Analysis of xx-top500-241-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 2...3......4...6.......8....3.6........4..1.......54..78......3....4..2....1..... initial

Autosolve

position: 268.34.1.3.4...682.1.2683.443.6..2..8..4.213.12.3.54..781.26.436.384..21.421.38.. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # C3: 5,9 => CTR => C3: 7
* DIS # H3: 7 => CTR => H3: 5,9
* DIS # E2: 1,9 => CTR => E2: 5
* DIS # F4: 1,9 => CTR => F4: 7
* PRF # F4: 7 => SOL
* DIS # E4: 7,9 => CTR => E4: 1,8
* DIS # E6: 7,9 => CTR => E6: 8
* DIS # C5: 7,9 => CTR => C5: 5,6
* DIS # I5: 7,9 => CTR => I5: 5,6
* DIS # E9: 5 => CTR => E9: 7,9
* DIS # G8: 5,9 => CTR => G8: 7
* PRF # G8: 7 => SOL
* DIS # B5: 5,9 => CTR => B5: 7
* DIS # E9: 5,9 => CTR => E9: 7
* PRF # E9: 7 => SOL
* DIS # H9: 5,9 => CTR => H9: 6,7
* PRF # I9: 5,9 => SOL
* DIS # E9: 5,9 => CTR => E9: 7
* PRF # E9: 7 => SOL
* DIS # D2: 5,9 => CTR => D2: 7
* DIS # E9: 5 => CTR => E9: 7,9
* DIS # G8: 5 => CTR => G8: 7,9
* DIS # F4: 1 => CTR => F4: 7,9
* DIS # G8: 5,9 => CTR => G8: 7
* PRF # G8: 7 => SOL
* DIS # H9: 5,9 => CTR => H9: 6,7
* PRF # I9: 5,9 => SOL
* PRF # G1: 5,9 => SOL
* DIS # G1: 7 => CTR => G1: 5,9
* CNT  29 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 # C3: 5,9 => CTR => C3: 7
* DIS C3: 7 # G8: 5,9 => CTR => G8: 7
* PRF C3: 7 + G8: 7 => SOL
* STA C3: 7 + G8: 7
* CNT   3 HDP CHAINS /   3 HYP OPENED

