Analysis of xx-top500-471-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: ....41...2.....5...........5..7..3.....2...6.........1.61....4..4..8.......53.... initial

Autosolve

position: .5..41...2.....5...........5..7..3.....2...6....4...513619..845.45186......534... autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # G3: 6,7,9 => CTR => G3: 1,4
* DIS # F5: 8,9 => CTR => F5: 3,5
* DIS # F6: 8,9 => CTR => F6: 3
* DIS # B4: 8,9 => CTR => B4: 1,2
* DIS # I4: 8,9 => CTR => I4: 2,4
* DIS # E4: 1 => CTR => E4: 6,9
* DIS # C6: 6,9 => CTR => C6: 2,3,7,8
* DIS # A6: 7,9 => CTR => A6: 6,8
* CNT   8 HDP CHAINS /  26 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 # G3: 6,7,9 => CTR => G3: 1,4
* DIS G3: 1,4 # F5: 8,9 => CTR => F5: 3,5
* DIS G3: 1,4 + F5: 3,5 # F6: 8,9 => CTR => F6: 3
* DIS G3: 1,4 + F5: 3,5 + F6: 3 # E4: 1 => CTR => E4: 6,9
* DIS G3: 1,4 + F5: 3,5 + F6: 3 + E4: 6,9 # C9: 7,9 => CTR => C9: 2
* PRF G3: 1,4 + F5: 3,5 + F6: 3 + E4: 6,9 + C9: 2 # B3: 3 => SOL
* STA G3: 1,4 + F5: 3,5 + F6: 3 + E4: 6,9 + C9: 2 + B3: 3
* CNT   6 HDP CHAINS /  10 HYP OPENED

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

Details

Positions

....41...2.....5...........5..7..3.....2...6.........1.61....4..4..8.......53.... initial
.5..41...2.....5...........5..7..3.....2...6....4...513619..845.45186......534... autosolve
957341682284679513136852497519768324473215968628493751361927845745186239892534176 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (11)
A3: 1,4
E2: 7,9
F2: 7,9
E3: 2,5
F3: 2,5
A5: 1,4
F4: 8,9
E6: 6,9
A8: 7,9
E7: 2,7
F7: 2,7

