Analysis of xx-top500-027-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 8.....3.5....67......4......7..1..6.5.....8............6.3.5.....2....1....8..... initial

Autosolve

position: 846192375.3.56748.7.5483..6.73.185645...3.8..68..5..3.168375.4.352.4.718497821653 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # C5: 1,9 => SOL
* DIS # G3: 1,2 => CTR => G3: 9
* PRF # G3: 9 => SOL
* DIS # G3: 1,2 => CTR => G3: 9
* PRF # G3: 9 => SOL
* DIS # I5: 1,2 => CTR => I5: 7,9
* PRF # I6: 1,2 => SOL
* PRF # G3: 2,9 => SOL
* DIS # G3: 1 => CTR => G3: 2,9
* DIS # I5: 1,2 => CTR => I5: 7,9
* DIS # D5: 2,9 => CTR => D5: 6,7
* PRF # F5: 4,9 => SOL
* DIS # C6: 1 => CTR => C6: 4,9
* DIS # I5: 2,9 => CTR => I5: 1,7
* DIS # G6: 2,9 => CTR => G6: 1
* PRF # G6: 1 => SOL
* PRF # I6: 2,9 => SOL
* DIS # D5: 2,9 => CTR => D5: 6,7
* PRF # D5: 6,9 => SOL
* PRF # F5: 4 => SOL
* PRF # G3: 2,9 => SOL
* DIS # G3: 1 => CTR => G3: 2,9
* DIS # G6: 2,9 => CTR => G6: 1
* PRF # G6: 1 => SOL
* DIS # I5: 2,9 => CTR => I5: 1,7
* PRF # I6: 2,9 => SOL
* CNT  26 HDP CHAINS /  42 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 # C5: 1,9 => SOL
* STA C5: 1,9
* CNT   1 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

