Analysis of xx-top500-011-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 1..5..3.....3.6...2........6.......2....3..4....7.......3...78..4..12............ initial

Autosolve

position: 1..5273.44.73.621.23.4.1.7.67415..32...23.6473.27641..92364578174..12..3....7342. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # C3: 6 => CTR => C3: 5,9
* PRF # B5: 5,9 => SOL
* DIS # I2: 5 => CTR => I2: 8,9
* DIS # I3: 8,9 => CTR => I3: 5,6
* DIS # I3: 5,8 => CTR => I3: 6,9
* DIS # C1: 6,9 => CTR => C1: 8
* DIS # H8: 5 => CTR => H8: 6,9
* DIS # B5: 5,8 => CTR => B5: 1,9
* DIS # C5: 5,8 => CTR => C5: 1,9
* PRF # B5: 8,9 => SOL
* DIS # I6: 5 => CTR => I6: 8,9
* DIS # B1: 8,9 => CTR => B1: 6
* PRF # B1: 6 => SOL
* PRF # B5: 8,9 => SOL
* DIS # I6: 5 => CTR => I6: 8,9
* DIS # I6: 8 => CTR => I6: 5,9
* DIS # H8: 5,9 => CTR => H8: 6
* DIS # B9: 5,8 => CTR => B9: 1,6
* DIS # C9: 5,8 => CTR => C9: 1,6
* DIS # H8: 5,9 => CTR => H8: 6
* DIS # G3: 8 => CTR => G3: 5,9
* CNT  21 HDP CHAINS /  50 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 # C3: 6 => CTR => C3: 5,9
* PRF C3: 5,9 # B5: 5,9 => SOL
* STA C3: 5,9 + B5: 5,9
* CNT   2 HDP CHAINS /   3 HYP OPENED

