Analysis of xx-top500-250-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 6..1......9.....8...........84....9....2..3...7...6.......87...1...3....2.....6.. initial

Autosolve

position: 62.1789.479..6..8284..2976.5847132969162..3783728964154.9.87.2.1.7.328.92.89.16.7 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # C2: 3,5 => CTR => C2: 1
* PRF # C2: 1 => SOL
* PRF # C3: 3,5 => SOL
* DIS # C3: 1 => CTR => C3: 3,5
* DIS # D2: 4,5 => CTR => D2: 3
* PRF # D2: 3 => SOL
* PRF # D2: 3,5 => SOL
* DIS # D2: 4 => CTR => D2: 3,5
* PRF # C3: 3,5 => SOL
* DIS # C3: 1 => CTR => C3: 3,5
* DIS # H9: 3,5 => CTR => H9: 4
* PRF # H9: 4 => SOL
* PRF # C2: 1,5 => SOL
* DIS # C2: 3 => CTR => C2: 1,5
* PRF # C3: 1,3 => SOL
* DIS # C3: 5 => CTR => C3: 1,3
* PRF # B7: 5,6 => SOL
* DIS # B7: 3 => CTR => B7: 5,6
* DIS # D8: 5,6 => CTR => D8: 4
* PRF # D8: 4 => SOL
* DIS # B7: 6 => CTR => B7: 3,5
* DIS # H9: 3,5 => CTR => H9: 4
* PRF # H9: 4 => SOL
* DIS # D8: 5,6 => CTR => D8: 4
* PRF # D8: 4 => SOL
* PRF # B7: 5,6 => SOL
* DIS # B7: 3 => CTR => B7: 5,6
* DIS # D8: 6 => CTR => D8: 4,5
* PRF # H9: 4,5 => SOL
* DIS # H9: 3 => CTR => H9: 4,5
* PRF # H9: 4,5 => SOL
* DIS # H9: 3 => CTR => H9: 4,5
* DIS # D8: 6 => CTR => D8: 4,5
* CNT  33 HDP CHAINS /  36 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 # C2: 3,5 => CTR => C2: 1
* PRF C2: 1 => SOL
* STA C2: 1
* CNT   2 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

6..1......9.....8...........84....9....2..3...7...6.......87...1...3....2.....6.. initial
62.1789.479..6..8284..2976.5847132969162..3783728964154.9.87.2.1.7.328.92.89.16.7 autosolve
625178934791364582843529761584713296916245378372896415459687123167432859238951647 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (15)
C1: 3,5
F2: 4,5
D3: 3,5
H1: 3,5
G2: 1,5
I3: 1,3
E5: 4,5
F5: 4,5
B8: 5,6
B9: 3,5
D7: 5,6
E9: 4,5
G7: 1,5
I7: 1,3
H8: 4,5

