Analysis of xx-top500-077-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 5..1...6.....3.7..8........4..5.6....7....2.....8......32.7...........51......... initial

Autosolve

position: 5.71.28632..6387.586375.12.4..5.6937.75...2..3..8.75..1324756..7..2...51.5...1.72 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # E5: 4,9 => CTR => E5: 1
* DIS # F5: 4,9 => CTR => F5: 3
* PRF # F5: 3 => SOL
* DIS # B4: 2 => CTR => B4: 1,8
* DIS # C6: 1 => CTR => C6: 6,9
* DIS # E6: 1,2 => CTR => E6: 4,9
* PRF # F5: 3,9 => SOL
* DIS # F5: 4 => CTR => F5: 3,9
* DIS # H5: 1,4 => CTR => H5: 8
* PRF # H5: 8 => SOL
* PRF # E6: 1,4 => SOL
* PRF # I5: 4,6 => SOL
* DIS # I5: 8 => CTR => I5: 4,6
* PRF # C9: 6,9 => SOL
* PRF # F5: 3,9 => SOL
* DIS # F5: 4 => CTR => F5: 3,9
* PRF # C9: 6,8 => SOL
* DIS # C9: 4,9 => CTR => C9: 6,8
* CNT  18 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 # E5: 4,9 => CTR => E5: 1
* DIS E5: 1 # F5: 4,9 => CTR => F5: 3
* PRF E5: 1 + F5: 3 => SOL
* STA E5: 1 + F5: 3
* CNT   3 HDP CHAINS /   6 HYP OPENED

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

Details

Positions

5..1...6.....3.7..8........4..5.6....7....2.....8......32.7...........51......... initial
5.71.28632..6387.586375.12.4..5.6937.75...2..3..8.75..1324756..7..2...51.5...1.72 autosolve
547192863291638745863754129418526937675913284329847516132475698784269351956381472 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (20)
B1: 4,9
E1: 4,9
F3: 4,9
H2: 4,9
I3: 4,9
C4: 1,8
A5: 6,9
E4: 1,2
D5: 3,9
H6: 1,4
I6: 4,6
A9: 6,9
E8: 6,8
F8: 3,9
D9: 3,9
E9: 6,8
H7: 8,9
I7: 8,9
G8: 3,4
G9: 3,4