8.....3.5....67......4......7..1..6.5.....8............6.3.5.....2....1....8..... initial
846192375.3.56748.7.5483..6.73.185645...3.8..68..5..3.168375.4.352.4.718497821653 autosolve
846192375239567481715483926973218564521634897684759132168375249352946718497821653 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (14)
A2: 2,9
C2: 1,9
B3: 1,2
I2: 1,2
H3: 2,9
A4: 2,9
B5: 1,2
D4: 2,9
F6: 4,9
H5: 2,9
D8: 6,9
F8: 6,9
G7: 2,9
I7: 2,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
C2,B3: 1.. / C2 = 1  =>  0 pairs (X) / B3 = 1  =>  0 pairs (_)
I2,G3: 1.. / I2 = 1  =>  0 pairs (*) / G3 = 1  =>  0 pairs (X)
C2,I2: 1.. / C2 = 1  =>  0 pairs (X) / I2 = 1  =>  0 pairs (_)
B3,G3: 1.. / B3 = 1  =>  0 pairs (*) / G3 = 1  =>  0 pairs (X)
B3,B5: 1.. / B3 = 1  =>  0 pairs (*) / B5 = 1  =>  0 pairs (X)
G3,G6: 1.. / G3 = 1  =>  0 pairs (X) / G6 = 1  =>  0 pairs (_)
A2,B3: 2.. / A2 = 2  =>  0 pairs (*) / B3 = 2  =>  0 pairs (X)
A4,B5: 2.. / A4 = 2  =>  0 pairs (X) / B5 = 2  =>  0 pairs (_)
G7,I7: 2.. / G7 = 2  => 16 pairs (_) / I7 = 2  =>  0 pairs (X)
A2,I2: 2.. / A2 = 2  =>  0 pairs (*) / I2 = 2  =>  0 pairs (X)
A4,D4: 2.. / A4 = 2  =>  0 pairs (X) / D4 = 2  =>  0 pairs (_)
A2,A4: 2.. / A2 = 2  =>  0 pairs (*) / A4 = 2  =>  0 pairs (X)
B3,B5: 2.. / B3 = 2  =>  0 pairs (X) / B5 = 2  =>  0 pairs (_)
H3,H5: 2.. / H3 = 2  =>  0 pairs (*) / H5 = 2  =>  0 pairs (X)
C5,C6: 4.. / C5 = 4  => 15 pairs (_) / C6 = 4  =>  0 pairs (*)
F5,F6: 4.. / F5 = 4  =>  0 pairs (*) / F6 = 4  =>  0 pairs (X)
C5,F5: 4.. / C5 = 4  => 15 pairs (_) / F5 = 4  =>  0 pairs (*)
C6,F6: 4.. / C6 = 4  =>  0 pairs (*) / F6 = 4  =>  0 pairs (X)
D5,F5: 6.. / D5 = 6  =>  0 pairs (*) / F5 = 6  =>  0 pairs (X)
D8,F8: 6.. / D8 = 6  => 12 pairs (_) / F8 = 6  =>  0 pairs (*)
D5,D8: 6.. / D5 = 6  =>  0 pairs (*) / D8 = 6  =>  0 pairs (X)
F5,F8: 6.. / F5 = 6  => 12 pairs (_) / F8 = 6  =>  0 pairs (*)
D5,D6: 7.. / D5 = 7  => 14 pairs (_) / D6 = 7  =>  0 pairs (*)
I5,I6: 7.. / I5 = 7  =>  0 pairs (*) / I6 = 7  =>  0 pairs (X)
D5,I5: 7.. / D5 = 7  => 14 pairs (_) / I5 = 7  =>  0 pairs (*)
D6,I6: 7.. / D6 = 7  =>  0 pairs (*) / I6 = 7  =>  0 pairs (X)
A2,C2: 9.. / A2 = 9  =>  0 pairs (X) / C2 = 9  =>  0 pairs (_)
G3,H3: 9.. / G3 = 9  =>  0 pairs (*) / H3 = 9  =>  0 pairs (X)
D8,F8: 9.. / D8 = 9  =>  0 pairs (*) / F8 = 9  =>  0 pairs (X)
G7,I7: 9.. / G7 = 9  =>  0 pairs (X) / I7 = 9  => 16 pairs (_)
A4,D4: 9.. / A4 = 9  =>  0 pairs (*) / D4 = 9  =>  0 pairs (X)
A2,A4: 9.. / A2 = 9  =>  0 pairs (X) / A4 = 9  =>  0 pairs (_)
H3,H5: 9.. / H3 = 9  =>  0 pairs (X) / H5 = 9  =>  0 pairs (_)
* DURATION: 0:01:05.472914  START: 03:31:55.763773  END: 03:33:01.236687 2017-05-04
* CP COUNT: (33)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A2,A4,B3,B5,C2,D4,D8,F6,F8,G7,H3,H5,I2,I7)
* 846192375.3.56748.7.5483..6.73.185645...3.8..68..5..3.168375.4.352.4.718497821653
* PAIR C2: 1,9 COL C
C5: 1,9,4                                # reduction candidate for 1,9
C5: 1,9 => SOLVED
* 846192375239567481715483926973218564521634897684759132168375249352946718497821653
C5: 4                                    # 15 pairs
C6: 1,9,4                                # reduction candidate for 1,9
C6: 1,9                                  # 15 pairs
* PAIR B3: 1,2 ROW 3
G3: 1,2,9                                # reduction candidate for 1,2
G3: 1,2 => CTR
* 846192375.3.56748.72548319627391856451.73682968.25..37168375.4.352.4.718497821653
G3: 9 => SOLVED
* 846192375239567481715483926973218564521634897684759132168375249352946718497821653
* PAIR I2: 1,2 BLK 3
G3: 1,2,9                                # reduction candidate for 1,2
G3: 1,2 => CTR
* 846192375.3.56748.72548319627391856451.73682968.25..37168375.4.352.4.718497821653
G3: 9 => SOLVED
* 846192375239567481715483926973218564521634897684759132168375249352946718497821653
* PAIR I2: 1,2 COL I
I5: 1,2,7,9                              # reduction candidate for 1,2
I5: 1,2 => CTR
* 846192375.3.56748.7.5483926.73.1856452473689168..54.37168375249352649718497821653
I5: 7,9                                  # 20 pairs
I6: 1,2,7,9                              # reduction candidate for 1,2
I6: 1,2 => SOLVED
* 846192375239567481715483926973218564521634897684759132168375249352946718497821653
I6: 7,9                                  # 15 pairs
* PAIR H3: 2,9 BLK 3
G3: 2,9,1                                # reduction candidate for 2,9
G3: 2,9 => SOLVED
* 846192375239567481715483926973218564521634897684759132168375249352946718497821653
G3: 1 => CTR
* 846192375.3.56748.7.5483196.73.1856451..3.82.68.25.93.168375.4.352.4.718497821653
* PAIR B5: 1,2 ROW 5
I5: 1,2,7,9                              # reduction candidate for 1,2
I5: 1,2 => CTR
* 846192375.3.56748.7.5483926.73.1856452473689168..54.37168375249352649718497821653
I5: 7,9                                  # 20 pairs