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
C2,C3: 1.. / C2 = 1  =>  0 pairs (*) / C3 = 1  =>  0 pairs (X)
G2,I3: 1.. / G2 = 1  =>  0 pairs (X) / I3 = 1  =>  0 pairs (_)
G7,I7: 1.. / G7 = 1  =>  0 pairs (*) / I7 = 1  =>  0 pairs (X)
C2,G2: 1.. / C2 = 1  =>  0 pairs (*) / G2 = 1  =>  0 pairs (X)
C3,I3: 1.. / C3 = 1  =>  0 pairs (X) / I3 = 1  =>  0 pairs (_)
G2,G7: 1.. / G2 = 1  =>  0 pairs (X) / G7 = 1  =>  0 pairs (_)
I3,I7: 1.. / I3 = 1  =>  0 pairs (*) / I7 = 1  =>  0 pairs (X)
D2,D3: 3.. / D2 = 3  =>  0 pairs (*) / D3 = 3  =>  0 pairs (X)
H1,I3: 3.. / H1 = 3  =>  0 pairs (*) / I3 = 3  =>  0 pairs (X)
B7,B9: 3.. / B7 = 3  =>  0 pairs (X) / B9 = 3  =>  0 pairs (_)
I7,H9: 3.. / I7 = 3  =>  0 pairs (*) / H9 = 3  =>  0 pairs (X)
C1,H1: 3.. / C1 = 3  =>  0 pairs (X) / H1 = 3  =>  0 pairs (_)
C2,D2: 3.. / C2 = 3  =>  0 pairs (X) / D2 = 3  =>  0 pairs (_)
B7,I7: 3.. / B7 = 3  =>  0 pairs (X) / I7 = 3  =>  0 pairs (_)
B9,H9: 3.. / B9 = 3  =>  0 pairs (*) / H9 = 3  =>  0 pairs (X)
H1,H9: 3.. / H1 = 3  =>  0 pairs (*) / H9 = 3  =>  0 pairs (X)
I3,I7: 3.. / I3 = 3  =>  0 pairs (X) / I7 = 3  =>  0 pairs (_)
D2,F2: 4.. / D2 = 4  =>  0 pairs (X) / F2 = 4  =>  0 pairs (_)
E5,F5: 4.. / E5 = 4  =>  0 pairs (*) / F5 = 4  =>  0 pairs (X)
D8,E9: 4.. / D8 = 4  =>  0 pairs (*) / E9 = 4  =>  0 pairs (X)
H8,H9: 4.. / H8 = 4  =>  0 pairs (X) / H9 = 4  =>  0 pairs (_)
D8,H8: 4.. / D8 = 4  =>  0 pairs (*) / H8 = 4  =>  0 pairs (X)
E9,H9: 4.. / E9 = 4  =>  0 pairs (X) / H9 = 4  =>  0 pairs (_)
D2,D8: 4.. / D2 = 4  =>  0 pairs (X) / D8 = 4  =>  0 pairs (_)
E5,E9: 4.. / E5 = 4  =>  0 pairs (*) / E9 = 4  =>  0 pairs (X)
F2,F5: 4.. / F2 = 4  =>  0 pairs (*) / F5 = 4  =>  0 pairs (X)
H1,G2: 5.. / H1 = 5  =>  0 pairs (X) / G2 = 5  =>  0 pairs (_)
E5,F5: 5.. / E5 = 5  =>  0 pairs (X) / F5 = 5  =>  0 pairs (_)
C1,H1: 5.. / C1 = 5  =>  0 pairs (*) / H1 = 5  =>  0 pairs (X)
C3,D3: 5.. / C3 = 5  =>  0 pairs (X) / D3 = 5  =>  0 pairs (_)
E5,E9: 5.. / E5 = 5  =>  0 pairs (X) / E9 = 5  =>  0 pairs (_)
F2,F5: 5.. / F2 = 5  =>  0 pairs (X) / F5 = 5  =>  0 pairs (_)
G2,G7: 5.. / G2 = 5  =>  0 pairs (*) / G7 = 5  =>  0 pairs (X)
B7,B8: 6.. / B7 = 6  =>  0 pairs (X) / B8 = 6  => 15 pairs (_)
D7,D8: 6.. / D7 = 6  => 15 pairs (_) / D8 = 6  =>  0 pairs (X)
B7,D7: 6.. / B7 = 6  =>  0 pairs (X) / D7 = 6  => 15 pairs (_)
B8,D8: 6.. / B8 = 6  => 15 pairs (_) / D8 = 6  =>  0 pairs (X)
* DURATION: 0:01:02.519974  START: 11:20:08.454026  END: 11:21:10.974000 2017-05-04
* CP COUNT: (37)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B8,B9,C1,D3,D7,E5,E9,F2,F5,G2,G7,H1,H8,I3,I7)
* 62.1789.479..6..8284..2976.5847132969162..3783728964154.9.87.2.1.7.328.92.89.16.7
* PAIR C1: 3,5 BLK 1
C2: 3,5,1                                # reduction candidate for 3,5
C2: 3,5 => CTR
* 62.1789.479..6.1828415297635847132969162.53783728964154396875211.7.328.92.89.16.7
C2: 1 => SOLVED
* 625178934791364582843529761584713296916245378372896415459687123167432859238951647
C3: 3,5,1                                # reduction candidate for 3,5
C3: 3,5 => SOLVED
* 625178934791364582843529761584713296916245378372896415459687123167432859238951647
C3: 1 => CTR
* 62.1789.479..6..828415297635847132969162.53783728964154396875211.7.328.92.89.16.7
* PAIR F2: 4,5 BLK 2
D2: 4,5,3                                # reduction candidate for 4,5
D2: 4,5 => CTR
* 62.1789.4793.6.182841.2976.5847132969162..3783728964154.9.87.2.1.7.328.92.89.16.7
D2: 3 => SOLVED
* 625178934791364582843529761584713296916245378372896415459687123167432859238951647
* PAIR D3: 3,5 BLK 2
D2: 3,5,4                                # reduction candidate for 3,5
D2: 3,5 => SOLVED
* 625178934791364582843529761584713296916245378372896415459687123167432859238951647
D2: 4 => CTR
* 62.1789.479346518284..2976.5847132969162..3783728964154.9.87.2.1.7.328.92.89.16.7
* PAIR D3: 3,5 ROW 3
C3: 3,5,1                                # reduction candidate for 3,5
C3: 3,5 => SOLVED
* 625178934791364582843529761584713296916245378372896415459687123167432859238951647
C3: 1 => CTR
* 62.1789.479..6..828415297635847132969162.53783728964154396875211.7.328.92.89.16.7
* PAIR H1: 3,5 COL H
H9: 3,5,4                                # reduction candidate for 3,5
H9: 3,5 => CTR
* 62.1789.479.46518284..2976.5847132969162..3783728964154.9.87.2.1.7.328492.89416.7
H9: 4 => SOLVED
* 625178934791364582843529761584713296916245378372896415459687123167432859238951647
* PAIR G2: 1,5 ROW 2
C2: 1,5,3                                # reduction candidate for 1,5
C2: 1,5 => SOLVED
* 625178934791364582843529761584713296916245378372896415459687123167432859238951647
C2: 3 => CTR
* 62.1789.4793.6.182841.2976.5847132969162..3783728964154.9.87.2.1.7.328.92.89.16.7
* PAIR I3: 1,3 ROW 3
C3: 1,3,5                                # reduction candidate for 1,3
