Analysis of xx-top500-341-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: ....175..6.......3....4....37.....6....2....8.15............71.8..3.............. initial

Autosolve

position: ....175..6.......3....43...378....6....2....8215......5.....71.8..3.............. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # C2: 4,9 => CTR => C2: 1,7
* DIS # C3: 1,7 => CTR => C3: 2,9
* DIS # I3: 2,6,9 => CTR => I3: 1,7
* DIS # D4: 5,9 => CTR => D4: 1,4
* DIS # F4: 5,9 => CTR => F4: 1,4
* DIS # E2: 5,9 => CTR => E2: 2,8
* DIS # E8: 5,9 => CTR => E8: 2,6,7
* PRF # E6: 3,7 => SOL
* DIS # E6: 6,8 => CTR => E6: 3,7
* PRF # H5: 3,7 => SOL
* DIS # H5: 5 => CTR => H5: 3,7
* DIS # F4: 1,5 => CTR => F4: 4,9
* DIS # F9: 1,5 => CTR => F9: 2,4,6,9
* DIS # E6: 7,8 => CTR => E6: 3,6
* DIS # E6: 6,8 => CTR => E6: 3,7
* PRF # E6: 3,7 => SOL
* DIS # I4: 1,2 => CTR => I4: 5
* PRF # I4: 5 => SOL
* DIS # G3: 1,2 => CTR => G3: 6,8,9
* DIS # C9: 1,7 => CTR => C9: 2,4,6,9
* DIS # D9: 4,5,9 => CTR => D9: 1,7
* CNT  21 HDP CHAINS /  48 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: 4,9 => CTR => C2: 1,7
* DIS C2: 1,7 # I3: 2,6,9 => CTR => I3: 1,7
* DIS C2: 1,7 + I3: 1,7 # D4: 5,9 => CTR => D4: 1,4
* DIS C2: 1,7 + I3: 1,7 + D4: 1,4 # F4: 5,9 => CTR => F4: 1,4
* PRF C2: 1,7 + I3: 1,7 + D4: 1,4 + F4: 1,4 => SOL
* STA C2: 1,7 + I3: 1,7 + D4: 1,4 + F4: 1,4
* CNT   5 HDP CHAINS /  17 HYP OPENED

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

Details

Positions

....175..6.......3....4....37.....6....2....8.15............71.8..3.............. initial
....175..6.......3....43...378....6....2....8215......5.....71.8..3.............. autosolve
483917526691582473752643891378194265964275138215836947539468712847321659126759384 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (13)
A1: 4,9
A3: 1,7
A5: 4,9
E4: 5,9
E5: 3,7
F5: 1,5
D6: 7,8
F6: 6,8
G4: 1,2
G5: 1,3
A9: 1,7
G9: 3,8
H9: 3,8