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

Details

Positions

1..5..3.....3.6...2........6.......2....3..4....7.......3...78..4..12............ initial
1..5273.44.73.621.23.4.1.7.67415..32...23.6473.27641..92364578174..12..3....7342. autosolve
168527394457396218239481576674159832591238647382764159923645781745812963816973425 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (14)
B2: 5,9
E2: 8,9
E3: 8,9
H1: 6,9
A5: 5,8
B6: 8,9
F4: 8,9
F5: 8,9
G4: 8,9
H6: 5,9
A9: 5,8
D8: 8,9
D9: 8,9
G8: 5,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
B5,C5: 1.. / B5 = 1  => 14 pairs (_) / C5 = 1  =>  0 pairs (*)
B9,C9: 1.. / B9 = 1  =>  0 pairs (*) / C9 = 1  =>  0 pairs (X)
B5,B9: 1.. / B5 = 1  => 14 pairs (_) / B9 = 1  =>  0 pairs (*)
C5,C9: 1.. / C5 = 1  =>  0 pairs (*) / C9 = 1  =>  0 pairs (X)
B2,C3: 5.. / B2 = 5  => 15 pairs (_) / C3 = 5  =>  0 pairs (X)
H6,I6: 5.. / H6 = 5  => 15 pairs (_) / I6 = 5  =>  0 pairs (X)
B2,I2: 5.. / B2 = 5  => 15 pairs (_) / I2 = 5  =>  0 pairs (X)
A5,A9: 5.. / A5 = 5  => 12 pairs (_) / A9 = 5  =>  0 pairs (X)
G3,G8: 5.. / G3 = 5  => 14 pairs (_) / G8 = 5  => 19 pairs (_)
H6,H8: 5.. / H6 = 5  => 15 pairs (_) / H8 = 5  =>  0 pairs (X)
H1,I3: 6.. / H1 = 6  =>  0 pairs (X) / I3 = 6  => 22 pairs (_)
H8,I9: 6.. / H8 = 6  => 22 pairs (_) / I9 = 6  =>  0 pairs (X)
C3,I3: 6.. / C3 = 6  =>  0 pairs (X) / I3 = 6  => 22 pairs (_)
C8,H8: 6.. / C8 = 6  =>  0 pairs (X) / H8 = 6  => 22 pairs (_)
B1,B9: 6.. / B1 = 6  =>  0 pairs (*) / B9 = 6  =>  0 pairs (X)
H1,H8: 6.. / H1 = 6  =>  0 pairs (X) / H8 = 6  => 22 pairs (_)
I3,I9: 6.. / I3 = 6  => 22 pairs (_) / I9 = 6  =>  0 pairs (X)
B1,C1: 8.. / B1 = 8  =>  0 pairs (X) / C1 = 8  => 15 pairs (_)
E2,E3: 8.. / E2 = 8  => 15 pairs (_) / E3 = 8  => 12 pairs (_)
F4,F5: 8.. / F4 = 8  =>  0 pairs (X) / F5 = 8  => 13 pairs (_)
G4,I6: 8.. / G4 = 8  => 13 pairs (_) / I6 = 8  =>  0 pairs (X)
D8,D9: 8.. / D8 = 8  => 14 pairs (_) / D9 = 8  =>  0 pairs (X)
E2,I2: 8.. / E2 = 8  => 15 pairs (_) / I2 = 8  => 12 pairs (_)
F4,G4: 8.. / F4 = 8  =>  0 pairs (X) / G4 = 8  => 13 pairs (_)
B6,I6: 8.. / B6 = 8  => 13 pairs (_) / I6 = 8  =>  0 pairs (X)
C8,D8: 8.. / C8 = 8  =>  0 pairs (X) / D8 = 8  => 14 pairs (_)
A5,A9: 8.. / A5 = 8  =>  0 pairs (X) / A9 = 8  => 12 pairs (_)
G3,G4: 8.. / G3 = 8  =>  0 pairs (X) / G4 = 8  => 13 pairs (_)
E2,E3: 9.. / E2 = 9  => 12 pairs (_) / E3 = 9  => 15 pairs (_)
F4,F5: 9.. / F4 = 9  => 13 pairs (_) / F5 = 9  =>  0 pairs (X)
D8,D9: 9.. / D8 = 9  =>  0 pairs (X) / D9 = 9  => 14 pairs (_)
F4,G4: 9.. / F4 = 9  => 13 pairs (_) / G4 = 9  =>  0 pairs (X)
D9,I9: 9.. / D9 = 9  => 14 pairs (_) / I9 = 9  =>  0 pairs (X)
* DURATION: 0:00:57.353748  START: 02:58:19.461278  END: 02:59:16.815026 2017-05-04
* CP COUNT: (33)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A5,A9,B2,B6,D8,D9,E2,E3,F4,F5,G4,G8,H1,H6)
* 1..5273.44.73.621.23.4.1.7.67415..32...23.6473.27641..92364578174..12..3....7342.
* PAIR B2: 5,9 BLK 1
C3: 5,9,6                                # reduction candidate for 5,9
C3: 6 => CTR
* 1..5273.44573.621.2364.1.7.67415..32...23.6473.27641..92364578174..12.63.61.7342.
C3: 5,9                                  # 22 pairs
* PAIR B2: 5,9 ROW 2
I2: 5,9,8                                # reduction candidate for 5,9
I2: 5,9                                  # 15 pairs
I2: 8                                    # 12 pairs
* PAIR B2: 5,9 COL B
B5: 5,9,1,8                              # reduction candidate for 5,9
B5: 5,9 => SOLVED
* 168527394457396218239481576674159832591238647382764159923645781745812963816973425
B5: 1,8                                  # 15 pairs
* PAIR E2: 8,9 ROW 2
I2: 8,9,5                                # reduction candidate for 8,9
I2: 5 => CTR
* 1..5273.44.7386215235491876674158932...2396473927641..92364578174..12..3....7342.
I2: 8,9                                  # 15 pairs
* PAIR E3: 8,9 ROW 3
G3: 8,9,5                                # reduction candidate for 8,9
G3: 8,9                                  # 19 pairs
I3: 8,9,5,6                              # reduction candidate for 8,9
I3: 8,9 => CTR
* 1..5273644.73.621.2364.157.67415.832...2386473827641..92364578174..129538...7342.
I3: 5,6                                  # 15 pairs
* PAIR H1: 6,9 BLK 3
I3: 6,9,5,8                              # reduction candidate for 6,9
I3: 5,8 => CTR
* 1..5273644.73.621.2364.1.7.67415..32...23.6473.27641..92364578174..12..3.61.7342.
I3: 6,9                                  # 17 pairs
* PAIR H1: 6,9 ROW 1
B1: 6,9,8                                # reduction candidate for 6,9
B1: 6,9                                  # 15 pairs
C1: 6,9,8                                # reduction candidate for 6,9
C1: 6,9 => CTR
* 18.5273.445738621923.49187.67415..32...23.64739276415892364578174..12..3.61.7342.
C1: 8                                    # 15 pairs
* PAIR H1: 6,9 COL H
H8: 6,9,5                                # reduction candidate for 6,9
H8: 5 => CTR
* 1..5273644.73.621.2364.1.7.67415..32...23.6473.276419592364578174..12.53.61.73429
H8: 6,9                                  # 15 pairs
* PAIR A5: 5,8 BLK 4
B5: 5,8,1,9                              # reduction candidate for 5,8
B5: 5,8 => CTR
* 1685273944573.621.23.4.1.7.67415..32..123964739276415892364578174..12..3.1..7342.