C3: 1,3 => SOLVED
* 625178934791364582843529761584713296916245378372896415459687123167432859238951647
C3: 5 => CTR
* 62.1789.479136458284..2976.5847132969162..3783728964154.9.87.2.1.7.328.92.89.16.7
* PAIR B8: 5,6 BLK 7
B7: 5,6,3                                # reduction candidate for 5,6
B7: 5,6 => SOLVED
* 625178934791364582843529761584713296916245378372896415459687123167432859238951647
B7: 3 => CTR
* 62.1789.479..6..8284..2976.5847132969162..378372896415439687521167532849258941637
* PAIR B8: 5,6 ROW 8
D8: 5,6,4                                # reduction candidate for 5,6
D8: 5,6 => CTR
* 62.1789.479.46518284..2976.5847132969162..3783728964154.9.87.2.1.7.328.92.89.16.7
D8: 4 => SOLVED
* 625178934791364582843529761584713296916245378372896415459687123167432859238951647
* PAIR B9: 3,5 BLK 7
B7: 3,5,6                                # reduction candidate for 3,5
B7: 6 => CTR
* 625178934791.6..8284..2976.5847132969162..378372896415469587123157632849238941657
B7: 3,5                                  # 15 pairs
* PAIR B9: 3,5 ROW 9
H9: 3,5,4                                # reduction candidate for 3,5
H9: 3,5 => CTR
* 62.1789.479.46518284..2976.5847132969162..3783728964154.9.87.2.1.7.328492.89416.7
H9: 4 => SOLVED
* 625178934791364582843529761584713296916245378372896415459687123167432859238951647
* PAIR D7: 5,6 BLK 8
D8: 5,6,4                                # reduction candidate for 5,6
D8: 5,6 => CTR
* 62.1789.479.46518284..2976.5847132969162..3783728964154.9.87.2.1.7.328.92.89.16.7
D8: 4 => SOLVED
* 625178934791364582843529761584713296916245378372896415459687123167432859238951647
* PAIR D7: 5,6 ROW 7
B7: 5,6,3                                # reduction candidate for 5,6
B7: 5,6 => SOLVED
* 625178934791364582843529761584713296916245378372896415459687123167432859238951647
B7: 3 => CTR
* 62.1789.479..6..8284..2976.5847132969162..378372896415439687521167532849258941637
* PAIR E9: 4,5 BLK 8
D8: 4,5,6                                # reduction candidate for 4,5
D8: 6 => CTR
* 62.1789.479.46518284..2976.5847132969162..3783728964154.9.87.2.1.7.328.92.89.16.7
D8: 4,5                                  # 15 pairs
* PAIR E9: 4,5 ROW 9
H9: 4,5,3                                # reduction candidate for 4,5
H9: 4,5 => SOLVED
* 625178934791364582843529761584713296916245378372896415459687123167432859238951647
H9: 3 => CTR
* 62317895479..6..8284..2976.5847132969162..3783728964154.9.87.2.1.7.328492.8941637
* PAIR H8: 4,5 BLK 9
H9: 4,5,3                                # reduction candidate for 4,5
H9: 4,5 => SOLVED
* 625178934791364582843529761584713296916245378372896415459687123167432859238951647
H9: 3 => CTR
* 62317895479..6..8284..2976.5847132969162..3783728964154.9.87.2.1.7.328492.8941637
* PAIR H8: 4,5 ROW 8
D8: 4,5,6                                # reduction candidate for 4,5
D8: 6 => CTR
* 62.1789.479.46518284..2976.5847132969162..3783728964154.9.87.2.1.7.328.92.89.16.7
D8: 4,5                                  # 15 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-250-base-pr-000.dot
* REASONING
* DIS # C2: 3,5 => CTR => C2: 1
* PRF # C2: 1 => SOL
* PRF # C3: 3,5 => SOL
* DIS # C3: 1 => CTR => C3: 3,5
* DIS # D2: 4,5 => CTR => D2: 3
* PRF # D2: 3 => SOL
* PRF # D2: 3,5 => SOL
* DIS # D2: 4 => CTR => D2: 3,5
* PRF # C3: 3,5 => SOL
* DIS # C3: 1 => CTR => C3: 3,5
* DIS # H9: 3,5 => CTR => H9: 4
* PRF # H9: 4 => SOL
* PRF # C2: 1,5 => SOL
* DIS # C2: 3 => CTR => C2: 1,5
* PRF # C3: 1,3 => SOL
* DIS # C3: 5 => CTR => C3: 1,3
* PRF # B7: 5,6 => SOL
* DIS # B7: 3 => CTR => B7: 5,6
* DIS # D8: 5,6 => CTR => D8: 4
* PRF # D8: 4 => SOL
* DIS # B7: 6 => CTR => B7: 3,5
* DIS # H9: 3,5 => CTR => H9: 4
* PRF # H9: 4 => SOL
* DIS # D8: 5,6 => CTR => D8: 4
* PRF # D8: 4 => SOL
* PRF # B7: 5,6 => SOL
* DIS # B7: 3 => CTR => B7: 5,6
* DIS # D8: 6 => CTR => D8: 4,5
* PRF # H9: 4,5 => SOL
* DIS # H9: 3 => CTR => H9: 4,5
* PRF # H9: 4,5 => SOL
* DIS # H9: 3 => CTR => H9: 4,5
* DIS # D8: 6 => CTR => D8: 4,5
* CNT  33 HDP CHAINS /  36 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B8,B9,C1,D3,D7,E5,E9,F2,F5,G2,G7,H1,H8,I3,I7)
* 62.1789.479..6..8284..2976.5847132969162..3783728964154.9.87.2.1.7.328.92.89.16.7
* PAIR C1: 3,5 BLK 1
C2: 3,5,1                                # reduction candidate for 3,5
C2: 3,5 => CTR
* 62.1789.479..6.1828415297635847132969162.53783728964154396875211.7.328.92.89.16.7
C2: 1 => SOLVED
* 625178934791364582843529761584713296916245378372896415459687123167432859238951647
* DURATION: 0:00:01.621903  START: 11:21:50.441698  END: 11:21:52.063601 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-250-base-pr-001.dot
* REASONING
* DIS # C2: 3,5 => CTR => C2: 1
* PRF C2: 1 => SOL
* STA C2: 1
* CNT   2 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 250

