749123851465.82737286...519351.78..8.72.51..451.867.23.2471568
* PAIR D9: 4,9 COL D
D5: 4,9,3,6                              # reduction candidate for 4,9
D5: 4,9 => SOLVED
* 683754219519832467274619385146528973728493651935167824897245136451386792362971548
D5: 3,6                                  # 22 pairs
* PAIR I7: 4,6 BLK 9
H7: 4,6,3,9                              # reduction candidate for 4,6
H7: 4,6 => CTR
* .83754.195198..4.7.74.1.3851465.8.73728....519351.78..8.72351..4519867323.2471598
H7: 3,9                                  # 22 pairs
H9: 4,6,9                                # reduction candidate for 4,6
H9: 4,6                                  # 22 pairs
* PAIR H8: 3,9 BLK 9
H7: 3,9,4,6                              # reduction candidate for 3,9
H7: 4,6 => CTR
* .83754.195198..4.7.74.1.3851465.8.73728....519351.78..8.72351..4519867323.2471598
H7: 3,9                                  # 22 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-127-base-pr-000.dot
* REASONING
* DIS # E5: 3,6 => CTR => E5: 4,9
* DIS # D5: 6,9 => CTR => D5: 3,4
* PRF # D5: 3,4 => SOL
* PRF # H6: 2,6 => SOL
* DIS # H6: 4 => CTR => H6: 2,6
* DIS # D5: 3,9 => CTR => D5: 4,6
* PRF # E5: 3,9 => SOL
* PRF # H6: 2,6 => SOL
* DIS # H6: 4 => CTR => H6: 2,6
* DIS # D5: 6,9 => CTR => D5: 3,4
* PRF # D5: 3,4 => SOL
* PRF # E5: 6,9 => SOL
* DIS # H6: 4,6 => CTR => H6: 2
* PRF # H6: 2 => SOL
* DIS # H7: 6,9 => CTR => H7: 3,4
* PRF # H9: 4 => SOL
* PRF # E7: 4 => SOL
* DIS # D5: 3,9 => CTR => D5: 4,6
* DIS # E7: 3 => CTR => E7: 4,9
* PRF # H9: 4,9 => SOL
* DIS # H9: 6 => CTR => H9: 4,9
* PRF # D5: 4,9 => SOL
* DIS # H7: 4,6 => CTR => H7: 3,9
* DIS # H7: 4,6 => CTR => H7: 3,9
* CNT  24 HDP CHAINS /  37 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,A3,B7,B9,D3,D8,D9,E2,E4,E6,F2,F3,F5,G1,G4,G5,H2,H8,I6,I7)
* .83754.195198..4.7.74.1.3851465.8.73728....519351.78..8.72.51..451.867.23.2.715.8
* PAIR E2: 3,6 COL E
E5: 3,6,4,9                              # reduction candidate for 3,6
E5: 3,6 => CTR
* .83754.195198..4.7.746193851465982737284.395193512786.8.7245136451386792362971548
* PAIR RESTART
* PAIR D3: 6,9 COL D
D5: 6,9,3,4                              # reduction candidate for 6,9
D5: 6,9 => CTR
* .83754.195198..4.7.74.1.3851465.8.73728.43.519351.78..8.72.51..4513867923.2471568
D5: 3,4 => SOLVED
* 683754219519832467274619385146528973728493651935167824897245136451386792362971548
* DURATION: 0:00:05.002275  START: 07:07:52.979336  END: 07:07:57.981611 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-127-base-pr-001.dot
* REASONING
* DIS # E5: 3,6 => CTR => E5: 4,9
* DIS E5: 4,9 # D5: 6,9 => CTR => D5: 3,4
* PRF E5: 4,9 + D5: 3,4 => SOL
* STA E5: 4,9 + D5: 3,4
* CNT   3 HDP CHAINS /   2 HYP OPENED

Header Info

Top 500 Minimum 17 127

solution: 683754219519832467274619385146528973728493651935167824897245136451386792362971548
info: 1809     FNBWY    S8.f     13471

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

Solution

position: 683754219519832467274619385146528973728493651935167824897245136451386792362971548 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 # E5: 3,6 => CTR => E5: 4,9
* INC # E5: 4,9 => UNS
* DIS # D5: 6,9 => CTR => D5: 3,4
* PRF # D5: 3,4 => SOL
* PRF # H6: 2,6 => SOL
* DIS # H6: 4 => CTR => H6: 2,6
* DIS # D5: 3,9 => CTR => D5: 4,6
* INC # D5: 4,6 => UNS
* PRF # E5: 3,9 => SOL
* INC # E5: 4,6 => UNS
* PRF # H6: 2,6 => SOL
* DIS # H6: 4 => CTR => H6: 2,6
* DIS # D5: 6,9 => CTR => D5: 3,4
* PRF # D5: 3,4 => SOL
* PRF # E5: 6,9 => SOL
* INC # E5: 3,4 => UNS
* DIS # H6: 4,6 => CTR => H6: 2
* PRF # H6: 2 => SOL
* DIS # H7: 6,9 => CTR => H7: 3,4
* INC # H7: 3,4 => UNS
* INC # H9: 6,9 => UNS
* PRF # H9: 4 => SOL
* INC # E7: 3,9 => UNS
* PRF # E7: 4 => SOL
* DIS # D5: 3,9 => CTR => D5: 4,6
* INC # D5: 4,6 => UNS
* INC # E7: 4,9 => UNS
* DIS # E7: 3 => CTR => E7: 4,9
* PRF # H9: 4,9 => SOL
* DIS # H9: 6 => CTR => H9: 4,9
* PRF # D5: 4,9 => SOL
* INC # D5: 3,6 => UNS
* DIS # H7: 4,6 => CTR => H7: 3,9
* INC # H7: 3,9 => UNS
* INC # H9: 4,6 => UNS
* INC # H7: 3,9 => UNS
* DIS # H7: 4,6 => CTR => H7: 3,9
* CNT  37 HDP CHAINS /  37 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # E5: 3,6 => CTR => E5: 4,9
* DIS E5: 4,9 # D5: 6,9 => CTR => D5: 3,4
* PRF E5: 4,9 + D5: 3,4 => SOL
* STA E5: 4,9 + D5: 3,4
* CNT   3 HDP CHAINS /   2 HYP OPENED