B5: 1,9                                  # 15 pairs
C5: 5,8,1,9                              # reduction candidate for 5,8
C5: 5,8 => CTR
* 16.5273.445738621923.491875674158932.1.23964739276415892364578174..125935.1973426
C5: 1,9                                  # 15 pairs
* PAIR B6: 8,9 BLK 4
B5: 8,9,1,5                              # reduction candidate for 8,9
B5: 8,9 => SOLVED
* 168527394457396218239481576674159832591238647382764159923645781745812963816973425
B5: 1,5                                  # 15 pairs
C5: 8,9,1,5                              # reduction candidate for 8,9
C5: 8,9                                  # 14 pairs
* PAIR B6: 8,9 ROW 6
I6: 8,9,5                                # reduction candidate for 8,9
I6: 5 => CTR
* 16.5273.44.73.621.23.4.1.7.67415.832...23864738276419592364578174..12.538..973426
I6: 8,9                                  # 15 pairs
* PAIR B6: 8,9 COL B
B1: 8,9,6                                # reduction candidate for 8,9
B1: 8,9 => CTR
* 1.652739445739621823948157667415.832.1.23.6473.27641..92364578174..12.63.61.7342.
B1: 6 => SOLVED
* 168527394457396218239481576674159832591238647382764159923645781745812963816973425
* PAIR F5: 8,9 ROW 5
B5: 8,9,1,5                              # reduction candidate for 8,9
B5: 8,9 => SOLVED
* 168527394457396218239481576674159832591238647382764159923645781745812963816973425
B5: 1,5                                  # 15 pairs
C5: 8,9,1,5                              # reduction candidate for 8,9
C5: 8,9                                  # 14 pairs
* PAIR G4: 8,9 BLK 6
I6: 8,9,5                                # reduction candidate for 8,9
I6: 5 => CTR
* 16.5273.44.73.621.23.4.1.7.67415.832...23864738276419592364578174..12.538..973426
I6: 8,9                                  # 15 pairs
* PAIR G4: 8,9 COL G
G3: 8,9,5                                # reduction candidate for 8,9
G3: 8,9                                  # 19 pairs
G3: 5                                    # 14 pairs
* PAIR H6: 5,9 BLK 6
I6: 5,9,8                                # reduction candidate for 5,9
I6: 8 => CTR
* 1.9527364457386219236491875674158932...2396473927641589236457817489125.3....7342.
I6: 5,9                                  # 13 pairs
* PAIR H6: 5,9 COL H
H8: 5,9,6                                # reduction candidate for 5,9
H8: 5,9 => CTR
* 1..5273644.73.621.2364.1.7.67415..32...23.6473.27641..92364578174..12..3.61.7342.
H8: 6                                    # 22 pairs
* PAIR A9: 5,8 BLK 7
C8: 5,8,6                                # reduction candidate for 5,8
C8: 5,8                                  # 22 pairs
B9: 5,8,1,6                              # reduction candidate for 5,8
B9: 5,8 => CTR
* 1685273944.73.621.23.4.1.7667415..32.1.23.6473.276415.92364578174.812963....7342.
B9: 1,6                                  # 15 pairs
C9: 5,8,1,6                              # reduction candidate for 5,8
C9: 5,8 => CTR
* 1685273944.73.621.23948157.67415..32..123.6473.27641..92364578174..12..3.1..73426
C9: 1,6                                  # 15 pairs
* PAIR G8: 5,9 BLK 9
H8: 5,9,6                                # reduction candidate for 5,9
H8: 5,9 => CTR
* 1..5273644.73.621.2364.1.7.67415..32...23.6473.27641..92364578174..12..3.61.7342.
H8: 6                                    # 22 pairs
I9: 5,9,6                                # reduction candidate for 5,9
I9: 5,9                                  # 22 pairs
* PAIR G8: 5,9 COL G
G3: 5,9,8                                # reduction candidate for 5,9
G3: 8 => CTR
* 16.5273.445738621923.491875674158932...23964739276415892364578174..12593...973426
G3: 5,9                                  # 13 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-011-base-pr-000.dot
* REASONING
* DIS # C3: 6 => CTR => C3: 5,9
* PRF # B5: 5,9 => SOL
* DIS # I2: 5 => CTR => I2: 8,9
* DIS # I3: 8,9 => CTR => I3: 5,6
* DIS # I3: 5,8 => CTR => I3: 6,9
* DIS # C1: 6,9 => CTR => C1: 8
* DIS # H8: 5 => CTR => H8: 6,9
* DIS # B5: 5,8 => CTR => B5: 1,9
* DIS # C5: 5,8 => CTR => C5: 1,9
* PRF # B5: 8,9 => SOL
* DIS # I6: 5 => CTR => I6: 8,9
* DIS # B1: 8,9 => CTR => B1: 6
* PRF # B1: 6 => SOL
* PRF # B5: 8,9 => SOL
* DIS # I6: 5 => CTR => I6: 8,9
* DIS # I6: 8 => CTR => I6: 5,9
* DIS # H8: 5,9 => CTR => H8: 6
* DIS # B9: 5,8 => CTR => B9: 1,6
* DIS # C9: 5,8 => CTR => C9: 1,6
* DIS # H8: 5,9 => CTR => H8: 6
* DIS # G3: 8 => CTR => G3: 5,9
* CNT  21 HDP CHAINS /  50 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A5,A9,B2,B6,D8,D9,E2,E3,F4,F5,G4,G8,H1,H6)
* 1..5273.44.73.621.23.4.1.7.67415..32...23.6473.27641..92364578174..12..3....7342.
* PAIR B2: 5,9 BLK 1
C3: 5,9,6                                # reduction candidate for 5,9
C3: 6 => CTR
* 1..5273.44573.621.2364.1.7.67415..32...23.6473.27641..92364578174..12.63.61.7342.
* PAIR B2: 5,9 COL B
B5: 5,9,1,8                              # reduction candidate for 5,9
B5: 5,9 => SOLVED
* 168527394457396218239481576674159832591238647382764159923645781745812963816973425
* DURATION: 0:00:03.974928  START: 03:00:03.459434  END: 03:00:07.434362 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-011-base-pr-001.dot
* REASONING
* DIS # C3: 6 => CTR => C3: 5,9
* PRF C3: 5,9 # B5: 5,9 => SOL
* STA C3: 5,9 + B5: 5,9
* CNT   2 HDP CHAINS /   3 HYP OPENED

