Analysis of xx-top500-332-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: ......1.7.9..2............4...4.15...2...3.6....7.........9..3.4..8.....1........ initial

Autosolve

position: ......1.7.9..2............4...4.15...2.9.3.6....7.2.......9..3.4..8.....1........ autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # C1: 3,4 => CTR => C1: 2,5,6,8
* PRF # E9: 7 => SOL
* DIS # A2: 5,8 => CTR => A2: 3,6,7
* DIS # C2: 5,8 => CTR => C2: 1,3,4,6,7
* DIS # F2: 5,8 => CTR => F2: 4,6,7
* DIS # H9: 5,8 => CTR => H9: 2,4,7,9
* DIS # E6: 5 => CTR => E6: 6,8
* DIS # A4: 6,8 => CTR => A4: 3,7,9
* DIS # A5: 5,8 => CTR => A5: 7
* PRF # A5: 7 => SOL
* DIS # C5: 5,8 => CTR => C5: 1,4,7
* PRF # H6: 1,8 => SOL
* DIS # H6: 4,9 => CTR => H6: 1,8
* DIS # I6: 1,8 => CTR => I6: 3,9
* PRF # C5: 1,8 => SOL
* DIS # C5: 4,5,7 => CTR => C5: 1,8
* DIS # I7: 2,5,6 => CTR => I7: 1,8
* CNT  17 HDP CHAINS /  36 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 # C1: 3,4 => CTR => C1: 2,5,6,8
* PRF C1: 2,5,6,8 # B1: 5,6,8 => SOL
* STA C1: 2,5,6,8 + B1: 5,6,8
* CNT   2 HDP CHAINS /   4 HYP OPENED

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

Details

Positions

......1.7.9..2............4...4.15...2...3.6....7.........9..3.4..8.....1........ initial
......1.7.9..2............4...4.15...2.9.3.6....7.2.......9..3.4..8.....1........ autosolve
358649127694127385217538694963481572721953468845762913576294831432816759189375246 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (5)
E1: 3,4
H2: 5,8
E4: 6,8
E5: 5,8
I5: 1,8