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
C2,G2: 1.. / C2 = 1  =>  0 pairs (*) / G2 = 1  =>  0 pairs (X)
F5,G5: 1.. / F5 = 1  =>  0 pairs (X) / G5 = 1  =>  0 pairs (_)
C8,F8: 1.. / C8 = 1  =>  0 pairs (X) / F8 = 1  =>  0 pairs (_)
A3,A9: 1.. / A3 = 1  =>  0 pairs (X) / A9 = 1  =>  0 pairs (_)
D4,D9: 1.. / D4 = 1  =>  0 pairs (*) / D9 = 1  =>  0 pairs (X)
I3,I4: 1.. / I3 = 1  =>  0 pairs (*) / I4 = 1  =>  0 pairs (X)
E2,F2: 2.. / E2 = 2  => 13 pairs (_) / F2 = 2  => 13 pairs (_)
G4,I4: 2.. / G4 = 2  => 13 pairs (_) / I4 = 2  =>  0 pairs (X)
B1,C1: 3.. / B1 = 3  => 18 pairs (_) / C1 = 3  => 13 pairs (_)
E5,E6: 3.. / E5 = 3  =>  0 pairs (X) / E6 = 3  =>  0 pairs (_)
B7,C7: 3.. / B7 = 3  => 13 pairs (_) / C7 = 3  => 18 pairs (_)
G9,H9: 3.. / G9 = 3  =>  0 pairs (*) / H9 = 3  =>  0 pairs (X)
B1,B7: 3.. / B1 = 3  => 18 pairs (_) / B7 = 3  => 13 pairs (_)
C1,C7: 3.. / C1 = 3  => 13 pairs (_) / C7 = 3  => 18 pairs (_)
D4,F4: 4.. / D4 = 4  =>  0 pairs (X) / F4 = 4  => 13 pairs (_)
A1,A5: 4.. / A1 = 4  => 17 pairs (_) / A5 = 4  => 14 pairs (_)
B2,B3: 5.. / B2 = 5  => 16 pairs (_) / B3 = 5  => 13 pairs (_)
I4,H5: 5.. / I4 = 5  =>  0 pairs (*) / H5 = 5  =>  0 pairs (X)
B3,D3: 5.. / B3 = 5  => 13 pairs (_) / D3 = 5  => 16 pairs (_)
F5,H5: 5.. / F5 = 5  =>  0 pairs (*) / H5 = 5  =>  0 pairs (X)
H5,H8: 5.. / H5 = 5  =>  0 pairs (X) / H8 = 5  =>  0 pairs (_)
D1,D3: 6.. / D1 = 6  => 13 pairs (_) / D3 = 6  => 14 pairs (_)
B5,C5: 6.. / B5 = 6  => 14 pairs (_) / C5 = 6  => 14 pairs (_)
E6,F6: 6.. / E6 = 6  =>  0 pairs (X) / F6 = 6  => 12 pairs (_)
D1,I1: 6.. / D1 = 6  => 13 pairs (_) / I1 = 6  => 14 pairs (_)
G3,G8: 6.. / G3 = 6  => 13 pairs (_) / G8 = 6  => 13 pairs (_)
C2,H2: 7.. / C2 = 7  =>  0 pairs (X) / H2 = 7  =>  0 pairs (_)
E5,H5: 7.. / E5 = 7  =>  0 pairs (*) / H5 = 7  =>  0 pairs (X)
C8,E8: 7.. / C8 = 7  =>  0 pairs (*) / E8 = 7  =>  0 pairs (X)
A3,A9: 7.. / A3 = 7  =>  0 pairs (*) / A9 = 7  =>  0 pairs (X)
D6,D9: 7.. / D6 = 7  =>  0 pairs (X) / D9 = 7  =>  0 pairs (_)
I3,I6: 7.. / I3 = 7  =>  0 pairs (X) / I6 = 7  =>  0 pairs (_)
G9,H9: 8.. / G9 = 8  => 12 pairs (_) / H9 = 8  =>  0 pairs (*)
A1,A5: 9.. / A1 = 9  => 14 pairs (_) / A5 = 9  => 17 pairs (_)
* DURATION: 0:01:00.868727  START: 14:23:21.148398  END: 14:24:22.017125 2017-05-04
* CP COUNT: (34)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,A3,A5,A9,D6,E4,E5,F5,F6,G4,G5,G9,H9)
* ....175..6.......3....43...378....6....2....8215......5.....71.8..3..............
* PAIR A1: 4,9 BLK 1
B1: 4,9,2,3,8                            # reduction candidate for 4,9
B1: 4,9                                  # 22 pairs
C1: 4,9,2,3                              # reduction candidate for 4,9
C1: 4,9                                  # 22 pairs
B2: 4,9,5,8                              # reduction candidate for 4,9
B2: 4,9                                  # 16 pairs
C2: 4,9,1,7                              # reduction candidate for 4,9
C2: 4,9 => CTR
* ....175..6.....173....43...378...261...2713582158.....5.....71.8..3..............
C2: 1,7                                  # 15 pairs
* PAIR A1: 4,9 ROW 1
H1: 4,9,2,8                              # reduction candidate for 4,9
H1: 4,9                                  # 17 pairs
I1: 4,9,2,6                              # reduction candidate for 4,9
I1: 4,9                                  # 16 pairs
* PAIR A3: 1,7 BLK 1
C2: 1,7,4,9                              # reduction candidate for 1,7
C2: 1,7                                  # 15 pairs
C3: 1,7,2,9                              # reduction candidate for 1,7
C3: 1,7 => CTR
* ....175..6.....173....43...378...261...2713582158.....5.....71.8..3..............
C3: 2,9                                  # 15 pairs
* PAIR A3: 1,7 ROW 3
I3: 1,7,2,6,9                            # reduction candidate for 1,7
I3: 2,6,9 => CTR
* ....175..6.......3....43...378....61...2.1358215.36..75.....71.8.137.............
I3: 1,7                                  # 16 pairs
* PAIR A5: 4,9 BLK 4
B5: 4,9,6                                # reduction candidate for 4,9
B5: 4,9                                  # 14 pairs
