Analysis of xx-top500-302-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: .8.....1.4...7........3.....1.2....5....6.7........3.....1.5...3.....9..7..8..... initial

Autosolve

position: .87.52.13435.718.21...3857..13287..55.836.72127.51.3..8..1.52373.17.69..7..8.31.. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # D1: 6,9 => SOL
* DIS # D1: 4 => CTR => D1: 6,9
* PRF # D1: 6,9 => SOL
* DIS # D1: 4 => CTR => D1: 6,9
* DIS # D3: 6,9 => CTR => D3: 4
* PRF # D3: 4 => SOL
* PRF # I3: 4,6 => SOL
* DIS # I3: 9 => CTR => I3: 4,6
* DIS # D1: 4,6 => CTR => D1: 9
* PRF # D1: 9 => SOL
* PRF # I3: 6,9 => SOL
* DIS # I3: 4 => CTR => I3: 6,9
* DIS # H4: 6,9 => CTR => H4: 4
* PRF # H4: 4 => SOL
* DIS # H6: 6,9 => CTR => H6: 8
* DIS # C6: 4 => CTR => C6: 6,9
* DIS # H4: 6,9 => CTR => H4: 4
* PRF # H4: 4 => SOL
* DIS # C6: 4,9 => CTR => C6: 6
* PRF # C6: 6 => SOL
* DIS # B7: 4,9 => CTR => B7: 6
* DIS # C6: 4,9 => CTR => C6: 6
* PRF # C6: 6 => SOL
* PRF # H4: 4,6 => SOL
* DIS # H4: 9 => CTR => H4: 4,6
* DIS # B7: 4,9 => CTR => B7: 6
* PRF # I3: 4,6 => SOL
* DIS # I3: 9 => CTR => I3: 4,6
* CNT  28 HDP CHAINS /  46 HYP OPENED

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

Pair Reduction

Pair Reduction

The following important HDP chains were detected:

* PRF # D1: 6,9 => SOL
* STA D1: 6,9
* CNT   1 HDP CHAINS /   3 HYP OPENED

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

Details

Positions

.8.....1.4...7........3.....1.2....5....6.7........3.....1.5...3.....9..7..8..... initial
.87.52.13435.718.21...3857..13287..55.836.72127.51.3..8..1.52373.17.69..7..8.31.. autosolve
687952413435671892192438576913287645548369721276514389864195237321746958759823164 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (13)
A1: 6,9
D2: 6,9
G1: 4,6
H2: 6,9
A4: 6,9
B5: 4,9
F5: 4,9
F6: 4,9
G4: 4,6
E7: 4,9
E8: 2,4
I8: 4,8
I9: 4,6