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
D7,E8: 1.. / D7 = 1  =>  0 pairs (X) / E8 = 1  =>  0 pairs (_)
C2,D2: 1.. / C2 = 1  =>  0 pairs (X) / D2 = 1  =>  0 pairs (_)
C5,I5: 1.. / C5 = 1  =>  0 pairs (*) / I5 = 1  =>  0 pairs (X)
D7,I7: 1.. / D7 = 1  =>  0 pairs (X) / I7 = 1  =>  0 pairs (_)
B3,B6: 1.. / B3 = 1  =>  0 pairs (*) / B6 = 1  =>  0 pairs (X)
E3,E8: 1.. / E3 = 1  =>  0 pairs (X) / E8 = 1  =>  0 pairs (_)
H6,H8: 1.. / H6 = 1  =>  0 pairs (*) / H8 = 1  =>  0 pairs (X)
H4,I4: 2.. / H4 = 2  =>  0 pairs (X) / I4 = 2  =>  5 pairs (_)
D7,D9: 2.. / D7 = 2  =>  0 pairs (*) / D9 = 2  =>  0 pairs (X)
C2,F2: 4.. / C2 = 4  =>  0 pairs (*) / F2 = 4  =>  0 pairs (X)
C5,G5: 4.. / C5 = 4  =>  0 pairs (X) / G5 = 4  =>  0 pairs (_)
F7,G7: 4.. / F7 = 4  =>  0 pairs (*) / G7 = 4  =>  0 pairs (X)
B1,B6: 4.. / B1 = 4  =>  0 pairs (X) / B6 = 4  =>  0 pairs (_)
E1,E9: 4.. / E1 = 4  =>  0 pairs (*) / E9 = 4  =>  0 pairs (X)
H6,H9: 4.. / H6 = 4  =>  0 pairs (X) / H9 = 4  =>  0 pairs (_)
E5,E6: 5.. / E5 = 5  =>  6 pairs (_) / E6 = 5  =>  0 pairs (X)
E4,E6: 6.. / E4 = 6  =>  5 pairs (_) / E6 = 6  =>  4 pairs (_)
H4,G5: 7.. / H4 = 7  =>  6 pairs (_) / G5 = 7  =>  0 pairs (X)
F1,F3: 9.. / F1 = 9  =>  5 pairs (_) / F3 = 9  =>  5 pairs (_)
A4,A6: 9.. / A4 = 9  =>  5 pairs (_) / A6 = 9  =>  0 pairs (X)
C8,C9: 9.. / C8 = 9  =>  5 pairs (_) / C9 = 9  =>  5 pairs (_)
F1,H1: 9.. / F1 = 9  =>  5 pairs (_) / H1 = 9  =>  5 pairs (_)
* DURATION: 0:00:32.705368  START: 14:08:28.372893  END: 14:09:01.078261 2017-05-04
* CP COUNT: (22)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (E1,E4,E5,H2,I5)
* ......1.7.9..2............4...4.15...2.9.3.6....7.2.......9..3.4..8.....1........
* PAIR E1: 3,4 ROW 1
B1: 3,4,5,6,8                            # reduction candidate for 3,4
B1: 3,4                                  #  7 pairs
C1: 3,4,2,5,6,8                          # reduction candidate for 3,4
C1: 3,4 => CTR
* ..3.4.1.7.9412.....1......4...4.1572.219.3468.4.7.2.1.....94.3143.81....1......4.
C1: 2,5,6,8                              #  5 pairs
* PAIR E1: 3,4 COL E
E9: 3,4,7                                # reduction candidate for 3,4
E9: 7 => SOLVED
* 358649127694127385217538694963481572721953468845762913576294831432816759189375246
E9: 3,4                                  #  8 pairs
* PAIR H2: 5,8 BLK 3
H1: 5,8,2,9                              # reduction candidate for 5,8
H1: 5,8                                  # 11 pairs
I2: 5,8,3,6                              # reduction candidate for 5,8
I2: 5,8                                  # 14 pairs
H3: 5,8,2,9                              # reduction candidate for 5,8
H3: 5,8                                  # 11 pairs
* PAIR H2: 5,8 ROW 2
A2: 5,8,3,6,7                            # reduction candidate for 5,8
A2: 5,8 => CTR
* 3..5491275941276832176389549..4.1572721953468.457.2319.5.294.314..81..9.1.937.24.
A2: 3,6,7                                #  5 pairs
C2: 5,8,1,3,4,6,7                        # reduction candidate for 5,8
C2: 5,8 => CTR
* ......1.7.9.124...........4...4.15...2.9.3.6....7.2.......9.4314..81....1...4....
C2: 1,3,4,6,7                            #  5 pairs
F2: 5,8,4,6,7                            # reduction candidate for 5,8
F2: 5,8 => CTR
* ....4.1.779412.....1......4...4.1572.2.9.346..4.7.2.......94.314..81....1......4.
F2: 4,6,7                                #  7 pairs
* PAIR H2: 5,8 COL H
H9: 5,8,2,4,7,9                          # reduction candidate for 5,8
H9: 5,8 => CTR
* .4..3.1.7.9..24.......17..4...4.1572.249.3861.1.7.2.4....19.43.4..87..1.1........
H9: 2,4,7,9                              #  5 pairs
* PAIR E4: 6,8 BLK 5
E6: 6,8,5                                # reduction candidate for 6,8
E6: 5 => CTR
* ......1.7.91.24.......17..4...4615...2.983.61.1.752......19.43.4..8...1.1..24....
E6: 6,8                                  #  6 pairs
* PAIR E4: 6,8 ROW 4