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
B2,C2: 1.. / B2 = 1  => 23 pairs (_) / C2 = 1  => 22 pairs (_)
H5,H6: 1.. / H5 = 1  =>  0 pairs (X) / H6 = 1  => 22 pairs (_)
E5,H5: 1.. / E5 = 1  => 22 pairs (_) / H5 = 1  =>  0 pairs (X)
B4,B6: 2.. / B4 = 2  =>  0 pairs (X) / B6 = 2  => 21 pairs (_)
E4,E6: 2.. / E4 = 2  => 21 pairs (_) / E6 = 2  =>  0 pairs (X)
B4,E4: 2.. / B4 = 2  =>  0 pairs (X) / E4 = 2  => 21 pairs (_)
B6,E6: 2.. / B6 = 2  => 21 pairs (_) / E6 = 2  =>  0 pairs (X)
D5,F5: 3.. / D5 = 3  =>  0 pairs (X) / F5 = 3  =>  0 pairs (_)
F8,D9: 3.. / F8 = 3  =>  0 pairs (X) / D9 = 3  =>  0 pairs (_)
G8,G9: 3.. / G8 = 3  =>  0 pairs (*) / G9 = 3  =>  0 pairs (X)
F8,G8: 3.. / F8 = 3  =>  0 pairs (X) / G8 = 3  =>  0 pairs (_)
D9,G9: 3.. / D9 = 3  =>  0 pairs (*) / G9 = 3  =>  0 pairs (X)
D5,D9: 3.. / D5 = 3  =>  0 pairs (X) / D9 = 3  =>  0 pairs (_)
F5,F8: 3.. / F5 = 3  =>  0 pairs (*) / F8 = 3  =>  0 pairs (X)
E1,F3: 4.. / E1 = 4  =>  0 pairs (X) / F3 = 4  =>  0 pairs (_)
H2,I3: 4.. / H2 = 4  =>  0 pairs (*) / I3 = 4  =>  0 pairs (X)
G8,G9: 4.. / G8 = 4  =>  0 pairs (X) / G9 = 4  =>  0 pairs (_)
B1,E1: 4.. / B1 = 4  =>  0 pairs (*) / E1 = 4  =>  0 pairs (X)
F3,I3: 4.. / F3 = 4  =>  0 pairs (*) / I3 = 4  =>  0 pairs (X)
C9,G9: 4.. / C9 = 4  =>  0 pairs (X) / G9 = 4  =>  0 pairs (_)
F3,F5: 4.. / F3 = 4  =>  0 pairs (*) / F5 = 4  =>  0 pairs (X)
A5,C6: 6.. / A5 = 6  =>  0 pairs (*) / C6 = 6  =>  0 pairs (X)
I5,I6: 6.. / I5 = 6  =>  0 pairs (X) / I6 = 6  =>  0 pairs (_)
E8,E9: 6.. / E8 = 6  => 18 pairs (_) / E9 = 6  =>  0 pairs (X)
A5,I5: 6.. / A5 = 6  =>  0 pairs (*) / I5 = 6  =>  0 pairs (X)
C6,I6: 6.. / C6 = 6  =>  0 pairs (X) / I6 = 6  =>  0 pairs (_)
C8,E8: 6.. / C8 = 6  =>  0 pairs (X) / E8 = 6  => 18 pairs (_)
A5,A9: 6.. / A5 = 6  =>  0 pairs (*) / A9 = 6  =>  0 pairs (X)
B4,C4: 8.. / B4 = 8  => 22 pairs (_) / C4 = 8  => 20 pairs (_)
H5,I5: 8.. / H5 = 8  =>  0 pairs (*) / I5 = 8  =>  0 pairs (X)
E8,E9: 8.. / E8 = 8  =>  0 pairs (X) / E9 = 8  => 18 pairs (_)
H7,I7: 8.. / H7 = 8  =>  0 pairs (X) / I7 = 8  =>  0 pairs (_)
C9,E9: 8.. / C9 = 8  =>  0 pairs (X) / E9 = 8  => 18 pairs (_)
B4,B8: 8.. / B4 = 8  => 22 pairs (_) / B8 = 8  => 20 pairs (_)
H5,H7: 8.. / H5 = 8  =>  0 pairs (*) / H7 = 8  =>  0 pairs (X)
I5,I7: 8.. / I5 = 8  =>  0 pairs (X) / I7 = 8  =>  0 pairs (_)
E1,F3: 9.. / E1 = 9  =>  0 pairs (*) / F3 = 9  =>  0 pairs (X)
H2,I3: 9.. / H2 = 9  =>  0 pairs (X) / I3 = 9  =>  0 pairs (_)
F8,D9: 9.. / F8 = 9  =>  0 pairs (*) / D9 = 9  =>  0 pairs (X)
H7,I7: 9.. / H7 = 9  =>  0 pairs (*) / I7 = 9  =>  0 pairs (X)
B1,E1: 9.. / B1 = 9  =>  0 pairs (X) / E1 = 9  =>  0 pairs (_)
F3,I3: 9.. / F3 = 9  =>  0 pairs (X) / I3 = 9  =>  0 pairs (_)
A5,A9: 9.. / A5 = 9  =>  0 pairs (X) / A9 = 9  =>  0 pairs (_)
D5,D9: 9.. / D5 = 9  =>  0 pairs (*) / D9 = 9  =>  0 pairs (X)
H2,H7: 9.. / H2 = 9  =>  0 pairs (X) / H7 = 9  =>  0 pairs (_)
I3,I7: 9.. / I3 = 9  =>  0 pairs (*) / I7 = 9  =>  0 pairs (X)
* DURATION: 0:01:43.348916  START: 05:21:18.738353  END: 05:23:02.087269 2017-05-04
* CP COUNT: (46)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A5,A9,B1,C4,D5,D9,E1,E4,E8,E9,F3,F8,G8,G9,H2,H6,H7,I3,I6,I7)
* 5.71.28632..6387.586375.12.4..5.6937.75...2..3..8.75..1324756..7..2...51.5...1.72
* PAIR B1: 4,9 BLK 1
B2: 4,9,1                                # reduction candidate for 4,9
B2: 4,9                                  # 22 pairs
C2: 4,9,1                                # reduction candidate for 4,9
C2: 4,9                                  # 23 pairs
* PAIR B1: 4,9 COL B
B8: 4,9,8                                # reduction candidate for 4,9
B8: 4,9                                  # 22 pairs
B8: 8                                    # 20 pairs
* PAIR E1: 4,9 COL E
E5: 4,9,1                                # reduction candidate for 4,9
E5: 4,9 => CTR
* 5.71.28632..6387958637591244..5.6937675..42183..8.75461324756897..2.345195...1.72
E5: 1                                    # 22 pairs
E6: 4,9,1,2                              # reduction candidate for 4,9
E6: 4,9                                  # 22 pairs
* PAIR F3: 4,9 COL F
F5: 4,9,3                                # reduction candidate for 4,9
F5: 4,9 => CTR
* 5.71.28632..6387.586375.12.4..5.69379753.42.63.68975.41324756.87..263451654981372
F5: 3 => SOLVED
* 547192863291638745863754129418526937675913284329847516132475698784269351956381472
* PAIR H2: 4,9 ROW 2
B2: 4,9,1                                # reduction candidate for 4,9
B2: 4,9                                  # 22 pairs
C2: 4,9,1                                # reduction candidate for 4,9
C2: 4,9                                  # 23 pairs
* PAIR C4: 1,8 BLK 4
B4: 1,8,2                                # reduction candidate for 1,8
B4: 2 => CTR
* 5.71.28632..638795863759124428516937675.942183..82754613247568978.26..51.56.81472
B4: 1,8                                  # 21 pairs
* PAIR A5: 6,9 BLK 4
C6: 6,9,1                                # reduction candidate for 6,9