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
B3,C3: 2.. / B3 = 2  => 16 pairs (_) / C3 = 2  => 17 pairs (_)
E8,E9: 2.. / E8 = 2  => 14 pairs (_) / E9 = 2  => 16 pairs (_)
B8,E8: 2.. / B8 = 2  => 16 pairs (_) / E8 = 2  => 14 pairs (_)
C3,C9: 2.. / C3 = 2  => 17 pairs (_) / C9 = 2  => 16 pairs (_)
D1,D3: 4.. / D1 = 4  =>  0 pairs (X) / D3 = 4  =>  0 pairs (_)
G1,I3: 4.. / G1 = 4  =>  0 pairs (*) / I3 = 4  =>  0 pairs (X)
B5,C6: 4.. / B5 = 4  => 13 pairs (_) / C6 = 4  =>  0 pairs (X)
F5,F6: 4.. / F5 = 4  =>  0 pairs (X) / F6 = 4  => 13 pairs (_)
G4,H4: 4.. / G4 = 4  =>  0 pairs (X) / H4 = 4  =>  0 pairs (_)
D1,G1: 4.. / D1 = 4  =>  0 pairs (X) / G1 = 4  =>  0 pairs (_)
D3,I3: 4.. / D3 = 4  =>  0 pairs (*) / I3 = 4  =>  0 pairs (X)
B5,F5: 4.. / B5 = 4  => 13 pairs (_) / F5 = 4  =>  0 pairs (X)
C6,F6: 4.. / C6 = 4  =>  0 pairs (X) / F6 = 4  => 13 pairs (_)
G1,G4: 4.. / G1 = 4  =>  0 pairs (*) / G4 = 4  =>  0 pairs (X)
B8,B9: 5.. / B8 = 5  => 15 pairs (_) / B9 = 5  => 17 pairs (_)
H8,H9: 5.. / H8 = 5  => 17 pairs (_) / H9 = 5  => 15 pairs (_)
B8,H8: 5.. / B8 = 5  => 15 pairs (_) / H8 = 5  => 17 pairs (_)
B9,H9: 5.. / B9 = 5  => 17 pairs (_) / H9 = 5  => 15 pairs (_)
A4,C6: 6.. / A4 = 6  =>  0 pairs (X) / C6 = 6  =>  0 pairs (_)
B7,C7: 6.. / B7 = 6  => 15 pairs (_) / C7 = 6  =>  0 pairs (X)
H9,I9: 6.. / H9 = 6  =>  0 pairs (*) / I9 = 6  =>  0 pairs (X)
D2,H2: 6.. / D2 = 6  =>  0 pairs (*) / H2 = 6  =>  0 pairs (X)
A1,A4: 6.. / A1 = 6  =>  0 pairs (*) / A4 = 6  =>  0 pairs (X)
B3,B7: 6.. / B3 = 6  =>  0 pairs (X) / B7 = 6  => 15 pairs (_)
G1,G4: 6.. / G1 = 6  =>  0 pairs (X) / G4 = 6  =>  0 pairs (_)
H6,I6: 8.. / H6 = 8  => 14 pairs (_) / I6 = 8  =>  0 pairs (X)
H8,I8: 8.. / H8 = 8  =>  0 pairs (X) / I8 = 8  => 14 pairs (_)
H6,H8: 8.. / H6 = 8  => 14 pairs (_) / H8 = 8  =>  0 pairs (X)
I6,I8: 8.. / I6 = 8  =>  0 pairs (X) / I8 = 8  => 14 pairs (_)
H2,I3: 9.. / H2 = 9  =>  0 pairs (*) / I3 = 9  =>  0 pairs (X)
F5,F6: 9.. / F5 = 9  => 13 pairs (_) / F6 = 9  =>  0 pairs (X)
E7,E9: 9.. / E7 = 9  => 17 pairs (_) / E9 = 9  => 15 pairs (_)
A1,D1: 9.. / A1 = 9  =>  0 pairs (X) / D1 = 9  =>  0 pairs (_)
D2,H2: 9.. / D2 = 9  =>  0 pairs (X) / H2 = 9  =>  0 pairs (_)
A4,H4: 9.. / A4 = 9  =>  0 pairs (*) / H4 = 9  =>  0 pairs (X)
B5,F5: 9.. / B5 = 9  =>  0 pairs (X) / F5 = 9  => 13 pairs (_)
A1,A4: 9.. / A1 = 9  =>  0 pairs (X) / A4 = 9  =>  0 pairs (_)
I3,I6: 9.. / I3 = 9  =>  0 pairs (X) / I6 = 9  =>  0 pairs (_)
* DURATION: 0:01:05.641100  START: 13:16:52.637268  END: 13:17:58.278368 2017-05-04
* CP COUNT: (38)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,A4,B5,D2,E7,E8,F5,F6,G1,G4,H2,I8,I9)
* .87.52.13435.718.21...3857..13287..55.836.72127.51.3..8..1.52373.17.69..7..8.31..
* PAIR A1: 6,9 BLK 1
B3: 6,9,2                                # reduction candidate for 6,9
B3: 6,9                                  # 17 pairs
C3: 6,9,2                                # reduction candidate for 6,9
C3: 6,9                                  # 16 pairs
* PAIR A1: 6,9 ROW 1
D1: 6,9,4                                # reduction candidate for 6,9
D1: 6,9 => SOLVED
* 687952413435671892192438576913287645548369721276514389864195237321746958759823164
D1: 4 => CTR
* 9874526134356718921..9385746132874.55.836.72127.51.3..8..1.52373.17.69..7..8.31..
* PAIR D2: 6,9 BLK 2
D1: 6,9,4                                # reduction candidate for 6,9
D1: 6,9 => SOLVED
* 687952413435671892192438576913287645548369721276514389864195237321746958759823164