solution: 625178934791364582843529761584713296916245378372896415459687123167432859238951647
info: 2073     FNBWXY   S8.f     34806

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

Solution

position: 625178934791364582843529761584713296916245378372896415459687123167432859238951647 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:

* DIS # C2: 3,5 => CTR => C2: 1
* PRF # C2: 1 => SOL
* PRF # C3: 3,5 => SOL
* DIS # C3: 1 => CTR => C3: 3,5
* DIS # D2: 4,5 => CTR => D2: 3
* PRF # D2: 3 => SOL
* PRF # D2: 3,5 => SOL
* DIS # D2: 4 => CTR => D2: 3,5
* PRF # C3: 3,5 => SOL
* DIS # C3: 1 => CTR => C3: 3,5
* DIS # H9: 3,5 => CTR => H9: 4
* PRF # H9: 4 => SOL
* PRF # C2: 1,5 => SOL
* DIS # C2: 3 => CTR => C2: 1,5
* PRF # C3: 1,3 => SOL
* DIS # C3: 5 => CTR => C3: 1,3
* PRF # B7: 5,6 => SOL
* DIS # B7: 3 => CTR => B7: 5,6
* DIS # D8: 5,6 => CTR => D8: 4
* PRF # D8: 4 => SOL
* INC # B7: 3,5 => UNS
* DIS # B7: 6 => CTR => B7: 3,5
* DIS # H9: 3,5 => CTR => H9: 4
* PRF # H9: 4 => SOL
* DIS # D8: 5,6 => CTR => D8: 4
* PRF # D8: 4 => SOL
* PRF # B7: 5,6 => SOL
* DIS # B7: 3 => CTR => B7: 5,6
* INC # D8: 4,5 => UNS
* DIS # D8: 6 => CTR => D8: 4,5
* PRF # H9: 4,5 => SOL
* DIS # H9: 3 => CTR => H9: 4,5
* PRF # H9: 4,5 => SOL
* DIS # H9: 3 => CTR => H9: 4,5
* INC # D8: 4,5 => UNS
* DIS # D8: 6 => CTR => D8: 4,5
* CNT  36 HDP CHAINS /  36 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # C2: 3,5 => CTR => C2: 1
* PRF C2: 1 => SOL
* STA C2: 1
* CNT   2 HDP CHAINS /   1 HYP OPENED