Analysis of xx-top500-462-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: ...28..3.1.5...6.....9......8....32.7...1.............4.....1.5.2.8.............. initial

Autosolve

position: 6..281539195...6828329...1..8....3217...128..21...8...4.8.2.1.5.218....33..1..2.8 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # G6: 4,7 => CTR => G6: 9
* DIS # C5: 4,6 => CTR => C5: 3,9
* DIS # D5: 4,6 => CTR => D5: 3,5
* DIS # B9: 6,7 => CTR => B9: 5
* DIS # F7: 6,7 => CTR => F7: 3,9
* DIS # H7: 6,7 => CTR => H7: 9
* PRF # E8: 5,9 => SOL
* CNT   7 HDP CHAINS /  27 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 # G6: 4,7 => CTR => G6: 9
* DIS G6: 9 # I6: 4,7 => CTR => I6: 6
* PRF G6: 9 + I6: 6 => SOL
* STA G6: 9 + I6: 6
* CNT   3 HDP CHAINS /   6 HYP OPENED

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

Details

Positions

...28..3.1.5...6.....9......8....32.7...1.............4.....1.5.2.8.............. initial
6..281539195...6828329...1..8....3217...128..21...8...4.8.2.1.5.218....33..1..2.8 autosolve
647281539195437682832965417584796321769312854213548976478623195921854763356179248 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (10)
B1: 4,7
C1: 4,7
E3: 5,6
F3: 5,6
G3: 4,7
I3: 4,7
A4: 5,9
I5: 4,6
B7: 6,7
A8: 5,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
C5,C6: 3.. / C5 = 3  =>  0 pairs (X) / C6 = 3  => 17 pairs (_)
D7,F7: 3.. / D7 = 3  =>  0 pairs (X) / F7 = 3  => 17 pairs (_)
C5,D5: 3.. / C5 = 3  =>  0 pairs (X) / D5 = 3  => 17 pairs (_)
E2,E6: 3.. / E2 = 3  => 17 pairs (_) / E6 = 3  =>  0 pairs (X)
F2,F7: 3.. / F2 = 3  =>  0 pairs (X) / F7 = 3  => 17 pairs (_)
B1,C1: 4.. / B1 = 4  => 10 pairs (_) / C1 = 4  =>  0 pairs (X)
G3,I3: 4.. / G3 = 4  => 12 pairs (_) / I3 = 4  => 11 pairs (_)
B1,B5: 4.. / B1 = 4  => 10 pairs (_) / B5 = 4  =>  0 pairs (X)
E3,F3: 5.. / E3 = 5  =>  8 pairs (_) / F3 = 5  =>  8 pairs (_)
A4,B5: 5.. / A4 = 5  => 17 pairs (_) / B5 = 5  =>  0 pairs (X)
H5,H6: 5.. / H5 = 5  => 17 pairs (_) / H6 = 5  => 12 pairs (_)
A8,B9: 5.. / A8 = 5  =>  0 pairs (X) / B9 = 5  => 17 pairs (_)
A4,D4: 5.. / A4 = 5  => 17 pairs (_) / D4 = 5  =>  0 pairs (X)
D6,H6: 5.. / D6 = 5  => 17 pairs (_) / H6 = 5  => 12 pairs (_)
A4,A8: 5.. / A4 = 5  => 17 pairs (_) / A8 = 5  =>  0 pairs (X)
B5,B9: 5.. / B5 = 5  =>  0 pairs (X) / B9 = 5  => 17 pairs (_)
E3,F3: 6.. / E3 = 6  =>  8 pairs (_) / F3 = 6  =>  8 pairs (_)
I5,I6: 6.. / I5 = 6  => 12 pairs (_) / I6 = 6  => 10 pairs (_)
B1,C1: 7.. / B1 = 7  =>  0 pairs (X) / C1 = 7  => 10 pairs (_)
G3,I3: 7.. / G3 = 7  => 11 pairs (_) / I3 = 7  => 12 pairs (_)
C1,C9: 7.. / C1 = 7  => 10 pairs (_) / C9 = 7  =>  0 pairs (X)
I3,I6: 7.. / I3 = 7  => 12 pairs (_) / I6 = 7  => 11 pairs (_)
A8,C9: 9.. / A8 = 9  => 17 pairs (_) / C9 = 9  =>  0 pairs (X)
C5,H5: 9.. / C5 = 9  => 17 pairs (_) / H5 = 9  =>  0 pairs (X)
F7,H7: 9.. / F7 = 9  =>  0 pairs (X) / H7 = 9  => 17 pairs (_)
A4,A8: 9.. / A4 = 9  =>  0 pairs (X) / A8 = 9  => 17 pairs (_)
G6,G8: 9.. / G6 = 9  => 17 pairs (_) / G8 = 9  =>  0 pairs (X)
* DURATION: 0:00:46.958929  START: 18:30:43.106095  END: 18:31:30.065024 2017-05-04
* CP COUNT: (27)
* CLUE FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A4,A8,B1,B7,C1,E3,F3,G3,I3,I5)
* 6..281539195...6828329...1..8....3217...128..21...8...4.8.2.1.5.218....33..1..2.8
* PAIR E3: 5,6 COL E
E8: 5,6,4,7,9                            # reduction candidate for 5,6
E8: 5,6                                  # 11 pairs
E9: 5,6,4,7,9                            # reduction candidate for 5,6
E9: 5,6                                  # 11 pairs
* PAIR F3: 5,6 COL F
F8: 5,6,4,7,9                            # reduction candidate for 5,6
F8: 5,6                                  # 11 pairs
F9: 5,6,4,7,9                            # reduction candidate for 5,6
F9: 5,6                                  # 11 pairs
* PAIR G3: 4,7 COL G
G6: 4,7,9                                # reduction candidate for 4,7
G6: 4,7 => CTR
* 647281539195.3.6828329...1.98.5..32175..1289.21..98.5.4.83291.55218..9.33.91..2.8
G6: 9                                    # 17 pairs
G8: 4,7,9                                # reduction candidate for 4,7
G8: 4,7                                  # 17 pairs