D1: 4 => CTR
* 9874526134356718921..9385746132874.55.836.72127.51.3..8..1.52373.17.69..7..8.31..
D3: 6,9,4                                # reduction candidate for 6,9
D3: 6,9 => CTR
* .874526134356718921..938574.13287..55.836.72127.51.3..8..1.52373.17.69..7..8.31..
D3: 4 => SOLVED
* 687952413435671892192438576913287645548369721276514389864195237321746958759823164
* PAIR G1: 4,6 BLK 3
I3: 4,6,9                                # reduction candidate for 4,6
I3: 4,6 => SOLVED
* 687952413435671892192438576913287645548369721276514389864195237321746958759823164
I3: 9 => CTR
* .87.52413435.718621..438579.132876455.836.72127651439886.1.52373.17.69847..8.3156
* PAIR G1: 4,6 ROW 1
D1: 4,6,9                                # reduction candidate for 4,6
D1: 4,6 => CTR
* 987.52.13435.718.21...3857.6132874955.836.72127.51.3..8..1.52373.17.69..7..8.31..
D1: 9 => SOLVED
* 687952413435671892192438576913287645548369721276514389864195237321746958759823164
* PAIR H2: 6,9 BLK 3
I3: 6,9,4                                # reduction candidate for 6,9
I3: 6,9 => SOLVED
* 687952413435671892192438576913287645548369721276514389864195237321746958759823164
I3: 4 => CTR
* .87.52.13435.718921...3857491328746554836972127651438986.1.52373.17.69.87..8.31.6
* PAIR H2: 6,9 COL H
H4: 6,9,4                                # reduction candidate for 6,9
H4: 6,9 => CTR
* .874526134356718921..938574.132874.55.836.72127.51.3..8..1.52373.17.69..7..8.31..
H4: 4 => SOLVED
* 687952413435671892192438576913287645548369721276514389864195237321746958759823164
H6: 6,9,8                                # reduction candidate for 6,9
H6: 6,9 => CTR
* .87.52413435.718621..438579.132876455.836.72127651439886.1.52373517269847..8.3156
H6: 8                                    # 14 pairs
* PAIR A4: 6,9 BLK 4
C6: 6,9,4                                # reduction candidate for 6,9
C6: 4 => CTR
* .87.52.13435.718.21...3857.6132874955983647212745193..8..1.52373.17.69..7..8.31..
C6: 6,9                                  # 13 pairs
* PAIR A4: 6,9 ROW 4
H4: 6,9,4                                # reduction candidate for 6,9
H4: 6,9 => CTR
* .874526134356718921..938574.132874.55.836.72127.51.3..8..1.52373.17.69..7..8.31..
H4: 4 => SOLVED
* 687952413435671892192438576913287645548369721276514389864195237321746958759823164
* PAIR B5: 4,9 BLK 4
C6: 4,9,6                                # reduction candidate for 4,9
C6: 4,9 => CTR
* .87.52.13435.718.21...3857.6132874955.836.72127.51.3..8..1.52373.17.69..7..8.31..
C6: 6 => SOLVED
* 687952413435671892192438576913287645548369721276514389864195237321746958759823164
* PAIR B5: 4,9 COL B
B7: 4,9,6                                # reduction candidate for 4,9
B7: 4,9 => CTR
* .87.52.13435.718.2162.3857.6132874955.836.72127.51.3..8.61.52373.17.69..7..8.31..
B7: 6                                    # 15 pairs
B9: 4,9,2,5                              # reduction candidate for 4,9
B9: 4,9                                  # 18 pairs
* PAIR F6: 4,9 ROW 6
C6: 4,9,6                                # reduction candidate for 4,9
C6: 4,9 => CTR
* .87.52.13435.718.21...3857.6132874955.836.72127.51.3..8..1.52373.17.69..7..8.31..
C6: 6 => SOLVED
* 687952413435671892192438576913287645548369721276514389864195237321746958759823164
* PAIR G4: 4,6 BLK 6
H4: 4,6,9                                # reduction candidate for 4,6
H4: 4,6 => SOLVED
* 687952413435671892192438576913287645548369721276514389864195237321746958759823164
H4: 9 => CTR
