Analysis of xx-top500-432-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: ......2.8....2.5...4..6.....2.....9....5.1......8.....8.31.....5.....7.........4. initial

Autosolve

position: ....1.2.8....2.5.424..6.....2.....9....5.1......8.2...8.31.....5.42..7....2....4. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # C4: 1,7 => CTR => C4: 5,8
* DIS # D1: 3,7 => CTR => D1: 4,9
* DIS # F1: 3,7 => CTR => F1: 4,5,9
* DIS # F2: 3,7 => CTR => F2: 8,9
* DIS # E9: 5,7 => CTR => E9: 3,8
* DIS # H8: 1 => CTR => H8: 3,8
* DIS # I8: 6,9 => CTR => I8: 1,3
* DIS # G9: 6,9 => CTR => G9: 1,3,8
* DIS # I9: 6,9 => CTR => I9: 1,3,5
* DIS # B7: 6,9 => CTR => B7: 7
* DIS # F7: 6,9 => CTR => F7: 4,7
* DIS # I7: 2,5 => CTR => I7: 6,9
* CNT  12 HDP CHAINS /  30 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 # C4: 1,7 => CTR => C4: 5,8
* DIS C4: 5,8 # D1: 3,7 => CTR => D1: 4,9
* DIS C4: 5,8 + D1: 4,9 # F1: 3,7 => CTR => F1: 4,5,9
* DIS C4: 5,8 + D1: 4,9 + F1: 4,5,9 # F2: 3,7 => CTR => F2: 8,9
* PRF C4: 5,8 + D1: 4,9 + F1: 4,5,9 + F2: 8,9 # E9: 3,8 => SOL
* STA C4: 5,8 + D1: 4,9 + F1: 4,5,9 + F2: 8,9 + E9: 3,8
* CNT   5 HDP CHAINS /   9 HYP OPENED

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

Details

Positions

......2.8....2.5...4..6.....2.....9....5.1......8.....8.31.....5.....7.........4. initial
....1.2.8....2.5.424..6.....2.....9....5.1......8.2...8.31.....5.42..7....2....4. autosolve
357419268961328574248765913125643897786591432439872156873154629594236781612987345 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (6)
C3: 5,8
D3: 3,7
F3: 5,8
E8: 3,8
G7: 6,9
H7: 2,5