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

Details

Positions

2...3......4...6.......8....3.6........4..1.......54..78......3....4..2....1..... initial
268.34.1.3.4...682.1.2683.443.6..2..8..4.213.12.3.54..781.26.436.384..21.421.38.. autosolve
268934517394751682517268394439617258875492136126385479781526943653849721942173865 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (8)
A3: 5,9
F2: 1,9
E5: 7,9
B8: 5,9
A9: 5,9
D7: 5,9
F8: 7,9
G7: 5,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
E2,F2: 1.. / E2 = 1  =>  0 pairs (X) / F2 = 1  =>  9 pairs (_)
E4,F4: 1.. / E4 = 1  =>  9 pairs (_) / F4 = 1  =>  0 pairs (X)
E2,E4: 1.. / E2 = 1  =>  0 pairs (X) / E4 = 1  =>  9 pairs (_)
F2,F4: 1.. / F2 = 1  =>  9 pairs (_) / F4 = 1  =>  0 pairs (X)
B8,A9: 5.. / B8 = 5  => 15 pairs (_) / A9 = 5  =>  0 pairs (X)
D7,E9: 5.. / D7 = 5  => 13 pairs (_) / E9 = 5  =>  0 pairs (X)
D7,G7: 5.. / D7 = 5  => 13 pairs (_) / G7 = 5  =>  0 pairs (X)
B8,G8: 5.. / B8 = 5  => 15 pairs (_) / G8 = 5  =>  0 pairs (X)
A3,A9: 5.. / A3 = 5  => 15 pairs (_) / A9 = 5  =>  0 pairs (X)
E2,E9: 5.. / E2 = 5  => 13 pairs (_) / E9 = 5  =>  0 pairs (X)
C5,C6: 6.. / C5 = 6  =>  9 pairs (_) / C6 = 6  => 10 pairs (_)
H9,I9: 6.. / H9 = 6  =>  9 pairs (_) / I9 = 6  =>  9 pairs (_)
C5,I5: 6.. / C5 = 6  =>  9 pairs (_) / I5 = 6  => 10 pairs (_)
H6,H9: 6.. / H6 = 6  =>  9 pairs (_) / H9 = 6  =>  9 pairs (_)
B2,C3: 7.. / B2 = 7  =>  0 pairs (X) / C3 = 7  => 18 pairs (_)
D1,D2: 7.. / D1 = 7  =>  0 pairs (X) / D2 = 7  => 18 pairs (_)
F8,E9: 7.. / F8 = 7  =>  0 pairs (X) / E9 = 7  =>  0 pairs (_)
B2,D2: 7.. / B2 = 7  =>  0 pairs (X) / D2 = 7  => 18 pairs (_)
C3,H3: 7.. / C3 = 7  => 18 pairs (_) / H3 = 7  =>  0 pairs (X)
F8,G8: 7.. / F8 = 7  =>  0 pairs (X) / G8 = 7  =>  0 pairs (_)
B2,B5: 7.. / B2 = 7  =>  0 pairs (X) / B5 = 7  => 18 pairs (_)
F4,F8: 7.. / F4 = 7  =>  0 pairs (*) / F8 = 7  =>  0 pairs (X)
G1,G8: 7.. / G1 = 7  =>  0 pairs (X) / G8 = 7  =>  0 pairs (_)
E4,E6: 8.. / E4 = 8  =>  0 pairs (X) / E6 = 8  =>  8 pairs (_)
I4,I6: 8.. / I4 = 8  =>  8 pairs (_) / I6 = 8  =>  0 pairs (X)
E4,I4: 8.. / E4 = 8  =>  0 pairs (X) / I4 = 8  =>  8 pairs (_)
E6,I6: 8.. / E6 = 8  =>  8 pairs (_) / I6 = 8  =>  0 pairs (X)
B8,A9: 9.. / B8 = 9  =>  0 pairs (X) / A9 = 9  => 15 pairs (_)
D7,G7: 9.. / D7 = 9  =>  0 pairs (X) / G7 = 9  => 13 pairs (_)
A3,A9: 9.. / A3 = 9  =>  0 pairs (X) / A9 = 9  => 15 pairs (_)
* DURATION: 0:00:48.119239  START: 11:02:26.868593  END: 11:03:14.987832 2017-05-04
* CP COUNT: (30)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A3,A9,B8,D7,E5,F2,F8,G7)
* 268.34.1.3.4...682.1.2683.443.6..2..8..4.213.12.3.54..781.26.436.384..21.421.38..
* PAIR A3: 5,9 BLK 1
B2: 5,9,7                                # reduction candidate for 5,9
B2: 5,9                                  # 18 pairs
C3: 5,9,7                                # reduction candidate for 5,9
C3: 5,9 => CTR
* 268734.1.374.51682.1.26837443.6172.88..49213.12.3854..7815269436.384.721.421738..
C3: 7                                    # 18 pairs
* PAIR A3: 5,9 ROW 3
H3: 5,9,7                                # reduction candidate for 5,9
H3: 7 => CTR
* 268734.1.374.51682.1.26837443.6172.88..49213.12.3854..7815269436.384.721.421738..
H3: 5,9                                  # 18 pairs
* PAIR F2: 1,9 BLK 2
E2: 1,9,5                                # reduction candidate for 1,9
E2: 1,9 => CTR
* 268.34.1.3.4...68251.2683.443.6..25.8.54.21361263.54..781926543653847921942153867
E2: 5                                    # 13 pairs
* PAIR F2: 1,9 COL F
F4: 1,9,7                                # reduction candidate for 1,9
F4: 1,9 => CTR
* 268.3471.3.47..682.172683.443.6..2..87.49213.12.3.54..7819265436538479219421538..
