Analysis of xx-top500-263-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 5.....72.....1....2...........2.3.8..9..........8.....4673...........9.13........ initial

Autosolve

position: 5.19..72.9...12..52....519.1..273689.9815.......8.951.467391.5.8....79313195284.. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # I1: 3,8 => SOL
* PRF # I1: 3,8 => SOL
* DIS # B3: 3,8 => CTR => B3: 4,7
* PRF # I1: 3,8 => SOL
* PRF # I3: 4,6 => SOL
* CNT   5 HDP CHAINS /  22 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 # I1: 3,8 => SOL
* STA I1: 3,8
* CNT   1 HDP CHAINS /   2 HYP OPENED

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

Details

Positions

5.....72.....1....2...........2.3.8..9..........8.....4673...........9.13........ initial
5.19..72.9...12..52....519.1..273689.9815.......8.951.467391.5.8....79313195284.. autosolve
541936728986712345273485196154273689698154273732869514467391852825647931319528467 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (25)
E1: 3,8
F1: 4,6
E3: 3,8
G2: 3,8
H2: 4,6
B4: 4,5
C4: 4,5
A5: 6,7
A6: 6,7
B6: 2,3
C6: 2,3
F5: 4,6
E6: 4,6
G5: 2,3
H5: 4,7
I5: 2,3
I6: 4,7
B8: 2,5
C8: 2,5
D8: 4,6
E8: 4,6
G7: 2,8
I7: 2,8
H9: 6,7
I9: 6,7