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
H5,I5: 2.. / H5 = 2  =>  0 pairs (X) / I5 = 2  => 14 pairs (_)
H7,I7: 2.. / H7 = 2  => 14 pairs (_) / I7 = 2  =>  0 pairs (X)
H5,H7: 2.. / H5 = 2  =>  0 pairs (X) / H7 = 2  => 14 pairs (_)
I5,I7: 2.. / I5 = 2  => 14 pairs (_) / I7 = 2  =>  0 pairs (X)
D1,F1: 4.. / D1 = 4  =>  6 pairs (_) / F1 = 4  =>  0 pairs (X)
E7,F7: 4.. / E7 = 4  =>  0 pairs (X) / F7 = 4  =>  7 pairs (_)
D1,D4: 4.. / D1 = 4  =>  6 pairs (_) / D4 = 4  =>  0 pairs (X)
F1,F3: 5.. / F1 = 5  =>  0 pairs (X) / F3 = 5  => 14 pairs (_)
E7,E9: 5.. / E7 = 5  => 14 pairs (_) / E9 = 5  =>  0 pairs (X)
C3,F3: 5.. / C3 = 5  =>  0 pairs (X) / F3 = 5  => 14 pairs (_)
C4,I4: 5.. / C4 = 5  => 14 pairs (_) / I4 = 5  =>  0 pairs (X)
E9,I9: 5.. / E9 = 5  =>  0 pairs (X) / I9 = 5  => 14 pairs (_)
B1,B6: 5.. / B1 = 5  => 14 pairs (_) / B6 = 5  =>  0 pairs (X)
H6,H7: 5.. / H6 = 5  => 14 pairs (_) / H7 = 5  =>  0 pairs (X)
H1,H2: 6.. / H1 = 6  =>  7 pairs (_) / H2 = 6  =>  7 pairs (_)
D4,F4: 6.. / D4 = 6  =>  6 pairs (_) / F4 = 6  =>  7 pairs (_)
D4,D9: 6.. / D4 = 6  =>  6 pairs (_) / D9 = 6  =>  7 pairs (_)
F2,F3: 8.. / F2 = 8  => 14 pairs (_) / F3 = 8  =>  0 pairs (X)
E8,E9: 8.. / E8 = 8  =>  0 pairs (X) / E9 = 8  => 14 pairs (_)
H8,G9: 8.. / H8 = 8  => 14 pairs (_) / G9 = 8  =>  0 pairs (X)
C3,F3: 8.. / C3 = 8  => 14 pairs (_) / F3 = 8  =>  0 pairs (X)
C4,G4: 8.. / C4 = 8  =>  0 pairs (X) / G4 = 8  => 14 pairs (_)
E8,H8: 8.. / E8 = 8  =>  0 pairs (X) / H8 = 8  => 14 pairs (_)
E9,G9: 8.. / E9 = 8  => 14 pairs (_) / G9 = 8  =>  0 pairs (X)
B2,B5: 8.. / B2 = 8  =>  0 pairs (X) / B5 = 8  => 14 pairs (_)
H5,H8: 8.. / H5 = 8  =>  0 pairs (X) / H8 = 8  => 14 pairs (_)
G3,I3: 9.. / G3 = 9  =>  6 pairs (_) / I3 = 9  =>  7 pairs (_)
E5,E6: 9.. / E5 = 9  =>  6 pairs (_) / E6 = 9  =>  6 pairs (_)
* DURATION: 0:00:50.096042  START: 17:31:48.560371  END: 17:32:38.656413 2017-05-04
* CP COUNT: (28)
* CLUE FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (C3,D3,E8,F3,G7,H7)
* ....1.2.8....2.5.424..6.....2.....9....5.1......8.2...8.31.....5.42..7....2....4.
* PAIR C3: 5,8 COL C
C4: 5,8,1,7                              # reduction candidate for 5,8
C4: 1,7 => CTR
* ....1.2.8....2.5.424..6.....2....895...5.1......8.2...8.31...525.42..78...2....4.
C4: 5,8                                  #  7 pairs
* PAIR D3: 3,7 BLK 2
D1: 3,7,4,9                              # reduction candidate for 3,7
D1: 3,7 => CTR
* ....142.8...9285.4248.65....2.4.6.9..8.5.1......8.2...8.314....5.428.7....265.84.
D1: 4,9                                  #  7 pairs
F1: 3,7,4,5,9                            # reduction candidate for 3,7
F1: 3,7 => CTR
* .5.4172.8761928534248.6591.125.4.89..8.5.14.243.8.2156873154629594236781612789345
F1: 4,5,9                                #  6 pairs
D2: 3,7,9                                # reduction candidate for 3,7
D2: 3,7                                  # 11 pairs
F2: 3,7,8,9                              # reduction candidate for 3,7
F2: 3,7 => CTR
* ....152.8....2.5.4245.68....2.....95...5.1....5.8.2...8.31...525.42..7....2.5.84.
F2: 8,9                                  #  7 pairs
* PAIR D3: 3,7 ROW 3
H3: 3,7,1                                # reduction candidate for 3,7
H3: 3,7                                  # 12 pairs
I3: 3,7,1,9                              # reduction candidate for 3,7
I3: 3,7                                  # 10 pairs
* PAIR D3: 3,7 COL D
D4: 3,7,4,6                              # reduction candidate for 3,7
D4: 3,7                                  #  9 pairs
D9: 3,7,6,9                              # reduction candidate for 3,7
D9: 3,7                                  #  7 pairs
* PAIR E8: 3,8 BLK 8
E9: 3,8,5,7                              # reduction candidate for 3,8
E9: 5,7 => CTR
* ....1.2.8....2.5.424..6.....28....95...5.1.82...8.2...8.31.....5.428.7....2...84.
E9: 3,8                                  # 14 pairs
* PAIR E8: 3,8 ROW 8
H8: 3,8,1                                # reduction candidate for 3,8
H8: 1 => CTR
* ....1.2.8.8..2.5.4245.68....28....95...5.1.82.5.8.2...8.3154.2.5.428.71..12...84.