C5: 4,9,6                                # reduction candidate for 4,9
C5: 4,9                                  # 14 pairs
* PAIR E4: 5,9 BLK 5
D4: 5,9,1,4                              # reduction candidate for 5,9
D4: 5,9 => CTR
* ....175..6.......3....43...378..4.6....2.1358215.36...5.....71.8.137.............
D4: 1,4                                  # 14 pairs
F4: 5,9,1,4                              # reduction candidate for 5,9
F4: 5,9 => CTR
* ....175..6.......3....43...3784...6....2.1358215.36...5.....71.8.137.............
F4: 1,4                                  # 14 pairs
* PAIR E4: 5,9 COL E
E2: 5,9,2,8                              # reduction candidate for 5,9
E2: 5,9 => CTR
* ....175..6....2..3....43..7378....61...23...82157.....5.....71.8..3..............
E2: 2,8                                  # 14 pairs
E8: 5,9,2,6,7                            # reduction candidate for 5,9
E8: 5,9 => CTR
* ....175..6......737...43...3781.4265...275138215836..75.....71.8.73.1.5.1..75.38.
E8: 2,6,7                                # 13 pairs
E9: 5,9,2,6,7                            # reduction candidate for 5,9
E9: 5,9                                  # 15 pairs
* PAIR E5: 3,7 BLK 5
E6: 3,7,6,8                              # reduction candidate for 3,7
E6: 3,7 => SOLVED
* 483917526691582473752643891378194265964275138215836947539468712847321659126759384
E6: 6,8 => CTR
* ....175..6.......3....43...378....6....23.1782157.....5.....71.8..3...5..........
* PAIR E5: 3,7 ROW 5
H5: 3,7,5                                # reduction candidate for 3,7
H5: 3,7 => SOLVED
* 483917526691582473752643891378194265964275138215836947539468712847321659126759384
H5: 5 => CTR
* ....175..6.......3....43...378....6....27.358215836...5.....71.8.73.1............
* PAIR F5: 1,5 BLK 5
D4: 1,5,4,9                              # reduction candidate for 1,5
D4: 1,5                                  # 13 pairs
F4: 1,5,4,9                              # reduction candidate for 1,5
F4: 1,5 => CTR
* ....175..6.......31...43...37849..61...2.13582157.....5.....71.8..3........1.....
F4: 4,9                                  # 14 pairs
* PAIR F5: 1,5 COL F
F8: 1,5,2,4,6,9                          # reduction candidate for 1,5
F8: 1,5                                  # 15 pairs
F9: 1,5,2,4,6,9                          # reduction candidate for 1,5
F9: 1,5 => CTR
* ....175..6.....1.31...43...378...261...23...8215......5.....71.8.137....7........
F9: 2,4,6,9                              # 13 pairs
* PAIR D6: 7,8 BLK 5
E6: 7,8,3,6                              # reduction candidate for 7,8
E6: 7,8 => CTR
* ....175..6.......3....43...378....6....23.178215..6...5.....71.8..3...5..........
E6: 3,6                                  # 14 pairs
* PAIR F6: 6,8 BLK 5
E6: 6,8,3,7                              # reduction candidate for 6,8
E6: 6,8 => CTR
* ....175..6.......3....43...378....6....23.1782157.....5.....71.8..3...5..........
E6: 3,7 => SOLVED
* 483917526691582473752643891378194265964275138215836947539468712847321659126759384
* PAIR F6: 6,8 COL F
F7: 6,8,2,4,9                            # reduction candidate for 6,8
F7: 6,8                                  # 14 pairs
F7: 2,4,9                                # 13 pairs
* PAIR G4: 1,2 BLK 6
I4: 1,2,5                                # reduction candidate for 1,2
I4: 1,2 => CTR
* ....175..6.......3....43...378....6....2713582158.....5.....71.8..3..............
I4: 5 => SOLVED
* 483917526691582473752643891378194265964275138215836947539468712847321659126759384
* PAIR G4: 1,2 COL G
G3: 1,2,6,8,9                            # reduction candidate for 1,2
G3: 1,2 => CTR
* ....175..6.1....737...43...378....6....2713582158.....5.....71.8..3..6...........
G3: 6,8,9                                # 13 pairs
* PAIR A9: 1,7 BLK 7
C8: 1,7,2,4,6,9                          # reduction candidate for 1,7
C8: 1,7                                  # 14 pairs
C9: 1,7,2,4,6,9                          # reduction candidate for 1,7
C9: 1,7 => CTR
* ....175..6.......3....43...3781.4265...2.51.82157.....5.....71.8..371.5..........
C9: 2,4,6,9                              # 14 pairs