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
B6,C6: 2.. / B6 = 2  => 26 pairs (_) / C6 = 2  => 22 pairs (_)
G5,I5: 2.. / G5 = 2  => 23 pairs (_) / I5 = 2  => 22 pairs (_)
B8,C8: 2.. / B8 = 2  => 22 pairs (_) / C8 = 2  => 26 pairs (_)
G7,I7: 2.. / G7 = 2  => 22 pairs (_) / I7 = 2  => 23 pairs (_)
B6,B8: 2.. / B6 = 2  => 26 pairs (_) / B8 = 2  => 22 pairs (_)
C6,C8: 2.. / C6 = 2  => 22 pairs (_) / C8 = 2  => 26 pairs (_)
G5,G7: 2.. / G5 = 2  => 23 pairs (_) / G7 = 2  => 22 pairs (_)
I5,I7: 2.. / I5 = 2  => 22 pairs (_) / I7 = 2  => 23 pairs (_)
E1,E3: 3.. / E1 = 3  => 24 pairs (_) / E3 = 3  => 27 pairs (_)
B6,C6: 3.. / B6 = 3  => 22 pairs (_) / C6 = 3  => 26 pairs (_)
G5,I5: 3.. / G5 = 3  => 22 pairs (_) / I5 = 3  => 23 pairs (_)
G2,G5: 3.. / G2 = 3  => 23 pairs (_) / G5 = 3  => 22 pairs (_)
B4,C4: 4.. / B4 = 4  => 26 pairs (_) / C4 = 4  => 22 pairs (_)
F5,E6: 4.. / F5 = 4  =>  0 pairs (*) / E6 = 4  =>  0 pairs (X)
H5,I6: 4.. / H5 = 4  =>  0 pairs (X) / I6 = 4  =>  0 pairs (_)
D8,E8: 4.. / D8 = 4  =>  0 pairs (X) / E8 = 4  =>  0 pairs (_)
F5,H5: 4.. / F5 = 4  =>  0 pairs (*) / H5 = 4  =>  0 pairs (X)
E6,I6: 4.. / E6 = 4  =>  0 pairs (X) / I6 = 4  =>  0 pairs (_)
E6,E8: 4.. / E6 = 4  =>  0 pairs (X) / E8 = 4  =>  0 pairs (_)
F1,F5: 4.. / F1 = 4  =>  0 pairs (X) / F5 = 4  =>  0 pairs (_)
H2,H5: 4.. / H2 = 4  =>  0 pairs (*) / H5 = 4  =>  0 pairs (X)
B4,C4: 5.. / B4 = 5  => 22 pairs (_) / C4 = 5  => 26 pairs (_)
B8,C8: 5.. / B8 = 5  => 26 pairs (_) / C8 = 5  => 22 pairs (_)
B4,B8: 5.. / B4 = 5  => 22 pairs (_) / B8 = 5  => 26 pairs (_)
C4,C8: 5.. / C4 = 5  => 26 pairs (_) / C8 = 5  => 22 pairs (_)
C2,C3: 6.. / C2 = 6  =>  0 pairs (*) / C3 = 6  =>  0 pairs (X)
A5,A6: 6.. / A5 = 6  =>  0 pairs (*) / A6 = 6  =>  0 pairs (X)
F5,E6: 6.. / F5 = 6  =>  0 pairs (X) / E6 = 6  =>  0 pairs (_)
D8,E8: 6.. / D8 = 6  =>  0 pairs (*) / E8 = 6  =>  0 pairs (X)
H9,I9: 6.. / H9 = 6  =>  0 pairs (*) / I9 = 6  =>  0 pairs (X)
F1,I1: 6.. / F1 = 6  =>  0 pairs (*) / I1 = 6  =>  0 pairs (X)
A5,F5: 6.. / A5 = 6  =>  0 pairs (*) / F5 = 6  =>  0 pairs (X)
A6,E6: 6.. / A6 = 6  =>  0 pairs (X) / E6 = 6  =>  0 pairs (_)
E6,E8: 6.. / E6 = 6  =>  0 pairs (*) / E8 = 6  =>  0 pairs (X)
F1,F5: 6.. / F1 = 6  =>  0 pairs (*) / F5 = 6  =>  0 pairs (X)
H2,H9: 6.. / H2 = 6  =>  0 pairs (X) / H9 = 6  =>  0 pairs (_)
B2,B3: 7.. / B2 = 7  => 18 pairs (_) / B3 = 7  => 26 pairs (_)
D2,D3: 7.. / D2 = 7  => 26 pairs (_) / D3 = 7  => 18 pairs (_)
A5,A6: 7.. / A5 = 7  =>  0 pairs (X) / A6 = 7  =>  0 pairs (_)
H5,I6: 7.. / H5 = 7  =>  0 pairs (*) / I6 = 7  =>  0 pairs (X)
H9,I9: 7.. / H9 = 7  =>  0 pairs (X) / I9 = 7  =>  0 pairs (_)
B2,D2: 7.. / B2 = 7  => 18 pairs (_) / D2 = 7  => 26 pairs (_)
B3,D3: 7.. / B3 = 7  => 26 pairs (_) / D3 = 7  => 18 pairs (_)
A5,H5: 7.. / A5 = 7  =>  0 pairs (X) / H5 = 7  =>  0 pairs (_)
A6,I6: 7.. / A6 = 7  =>  0 pairs (*) / I6 = 7  =>  0 pairs (X)
H5,H9: 7.. / H5 = 7  =>  0 pairs (*) / H9 = 7  =>  0 pairs (X)
I6,I9: 7.. / I6 = 7  =>  0 pairs (X) / I9 = 7  =>  0 pairs (_)
E1,E3: 8.. / E1 = 8  => 27 pairs (_) / E3 = 8  => 24 pairs (_)
G7,I7: 8.. / G7 = 8  => 23 pairs (_) / I7 = 8  => 22 pairs (_)
B2,G2: 8.. / B2 = 8  => 23 pairs (_) / G2 = 8  => 22 pairs (_)
G2,G7: 8.. / G2 = 8  => 22 pairs (_) / G7 = 8  => 23 pairs (_)
* DURATION: 0:01:58.209494  START: 11:50:26.544625  END: 11:52:24.754119 2017-05-04
* CP COUNT: (51)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A5,A6,B4,B6,B8,C4,C6,C8,D8,E1,E3,E6,E8,F1,F5,G2,G5,G7,H2,H5,H9,I5,I6,I7,I9)
* 5.19..72.9...12..52....519.1..273689.9815.......8.951.467391.5.8....79313195284..
* PAIR E1: 3,8 ROW 1
B1: 3,8,4                                # reduction candidate for 3,8
B1: 3,8                                  # 30 pairs
I1: 3,8,4,6                              # reduction candidate for 3,8
I1: 3,8 => SOLVED
* 541936728986712345273485196154273689698154273732869514467391852825647931319528467
I1: 4,6                                  # 30 pairs
* PAIR F1: 4,6 BLK 2
D2: 4,6,7                                # reduction candidate for 4,6
D2: 4,6                                  # 18 pairs
D3: 4,6,7                                # reduction candidate for 4,6
D3: 4,6                                  # 26 pairs
* PAIR F1: 4,6 ROW 1
I1: 4,6,3,8                              # reduction candidate for 4,6
I1: 3,8 => SOLVED
* 541936728986712345273485196154273689698154273732869514467391852825647931319528467
I1: 4,6                                  # 30 pairs
* PAIR E3: 3,8 ROW 3
B3: 3,8,4,7                              # reduction candidate for 3,8
B3: 3,8 => CTR
* 5.19..72.973.128.52867351941.4273689.9815.342.32849517467391258825467931319528476
B3: 4,7                                  # 26 pairs
I3: 3,8,4,6                              # reduction candidate for 3,8
I3: 3,8                                  # 30 pairs
* PAIR G2: 3,8 BLK 3
I1: 3,8,4,6                              # reduction candidate for 3,8
I1: 3,8 => SOLVED
* 541936728986712345273485196154273689698154273732869514467391852825647931319528467
I1: 4,6                                  # 30 pairs
I3: 3,8,4,6                              # reduction candidate for 3,8
I3: 3,8                                  # 30 pairs
* PAIR G2: 3,8 ROW 2
B2: 3,8,4,7                              # reduction candidate for 3,8
B2: 3,8                                  # 28 pairs
B2: 4,7                                  # 18 pairs
* PAIR H2: 4,6 BLK 3
I1: 4,6,3,8                              # reduction candidate for 4,6
I1: 4,6                                  # 30 pairs
I3: 4,6,3,8                              # reduction candidate for 4,6
I3: 4,6 => SOLVED
* 541936728986712345273485196154273689698154273732869514467391852825647931319528467
I3: 3,8                                  # 30 pairs
* PAIR H2: 4,6 ROW 2
C2: 4,6,3                                # reduction candidate for 4,6
C2: 4,6                                  # 28 pairs
D2: 4,6,7                                # reduction candidate for 4,6
D2: 4,6                                  # 18 pairs
* PAIR D8: 4,6 COL D
D2: 4,6,7                                # reduction candidate for 4,6
D2: 4,6                                  # 18 pairs
D3: 4,6,7                                # reduction candidate for 4,6
D3: 4,6                                  # 26 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-263-base-pr-000.dot
* REASONING
* PRF # I1: 3,8 => SOL
* PRF # I1: 3,8 => SOL
* DIS # B3: 3,8 => CTR => B3: 4,7
* PRF # I1: 3,8 => SOL
* PRF # I3: 4,6 => SOL
* CNT   5 HDP CHAINS /  22 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A5,A6,B4,B6,B8,C4,C6,C8,D8,E1,E3,E6,E8,F1,F5,G2,G5,G7,H2,H5,H9,I5,I6,I7,I9)
* 5.19..72.9...12..52....519.1..273689.9815.......8.951.467391.5.8....79313195284..
* PAIR E1: 3,8 ROW 1
B1: 3,8,4                                # reduction candidate for 3,8
B1: 3,8                                  # 30 pairs
I1: 3,8,4,6                              # reduction candidate for 3,8
I1: 3,8 => SOLVED
* 541936728986712345273485196154273689698154273732869514467391852825647931319528467
* DURATION: 0:00:03.673145  START: 11:52:56.290155  END: 11:52:59.963300 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-263-base-pr-001.dot
* REASONING
* PRF # I1: 3,8 => SOL
* STA I1: 3,8
* CNT   1 HDP CHAINS /   2 HYP OPENED