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
E4,E5: 1.. / E4 = 1  =>  0 pairs (X) / E5 = 1  => 12 pairs (_)
G9,H9: 1.. / G9 = 1  => 12 pairs (_) / H9 = 1  =>  0 pairs (X)
B2,H2: 1.. / B2 = 1  =>  0 pairs (X) / H2 = 1  => 13 pairs (_)
B4,E4: 1.. / B4 = 1  => 12 pairs (_) / E4 = 1  =>  0 pairs (X)
A3,A5: 1.. / A3 = 1  => 12 pairs (_) / A5 = 1  =>  0 pairs (X)
G3,G9: 1.. / G3 = 1  =>  0 pairs (X) / G9 = 1  => 12 pairs (_)
E3,F3: 2.. / E3 = 2  =>  0 pairs (X) / F3 = 2  =>  7 pairs (_)
B9,C9: 2.. / B9 = 2  => 11 pairs (_) / C9 = 2  => 11 pairs (_)
E7,F7: 2.. / E7 = 2  =>  7 pairs (_) / F7 = 2  =>  0 pairs (X)
E3,E7: 2.. / E3 = 2  =>  0 pairs (X) / E7 = 2  =>  7 pairs (_)
F3,F7: 2.. / F3 = 2  =>  7 pairs (_) / F7 = 2  =>  0 pairs (X)
F5,F6: 3.. / F5 = 3  =>  0 pairs (X) / F6 = 3  => 11 pairs (_)
H8,I8: 3.. / H8 = 3  => 12 pairs (_) / I8 = 3  => 11 pairs (_)
C2,I2: 4.. / C2 = 4  => 12 pairs (_) / I2 = 4  =>  0 pairs (X)
C4,I4: 4.. / C4 = 4  =>  0 pairs (X) / I4 = 4  => 12 pairs (_)
A3,A5: 4.. / A3 = 4  =>  0 pairs (X) / A5 = 4  => 12 pairs (_)
G3,G5: 4.. / G3 = 4  => 12 pairs (_) / G5 = 4  =>  0 pairs (X)
E3,F3: 5.. / E3 = 5  =>  7 pairs (_) / F3 = 5  =>  0 pairs (X)
E5,F5: 5.. / E5 = 5  =>  0 pairs (X) / F5 = 5  =>  7 pairs (_)
E3,E5: 5.. / E3 = 5  =>  7 pairs (_) / E5 = 5  =>  0 pairs (X)
F3,F5: 5.. / F3 = 5  =>  0 pairs (X) / F5 = 5  =>  7 pairs (_)
E4,E6: 6.. / E4 = 6  => 12 pairs (_) / E6 = 6  =>  0 pairs (X)
G9,I9: 6.. / G9 = 6  =>  0 pairs (X) / I9 = 6  => 11 pairs (_)
C4,E4: 6.. / C4 = 6  =>  0 pairs (X) / E4 = 6  => 12 pairs (_)
A1,A6: 6.. / A1 = 6  =>  0 pairs (X) / A6 = 6  => 12 pairs (_)
E2,F2: 7.. / E2 = 7  =>  7 pairs (_) / F2 = 7  =>  0 pairs (X)
E7,F7: 7.. / E7 = 7  =>  0 pairs (X) / F7 = 7  =>  7 pairs (_)
E2,E7: 7.. / E2 = 7  =>  7 pairs (_) / E7 = 7  =>  0 pairs (X)
F2,F7: 7.. / F2 = 7  =>  0 pairs (X) / F7 = 7  =>  7 pairs (_)
E2,F2: 9.. / E2 = 9  =>  0 pairs (X) / F2 = 9  =>  7 pairs (_)
* DURATION: 0:00:54.552485  START: 18:46:41.327121  END: 18:47:35.879606 2017-05-04
* CP COUNT: (30)
* CLUE FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A3,A5,A8,E2,E3,E6,E7,F2,F3,F4,F7)
* .5..41...2.....5...........5..7..3.....2...6....4...513619..845.45186......534...
* PAIR A3: 1,4 ROW 3
G3: 1,4,6,7,9                            # reduction candidate for 1,4
G3: 6,7,9 => CTR
* .5..41...2.....5..4........5.476.3..1..2..46....49..513619..845.45186......5341.6
G3: 1,4                                  # 12 pairs
* PAIR F4: 8,9 BLK 5
F5: 8,9,3,5                              # reduction candidate for 8,9
F5: 8,9 => CTR
* 65..41...2.4.975..1...254..5.671.3.441325..6....463.51361972845.45186......534...
F5: 3,5                                  # 12 pairs
F6: 8,9,3                                # reduction candidate for 8,9
F6: 8,9 => CTR
* 65..41...2.4.975..1...254..5.671.3.441.253.6....46..51361972845.45186......534...
F6: 3                                    # 11 pairs
* PAIR F4: 8,9 ROW 4
B4: 8,9,1,2                              # reduction candidate for 8,9
B4: 8,9 => CTR
* 65..41...2.4...5..1.....4..5.671.32441.2...68...46..513619..845.45186......534...
B4: 1,2                                  # 12 pairs
C4: 8,9,2,4,6                            # reduction candidate for 8,9
C4: 8,9                                  # 11 pairs
H4: 8,9,2                                # reduction candidate for 8,9
H4: 8,9                                  # 15 pairs
I4: 8,9,2,4                              # reduction candidate for 8,9
I4: 8,9 => CTR
* .5..41...2.....5...........5.476.3..1..2...6....49..513619..845.45186......534...
I4: 2,4                                  # 12 pairs
* PAIR E6: 6,9 BLK 5
E4: 6,9,1                                # reduction candidate for 6,9
E4: 1 => CTR
* 65..41...2.4...5..1.....4..5.671.3.441.2...6....46..513619..845.45186......534...
E4: 6,9                                  # 12 pairs
* PAIR E6: 6,9 ROW 6
A6: 6,9,7,8                              # reduction candidate for 6,9
A6: 6,9                                  # 14 pairs
C6: 6,9,2,3,7,8                          # reduction candidate for 6,9
C6: 6,9 => CTR
* 65..41...2.....5..4........5.476.3..1..2..46...649..513619..845.45186.....2534...
C6: 2,3,7,8                              # 11 pairs
* PAIR A8: 7,9 BLK 7
A9: 7,9,8                                # reduction candidate for 7,9
A9: 7,9                                  # 16 pairs
B9: 7,9,2,8                              # reduction candidate for 7,9
B9: 7,9                                  # 12 pairs
C9: 7,9,2,8                              # reduction candidate for 7,9
C9: 7,9                                  # 12 pairs
* PAIR A8: 7,9 ROW 8
G8: 7,9,2                                # reduction candidate for 7,9
G8: 7,9                                  # 14 pairs
H8: 7,9,2,3                              # reduction candidate for 7,9
H8: 7,9                                  # 13 pairs
I8: 7,9,2,3                              # reduction candidate for 7,9
I8: 7,9                                  # 14 pairs
* PAIR A8: 7,9 COL A
A1: 7,9,6,8                              # reduction candidate for 7,9
A1: 7,9                                  # 12 pairs
A6: 7,9,6,8                              # reduction candidate for 7,9
A6: 7,9 => CTR
* 65..41...2.....5..4........5.476.3..1..2..46...649..513619..845945186...8.2534...
A6: 6,8                                  # 12 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-471-base-pr-000.dot
* REASONING
* DIS # G3: 6,7,9 => CTR => G3: 1,4
* DIS # F5: 8,9 => CTR => F5: 3,5
* DIS # F6: 8,9 => CTR => F6: 3
* DIS # B4: 8,9 => CTR => B4: 1,2
* DIS # I4: 8,9 => CTR => I4: 2,4
* DIS # E4: 1 => CTR => E4: 6,9
* DIS # C6: 6,9 => CTR => C6: 2,3,7,8
* DIS # A6: 7,9 => CTR => A6: 6,8
* CNT   8 HDP CHAINS /  26 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A3,A5,A8,E2,E3,E6,E7,F2,F3,F4,F7)
* .5..41...2.....5...........5..7..3.....2...6....4...513619..845.45186......534...
* PAIR A3: 1,4 ROW 3
G3: 1,4,6,7,9                            # reduction candidate for 1,4
G3: 6,7,9 => CTR
* .5..41...2.....5..4........5.476.3..1..2..46....49..513619..845.45186......5341.6
* PAIR RESTART
* PAIR F4: 8,9 BLK 5
F5: 8,9,3,5                              # reduction candidate for 8,9
F5: 8,9 => CTR
* 65..41...2...975......25...5.671.3.4...25..6....463.51361972845.45186......53461.
F6: 8,9,3                                # reduction candidate for 8,9
F6: 8,9 => CTR
* 65..41...2...975......25...5.671.3.4...253.6....46..51361972845.45186......53461.
* PAIR E6: 6,9 BLK 5
E4: 6,9,1                                # reduction candidate for 6,9
E4: 1 => CTR
* 65..41...2.4.795..1...524..5.67183.4...295768...463.51361927845.45186......534...
* PAIR A8: 7,9 BLK 7
B9: 7,9,2                                # reduction candidate for 7,9
B9: 7,9                                  # 11 pairs
C9: 7,9,2                                # reduction candidate for 7,9
C9: 7,9 => CTR
* 957.416..2846795131.6.524..5127683944..215768678493251361927845.45186932829534176
* RESTART