* PAIR A9: 1,7 ROW 9
D9: 1,7,4,5,9                            # reduction candidate for 1,7
D9: 4,5,9 => CTR
* ....175..6.......3....43...3781.4265...2.51.82157.....5.....71.8..3...5..........
D9: 1,7                                  # 15 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-341-base-pr-000.dot
* REASONING
* DIS # C2: 4,9 => CTR => C2: 1,7
* DIS # C3: 1,7 => CTR => C3: 2,9
* DIS # I3: 2,6,9 => CTR => I3: 1,7
* DIS # D4: 5,9 => CTR => D4: 1,4
* DIS # F4: 5,9 => CTR => F4: 1,4
* DIS # E2: 5,9 => CTR => E2: 2,8
* DIS # E8: 5,9 => CTR => E8: 2,6,7
* PRF # E6: 3,7 => SOL
* DIS # E6: 6,8 => CTR => E6: 3,7
* PRF # H5: 3,7 => SOL
* DIS # H5: 5 => CTR => H5: 3,7
* DIS # F4: 1,5 => CTR => F4: 4,9
* DIS # F9: 1,5 => CTR => F9: 2,4,6,9
* DIS # E6: 7,8 => CTR => E6: 3,6
* DIS # E6: 6,8 => CTR => E6: 3,7
* PRF # E6: 3,7 => SOL
* DIS # I4: 1,2 => CTR => I4: 5
* PRF # I4: 5 => SOL
* DIS # G3: 1,2 => CTR => G3: 6,8,9
* DIS # C9: 1,7 => CTR => C9: 2,4,6,9
* DIS # D9: 4,5,9 => CTR => D9: 1,7
* CNT  21 HDP CHAINS /  48 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,A3,A5,A9,D6,E4,E5,F5,F6,G4,G5,G9,H9)
* ....175..6.......3....43...378....6....2....8215......5.....71.8..3..............
* PAIR A1: 4,9 BLK 1
B1: 4,9,2,3,8                            # reduction candidate for 4,9
B1: 4,9                                  # 22 pairs
C1: 4,9,2,3                              # reduction candidate for 4,9
C1: 4,9                                  # 22 pairs
B2: 4,9,5,8                              # reduction candidate for 4,9
B2: 4,9                                  # 16 pairs
C2: 4,9,1,7                              # reduction candidate for 4,9
C2: 4,9 => CTR
* ....175..6.....173....43...378...261...2713582158.....5.....71.8..3..............
* PAIR A1: 4,9 ROW 1
H1: 4,9,2,8                              # reduction candidate for 4,9
H1: 4,9                                  # 19 pairs
I1: 4,9,2,6                              # reduction candidate for 4,9
I1: 4,9                                  # 18 pairs
* PAIR RESTART
* PAIR A1: 4,9 BLK 1
B1: 4,9,2,3,8                            # reduction candidate for 4,9
B1: 4,9                                  # 22 pairs
C1: 4,9,2,3                              # reduction candidate for 4,9
C1: 4,9                                  # 22 pairs
B2: 4,9,5,8                              # reduction candidate for 4,9
B2: 4,9                                  # 16 pairs
* PAIR A1: 4,9 ROW 1
H1: 4,9,2,8                              # reduction candidate for 4,9
H1: 4,9                                  # 19 pairs
I1: 4,9,2,6                              # reduction candidate for 4,9
I1: 4,9                                  # 18 pairs
* PAIR A3: 1,7 ROW 3
I3: 1,7,2,6,9                            # reduction candidate for 1,7
I3: 2,6,9 => CTR
* ....175..6.......3....43...378....61...2.1358215.36..75.....71.8.137.............
* PAIR RESTART
* PAIR A5: 4,9 BLK 4
B5: 4,9,6                                # reduction candidate for 4,9
B5: 4,9                                  # 17 pairs
C5: 4,9,6                                # reduction candidate for 4,9
C5: 4,9                                  # 17 pairs
* PAIR E4: 5,9 BLK 5
D4: 5,9,1,4                              # reduction candidate for 5,9
D4: 5,9 => CTR
* ....175..6.......3....43...378..4.6....2.1358215.36...5.....71.8.137.............
F4: 5,9,1,4                              # reduction candidate for 5,9
F4: 5,9 => CTR
* ....175..6.......3....43...3784...6....2.1358215.36...5.....71.8.137.............
F4: 1,4 => SOLVED
* 483917526691582473752643891378194265964275138215836947539468712847321659126759384
* DURATION: 0:00:16.413587  START: 14:25:05.434097  END: 14:25:21.847684 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-341-base-pr-001.dot
* REASONING
* DIS # C2: 4,9 => CTR => C2: 1,7
* DIS C2: 1,7 # I3: 2,6,9 => CTR => I3: 1,7
* DIS C2: 1,7 + I3: 1,7 # D4: 5,9 => CTR => D4: 1,4
* DIS C2: 1,7 + I3: 1,7 + D4: 1,4 # F4: 5,9 => CTR => F4: 1,4
* PRF C2: 1,7 + I3: 1,7 + D4: 1,4 + F4: 1,4 => SOL
* STA C2: 1,7 + I3: 1,7 + D4: 1,4 + F4: 1,4
* CNT   5 HDP CHAINS /  17 HYP OPENED