F4: 7 => SOLVED
* 268934517394751682517268394439617258875492136126385479781526943653849721942173865
* PAIR E5: 7,9 BLK 5
E4: 7,9,1,8                              # reduction candidate for 7,9
E4: 7,9 => CTR
* 268.34719374.19682.1.2683.443.6.12.88..4.213.12.3854..7819265436538479219421538..
E4: 1,8                                  #  9 pairs
F4: 7,9,1                                # reduction candidate for 7,9
F4: 7,9                                  #  9 pairs
E6: 7,9,8                                # reduction candidate for 7,9
E6: 7,9 => CTR
* 268.3471.3.4719682.172683.443.6812..87.49213.12.3754.87819265436.3847.21.421.38..
E6: 8                                    #  8 pairs
* PAIR E5: 7,9 ROW 5
B5: 7,9,5                                # reduction candidate for 7,9
B5: 7,9                                  # 12 pairs
C5: 7,9,5,6                              # reduction candidate for 7,9
C5: 7,9 => CTR
* 268.3471.374...682.1.2683.443.6..2..85.4.21361263.54..781.26.43693847521542193867
C5: 5,6                                  #  9 pairs
I5: 7,9,5,6                              # reduction candidate for 7,9
I5: 7,9 => CTR
* 268.3471.374...682.1.2683.443.6..2..8564.213.12.3.54..781.26.436938475215421938..
I5: 5,6                                  #  9 pairs
* PAIR E5: 7,9 COL E
E9: 7,9,5                                # reduction candidate for 7,9
E9: 5 => CTR
* 268.3471.3.47..68251726839443.6..25.8754921361263.5479781926.436.3847.21.421538..
E9: 7,9                                  # 13 pairs
* PAIR B8: 5,9 ROW 8
G8: 5,9,7                                # reduction candidate for 5,9
G8: 5,9 => CTR
* 2685347193547..682.172683.443.6..2..87.49213.12.3.54..781.26.436.3847.21.421538..
G8: 7 => SOLVED
* 268934517394751682517268394439617258875492136126385479781526943653849721942173865
* PAIR B8: 5,9 COL B
B2: 5,9,7                                # reduction candidate for 5,9
B2: 5,9                                  # 18 pairs
B5: 5,9,7                                # reduction candidate for 5,9
B5: 5,9 => CTR
* 268734.1.374.51682.1.26837443.6172.88..49213.12.3854..7815269436.384.721.421738..
B5: 7                                    # 18 pairs
* PAIR A9: 5,9 ROW 9
E9: 5,9,7                                # reduction candidate for 5,9
E9: 5,9 => CTR
* 268.3471.3.47..682.172683.443.6..2..87.49213.12.3.54..7819265436538479219421538..
E9: 7 => SOLVED
* 268934517394751682517268394439617258875492136126385479781526943653849721942173865
H9: 5,9,6,7                              # reduction candidate for 5,9
H9: 5,9 => CTR
* 268.3451.39475168251.2683.443.6172.88.649213.12.38546.781526943653849721942173856
H9: 6,7                                  #  9 pairs
I9: 5,9,6,7                              # reduction candidate for 5,9
I9: 5,9 => SOLVED
* 268934517394751682517268394439617258875492136126385479781526943653849721942173865
I9: 6,7                                  #  9 pairs
* PAIR D7: 5,9 BLK 8
E9: 5,9,7                                # reduction candidate for 5,9
E9: 5,9 => CTR
* 268.3471.3.47..682.172683.443.6..2..87.49213.12.3.54..7819265436538479219421538..
E9: 7 => SOLVED
* 268934517394751682517268394439617258875492136126385479781526943653849721942173865
* PAIR D7: 5,9 COL D
D1: 5,9,7                                # reduction candidate for 5,9
D1: 5,9                                  # 18 pairs
D2: 5,9,7                                # reduction candidate for 5,9
D2: 5,9 => CTR
* 268734.1.374.51682.1.26837443.6172.88..49213.12.3854..7815269436.384.721.421738..
D2: 7                                    # 18 pairs
* PAIR F8: 7,9 BLK 8
E9: 7,9,5                                # reduction candidate for 7,9
E9: 5 => CTR