* LEVEL 0 PASS 1 ROUND 2 (AUTO SOLVE) (A1,A8,B5,B9,C1,C5,D1,D3,H9,I3,I8)
* .5..416.22846795131.6.524..5197683244..215968628493751361927845.4518623.8.25341.6
* PAIR A1: 7,9 BLK 1
B3: 7,9,3                                # reduction candidate for 7,9
B3: 3 => SOLVED
* 957341682284679513136852497519768324473215968628493751361927845745186239892534176
* DURATION: 0:00:15.393901  START: 18:48:00.262519  END: 18:48:15.656420 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-471-base-pr-001.dot
* REASONING
* DIS # G3: 6,7,9 => CTR => G3: 1,4
* DIS G3: 1,4 # F5: 8,9 => CTR => F5: 3,5
* DIS G3: 1,4 + F5: 3,5 # F6: 8,9 => CTR => F6: 3
* DIS G3: 1,4 + F5: 3,5 + F6: 3 # E4: 1 => CTR => E4: 6,9
* DIS G3: 1,4 + F5: 3,5 + F6: 3 + E4: 6,9 # C9: 7,9 => CTR => C9: 2
* PRF G3: 1,4 + F5: 3,5 + F6: 3 + E4: 6,9 + C9: 2 # B3: 3 => SOL
* STA G3: 1,4 + F5: 3,5 + F6: 3 + E4: 6,9 + C9: 2 + B3: 3
* CNT   6 HDP CHAINS /  10 HYP OPENED