Header Info

Top 500 Minimum 17 341

solution: 483917526691582473752643891378194265964275138215836947539468712847321659126759384
info: 3230     FNBTHWY  S8.f     3129

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

Solution

position: 483917526691582473752643891378194265964275138215836947539468712847321659126759384 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: 4,9 => UNS
* INC # C1: 4,9 => UNS
* INC # B2: 4,9 => UNS
* DIS # C2: 4,9 => CTR => C2: 1,7
* INC # C2: 1,7 => UNS
* INC # H1: 4,9 => UNS
* INC # I1: 4,9 => UNS
* INC # C2: 1,7 => UNS
* DIS # C3: 1,7 => CTR => C3: 2,9
* INC # C3: 2,9 => UNS
* INC # I3: 1,7 => UNS
* DIS # I3: 2,6,9 => CTR => I3: 1,7
* INC # B5: 4,9 => UNS
* INC # C5: 4,9 => UNS
* DIS # D4: 5,9 => CTR => D4: 1,4
* INC # D4: 1,4 => UNS
* DIS # F4: 5,9 => CTR => F4: 1,4
* INC # F4: 1,4 => UNS
* DIS # E2: 5,9 => CTR => E2: 2,8
* INC # E2: 2,8 => UNS
* DIS # E8: 5,9 => CTR => E8: 2,6,7
* INC # E8: 2,6,7 => UNS
* INC # E9: 5,9 => UNS
* PRF # E6: 3,7 => SOL
* DIS # E6: 6,8 => CTR => E6: 3,7
* PRF # H5: 3,7 => SOL
* DIS # H5: 5 => CTR => H5: 3,7
* INC # D4: 1,5 => UNS
* DIS # F4: 1,5 => CTR => F4: 4,9
* INC # F4: 4,9 => UNS
* INC # F8: 1,5 => UNS
* DIS # F9: 1,5 => CTR => F9: 2,4,6,9
* INC # F9: 2,4,6,9 => UNS
* DIS # E6: 7,8 => CTR => E6: 3,6
* INC # E6: 3,6 => UNS
* DIS # E6: 6,8 => CTR => E6: 3,7
* PRF # E6: 3,7 => SOL
* INC # F7: 6,8 => UNS
* INC # F7: 2,4,9 => UNS
* DIS # I4: 1,2 => CTR => I4: 5
* PRF # I4: 5 => SOL
* DIS # G3: 1,2 => CTR => G3: 6,8,9
* INC # G3: 6,8,9 => UNS
* INC # C8: 1,7 => UNS
* DIS # C9: 1,7 => CTR => C9: 2,4,6,9
* INC # C9: 2,4,6,9 => UNS
* INC # D9: 1,7 => UNS
* DIS # D9: 4,5,9 => CTR => D9: 1,7
* CNT  48 HDP CHAINS /  48 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # B1: 4,9 => UNS
* INC # C1: 4,9 => UNS
* INC # B2: 4,9 => UNS
* DIS # C2: 4,9 => CTR => C2: 1,7
* INC C2: 1,7 # H1: 4,9 => UNS
* INC C2: 1,7 # I1: 4,9 => UNS
* INC C2: 1,7 # B1: 4,9 => UNS
* INC C2: 1,7 # C1: 4,9 => UNS
* INC C2: 1,7 # B2: 4,9 => UNS
* INC C2: 1,7 # H1: 4,9 => UNS
* INC C2: 1,7 # I1: 4,9 => UNS
* INC C2: 1,7 # I3: 1,7 => UNS
* DIS C2: 1,7 # I3: 2,6,9 => CTR => I3: 1,7
* INC C2: 1,7 + I3: 1,7 # B5: 4,9 => UNS
* INC C2: 1,7 + I3: 1,7 # C5: 4,9 => UNS
* DIS C2: 1,7 + I3: 1,7 # D4: 5,9 => CTR => D4: 1,4
* DIS C2: 1,7 + I3: 1,7 + D4: 1,4 # F4: 5,9 => CTR => F4: 1,4
* PRF C2: 1,7 + I3: 1,7 + D4: 1,4 + F4: 1,4 => SOL
* STA C2: 1,7 + I3: 1,7 + D4: 1,4 + F4: 1,4
* CNT  18 HDP CHAINS /  17 HYP OPENED