* .87.52.13435.718.21...3857..132874955.836.72127.51.3..8..1.52373.17.69..7..8.31..
* PAIR E7: 4,9 BLK 8
E9: 4,9,2                                # reduction candidate for 4,9
E9: 2                                    # 16 pairs
E9: 4,9                                  # 14 pairs
* PAIR E7: 4,9 ROW 7
B7: 4,9,6                                # reduction candidate for 4,9
B7: 4,9 => CTR
* .87.52.13435.718.2162.3857.6132874955.836.72127.51.3..8.61.52373.17.69..7..8.31..
B7: 6                                    # 15 pairs
C7: 4,9,6                                # reduction candidate for 4,9
C7: 4,9                                  # 15 pairs
* PAIR E8: 2,4 BLK 8
E9: 2,4,9                                # reduction candidate for 2,4
E9: 2,4                                  # 17 pairs
E9: 9                                    # 15 pairs
* PAIR E8: 2,4 ROW 8
B8: 2,4,5                                # reduction candidate for 2,4
B8: 2,4                                  # 17 pairs
B8: 5                                    # 15 pairs
* PAIR I8: 4,8 BLK 9
H8: 4,8,5                                # reduction candidate for 4,8
H8: 5                                    # 17 pairs
H8: 4,8                                  # 15 pairs
* PAIR I9: 4,6 BLK 9
H9: 4,6,5                                # reduction candidate for 4,6
H9: 4,6                                  # 17 pairs
H9: 5                                    # 15 pairs
* PAIR I9: 4,6 COL I
I3: 4,6,9                                # reduction candidate for 4,6
I3: 4,6 => SOLVED
* 687952413435671892192438576913287645548369721276514389864195237321746958759823164
I3: 9 => CTR
* .87.52413435.718621..438579.132876455.836.72127651439886.1.52373.17.69847..8.3156
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-302-base-pr-000.dot
* REASONING
* PRF # D1: 6,9 => SOL
* DIS # D1: 4 => CTR => D1: 6,9
* PRF # D1: 6,9 => SOL
* DIS # D1: 4 => CTR => D1: 6,9
* DIS # D3: 6,9 => CTR => D3: 4
* PRF # D3: 4 => SOL
* PRF # I3: 4,6 => SOL
* DIS # I3: 9 => CTR => I3: 4,6
* DIS # D1: 4,6 => CTR => D1: 9
* PRF # D1: 9 => SOL
* PRF # I3: 6,9 => SOL
* DIS # I3: 4 => CTR => I3: 6,9
* DIS # H4: 6,9 => CTR => H4: 4
* PRF # H4: 4 => SOL
* DIS # H6: 6,9 => CTR => H6: 8
* DIS # C6: 4 => CTR => C6: 6,9
* DIS # H4: 6,9 => CTR => H4: 4
* PRF # H4: 4 => SOL
* DIS # C6: 4,9 => CTR => C6: 6
* PRF # C6: 6 => SOL
* DIS # B7: 4,9 => CTR => B7: 6
* DIS # C6: 4,9 => CTR => C6: 6
* PRF # C6: 6 => SOL
* PRF # H4: 4,6 => SOL
* DIS # H4: 9 => CTR => H4: 4,6
* DIS # B7: 4,9 => CTR => B7: 6
* PRF # I3: 4,6 => SOL
* DIS # I3: 9 => CTR => I3: 4,6
* CNT  28 HDP CHAINS /  46 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,A4,B5,D2,E7,E8,F5,F6,G1,G4,H2,I8,I9)
* .87.52.13435.718.21...3857..13287..55.836.72127.51.3..8..1.52373.17.69..7..8.31..
* PAIR A1: 6,9 BLK 1
B3: 6,9,2                                # reduction candidate for 6,9
B3: 6,9                                  # 17 pairs
C3: 6,9,2                                # reduction candidate for 6,9
C3: 6,9                                  # 16 pairs
* PAIR A1: 6,9 ROW 1
D1: 6,9,4                                # reduction candidate for 6,9
D1: 6,9 => SOLVED
* 687952413435671892192438576913287645548369721276514389864195237321746958759823164
* DURATION: 0:00:03.874930  START: 13:18:45.602573  END: 13:18:49.477503 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-302-base-pr-001.dot
* REASONING
* PRF # D1: 6,9 => SOL
* STA D1: 6,9
* CNT   1 HDP CHAINS /   3 HYP OPENED

