Analysis of xx-top500-339-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: ....23..71.....6......5....63.....1..27.........4..8..8..6.............3.......2. initial

Autosolve

position: ....23..71.....6......56...638....1.427.........4..8..8..6.............3.......2. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # C2: 5,9 => CTR => C2: 2,3
* DIS # D4: 7,9 => CTR => D4: 2,5
* DIS # F4: 7,9 => CTR => F4: 2,5
* DIS # E2: 7,9 => CTR => E2: 4,8
* DIS # E7: 7,9 => CTR => E7: 1,3,4
* DIS # E5: 3,8 => CTR => E5: 1,6
* DIS # D9: 5,7,9 => CTR => D9: 3,8
* DIS # E5: 1,8 => CTR => E5: 3,6
* PRF # E5: 3,6 => SOL
* PRF # E5: 3,6 => SOL
* DIS # E5: 1,8 => CTR => E5: 3,6
* PRF # H6: 3,6 => SOL
* DIS # H6: 7 => CTR => H6: 3,6
* DIS # F4: 2,7 => CTR => F4: 5,9
* DIS # F8: 2,7 => CTR => F8: 1,4,5,8,9
* DIS # G4: 2,4 => CTR => G4: 7
* PRF # G4: 7 => SOL
* DIS # I3: 2,4 => CTR => I3: 1,8,9
* DIS # F8: 2,7 => CTR => F8: 1,4,5,8,9
* DIS # A3: 2,7 => CTR => A3: 3
* PRF # A3: 3 => SOL
* DIS # E9: 3,7 => CTR => E9: 1,4,8,9
* PRF # A3: 3,7 => SOL
* DIS # A3: 2 => CTR => A3: 3,7
* CNT  24 HDP CHAINS /  51 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 # C2: 5,9 => CTR => C2: 2,3
* DIS C2: 2,3 # D4: 7,9 => CTR => D4: 2,5
* DIS C2: 2,3 + D4: 2,5 # F4: 7,9 => CTR => F4: 2,5
* PRF C2: 2,3 + D4: 2,5 + F4: 2,5 => SOL
* STA C2: 2,3 + D4: 2,5 + F4: 2,5
* CNT   4 HDP CHAINS /  15 HYP OPENED

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

Details

Positions

....23..71.....6......5....63.....1..27.........4..8..8..6.............3.......2. initial
....23..71.....6......56...638....1.427.........4..8..8..6.............3.......2. autosolve
586923147192784635374156298638295714427861359915437862853642971261579483749318526 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (13)
A1: 5,9
A6: 5,9
E4: 7,9
D5: 3,8
F5: 1,8
E6: 3,6
F6: 2,7
I4: 2,4
I6: 2,6
A8: 2,7
A9: 3,7
H8: 6,8
I9: 6,8