* PAIR I3: 4,7 COL I
I6: 4,7,6                                # reduction candidate for 4,7
I6: 4,7                                  # 12 pairs
I6: 6                                    # 10 pairs
* PAIR I5: 4,6 BLK 6
I6: 4,6,7                                # reduction candidate for 4,6
I6: 4,6                                  # 12 pairs
I6: 7                                    # 11 pairs
* PAIR I5: 4,6 ROW 5
B5: 4,6,5                                # reduction candidate for 4,6
B5: 4,6                                  # 17 pairs
C5: 4,6,3,9                              # reduction candidate for 4,6
C5: 4,6 => CTR
* 6..281539195...6828329...1..8....3217..31289.213.98.5.4.8.2.1.5.218....33..1..2.8
C5: 3,9                                  # 11 pairs
D5: 4,6,3,5                              # reduction candidate for 4,6
D5: 4,6 => CTR
* 6.7281539195..36828329...1.98.5..3217.3.1289.21...8.5.4.8.291.5.218..9.33.91..2.8
D5: 3,5                                  # 11 pairs
* PAIR B7: 6,7 BLK 7
B9: 6,7,5                                # reduction candidate for 6,7
B9: 6,7 => CTR
* 647281539195.3.6828329...1.98.5..32175..1289.21..98.5.4.83291.55218..9.33.91..2.8
B9: 5                                    # 17 pairs
C9: 6,7,9                                # reduction candidate for 6,7
C9: 6,7                                  # 17 pairs
* PAIR B7: 6,7 ROW 7
D7: 6,7,3                                # reduction candidate for 6,7
D7: 6,7                                  # 17 pairs
F7: 6,7,3,9                              # reduction candidate for 6,7
F7: 6,7 => CTR
* 6..281539195..36828329...1..8....3217...128..21..38...4.832.195.218....33..1..2.8
F7: 3,9                                  # 11 pairs
H7: 6,7,9                                # reduction candidate for 6,7
H7: 6,7 => CTR
* 6..281539195..36828329...1..8..9.3217.3.1289.219.38.5.4.83291.59218....335.1..2.8
H7: 9                                    # 17 pairs
* PAIR A8: 5,9 ROW 8
E8: 5,9,4,6,7                            # reduction candidate for 5,9
E8: 5,9 => SOLVED
* 647281539195437682832965417584796321769312854213548976478623195921854763356179248
E8: 4,6,7                                # 10 pairs
F8: 5,9,4,6,7                            # reduction candidate for 5,9
F8: 5,9                                  # 15 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-462-base-pr-000.dot
* REASONING
* DIS # G6: 4,7 => CTR => G6: 9
* DIS # C5: 4,6 => CTR => C5: 3,9
* DIS # D5: 4,6 => CTR => D5: 3,5
* DIS # B9: 6,7 => CTR => B9: 5
* DIS # F7: 6,7 => CTR => F7: 3,9
* DIS # H7: 6,7 => CTR => H7: 9
* PRF # E8: 5,9 => SOL
* CNT   7 HDP CHAINS /  27 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A4,A8,B1,B7,C1,E3,F3,G3,I3,I5)
* 6..281539195...6828329...1..8....3217...128..21...8...4.8.2.1.5.218....33..1..2.8
* PAIR E3: 5,6 COL E
E8: 5,6,4,7,9                            # reduction candidate for 5,6
E8: 5,6                                  # 11 pairs
E9: 5,6,4,7,9                            # reduction candidate for 5,6
E9: 5,6                                  # 11 pairs
* PAIR F3: 5,6 COL F
F8: 5,6,4,7,9                            # reduction candidate for 5,6
F8: 5,6                                  # 11 pairs
F9: 5,6,4,7,9                            # reduction candidate for 5,6
F9: 5,6                                  # 11 pairs
* PAIR G3: 4,7 COL G
G6: 4,7,9                                # reduction candidate for 4,7
G6: 4,7 => CTR
* 647281539195.3.6828329...1.98.5..32175..1289.21..98.5.4.83291.55218..9.33.91..2.8
* RESTART
* PAIR RESTART
* PAIR I3: 4,7 COL I
I6: 4,7,6                                # reduction candidate for 4,7
I6: 4,7 => CTR
* 6..281539195.3.6828329...1.58....3217.93128562135689..4687231959218....33571..2.8
I6: 6 => SOLVED
* 647281539195437682832965417584796321769312854213548976478623195921854763356179248
* DURATION: 0:00:07.816034  START: 18:31:55.119191  END: 18:32:02.935225 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-462-base-pr-001.dot
* REASONING
* DIS # G6: 4,7 => CTR => G6: 9
* DIS G6: 9 # I6: 4,7 => CTR => I6: 6
* PRF G6: 9 + I6: 6 => SOL
* STA G6: 9 + I6: 6
* CNT   3 HDP CHAINS /   6 HYP OPENED