C6: 1 => CTR
* 5471928632196387.586375.12.4..5.6937675...2..3918275461324756..7..2...5195.3.1472
C6: 6,9                                  # 22 pairs
* PAIR E4: 1,2 BLK 5
E6: 1,2,4,9                              # reduction candidate for 1,2
E6: 1,2 => CTR
* 5.71.28632..6387.586375.12.4..5.6937675...2.83..8.75.61324756897..2.935195.3.1472
E6: 4,9                                  # 22 pairs
* PAIR E4: 1,2 ROW 4
B4: 1,2,8                                # reduction candidate for 1,2
B4: 8                                    # 22 pairs
B4: 1,2                                  # 20 pairs
* PAIR D5: 3,9 BLK 5
F5: 3,9,4                                # reduction candidate for 3,9
F5: 3,9 => SOLVED
* 547192863291638745863754129418526937675913284329847516132475698784269351956381472
F5: 4 => CTR
* 5.71428632416387958637591244.85.693797531428.3..8.75..1324756..7..2.3451.54981372
* PAIR H6: 1,4 BLK 6
H5: 1,4,8                                # reduction candidate for 1,4
H5: 1,4 => CTR
* 5.71.28632..6387958637591244..5.6937675..42183..8.75461324756897..2.345195...1.72
H5: 8 => SOLVED
* 547192863291638745863754129418526937675913284329847516132475698784269351956381472
* PAIR H6: 1,4 ROW 6
E6: 1,4,2,9                              # reduction candidate for 1,4
E6: 1,4 => SOLVED
* 547192863291638745863754129418526937675913284329847516132475698784269351956381472
E6: 2,9                                  # 23 pairs
* PAIR I6: 4,6 BLK 6
I5: 4,6,8                                # reduction candidate for 4,6
I5: 4,6 => SOLVED
* 547192863291638745863754129418526937675913284329847516132475698784269351956381472
I5: 8 => CTR
* 5.71.28632..63879586375912.4..5.6937675...2.83..8.75.61324756897..2...5195.3.1472
* PAIR A9: 6,9 BLK 7
C8: 6,9,4,8                              # reduction candidate for 6,9
C8: 6,9                                  # 23 pairs
C9: 6,9,4,8                              # reduction candidate for 6,9
C9: 6,9 => SOLVED
* 547192863291638745863754129418526937675913284329847516132475698784269351956381472
C9: 4,8                                  # 21 pairs
* PAIR E8: 6,8 ROW 8
C8: 6,8,4,9                              # reduction candidate for 6,8
C8: 6,8                                  # 22 pairs
C8: 4,9                                  # 20 pairs
* PAIR F8: 3,9 COL F
F5: 3,9,4                                # reduction candidate for 3,9
F5: 3,9 => SOLVED
* 547192863291638745863754129418526937675913284329847516132475698784269351956381472
F5: 4 => CTR
* 5.71428632416387958637591244.85.693797531428.3..8.75..1324756..7..2.3451.54981372
* PAIR E9: 6,8 ROW 9
C9: 6,8,4,9                              # reduction candidate for 6,8
C9: 6,8 => SOLVED
* 547192863291638745863754129418526937675913284329847516132475698784269351956381472
C9: 4,9 => CTR
* 5.71.28632..6387.586375.12.4..5.69379753.42.63.68975.41324756.87..263451654981372
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-077-base-pr-000.dot
* REASONING
* DIS # E5: 4,9 => CTR => E5: 1
* DIS # F5: 4,9 => CTR => F5: 3
* PRF # F5: 3 => SOL
* DIS # B4: 2 => CTR => B4: 1,8
* DIS # C6: 1 => CTR => C6: 6,9
* DIS # E6: 1,2 => CTR => E6: 4,9
* PRF # F5: 3,9 => SOL
* DIS # F5: 4 => CTR => F5: 3,9
* DIS # H5: 1,4 => CTR => H5: 8
* PRF # H5: 8 => SOL
* PRF # E6: 1,4 => SOL
* PRF # I5: 4,6 => SOL
* DIS # I5: 8 => CTR => I5: 4,6
* PRF # C9: 6,9 => SOL
* PRF # F5: 3,9 => SOL
* DIS # F5: 4 => CTR => F5: 3,9
* PRF # C9: 6,8 => SOL
* DIS # C9: 4,9 => CTR => C9: 6,8
* CNT  18 HDP CHAINS /  36 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A5,A9,B1,C4,D5,D9,E1,E4,E8,E9,F3,F8,G8,G9,H2,H6,H7,I3,I6,I7)
* 5.71.28632..6387.586375.12.4..5.6937.75...2..3..8.75..1324756..7..2...51.5...1.72
* PAIR B1: 4,9 BLK 1
B2: 4,9,1                                # reduction candidate for 4,9
B2: 4,9                                  # 22 pairs
C2: 4,9,1                                # reduction candidate for 4,9
C2: 4,9                                  # 23 pairs
* PAIR B1: 4,9 COL B
B8: 4,9,8                                # reduction candidate for 4,9
B8: 4,9                                  # 22 pairs
B8: 8                                    # 20 pairs
* PAIR E1: 4,9 COL E
E5: 4,9,1                                # reduction candidate for 4,9
E5: 4,9 => CTR
* 5.71.28632..6387958637591244..5.6937675..42183..8.75461324756897..2.345195...1.72
* RESTART
* PAIR RESTART
* PAIR F3: 4,9 COL F
F5: 4,9,3                                # reduction candidate for 4,9
F5: 4,9 => CTR
* 5.71.28632..6387.586375.12.4..5269379753142863268975141324756987..263451654981372
F5: 3 => SOLVED
* 547192863291638745863754129418526937675913284329847516132475698784269351956381472
* DURATION: 0:00:09.898850  START: 05:23:50.182456  END: 05:24:00.081306 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-077-base-pr-001.dot
* REASONING
* DIS # E5: 4,9 => CTR => E5: 1
* DIS E5: 1 # F5: 4,9 => CTR => F5: 3
* PRF E5: 1 + F5: 3 => SOL
* STA E5: 1 + F5: 3
* CNT   3 HDP CHAINS /   6 HYP OPENED