Header Info

Top 500 Minimum 17 011

solution: 168527394457396218239481576674159832591238647382764159923645781745812963816973425
info: 1308     FNBTWXY  S8.f     25693

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

Solution

position: 168527394457396218239481576674159832591238647382764159923645781745812963816973425 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 # C3: 5,9 => UNS
* DIS # C3: 6 => CTR => C3: 5,9
* INC # I2: 5,9 => UNS
* INC # I2: 8 => UNS
* PRF # B5: 5,9 => SOL
* INC # B5: 1,8 => UNS
* INC # I2: 8,9 => UNS
* DIS # I2: 5 => CTR => I2: 8,9
* INC # G3: 8,9 => UNS
* DIS # I3: 8,9 => CTR => I3: 5,6
* INC # I3: 5,6 => UNS
* INC # I3: 6,9 => UNS
* DIS # I3: 5,8 => CTR => I3: 6,9
* INC # B1: 6,9 => UNS
* DIS # C1: 6,9 => CTR => C1: 8
* INC # C1: 8 => UNS
* INC # H8: 6,9 => UNS
* DIS # H8: 5 => CTR => H8: 6,9
* DIS # B5: 5,8 => CTR => B5: 1,9
* INC # B5: 1,9 => UNS
* DIS # C5: 5,8 => CTR => C5: 1,9
* INC # C5: 1,9 => UNS
* PRF # B5: 8,9 => SOL
* INC # B5: 1,5 => UNS
* INC # C5: 8,9 => UNS
* INC # I6: 8,9 => UNS
* DIS # I6: 5 => CTR => I6: 8,9
* DIS # B1: 8,9 => CTR => B1: 6
* PRF # B1: 6 => SOL
* PRF # B5: 8,9 => SOL
* INC # B5: 1,5 => UNS
* INC # C5: 8,9 => UNS
* INC # I6: 8,9 => UNS
* DIS # I6: 5 => CTR => I6: 8,9
* INC # G3: 8,9 => UNS
* INC # G3: 5 => UNS
* INC # I6: 5,9 => UNS
* DIS # I6: 8 => CTR => I6: 5,9
* DIS # H8: 5,9 => CTR => H8: 6
* INC # H8: 6 => UNS
* INC # C8: 5,8 => UNS
* DIS # B9: 5,8 => CTR => B9: 1,6
* INC # B9: 1,6 => UNS
* DIS # C9: 5,8 => CTR => C9: 1,6
* INC # C9: 1,6 => UNS
* DIS # H8: 5,9 => CTR => H8: 6
* INC # H8: 6 => UNS
* INC # I9: 5,9 => UNS
* INC # G3: 5,9 => UNS
* DIS # G3: 8 => CTR => G3: 5,9
* CNT  50 HDP CHAINS /  50 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # C3: 5,9 => UNS
* DIS # C3: 6 => CTR => C3: 5,9
* PRF C3: 5,9 # B5: 5,9 => SOL
* STA C3: 5,9 + B5: 5,9
* CNT   3 HDP CHAINS /   3 HYP OPENED