Header Info

Top 500 Minimum 17 302

solution: 687952413435671892192438576913287645548369721276514389864195237321746958759823164
info: 2585     FNBWY    S8.f     23272

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

Solution

position: 687952413435671892192438576913287645548369721276514389864195237321746958759823164 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 # B3: 6,9 => UNS
* INC # C3: 6,9 => UNS
* PRF # D1: 6,9 => SOL
* DIS # D1: 4 => CTR => D1: 6,9
* PRF # D1: 6,9 => SOL
* DIS # D1: 4 => CTR => D1: 6,9
* DIS # D3: 6,9 => CTR => D3: 4
* PRF # D3: 4 => SOL
* PRF # I3: 4,6 => SOL
* DIS # I3: 9 => CTR => I3: 4,6
* DIS # D1: 4,6 => CTR => D1: 9
* PRF # D1: 9 => SOL
* PRF # I3: 6,9 => SOL
* DIS # I3: 4 => CTR => I3: 6,9
* DIS # H4: 6,9 => CTR => H4: 4
* PRF # H4: 4 => SOL
* DIS # H6: 6,9 => CTR => H6: 8
* INC # H6: 8 => UNS
* INC # C6: 6,9 => UNS
* DIS # C6: 4 => CTR => C6: 6,9
* DIS # H4: 6,9 => CTR => H4: 4
* PRF # H4: 4 => SOL
* DIS # C6: 4,9 => CTR => C6: 6
* PRF # C6: 6 => SOL
* DIS # B7: 4,9 => CTR => B7: 6
* INC # B7: 6 => UNS
* INC # B9: 4,9 => UNS
* DIS # C6: 4,9 => CTR => C6: 6
* PRF # C6: 6 => SOL
* PRF # H4: 4,6 => SOL
* DIS # H4: 9 => CTR => H4: 4,6
* INC # E9: 4,9 => UNS
* INC # E9: 2 => UNS
* DIS # B7: 4,9 => CTR => B7: 6
* INC # B7: 6 => UNS
* INC # C7: 4,9 => UNS
* INC # E9: 2,4 => UNS
* INC # E9: 9 => UNS
* INC # B8: 2,4 => UNS
* INC # B8: 5 => UNS
* INC # H8: 4,8 => UNS
* INC # H8: 5 => UNS
* INC # H9: 4,6 => UNS
* INC # H9: 5 => UNS
* PRF # I3: 4,6 => SOL
* DIS # I3: 9 => CTR => I3: 4,6
* CNT  46 HDP CHAINS /  46 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # B3: 6,9 => UNS
* INC # C3: 6,9 => UNS
* PRF # D1: 6,9 => SOL
* STA D1: 6,9
* CNT   3 HDP CHAINS /   3 HYP OPENED