Header Info

Top 500 Minimum 17 077

solution: 547192863291638745863754129418526937675913284329847516132475698784269351956381472
info: 1498     FNBHWXY  S8.f     32683

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

Solution

position: 547192863291638745863754129418526937675913284329847516132475698784269351956381472 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: 4,9 => UNS
* INC # C2: 4,9 => UNS
* INC # B8: 4,9 => UNS
* INC # B8: 8 => UNS
* DIS # E5: 4,9 => CTR => E5: 1
* INC # E5: 1 => UNS
* INC # E6: 4,9 => UNS
* DIS # F5: 4,9 => CTR => F5: 3
* PRF # F5: 3 => SOL
* INC # B2: 4,9 => UNS
* INC # C2: 4,9 => UNS
* INC # B4: 1,8 => UNS
* DIS # B4: 2 => CTR => B4: 1,8
* INC # C6: 6,9 => UNS
* DIS # C6: 1 => CTR => C6: 6,9
* DIS # E6: 1,2 => CTR => E6: 4,9
* INC # E6: 4,9 => UNS
* INC # B4: 1,2 => UNS
* INC # B4: 8 => UNS
* PRF # F5: 3,9 => SOL
* DIS # F5: 4 => CTR => F5: 3,9
* DIS # H5: 1,4 => CTR => H5: 8
* PRF # H5: 8 => SOL
* PRF # E6: 1,4 => SOL
* INC # E6: 2,9 => UNS
* PRF # I5: 4,6 => SOL
* DIS # I5: 8 => CTR => I5: 4,6
* INC # C8: 6,9 => UNS
* PRF # C9: 6,9 => SOL
* INC # C9: 4,8 => UNS
* INC # C8: 6,8 => UNS
* INC # C8: 4,9 => UNS
* PRF # F5: 3,9 => SOL
* DIS # F5: 4 => CTR => F5: 3,9
* PRF # C9: 6,8 => SOL
* DIS # C9: 4,9 => CTR => C9: 6,8
* CNT  36 HDP CHAINS /  36 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # B2: 4,9 => UNS
* INC # C2: 4,9 => UNS
* INC # B8: 4,9 => UNS
* INC # B8: 8 => UNS
* DIS # E5: 4,9 => CTR => E5: 1
* DIS E5: 1 # F5: 4,9 => CTR => F5: 3
* PRF E5: 1 + F5: 3 => SOL
* STA E5: 1 + F5: 3
* CNT   7 HDP CHAINS /   6 HYP OPENED