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
D1,D3: 1.. / D1 = 1  => 13 pairs (_) / D3 = 1  => 14 pairs (_)
B6,C6: 1.. / B6 = 1  => 14 pairs (_) / C6 = 1  => 14 pairs (_)
E5,F5: 1.. / E5 = 1  =>  0 pairs (X) / F5 = 1  => 12 pairs (_)
D1,G1: 1.. / D1 = 1  => 13 pairs (_) / G1 = 1  => 14 pairs (_)
I3,I7: 1.. / I3 = 1  => 13 pairs (_) / I7 = 1  => 13 pairs (_)
C2,I2: 2.. / C2 = 2  =>  0 pairs (*) / I2 = 2  =>  0 pairs (X)
F6,I6: 2.. / F6 = 2  =>  0 pairs (X) / I6 = 2  =>  0 pairs (_)
C7,F7: 2.. / C7 = 2  =>  0 pairs (X) / F7 = 2  =>  0 pairs (_)
A3,A8: 2.. / A3 = 2  =>  0 pairs (X) / A8 = 2  =>  0 pairs (_)
D4,D8: 2.. / D4 = 2  =>  0 pairs (*) / D8 = 2  =>  0 pairs (X)
G3,G4: 2.. / G3 = 2  =>  0 pairs (*) / G4 = 2  =>  0 pairs (X)
C2,H2: 3.. / C2 = 3  =>  0 pairs (X) / H2 = 3  =>  0 pairs (_)
E6,H6: 3.. / E6 = 3  =>  0 pairs (*) / H6 = 3  =>  0 pairs (X)
C7,E7: 3.. / C7 = 3  =>  0 pairs (*) / E7 = 3  =>  0 pairs (X)
A3,A9: 3.. / A3 = 3  =>  0 pairs (*) / A9 = 3  =>  0 pairs (X)
D5,D9: 3.. / D5 = 3  =>  0 pairs (X) / D9 = 3  =>  0 pairs (_)
G3,G5: 3.. / G3 = 3  =>  0 pairs (X) / G5 = 3  =>  0 pairs (_)
E2,F2: 4.. / E2 = 4  => 13 pairs (_) / F2 = 4  => 13 pairs (_)
G4,I4: 4.. / G4 = 4  =>  0 pairs (X) / I4 = 4  => 13 pairs (_)
D4,F4: 5.. / D4 = 5  =>  0 pairs (X) / F4 = 5  => 13 pairs (_)
A1,A6: 5.. / A1 = 5  => 16 pairs (_) / A6 = 5  => 14 pairs (_)
B1,C1: 6.. / B1 = 6  => 13 pairs (_) / C1 = 6  => 13 pairs (_)
E5,E6: 6.. / E5 = 6  =>  0 pairs (*) / E6 = 6  =>  0 pairs (X)
H8,I9: 6.. / H8 = 6  => 12 pairs (_) / I9 = 6  =>  0 pairs (*)
G4,H6: 7.. / G4 = 7  =>  0 pairs (*) / H6 = 7  =>  0 pairs (X)
F6,H6: 7.. / F6 = 7  =>  0 pairs (*) / H6 = 7  =>  0 pairs (X)
H6,H7: 7.. / H6 = 7  =>  0 pairs (X) / H7 = 7  =>  0 pairs (_)
H8,I9: 8.. / H8 = 8  =>  0 pairs (*) / I9 = 8  =>  0 pairs (X)
A1,A6: 9.. / A1 = 9  => 14 pairs (_) / A6 = 9  => 16 pairs (_)
* DURATION: 0:00:47.981021  START: 14:20:18.523685  END: 14:21:06.504706 2017-05-04
* CP COUNT: (29)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,A6,A8,A9,D5,E4,E6,F5,F6,H8,I4,I6,I9)
* ....23..71.....6......56...638....1.427.........4..8..8..6.............3.......2.
* PAIR A1: 5,9 BLK 1
B1: 5,9,4,6,8                            # reduction candidate for 5,9
B1: 5,9                                  # 21 pairs
C1: 5,9,4,6                              # reduction candidate for 5,9
C1: 5,9                                  # 21 pairs
B2: 5,9,7,8                              # reduction candidate for 5,9
B2: 5,9                                  # 16 pairs
C2: 5,9,2,3                              # reduction candidate for 5,9
C2: 5,9 => CTR
* ....23..71.....632....56...638...214427...3.....4328768..6.............3.......2.
C2: 2,3                                  # 14 pairs
* PAIR A1: 5,9 ROW 1
G1: 5,9,1,4                              # reduction candidate for 5,9
G1: 5,9                                  # 16 pairs
H1: 5,9,4,8                              # reduction candidate for 5,9
H1: 5,9                                  # 17 pairs
* PAIR A6: 5,9 BLK 4
B6: 5,9,1                                # reduction candidate for 5,9
B6: 5,9                                  # 14 pairs
C6: 5,9,1                                # reduction candidate for 5,9
C6: 5,9                                  # 14 pairs
* PAIR E4: 7,9 BLK 5
D4: 7,9,2,5                              # reduction candidate for 7,9
D4: 7,9 => CTR
* ....23..71.....6......56...638..5.1.427.........4.28768.263............3.......2.
D4: 2,5                                  # 14 pairs
F4: 7,9,2,5                              # reduction candidate for 7,9
F4: 7,9 => CTR
* ....23..71.....6......56...6385...1.427.........4.28768.263............3.......2.
F4: 2,5                                  # 14 pairs
* PAIR E4: 7,9 COL E
E2: 7,9,4,8                              # reduction candidate for 7,9
E2: 7,9 => CTR
* ....23..71....46......56...638....1.4273........46.8328..6...7.........3.......2.
E2: 4,8                                  # 14 pairs
E7: 7,9,1,3,4                            # reduction candidate for 7,9
E7: 7,9 => CTR