H8: 3,8                                  #  8 pairs
* PAIR G7: 6,9 BLK 9
I7: 6,9,2,5                              # reduction candidate for 6,9
I7: 6,9                                  # 14 pairs
I8: 6,9,1,3                              # reduction candidate for 6,9
I8: 6,9 => CTR
* ....1.2.8....2.5.424..6.....28....95...5.1.82...8.2...8.31.....5.42..7....2.5.84.
I8: 1,3                                  #  9 pairs
G9: 6,9,1,3,8                            # reduction candidate for 6,9
G9: 6,9 => CTR
* ....1.2.8....2.5.424..6.....2.....9....5.1......8.2...8.31.....5.42..78...2.8..45
G9: 1,3,8                                #  6 pairs
I9: 6,9,1,3,5                            # reduction candidate for 6,9
I9: 6,9 => CTR
* ....1.2.8....2.5.424..6.....28....95...5.1.82...8.2...8.31.....5.42..7....2.5.84.
I9: 1,3,5                                #  6 pairs
* PAIR G7: 6,9 ROW 7
B7: 6,9,7                                # reduction candidate for 6,9
B7: 6,9 => CTR
* ....1.2.8....2.5.424..6.....28....95...5.1.82...8.2...8.31.....5.428.7....2.5.84.
B7: 7                                    #  7 pairs
F7: 6,9,4,7                              # reduction candidate for 6,9
F7: 6,9 => CTR
* ....1.2.8....2.5.424..6.....28....95...5.1.82...8.2...8.314....5.42..7....2.5.84.
F7: 4,7                                  #  7 pairs
* PAIR H7: 2,5 BLK 9
I7: 2,5,6,9                              # reduction candidate for 2,5
I7: 2,5 => CTR
* ....1.2.8....2.5.424..6.....28....95...5.1.82...8.2...8.31.....5.42..7....2.5.84.
I7: 6,9                                  # 14 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-432-base-pr-000.dot
* REASONING
* DIS # C4: 1,7 => CTR => C4: 5,8
* DIS # D1: 3,7 => CTR => D1: 4,9
* DIS # F1: 3,7 => CTR => F1: 4,5,9
* DIS # F2: 3,7 => CTR => F2: 8,9
* DIS # E9: 5,7 => CTR => E9: 3,8
* DIS # H8: 1 => CTR => H8: 3,8
* DIS # I8: 6,9 => CTR => I8: 1,3
* DIS # G9: 6,9 => CTR => G9: 1,3,8
* DIS # I9: 6,9 => CTR => I9: 1,3,5
* DIS # B7: 6,9 => CTR => B7: 7
* DIS # F7: 6,9 => CTR => F7: 4,7
* DIS # I7: 2,5 => CTR => I7: 6,9
* CNT  12 HDP CHAINS /  30 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (C3,D3,E8,F3,G7,H7)
* ....1.2.8....2.5.424..6.....2.....9....5.1......8.2...8.31.....5.42..7....2....4.
* PAIR C3: 5,8 COL C
C4: 5,8,1,7                              # reduction candidate for 5,8
C4: 1,7 => CTR
* ....1.2.8....2.5.424..6.....2....895...5.1......8.2...8.31...525.42..78...2....4.
* PAIR RESTART
* PAIR D3: 3,7 BLK 2
D1: 3,7,4,9                              # reduction candidate for 3,7
D1: 3,7 => CTR
* ....142.8....2.5.424..65....254.689..8.5.1......8.2...8.314....5.42..78...26...4.
F1: 3,7,4,5,9                            # reduction candidate for 3,7
F1: 3,7 => CTR
* .5.4172.8761928534248.6591.125.4.89..8.5.14.243.8.2156873154629594236781612789345
D2: 3,7,9                                # reduction candidate for 3,7
D2: 3,7                                  # 12 pairs
F2: 3,7,8,9                              # reduction candidate for 3,7
F2: 3,7 => CTR
* ....1.2.8.8..2.5.4245.68....28....95...5.1....5.8.2...8.31...525.42..7....2.5.84.
* RESTART
* PAIR D3: 3,7 ROW 3
H3: 3,7,1                                # reduction candidate for 3,7
H3: 3,7                                  # 18 pairs
I3: 3,7,1,9                              # reduction candidate for 3,7
I3: 3,7                                  # 18 pairs
* PAIR E8: 3,8 BLK 8
E9: 3,8,5,7                              # reduction candidate for 3,8
E9: 3,8 => SOLVED
* 357419268961328574248765913125643897786591432439872156873154629594236781612987345
* DURATION: 0:00:10.571144  START: 17:33:03.649714  END: 17:33:14.220858 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-432-base-pr-001.dot
* REASONING
* DIS # C4: 1,7 => CTR => C4: 5,8
* DIS C4: 5,8 # D1: 3,7 => CTR => D1: 4,9
* DIS C4: 5,8 + D1: 4,9 # F1: 3,7 => CTR => F1: 4,5,9
* DIS C4: 5,8 + D1: 4,9 + F1: 4,5,9 # F2: 3,7 => CTR => F2: 8,9
* PRF C4: 5,8 + D1: 4,9 + F1: 4,5,9 + F2: 8,9 # E9: 3,8 => SOL
* STA C4: 5,8 + D1: 4,9 + F1: 4,5,9 + F2: 8,9 + E9: 3,8
* CNT   5 HDP CHAINS /   9 HYP OPENED