* 268.3471.3.47..68251726839443.6..25.8754921361263.5479781926.436.3847.21.421538..
E9: 7,9                                  # 13 pairs
* PAIR F8: 7,9 ROW 8
G8: 7,9,5                                # reduction candidate for 7,9
G8: 5 => CTR
* 268.3471.3.47..682.172683.443.6..2..87.49213.12.3.54..781.269436.384..21.421.38..
G8: 7,9                                  # 15 pairs
* PAIR F8: 7,9 COL F
F4: 7,9,1                                # reduction candidate for 7,9
F4: 1 => CTR
* 268.3471.3.4719682.172683.443.6.12..87.49213.12.3.54..7819265436.3847.21.421.38..
F4: 7,9                                  #  9 pairs
* PAIR G7: 5,9 BLK 9
G8: 5,9,7                                # reduction candidate for 5,9
G8: 5,9 => CTR
* 2685347193547..682.172683.443.6..2..87.49213.12.3.54..781.26.436.3847.21.421538..
G8: 7 => SOLVED
* 268934517394751682517268394439617258875492136126385479781526943653849721942173865
H9: 5,9,6,7                              # reduction candidate for 5,9
H9: 5,9 => CTR
* 268.3451.39475168251.2683.443.6172.88.649213.12.38546.781526943653849721942173856
H9: 6,7                                  #  9 pairs
I9: 5,9,6,7                              # reduction candidate for 5,9
I9: 5,9 => SOLVED
* 268934517394751682517268394439617258875492136126385479781526943653849721942173865
I9: 6,7                                  #  9 pairs
* PAIR G7: 5,9 COL G
G1: 5,9,7                                # reduction candidate for 5,9
G1: 5,9 => SOLVED
* 268934517394751682517268394439617258875492136126385479781526943653849721942173865
G1: 7 => CTR
* 2685347193547..682.172683.443.6..2..87.49213.12.3.54..781.26.436.3847.21.421538..
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-241-base-pr-000.dot
* REASONING
* DIS # C3: 5,9 => CTR => C3: 7
* DIS # H3: 7 => CTR => H3: 5,9
* DIS # E2: 1,9 => CTR => E2: 5
* DIS # F4: 1,9 => CTR => F4: 7
* PRF # F4: 7 => SOL
* DIS # E4: 7,9 => CTR => E4: 1,8
* DIS # E6: 7,9 => CTR => E6: 8
* DIS # C5: 7,9 => CTR => C5: 5,6
* DIS # I5: 7,9 => CTR => I5: 5,6
* DIS # E9: 5 => CTR => E9: 7,9
* DIS # G8: 5,9 => CTR => G8: 7
* PRF # G8: 7 => SOL
* DIS # B5: 5,9 => CTR => B5: 7
* DIS # E9: 5,9 => CTR => E9: 7
* PRF # E9: 7 => SOL
* DIS # H9: 5,9 => CTR => H9: 6,7
* PRF # I9: 5,9 => SOL
* DIS # E9: 5,9 => CTR => E9: 7
* PRF # E9: 7 => SOL
* DIS # D2: 5,9 => CTR => D2: 7
* DIS # E9: 5 => CTR => E9: 7,9
* DIS # G8: 5 => CTR => G8: 7,9
* DIS # F4: 1 => CTR => F4: 7,9
* DIS # G8: 5,9 => CTR => G8: 7
* PRF # G8: 7 => SOL
* DIS # H9: 5,9 => CTR => H9: 6,7
* PRF # I9: 5,9 => SOL
* PRF # G1: 5,9 => SOL
* DIS # G1: 7 => CTR => G1: 5,9
* CNT  29 HDP CHAINS /  51 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A3,A9,B8,D7,E5,F2,F8,G7)
* 268.34.1.3.4...682.1.2683.443.6..2..8..4.213.12.3.54..781.26.436.384..21.421.38..
* PAIR A3: 5,9 BLK 1
B2: 5,9,7                                # reduction candidate for 5,9
B2: 5,9                                  # 18 pairs
C3: 5,9,7                                # reduction candidate for 5,9
C3: 5,9 => CTR
* 268734.1.374.51682.1.26837443.6172.88..49213.12.3854..7815269436.384.721.421738..
* RESTART
* PAIR B8: 5,9 ROW 8
G8: 5,9,7                                # reduction candidate for 5,9
G8: 5,9 => CTR
* 2685347193547..682.172683.443.6..2..87.49213.12.3.54..781.26.436.3847.21.421538..
G8: 7 => SOLVED
* 268934517394751682517268394439617258875492136126385479781526943653849721942173865
* DURATION: 0:00:04.856749  START: 11:04:02.871099  END: 11:04:07.727848 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-241-base-pr-001.dot
* REASONING
* DIS # C3: 5,9 => CTR => C3: 7
* DIS C3: 7 # G8: 5,9 => CTR => G8: 7
* PRF C3: 7 + G8: 7 => SOL
* STA C3: 7 + G8: 7
* CNT   3 HDP CHAINS /   3 HYP OPENED