* ....23..71.....63.3...56...6382.5.14427...3.....4378628.36.2.7.2......837..3...26
E7: 1,3,4                                # 13 pairs
E8: 7,9,1,4,8                            # reduction candidate for 7,9
E8: 7,9                                  # 15 pairs
E9: 7,9,1,3,4,8                          # reduction candidate for 7,9
E9: 7,9                                  # 15 pairs
* PAIR D5: 3,8 BLK 5
E5: 3,8,1,6                              # reduction candidate for 3,8
E5: 3,8 => CTR
* ....23..71.....6......56...638....1.427..1......46.8328..6...7.........3.......2.
E5: 1,6                                  # 14 pairs
* PAIR D5: 3,8 COL D
D9: 3,8,5,7,9                            # reduction candidate for 3,8
D9: 5,7,9 => CTR
* ....23..71.....6......56...638....1.4273........46.8328..6...7.........3.......2.
D9: 3,8                                  # 20 pairs
* PAIR F5: 1,8 BLK 5
E5: 1,8,3,6                              # reduction candidate for 1,8
E5: 1,8 => CTR
* ....23..71.....6......56...638....1.427.........46.8328..6...7.........3.......2.
E5: 3,6 => SOLVED
* 586923147192784635374156298638295714427861359915437862853642971261579483749318526
* PAIR F5: 1,8 COL F
F8: 1,8,2,4,5,7,9                        # reduction candidate for 1,8
F8: 1,8                                  # 14 pairs
F9: 1,8,4,5,7,9                          # reduction candidate for 1,8
F9: 1,8                                  # 14 pairs
* PAIR E6: 3,6 BLK 5
E5: 3,6,1,8                              # reduction candidate for 3,6
E5: 3,6 => SOLVED
* 586923147192784635374156298638295714427861359915437862853642971261579483749318526
E5: 1,8 => CTR
* ....23..71.....6......56...638....1.427.........46.8328..6...7.........3.......2.
* PAIR E6: 3,6 ROW 6
H6: 3,6,7                                # reduction candidate for 3,6
H6: 3,6 => SOLVED
* 586923147192784635374156298638295714427861359915437862853642971261579483749318526
H6: 7 => CTR
* ....23..71.....6......56...638....1.427.........43.8768.36.2...........3.......2.
* PAIR F6: 2,7 BLK 5
D4: 2,7,5,9                              # reduction candidate for 2,7
D4: 2,7                                  # 13 pairs
F4: 2,7,5,9                              # reduction candidate for 2,7
F4: 2,7 => CTR
* ....23..71.....6..2...56...63859.214427.........4.28768.263.......2....3.......2.
F4: 5,9                                  # 14 pairs
* PAIR F6: 2,7 COL F
F7: 2,7,1,4,5,9                          # reduction candidate for 2,7
F7: 2,7                                  # 15 pairs
F8: 2,7,1,4,5,8,9                        # reduction candidate for 2,7
F8: 2,7 => CTR
* ....23..71.....6......56...6382.5.14427.........4.78.28.263..7.7....2..33......2.
F8: 1,4,5,8,9                            # 13 pairs
* PAIR I4: 2,4 BLK 6
G4: 2,4,7                                # reduction candidate for 2,4
G4: 2,4 => CTR
* ....23..71.....6......56...638....1.427.........4328768..6.............3.......2.
G4: 7 => SOLVED
* 586923147192784635374156298638295714427861359915437862853642971261579483749318526
* PAIR I4: 2,4 COL I
I3: 2,4,1,8,9                            # reduction candidate for 2,4
I3: 2,4 => CTR
* ....23..71.2...63.....56...638....1.427...3.....4328768.36....12......637..3...28
I3: 1,8,9                                # 13 pairs
* PAIR A8: 2,7 ROW 8
D8: 2,7,5,8,9                            # reduction candidate for 2,7
D8: 2,7                                  # 14 pairs
F8: 2,7,1,4,5,8,9                        # reduction candidate for 2,7
F8: 2,7 => CTR
* ....23..71.....6......56...6382.5.14427.........4.78.28.263..7.7....2..33......2.
F8: 1,4,5,8,9                            # 13 pairs
* PAIR A8: 2,7 COL A
A3: 2,7,3                                # reduction candidate for 2,7
A3: 2,7 => CTR
* ....23..71.....6......56...638....1.4273........46.8328..63..7.........33......2.
A3: 3 => SOLVED
* 586923147192784635374156298638295714427861359915437862853642971261579483749318526
* PAIR A9: 3,7 ROW 9
D9: 3,7,5,8,9                            # reduction candidate for 3,7
D9: 3,7                                  # 16 pairs
E9: 3,7,1,4,8,9                          # reduction candidate for 3,7