Header Info

Top 500 Minimum 17 462

solution: 647281539195437682832965417584796321769312854213548976478623195921854763356179248
info: 95545    FNBXYK   S8.f     8079

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

Solution

position: 647281539195437682832965417584796321769312854213548976478623195921854763356179248 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 # E8: 5,6 => UNS
* INC # E9: 5,6 => UNS
* INC # F8: 5,6 => UNS
* INC # F9: 5,6 => UNS
* DIS # G6: 4,7 => CTR => G6: 9
* INC # G6: 9 => UNS
* INC # G8: 4,7 => UNS
* INC # I6: 4,7 => UNS
* INC # I6: 6 => UNS
* INC # I6: 4,6 => UNS
* INC # I6: 7 => UNS
* INC # B5: 4,6 => UNS
* DIS # C5: 4,6 => CTR => C5: 3,9
* INC # C5: 3,9 => UNS
* DIS # D5: 4,6 => CTR => D5: 3,5
* INC # D5: 3,5 => UNS
* DIS # B9: 6,7 => CTR => B9: 5
* INC # B9: 5 => UNS
* INC # C9: 6,7 => UNS
* INC # D7: 6,7 => UNS
* DIS # F7: 6,7 => CTR => F7: 3,9
* INC # F7: 3,9 => UNS
* DIS # H7: 6,7 => CTR => H7: 9
* INC # H7: 9 => UNS
* PRF # E8: 5,9 => SOL
* INC # E8: 4,6,7 => UNS
* INC # F8: 5,9 => UNS
* CNT  27 HDP CHAINS /  27 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # E8: 5,6 => UNS
* INC # E9: 5,6 => UNS
* INC # F8: 5,6 => UNS
* INC # F9: 5,6 => UNS
* DIS # G6: 4,7 => CTR => G6: 9
* DIS G6: 9 # I6: 4,7 => CTR => I6: 6
* PRF G6: 9 + I6: 6 => SOL
* STA G6: 9 + I6: 6
* CNT   7 HDP CHAINS /   6 HYP OPENED