Header Info

Top 500 Minimum 17 241

solution: 268934517394751682517268394439617258875492136126385479781526943653849721942173865
info: 2069     FNBWXY   S8.f     27320

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

Solution

position: 268934517394751682517268394439617258875492136126385479781526943653849721942173865 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 # B2: 5,9 => UNS
* DIS # C3: 5,9 => CTR => C3: 7
* INC # C3: 7 => UNS
* INC # H3: 5,9 => UNS
* DIS # H3: 7 => CTR => H3: 5,9
* DIS # E2: 1,9 => CTR => E2: 5
* INC # E2: 5 => UNS
* DIS # F4: 1,9 => CTR => F4: 7
* PRF # F4: 7 => SOL
* DIS # E4: 7,9 => CTR => E4: 1,8
* INC # E4: 1,8 => UNS
* INC # F4: 7,9 => UNS
* DIS # E6: 7,9 => CTR => E6: 8
* INC # E6: 8 => UNS
* INC # B5: 7,9 => UNS
* DIS # C5: 7,9 => CTR => C5: 5,6
* INC # C5: 5,6 => UNS
* DIS # I5: 7,9 => CTR => I5: 5,6
* INC # I5: 5,6 => UNS
* INC # E9: 7,9 => UNS
* DIS # E9: 5 => CTR => E9: 7,9
* DIS # G8: 5,9 => CTR => G8: 7
* PRF # G8: 7 => SOL
* INC # B2: 5,9 => UNS
* DIS # B5: 5,9 => CTR => B5: 7
* INC # B5: 7 => UNS
* DIS # E9: 5,9 => CTR => E9: 7
* PRF # E9: 7 => SOL
* DIS # H9: 5,9 => CTR => H9: 6,7
* INC # H9: 6,7 => UNS
* PRF # I9: 5,9 => SOL
* INC # I9: 6,7 => UNS
* DIS # E9: 5,9 => CTR => E9: 7
* PRF # E9: 7 => SOL
* INC # D1: 5,9 => UNS
* DIS # D2: 5,9 => CTR => D2: 7
* INC # D2: 7 => UNS
* INC # E9: 7,9 => UNS
* DIS # E9: 5 => CTR => E9: 7,9
* INC # G8: 7,9 => UNS
* DIS # G8: 5 => CTR => G8: 7,9
* INC # F4: 7,9 => UNS
* DIS # F4: 1 => CTR => F4: 7,9
* DIS # G8: 5,9 => CTR => G8: 7
* PRF # G8: 7 => SOL
* DIS # H9: 5,9 => CTR => H9: 6,7
* INC # H9: 6,7 => UNS
* PRF # I9: 5,9 => SOL
* INC # I9: 6,7 => UNS
* PRF # G1: 5,9 => SOL
* DIS # G1: 7 => CTR => G1: 5,9
* CNT  51 HDP CHAINS /  51 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # B2: 5,9 => UNS
* DIS # C3: 5,9 => CTR => C3: 7
* DIS C3: 7 # G8: 5,9 => CTR => G8: 7
* PRF C3: 7 + G8: 7 => SOL
* STA C3: 7 + G8: 7
* CNT   4 HDP CHAINS /   3 HYP OPENED