E9: 3,7 => CTR
* ....23..71.....6......56...638....1.4273........46.8328..6...7.........3.......2.
E9: 1,4,8,9                              # 13 pairs
* PAIR A9: 3,7 COL A
A3: 3,7,2                                # reduction candidate for 3,7
A3: 3,7 => SOLVED
* 586923147192784635374156298638295714427861359915437862853642971261579483749318526
A3: 2 => CTR
* ....23..71.....6..2...56...638...214427.........4.28768.263............3.......2.
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-339-base-pr-000.dot
* REASONING
* DIS # C2: 5,9 => CTR => C2: 2,3
* DIS # D4: 7,9 => CTR => D4: 2,5
* DIS # F4: 7,9 => CTR => F4: 2,5
* DIS # E2: 7,9 => CTR => E2: 4,8
* DIS # E7: 7,9 => CTR => E7: 1,3,4
* DIS # E5: 3,8 => CTR => E5: 1,6
* DIS # D9: 5,7,9 => CTR => D9: 3,8
* DIS # E5: 1,8 => CTR => E5: 3,6
* PRF # E5: 3,6 => SOL
* PRF # E5: 3,6 => SOL
* DIS # E5: 1,8 => CTR => E5: 3,6
* PRF # H6: 3,6 => SOL
* DIS # H6: 7 => CTR => H6: 3,6
* DIS # F4: 2,7 => CTR => F4: 5,9
* DIS # F8: 2,7 => CTR => F8: 1,4,5,8,9
* DIS # G4: 2,4 => CTR => G4: 7
* PRF # G4: 7 => SOL
* DIS # I3: 2,4 => CTR => I3: 1,8,9
* DIS # F8: 2,7 => CTR => F8: 1,4,5,8,9
* DIS # A3: 2,7 => CTR => A3: 3
* PRF # A3: 3 => SOL
* DIS # E9: 3,7 => CTR => E9: 1,4,8,9
* PRF # A3: 3,7 => SOL
* DIS # A3: 2 => CTR => A3: 3,7
* CNT  24 HDP CHAINS /  51 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,A6,A8,A9,D5,E4,E6,F5,F6,H8,I4,I6,I9)
* ....23..71.....6......56...638....1.427.........4..8..8..6.............3.......2.
* PAIR A1: 5,9 BLK 1
B1: 5,9,4,6,8                            # reduction candidate for 5,9
B1: 5,9                                  # 21 pairs
C1: 5,9,4,6                              # reduction candidate for 5,9
C1: 5,9                                  # 21 pairs
B2: 5,9,7,8                              # reduction candidate for 5,9
B2: 5,9                                  # 16 pairs
C2: 5,9,2,3                              # reduction candidate for 5,9
C2: 5,9 => CTR
* ....23..71.....632....56...638...214427...3.....4328768..6.............3.......2.
* PAIR A1: 5,9 ROW 1
G1: 5,9,1,4                              # reduction candidate for 5,9
G1: 5,9                                  # 17 pairs
H1: 5,9,4,8                              # reduction candidate for 5,9
H1: 5,9                                  # 18 pairs
* PAIR RESTART
* PAIR A1: 5,9 BLK 1
B1: 5,9,4,6,8                            # reduction candidate for 5,9
B1: 5,9                                  # 21 pairs
C1: 5,9,4,6                              # reduction candidate for 5,9
C1: 5,9                                  # 21 pairs
B2: 5,9,7,8                              # reduction candidate for 5,9
B2: 5,9                                  # 16 pairs
* PAIR A1: 5,9 ROW 1
G1: 5,9,1,4                              # reduction candidate for 5,9
G1: 5,9                                  # 17 pairs
H1: 5,9,4,8                              # reduction candidate for 5,9
H1: 5,9                                  # 18 pairs
* PAIR A6: 5,9 BLK 4
B6: 5,9,1                                # reduction candidate for 5,9
B6: 5,9                                  # 15 pairs
C6: 5,9,1                                # reduction candidate for 5,9
C6: 5,9                                  # 15 pairs
* PAIR E4: 7,9 BLK 5
D4: 7,9,2,5                              # reduction candidate for 7,9
D4: 7,9 => CTR
* ....23..71.....6......56...638..5.1.427.........4.28768.263............3.......2.
F4: 7,9,2,5                              # reduction candidate for 7,9
F4: 7,9 => CTR
* ....23..71.....6......56...6385...1.427.........4.28768.263............3.......2.
F4: 2,5 => SOLVED
* 586923147192784635374156298638295714427861359915437862853642971261579483749318526
* DURATION: 0:00:12.837036  START: 14:21:50.075538  END: 14:22:02.912574 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-339-base-pr-001.dot
* REASONING
* DIS # C2: 5,9 => CTR => C2: 2,3
* DIS C2: 2,3 # D4: 7,9 => CTR => D4: 2,5
* DIS C2: 2,3 + D4: 2,5 # F4: 7,9 => CTR => F4: 2,5
* PRF C2: 2,3 + D4: 2,5 + F4: 2,5 => SOL
* STA C2: 2,3 + D4: 2,5 + F4: 2,5
* CNT   4 HDP CHAINS /  15 HYP OPENED