A4: 6,8,3,7,9                            # reduction candidate for 6,8
A4: 6,8 => CTR
* .4..3.1.7.91.24.......17..4...4.15...249.376191.7.2.4....19.43.4..87..1.1..24..7.
A4: 3,7,9                                #  5 pairs
B4: 6,8,3,7                              # reduction candidate for 6,8
B4: 6,8                                  #  7 pairs
C4: 6,8,3,7                              # reduction candidate for 6,8
C4: 6,8                                  #  7 pairs
* PAIR E5: 5,8 BLK 5
E6: 5,8,6                                # reduction candidate for 5,8
E6: 5,8                                  #  5 pairs
E6: 6                                    #  4 pairs
* PAIR E5: 5,8 ROW 5
A5: 5,8,7                                # reduction candidate for 5,8
A5: 5,8 => CTR
* ......1.7.91.24.......17..4...4.15...2.9.3.61.1.7.2......19.43.4..8...1.1..24....
A5: 7 => SOLVED
* 358649127694127385217538694963481572721953468845762913576294831432816759189375246
C5: 5,8,1,4,7                            # reduction candidate for 5,8
C5: 5,8 => CTR
* ......1.7.9..2............4...4.15...2.9.3461...7.2......194.3.4..8...1.1..2...4.
C5: 1,4,7                                #  5 pairs
* PAIR I5: 1,8 BLK 6
H6: 1,8,4,9                              # reduction candidate for 1,8
H6: 1,8 => SOLVED
* 358649127694127385217538694963481572721953468845762913576294831432816759189375246
H6: 4,9 => CTR
* .4..3.1.7.91.24.......17..4...4.15...2.9.3.61.1.7.2......19.43.4..87..1.1..24....
I6: 1,8,3,9                              # reduction candidate for 1,8
I6: 1,8 => CTR
* ......1.7.91.24.......17..4...4.15...2.9.3.61.1.7.2..8...19.43.4..8...1.1..24....
I6: 3,9                                  #  6 pairs
* PAIR I5: 1,8 ROW 5
C5: 1,8,4,5,7                            # reduction candidate for 1,8
C5: 1,8 => SOLVED
* 358649127694127385217538694963481572721953468845762913576294831432816759189375246
C5: 4,5,7 => CTR
* ......1.7.91.24.......17..4...4.15...2.9.3.61.1.7.2......19.43.4..8...1.1..24....
* PAIR I5: 1,8 COL I
I7: 1,8,2,5,6                            # reduction candidate for 1,8
I7: 2,5,6 => CTR
* ......1.7.91.24.......17..4...4.15...2.9.3.61.1.7.2......19.43.4..8...1.1..24....
I7: 1,8                                  #  7 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-332-base-pr-000.dot
* REASONING
* DIS # C1: 3,4 => CTR => C1: 2,5,6,8
* PRF # E9: 7 => SOL
* DIS # A2: 5,8 => CTR => A2: 3,6,7
* DIS # C2: 5,8 => CTR => C2: 1,3,4,6,7
* DIS # F2: 5,8 => CTR => F2: 4,6,7
* DIS # H9: 5,8 => CTR => H9: 2,4,7,9
* DIS # E6: 5 => CTR => E6: 6,8
* DIS # A4: 6,8 => CTR => A4: 3,7,9
* DIS # A5: 5,8 => CTR => A5: 7
* PRF # A5: 7 => SOL
* DIS # C5: 5,8 => CTR => C5: 1,4,7
* PRF # H6: 1,8 => SOL
* DIS # H6: 4,9 => CTR => H6: 1,8
* DIS # I6: 1,8 => CTR => I6: 3,9
* PRF # C5: 1,8 => SOL
* DIS # C5: 4,5,7 => CTR => C5: 1,8
* DIS # I7: 2,5,6 => CTR => I7: 1,8
* CNT  17 HDP CHAINS /  36 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (E1,E4,E5,H2,I5)
* ......1.7.9..2............4...4.15...2.9.3.6....7.2.......9..3.4..8.....1........
* PAIR E1: 3,4 ROW 1
B1: 3,4,5,6,8                            # reduction candidate for 3,4
B1: 3,4                                  #  7 pairs
C1: 3,4,2,5,6,8                          # reduction candidate for 3,4
C1: 3,4 => CTR
* ..3.4.1.7.9412.....1......4...4.1572.219.3468.4.7.2.1.....94.3143.81....1......4.
* RESTART
* PAIR E1: 3,4 ROW 1
B1: 3,4,5,6,8                            # reduction candidate for 3,4
B1: 5,6,8 => SOLVED
* 358649127694127385217538694963481572721953468845762913576294831432816759189375246
* DURATION: 0:00:04.659957  START: 14:09:25.803208  END: 14:09:30.463165 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-332-base-pr-001.dot
* REASONING
* DIS # C1: 3,4 => CTR => C1: 2,5,6,8
* PRF C1: 2,5,6,8 # B1: 5,6,8 => SOL
* STA C1: 2,5,6,8 + B1: 5,6,8
* CNT   2 HDP CHAINS /   4 HYP OPENED

