Analysis of xx-top500-049-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 7......1....4....3.........14.....6.....9.2...8..3....6..1.5........28........3.. initial

Autosolve

position: 7....3.1....4....33........143..79685..891234.8.63417563.1.5......3.28........3.. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # H3: 2,9 => SOL
* DIS # I3: 2,9 => CTR => I3: 7
* DIS # B1: 2,9 => CTR => B1: 5,6
* DIS # C1: 2,9 => CTR => C1: 4,5,6,8
* DIS # I7: 7 => CTR => I7: 2,9
* DIS # A2: 8 => CTR => A2: 2,9
* DIS # C1: 2,9 => CTR => C1: 4,5,6,8
* DIS # C2: 2,9 => CTR => C2: 1,5,6,8
* DIS # C3: 2,9 => CTR => C3: 1,4,5,6,8
* PRF # D3: 2,5 => SOL
* DIS # E2: 2,5 => CTR => E2: 1,6,7,8
* DIS # E3: 2,5 => CTR => E3: 1,6,7,8
* PRF # D3: 2,5 => SOL
* DIS # G3: 4,7 => CTR => G3: 5,6
* CNT  14 HDP CHAINS /  37 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 # H3: 2,9 => SOL
* STA H3: 2,9
* CNT   1 HDP CHAINS /   2 HYP OPENED

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

Details

Positions

7......1....4....3.........14.....6.....9.2...8..3....6..1.5........28........3.. initial
7....3.1....4....33........143..79685..891234.8.63417563.1.5......3.28........3.. autosolve
768953412921476583354218697143527968576891234289634175632185749497362851815749326 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (13)
I1: 2,9
B5: 6,7
C5: 6,7
A6: 2,9
C6: 2,9
D4: 2,5
E4: 2,5
A8: 4,9
E7: 4,8
D9: 7,9
G7: 4,7
I8: 1,6
I9: 1,6