Header Info

Top 500 Minimum 17 432

solution: 357419268961328574248765913125643897786591432439872156873154629594236781612987345
info: 95204    FNBHXYK  S8.f     41753

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

Solution

position: 357419268961328574248765913125643897786591432439872156873154629594236781612987345 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 # C4: 5,8 => UNS
* DIS # C4: 1,7 => CTR => C4: 5,8
* DIS # D1: 3,7 => CTR => D1: 4,9
* INC # D1: 4,9 => UNS
* DIS # F1: 3,7 => CTR => F1: 4,5,9
* INC # F1: 4,5,9 => UNS
* INC # D2: 3,7 => UNS
* DIS # F2: 3,7 => CTR => F2: 8,9
* INC # F2: 8,9 => UNS
* INC # H3: 3,7 => UNS
* INC # I3: 3,7 => UNS
* INC # D4: 3,7 => UNS
* INC # D9: 3,7 => UNS
* INC # E9: 3,8 => UNS
* DIS # E9: 5,7 => CTR => E9: 3,8
* INC # H8: 3,8 => UNS
* DIS # H8: 1 => CTR => H8: 3,8
* INC # I7: 6,9 => UNS
* DIS # I8: 6,9 => CTR => I8: 1,3
* INC # I8: 1,3 => UNS
* DIS # G9: 6,9 => CTR => G9: 1,3,8
* INC # G9: 1,3,8 => UNS
* DIS # I9: 6,9 => CTR => I9: 1,3,5
* INC # I9: 1,3,5 => UNS
* DIS # B7: 6,9 => CTR => B7: 7
* INC # B7: 7 => UNS
* DIS # F7: 6,9 => CTR => F7: 4,7
* INC # F7: 4,7 => UNS
* DIS # I7: 2,5 => CTR => I7: 6,9
* INC # I7: 6,9 => UNS
* CNT  30 HDP CHAINS /  30 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # C4: 5,8 => UNS
* DIS # C4: 1,7 => CTR => C4: 5,8
* DIS C4: 5,8 # D1: 3,7 => CTR => D1: 4,9
* DIS C4: 5,8 + D1: 4,9 # F1: 3,7 => CTR => F1: 4,5,9
* INC C4: 5,8 + D1: 4,9 + F1: 4,5,9 # D2: 3,7 => UNS
* DIS C4: 5,8 + D1: 4,9 + F1: 4,5,9 # F2: 3,7 => CTR => F2: 8,9
* INC C4: 5,8 + D1: 4,9 + F1: 4,5,9 + F2: 8,9 # H3: 3,7 => UNS
* INC C4: 5,8 + D1: 4,9 + F1: 4,5,9 + F2: 8,9 # I3: 3,7 => UNS
* PRF C4: 5,8 + D1: 4,9 + F1: 4,5,9 + F2: 8,9 # E9: 3,8 => SOL
* STA C4: 5,8 + D1: 4,9 + F1: 4,5,9 + F2: 8,9 + E9: 3,8
* CNT   9 HDP CHAINS /   9 HYP OPENED