Header Info

Top 500 Minimum 17 339

solution: 586923147192784635374156298638295714427861359915437862853642971261579483749318526
info: 3173     FNBTHWY  S8.f     3546

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

Solution

position: 586923147192784635374156298638295714427861359915437862853642971261579483749318526 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: 5,9 => UNS
* INC # C1: 5,9 => UNS
* INC # B2: 5,9 => UNS
* DIS # C2: 5,9 => CTR => C2: 2,3
* INC # C2: 2,3 => UNS
* INC # G1: 5,9 => UNS
* INC # H1: 5,9 => UNS
* INC # B6: 5,9 => UNS
* INC # C6: 5,9 => UNS
* DIS # D4: 7,9 => CTR => D4: 2,5
* INC # D4: 2,5 => UNS
* DIS # F4: 7,9 => CTR => F4: 2,5
* INC # F4: 2,5 => UNS
* DIS # E2: 7,9 => CTR => E2: 4,8
* INC # E2: 4,8 => UNS
* DIS # E7: 7,9 => CTR => E7: 1,3,4
* INC # E7: 1,3,4 => UNS
* INC # E8: 7,9 => UNS
* INC # E9: 7,9 => UNS
* DIS # E5: 3,8 => CTR => E5: 1,6
* INC # E5: 1,6 => UNS
* INC # D9: 3,8 => UNS
* DIS # D9: 5,7,9 => CTR => D9: 3,8
* DIS # E5: 1,8 => CTR => E5: 3,6
* PRF # E5: 3,6 => SOL
* INC # F8: 1,8 => UNS
* INC # F9: 1,8 => UNS
* PRF # E5: 3,6 => SOL
* DIS # E5: 1,8 => CTR => E5: 3,6
* PRF # H6: 3,6 => SOL
* DIS # H6: 7 => CTR => H6: 3,6
* INC # D4: 2,7 => UNS
* DIS # F4: 2,7 => CTR => F4: 5,9
* INC # F4: 5,9 => UNS
* INC # F7: 2,7 => UNS
* DIS # F8: 2,7 => CTR => F8: 1,4,5,8,9
* INC # F8: 1,4,5,8,9 => UNS
* DIS # G4: 2,4 => CTR => G4: 7
* PRF # G4: 7 => SOL
* DIS # I3: 2,4 => CTR => I3: 1,8,9
* INC # I3: 1,8,9 => UNS
* INC # D8: 2,7 => UNS
* DIS # F8: 2,7 => CTR => F8: 1,4,5,8,9
* INC # F8: 1,4,5,8,9 => UNS
* DIS # A3: 2,7 => CTR => A3: 3
* PRF # A3: 3 => SOL
* INC # D9: 3,7 => UNS
* DIS # E9: 3,7 => CTR => E9: 1,4,8,9
* INC # E9: 1,4,8,9 => UNS
* PRF # A3: 3,7 => SOL
* DIS # A3: 2 => CTR => A3: 3,7
* CNT  51 HDP CHAINS /  51 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # B1: 5,9 => UNS
* INC # C1: 5,9 => UNS
* INC # B2: 5,9 => UNS
* DIS # C2: 5,9 => CTR => C2: 2,3
* INC C2: 2,3 # G1: 5,9 => UNS
* INC C2: 2,3 # H1: 5,9 => UNS
* INC C2: 2,3 # B1: 5,9 => UNS
* INC C2: 2,3 # C1: 5,9 => UNS
* INC C2: 2,3 # B2: 5,9 => UNS
* INC C2: 2,3 # G1: 5,9 => UNS
* INC C2: 2,3 # H1: 5,9 => UNS
* INC C2: 2,3 # B6: 5,9 => UNS
* INC C2: 2,3 # C6: 5,9 => UNS
* DIS C2: 2,3 # D4: 7,9 => CTR => D4: 2,5
* DIS C2: 2,3 + D4: 2,5 # F4: 7,9 => CTR => F4: 2,5
* PRF C2: 2,3 + D4: 2,5 + F4: 2,5 => SOL
* STA C2: 2,3 + D4: 2,5 + F4: 2,5
* CNT  16 HDP CHAINS /  15 HYP OPENED