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
E2,E3: 1.. / E2 = 1  =>  0 pairs (X) / E3 = 1  => 13 pairs (_)
I8,I9: 1.. / I8 = 1  => 12 pairs (_) / I9 = 1  => 12 pairs (_)
A6,C6: 2.. / A6 = 2  => 15 pairs (_) / C6 = 2  => 16 pairs (_)
D4,E4: 2.. / D4 = 2  => 12 pairs (_) / E4 = 2  => 13 pairs (_)
C1,C3: 4.. / C1 = 4  =>  0 pairs (X) / C3 = 4  => 19 pairs (_)
A8,A9: 4.. / A8 = 4  => 15 pairs (_) / A9 = 4  =>  0 pairs (X)
C1,G1: 4.. / C1 = 4  =>  0 pairs (X) / G1 = 4  => 19 pairs (_)
D4,E4: 5.. / D4 = 5  => 13 pairs (_) / E4 = 5  => 12 pairs (_)
H8,H9: 5.. / H8 = 5  => 15 pairs (_) / H9 = 5  => 17 pairs (_)
B5,C5: 6.. / B5 = 6  =>  0 pairs (X) / C5 = 6  => 11 pairs (_)
I8,I9: 6.. / I8 = 6  => 12 pairs (_) / I9 = 6  => 12 pairs (_)
E8,I8: 6.. / E8 = 6  => 12 pairs (_) / I8 = 6  => 12 pairs (_)
B5,C5: 7.. / B5 = 7  => 11 pairs (_) / C5 = 7  =>  0 pairs (X)
G7,I7: 7.. / G7 = 7  => 19 pairs (_) / I7 = 7  =>  0 pairs (X)
E2,G2: 7.. / E2 = 7  => 19 pairs (_) / G2 = 7  =>  0 pairs (X)
D3,D9: 7.. / D3 = 7  =>  0 pairs (X) / D9 = 7  => 19 pairs (_)
I3,I7: 7.. / I3 = 7  => 19 pairs (_) / I7 = 7  =>  0 pairs (X)
H2,H3: 8.. / H2 = 8  =>  0 pairs (*) / H3 = 8  =>  0 pairs (X)
C1,E1: 8.. / C1 = 8  => 19 pairs (_) / E1 = 8  =>  0 pairs (X)
C7,E7: 8.. / C7 = 8  =>  0 pairs (X) / E7 = 8  => 19 pairs (_)
A2,A9: 8.. / A2 = 8  =>  0 pairs (X) / A9 = 8  => 19 pairs (_)
A6,C6: 9.. / A6 = 9  => 16 pairs (_) / C6 = 9  => 15 pairs (_)
D9,F9: 9.. / D9 = 9  =>  0 pairs (X) / F9 = 9  => 19 pairs (_)
* DURATION: 0:00:39.265067  START: 04:20:28.614745  END: 04:21:07.879812 2017-05-04
* CP COUNT: (23)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A6,A8,B5,C5,C6,D4,D9,E4,E7,G7,I1,I8,I9)
* 7....3.1....4....33........143..79685..891234.8.63417563.1.5......3.28........3..
* PAIR I1: 2,9 BLK 3
H2: 2,9,8                                # reduction candidate for 2,9
H2: 2,9                                  # 18 pairs
H3: 2,9,4,8                              # reduction candidate for 2,9
H3: 2,9 => SOLVED
* 768953412921476583354218697143527968576891234289634175632185749497362851815749326
H3: 4,8                                  # 14 pairs
I3: 2,9,7                                # reduction candidate for 2,9
I3: 2,9 => CTR
* 7.4.83.1....4....33........143..79685..891234.8.63417563.1.54.7...3.28........3..
I3: 7                                    # 19 pairs
* PAIR I1: 2,9 ROW 1
B1: 2,9,5,6                              # reduction candidate for 2,9
B1: 2,9 => CTR
* 7.4583.1....4..7.33..7..5..1432579685..891234.8.63417563.1.54.7...3.28.....9..3..
B1: 5,6                                  # 14 pairs
C1: 2,9,4,5,6,8                          # reduction candidate for 2,9
C1: 2,9 => CTR
* 76.58341.8..47...33.4.1..871432.79685..891234.8.6341756381457.....3.28.......83..
C1: 4,5,6,8                              # 13 pairs
D1: 2,9,5                                # reduction candidate for 2,9
D1: 2,9                                  # 15 pairs
* PAIR I1: 2,9 COL I
I7: 2,9,7                                # reduction candidate for 2,9
I7: 7 => CTR
* 7.4.83.1....4....33........143..79685..891234.8.63417563.1.54.7...3.28........3..
I7: 2,9                                  # 19 pairs
* PAIR A6: 2,9 COL A
A2: 2,9,8                                # reduction candidate for 2,9
A2: 8 => CTR
* 7...83.1.8..47...33...1..87143..79685..891234.8.6341756381457.....3.28.....9.83..
A2: 2,9                                  # 19 pairs
* PAIR C6: 2,9 COL C
C1: 2,9,4,5,6,8                          # reduction candidate for 2,9
C1: 2,9 => CTR
* 76.58341.8..47...33.4.1..871432.79685..891234.8.6341756381457.....3.28.......83..
C1: 4,5,6,8                              # 13 pairs
C2: 2,9,1,5,6,8                          # reduction candidate for 2,9
C2: 2,9 => CTR
* 7...83.1.8..4765.33...19.87143..79685..891234.8.6341756381457.....3.28........3..
C2: 1,5,6,8                              # 13 pairs
C3: 2,9,1,4,5,6,8                        # reduction candidate for 2,9
C3: 2,9 => CTR
* 7.4.83.1.8..47...33...1.487143..79685..891234.8.6341756381457.....3.28.......83..
C3: 1,4,5,6,8                            # 13 pairs
C7: 2,9,8                                # reduction candidate for 2,9
C7: 2,9                                  # 19 pairs
* PAIR D4: 2,5 COL D
D1: 2,5,9                                # reduction candidate for 2,5
D1: 2,5                                  # 15 pairs
D3: 2,5,7,9                              # reduction candidate for 2,5
D3: 2,5 => SOLVED
* 768953412921476583354218697143527968576891234289634175632185749497362851815749326
D3: 7,9                                  # 15 pairs
* PAIR E4: 2,5 COL E
E1: 2,5,6,8                              # reduction candidate for 2,5
E1: 2,5                                  # 19 pairs
E2: 2,5,1,6,7,8                          # reduction candidate for 2,5
E2: 2,5 => CTR
* 7.4.83.1....4..7.33...1....143..79685..891234.8.63417563.1.54.7...3.28........3..
E2: 1,6,7,8                              # 13 pairs
E3: 2,5,1,6,7,8                          # reduction candidate for 2,5
E3: 2,5 => CTR
* 7.4.83.1....41.7.33..7.....143..79685..891234.8.63417563.1.54.7...3.28.....9..3..
E3: 1,6,7,8                              # 13 pairs
* PAIR A8: 4,9 ROW 8
H8: 4,9,5                                # reduction candidate for 4,9
H8: 4,9                                  # 17 pairs
H8: 5                                    # 15 pairs
* PAIR E7: 4,8 BLK 8
E9: 4,8,6,7                              # reduction candidate for 4,8
E9: 4,8                                  # 19 pairs
E9: 6,7                                  # 14 pairs
* PAIR D9: 7,9 COL D
D3: 7,9,2,5                              # reduction candidate for 7,9
D3: 2,5 => SOLVED
* 768953412921476583354218697143527968576891234289634175632185749497362851815749326
D3: 7,9                                  # 15 pairs
* PAIR G7: 4,7 COL G
G3: 4,7,5,6                              # reduction candidate for 4,7
G3: 4,7 => CTR
* 7.4.83.1....47...33...1....143..79685..891234.8.63417563.1.5......3.28........3..
G3: 5,6                                  # 14 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-049-base-pr-000.dot
* REASONING
* PRF # H3: 2,9 => SOL
* DIS # I3: 2,9 => CTR => I3: 7
* DIS # B1: 2,9 => CTR => B1: 5,6
* DIS # C1: 2,9 => CTR => C1: 4,5,6,8
* DIS # I7: 7 => CTR => I7: 2,9
* DIS # A2: 8 => CTR => A2: 2,9
* DIS # C1: 2,9 => CTR => C1: 4,5,6,8
* DIS # C2: 2,9 => CTR => C2: 1,5,6,8
* DIS # C3: 2,9 => CTR => C3: 1,4,5,6,8
* PRF # D3: 2,5 => SOL
* DIS # E2: 2,5 => CTR => E2: 1,6,7,8
* DIS # E3: 2,5 => CTR => E3: 1,6,7,8
* PRF # D3: 2,5 => SOL
* DIS # G3: 4,7 => CTR => G3: 5,6
* CNT  14 HDP CHAINS /  37 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A6,A8,B5,C5,C6,D4,D9,E4,E7,G7,I1,I8,I9)
* 7....3.1....4....33........143..79685..891234.8.63417563.1.5......3.28........3..
* PAIR I1: 2,9 BLK 3
H2: 2,9,8                                # reduction candidate for 2,9
H2: 2,9                                  # 18 pairs
H3: 2,9,4,8                              # reduction candidate for 2,9
H3: 2,9 => SOLVED
* 768953412921476583354218697143527968576891234289634175632185749497362851815749326
* DURATION: 0:00:03.821465  START: 04:21:44.703389  END: 04:21:48.524854 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-049-base-pr-001.dot
* REASONING
* PRF # H3: 2,9 => SOL
* STA H3: 2,9
* CNT   1 HDP CHAINS /   2 HYP OPENED