* PAIR D4: 2,9 BLK 5
D5: 2,9,6,7                              # reduction candidate for 2,9
D5: 2,9 => CTR
* 846192375.3.56748.7.5483..6.73.18564514.368.7689754.3.168375.49352649718497821653
D5: 6,7                                  # 15 pairs
D6: 2,9,7                                # reduction candidate for 2,9
D6: 2,9                                  # 14 pairs
* PAIR F6: 4,9 BLK 5
F5: 4,9,6                                # reduction candidate for 4,9
F5: 4,9 => SOLVED
* 846192375239567481715483926973218564521634897684759132168375249352946718497821653
F5: 6                                    # 12 pairs
* PAIR F6: 4,9 ROW 6
C6: 4,9,1                                # reduction candidate for 4,9
C6: 1 => CTR
* 846192375.39567481715483..6973218564524.3.897681.54.3.168375.4.352.4.718497821653
C6: 4,9                                  # 19 pairs
* PAIR H5: 2,9 BLK 6
I5: 2,9,1,7                              # reduction candidate for 2,9
I5: 2,9 => CTR
* 846192375.3.567481715483..6.73.1856452.7368..68..54.37168375.4.352649718497821653
I5: 1,7                                  # 15 pairs
G6: 2,9,1                                # reduction candidate for 2,9
G6: 2,9 => CTR
* 846192375.3.56748.7.5483196.73.1856451..3.82.68.25.93.168375.4.352.4.718497821653
G6: 1 => SOLVED
* 846192375239567481715483926973218564521634897684759132168375249352946718497821653
I6: 2,9,1,7                              # reduction candidate for 2,9
I6: 2,9 => SOLVED
* 846192375239567481715483926973218564521634897684759132168375249352946718497821653
I6: 1,7                                  # 15 pairs
* PAIR H5: 2,9 ROW 5
D5: 2,9,6,7                              # reduction candidate for 2,9
D5: 2,9 => CTR
* 846192375.3.56748.7.5483..6.73.18564514.368.7689754.3.168375.49352649718497821653
D5: 6,7                                  # 15 pairs
* PAIR D8: 6,9 COL D
D5: 6,9,2,7                              # reduction candidate for 6,9
D5: 6,9 => SOLVED
* 846192375239567481715483926973218564521634897684759132168375249352946718497821653
D5: 2,7                                  # 14 pairs
* PAIR F8: 6,9 COL F
F5: 6,9,4                                # reduction candidate for 6,9
F5: 4 => SOLVED
* 846192375239567481715483926973218564521634897684759132168375249352946718497821653
F5: 6,9                                  # 15 pairs
* PAIR G7: 2,9 COL G
G3: 2,9,1                                # reduction candidate for 2,9
G3: 2,9 => SOLVED
* 846192375239567481715483926973218564521634897684759132168375249352946718497821653
G3: 1 => CTR
* 846192375.3.56748.7.5483196.73.1856451..3.82.68.25.93.168375.4.352.4.718497821653
G6: 2,9,1                                # reduction candidate for 2,9
G6: 2,9 => CTR
* 846192375.3.56748.7.5483196.73.1856451..3.82.68.25.93.168375.4.352.4.718497821653
G6: 1 => SOLVED
* 846192375239567481715483926973218564521634897684759132168375249352946718497821653
* PAIR I7: 2,9 COL I
I5: 2,9,1,7                              # reduction candidate for 2,9
I5: 2,9 => CTR
* 846192375.3.567481715483..6.73.1856452.7368..68..54.37168375.4.352649718497821653
I5: 1,7                                  # 15 pairs
I6: 2,9,1,7                              # reduction candidate for 2,9
I6: 2,9 => SOLVED
* 846192375239567481715483926973218564521634897684759132168375249352946718497821653
I6: 1,7                                  # 15 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-027-base-pr-000.dot
* REASONING
* PRF # C5: 1,9 => SOL
* DIS # G3: 1,2 => CTR => G3: 9
* PRF # G3: 9 => SOL
* DIS # G3: 1,2 => CTR => G3: 9
* PRF # G3: 9 => SOL
* DIS # I5: 1,2 => CTR => I5: 7,9
* PRF # I6: 1,2 => SOL
* PRF # G3: 2,9 => SOL
* DIS # G3: 1 => CTR => G3: 2,9
* DIS # I5: 1,2 => CTR => I5: 7,9
* DIS # D5: 2,9 => CTR => D5: 6,7
* PRF # F5: 4,9 => SOL
* DIS # C6: 1 => CTR => C6: 4,9
* DIS # I5: 2,9 => CTR => I5: 1,7
* DIS # G6: 2,9 => CTR => G6: 1
* PRF # G6: 1 => SOL
* PRF # I6: 2,9 => SOL
* DIS # D5: 2,9 => CTR => D5: 6,7
* PRF # D5: 6,9 => SOL
* PRF # F5: 4 => SOL
* PRF # G3: 2,9 => SOL
* DIS # G3: 1 => CTR => G3: 2,9
* DIS # G6: 2,9 => CTR => G6: 1
* PRF # G6: 1 => SOL
* DIS # I5: 2,9 => CTR => I5: 1,7
* PRF # I6: 2,9 => SOL
* CNT  26 HDP CHAINS /  42 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A2,A4,B3,B5,C2,D4,D8,F6,F8,G7,H3,H5,I2,I7)
* 846192375.3.56748.7.5483..6.73.185645...3.8..68..5..3.168375.4.352.4.718497821653
* PAIR C2: 1,9 COL C
C5: 1,9,4                                # reduction candidate for 1,9
C5: 1,9 => SOLVED
* 846192375239567481715483926973218564521634897684759132168375249352946718497821653
* DURATION: 0:00:02.186436  START: 03:33:54.399244  END: 03:33:56.585680 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-027-base-pr-001.dot
* REASONING
* PRF # C5: 1,9 => SOL
* STA C5: 1,9
* CNT   1 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 027