Header Info

Top 500 Minimum 17 263

solution: 541936728986712345273485196154273689698154273732869514467391852825647931319528467
info: 2097     FNBTWXY  S8.f     32160

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

Solution

position: 541936728986712345273485196154273689698154273732869514467391852825647931319528467 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 # B1: 3,8 => UNS
* PRF # I1: 3,8 => SOL
* INC # I1: 4,6 => UNS
* INC # D2: 4,6 => UNS
* INC # D3: 4,6 => UNS
* INC # I1: 4,6 => UNS
* PRF # I1: 3,8 => SOL
* DIS # B3: 3,8 => CTR => B3: 4,7
* INC # B3: 4,7 => UNS
* INC # I3: 3,8 => UNS
* PRF # I1: 3,8 => SOL
* INC # I1: 4,6 => UNS
* INC # I3: 3,8 => UNS
* INC # B2: 3,8 => UNS
* INC # B2: 4,7 => UNS
* INC # I1: 4,6 => UNS
* PRF # I3: 4,6 => SOL
* INC # I3: 3,8 => UNS
* INC # C2: 4,6 => UNS
* INC # D2: 4,6 => UNS
* INC # D2: 4,6 => UNS
* INC # D3: 4,6 => UNS
* CNT  22 HDP CHAINS /  22 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # B1: 3,8 => UNS
* PRF # I1: 3,8 => SOL
* STA I1: 3,8
* CNT   2 HDP CHAINS /   2 HYP OPENED