Header Info

Top 500 Minimum 17 332

solution: 358649127694127385217538694963481572721953468845762913576294831432816759189375246
info: 3039     FNBHWY   S8.f     899

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

Solution

position: 358649127694127385217538694963481572721953468845762913576294831432816759189375246 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 # B1: 3,4 => UNS
* DIS # C1: 3,4 => CTR => C1: 2,5,6,8
* INC # C1: 2,5,6,8 => UNS
* INC # E9: 3,4 => UNS
* PRF # E9: 7 => SOL
* INC # H1: 5,8 => UNS
* INC # I2: 5,8 => UNS
* INC # H3: 5,8 => UNS
* DIS # A2: 5,8 => CTR => A2: 3,6,7
* INC # A2: 3,6,7 => UNS
* DIS # C2: 5,8 => CTR => C2: 1,3,4,6,7
* INC # C2: 1,3,4,6,7 => UNS
* DIS # F2: 5,8 => CTR => F2: 4,6,7
* INC # F2: 4,6,7 => UNS
* DIS # H9: 5,8 => CTR => H9: 2,4,7,9
* INC # H9: 2,4,7,9 => UNS
* INC # E6: 6,8 => UNS
* DIS # E6: 5 => CTR => E6: 6,8
* DIS # A4: 6,8 => CTR => A4: 3,7,9
* INC # A4: 3,7,9 => UNS
* INC # B4: 6,8 => UNS
* INC # C4: 6,8 => UNS
* INC # E6: 5,8 => UNS
* INC # E6: 6 => UNS
* DIS # A5: 5,8 => CTR => A5: 7
* PRF # A5: 7 => SOL
* DIS # C5: 5,8 => CTR => C5: 1,4,7
* INC # C5: 1,4,7 => UNS
* PRF # H6: 1,8 => SOL
* DIS # H6: 4,9 => CTR => H6: 1,8
* DIS # I6: 1,8 => CTR => I6: 3,9
* INC # I6: 3,9 => UNS
* PRF # C5: 1,8 => SOL
* DIS # C5: 4,5,7 => CTR => C5: 1,8
* INC # I7: 1,8 => UNS
* DIS # I7: 2,5,6 => CTR => I7: 1,8
* CNT  36 HDP CHAINS /  36 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # B1: 3,4 => UNS
* DIS # C1: 3,4 => CTR => C1: 2,5,6,8
* INC C1: 2,5,6,8 # B1: 3,4 => UNS
* PRF C1: 2,5,6,8 # B1: 5,6,8 => SOL
* STA C1: 2,5,6,8 + B1: 5,6,8
* CNT   4 HDP CHAINS /   4 HYP OPENED