Header Info

Top 500 Minimum 17 471

solution: 957341682284679513136852497519768324473215968628493751361927845745186239892534176
info: 95641    FNBTHWXYK S8.f     40794

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

Solution

position: 957341682284679513136852497519768324473215968628493751361927845745186239892534176 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 # G3: 1,4 => UNS
* DIS # G3: 6,7,9 => CTR => G3: 1,4
* DIS # F5: 8,9 => CTR => F5: 3,5
* INC # F5: 3,5 => UNS
* DIS # F6: 8,9 => CTR => F6: 3
* INC # F6: 3 => UNS
* DIS # B4: 8,9 => CTR => B4: 1,2
* INC # B4: 1,2 => UNS
* INC # C4: 8,9 => UNS
* INC # H4: 8,9 => UNS
* DIS # I4: 8,9 => CTR => I4: 2,4
* INC # I4: 2,4 => UNS
* INC # E4: 6,9 => UNS
* DIS # E4: 1 => CTR => E4: 6,9
* INC # A6: 6,9 => UNS
* DIS # C6: 6,9 => CTR => C6: 2,3,7,8
* INC # C6: 2,3,7,8 => UNS
* INC # A9: 7,9 => UNS
* INC # B9: 7,9 => UNS
* INC # C9: 7,9 => UNS
* INC # G8: 7,9 => UNS
* INC # H8: 7,9 => UNS
* INC # I8: 7,9 => UNS
* INC # A1: 7,9 => UNS
* DIS # A6: 7,9 => CTR => A6: 6,8
* INC # A6: 6,8 => UNS
* CNT  26 HDP CHAINS /  26 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # G3: 1,4 => UNS
* DIS # G3: 6,7,9 => CTR => G3: 1,4
* DIS G3: 1,4 # F5: 8,9 => CTR => F5: 3,5
* DIS G3: 1,4 + F5: 3,5 # F6: 8,9 => CTR => F6: 3
* INC G3: 1,4 + F5: 3,5 + F6: 3 # E4: 6,9 => UNS
* DIS G3: 1,4 + F5: 3,5 + F6: 3 # E4: 1 => CTR => E4: 6,9
* INC G3: 1,4 + F5: 3,5 + F6: 3 + E4: 6,9 # B9: 7,9 => UNS
* DIS G3: 1,4 + F5: 3,5 + F6: 3 + E4: 6,9 # C9: 7,9 => CTR => C9: 2
* INC G3: 1,4 + F5: 3,5 + F6: 3 + E4: 6,9 + C9: 2 # B3: 7,9 => UNS
* PRF G3: 1,4 + F5: 3,5 + F6: 3 + E4: 6,9 + C9: 2 # B3: 3 => SOL
* STA G3: 1,4 + F5: 3,5 + F6: 3 + E4: 6,9 + C9: 2 + B3: 3
* CNT  10 HDP CHAINS /  10 HYP OPENED