Header Info

Top 500 Minimum 17 049

solution: 768953412921476583354218697143527968576891234289634175632185749497362851815749326
info: 1384     FNBTHWXY S8.f     42645

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

Solution

position: 768953412921476583354218697143527968576891234289634175632185749497362851815749326 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 # H2: 2,9 => UNS
* PRF # H3: 2,9 => SOL
* INC # H3: 4,8 => UNS
* DIS # I3: 2,9 => CTR => I3: 7
* INC # I3: 7 => UNS
* DIS # B1: 2,9 => CTR => B1: 5,6
* INC # B1: 5,6 => UNS
* DIS # C1: 2,9 => CTR => C1: 4,5,6,8
* INC # C1: 4,5,6,8 => UNS
* INC # D1: 2,9 => UNS
* INC # I7: 2,9 => UNS
* DIS # I7: 7 => CTR => I7: 2,9
* INC # A2: 2,9 => UNS
* DIS # A2: 8 => CTR => A2: 2,9
* DIS # C1: 2,9 => CTR => C1: 4,5,6,8
* INC # C1: 4,5,6,8 => UNS
* DIS # C2: 2,9 => CTR => C2: 1,5,6,8
* INC # C2: 1,5,6,8 => UNS
* DIS # C3: 2,9 => CTR => C3: 1,4,5,6,8
* INC # C3: 1,4,5,6,8 => UNS
* INC # C7: 2,9 => UNS
* INC # D1: 2,5 => UNS
* PRF # D3: 2,5 => SOL
* INC # D3: 7,9 => UNS
* INC # E1: 2,5 => UNS
* DIS # E2: 2,5 => CTR => E2: 1,6,7,8
* INC # E2: 1,6,7,8 => UNS
* DIS # E3: 2,5 => CTR => E3: 1,6,7,8
* INC # E3: 1,6,7,8 => UNS
* INC # H8: 4,9 => UNS
* INC # H8: 5 => UNS
* INC # E9: 4,8 => UNS
* INC # E9: 6,7 => UNS
* INC # D3: 7,9 => UNS
* PRF # D3: 2,5 => SOL
* DIS # G3: 4,7 => CTR => G3: 5,6
* INC # G3: 5,6 => UNS
* CNT  37 HDP CHAINS /  37 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # H2: 2,9 => UNS
* PRF # H3: 2,9 => SOL
* STA H3: 2,9
* CNT   2 HDP CHAINS /   2 HYP OPENED