solution: 846192375239567481715483926973218564521634897684759132168375249352946718497821653
info: 1323     FNBTWXY  S8.f     38008

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

Solution

position: 846192375239567481715483926973218564521634897684759132168375249352946718497821653 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:

* PRF # C5: 1,9 => SOL
* INC # C5: 4 => UNS
* INC # C6: 1,9 => UNS
* DIS # G3: 1,2 => CTR => G3: 9
* PRF # G3: 9 => SOL
* DIS # G3: 1,2 => CTR => G3: 9
* PRF # G3: 9 => SOL
* DIS # I5: 1,2 => CTR => I5: 7,9
* INC # I5: 7,9 => UNS
* PRF # I6: 1,2 => SOL
* INC # I6: 7,9 => UNS
* PRF # G3: 2,9 => SOL
* DIS # G3: 1 => CTR => G3: 2,9
* DIS # I5: 1,2 => CTR => I5: 7,9
* INC # I5: 7,9 => UNS
* DIS # D5: 2,9 => CTR => D5: 6,7
* INC # D5: 6,7 => UNS
* INC # D6: 2,9 => UNS
* PRF # F5: 4,9 => SOL
* INC # F5: 6 => UNS
* INC # C6: 4,9 => UNS
* DIS # C6: 1 => CTR => C6: 4,9
* DIS # I5: 2,9 => CTR => I5: 1,7
* INC # I5: 1,7 => UNS
* DIS # G6: 2,9 => CTR => G6: 1
* PRF # G6: 1 => SOL
* PRF # I6: 2,9 => SOL
* INC # I6: 1,7 => UNS
* DIS # D5: 2,9 => CTR => D5: 6,7
* INC # D5: 6,7 => UNS
* PRF # D5: 6,9 => SOL
* INC # D5: 2,7 => UNS
* INC # F5: 6,9 => UNS
* PRF # F5: 4 => SOL
* PRF # G3: 2,9 => SOL
* DIS # G3: 1 => CTR => G3: 2,9
* DIS # G6: 2,9 => CTR => G6: 1
* PRF # G6: 1 => SOL
* DIS # I5: 2,9 => CTR => I5: 1,7
* INC # I5: 1,7 => UNS
* PRF # I6: 2,9 => SOL
* INC # I6: 1,7 => UNS
* CNT  42 HDP CHAINS /  42 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* PRF # C5: 1,9 => SOL
* STA C5: 1,9
* CNT   1 HDP CHAINS /   1 HYP OPENED