Analysis of xx-top500-002-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 6..35....2......8.........15..4..3.....2.1.7...........17..........9.5...8....... initial

Autosolve

position: 6.13587..25.71..837389...5157.48.31.8..2.1.751..57.8...178.52.....1975.8.856..1.7 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # B6: 4,9 => SOL
* PRF # G2: 6 => SOL
* PRF # C5: 4,9 => SOL
* PRF # G2: 4,6 => SOL
* DIS # G2: 9 => CTR => G2: 4,6
* PRF # G2: 4,6 => SOL
* DIS # G2: 9 => CTR => G2: 4,6
* PRF # F6: 6,9 => SOL
* DIS # F6: 9 => CTR => F6: 3,6
* PRF # C5: 4,9 => SOL
* PRF # C5: 4,9 => SOL
* PRF # G2: 6 => SOL
* PRF # B6: 4,9 => SOL
* DIS # C6: 2,6 => CTR => C6: 3,4,9
* CNT  14 HDP CHAINS /  46 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 # B6: 4,9 => SOL
* STA B6: 4,9
* CNT   1 HDP CHAINS /   4 HYP OPENED

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

Details

Positions

6..35....2......8.........15..4..3.....2.1.7...........17..........9.5...8....... initial
6.13587..25.71..837389...5157.48.31.8..2.1.751..57.8...178.52.....1975.8.856..1.7 autosolve
641358792259714683738962451572489316864231975193576824317845269426197538985623147 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (12)
B1: 4,9
C2: 4,9
F2: 4,6
G3: 4,6
F4: 6,9
E5: 3,6
G5: 4,9
A8: 3,4
B8: 2,6
C8: 2,6
E7: 3,4
H8: 3,4

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
E3,F3: 2.. / E3 = 2  => 17 pairs (_) / F3 = 2  => 14 pairs (_)
H1,I1: 2.. / H1 = 2  => 13 pairs (_) / I1 = 2  => 13 pairs (_)
B8,C8: 2.. / B8 = 2  => 11 pairs (_) / C8 = 2  => 15 pairs (_)
E9,F9: 2.. / E9 = 2  => 14 pairs (_) / F9 = 2  => 17 pairs (_)
C4,I4: 2.. / C4 = 2  => 11 pairs (_) / I4 = 2  => 15 pairs (_)
B6,B8: 2.. / B6 = 2  => 15 pairs (_) / B8 = 2  => 11 pairs (_)
E3,E9: 2.. / E3 = 2  => 17 pairs (_) / E9 = 2  => 14 pairs (_)
F3,F9: 2.. / F3 = 2  => 14 pairs (_) / F9 = 2  => 17 pairs (_)
H1,H6: 2.. / H1 = 2  => 13 pairs (_) / H6 = 2  => 13 pairs (_)
C5,C6: 3.. / C5 = 3  => 17 pairs (_) / C6 = 3  =>  0 pairs (*)
E5,F6: 3.. / E5 = 3  =>  0 pairs (*) / F6 = 3  =>  0 pairs (X)
C5,E5: 3.. / C5 = 3  => 17 pairs (_) / E5 = 3  =>  0 pairs (*)
C6,F6: 3.. / C6 = 3  =>  0 pairs (*) / F6 = 3  =>  0 pairs (X)
A8,H8: 3.. / A8 = 3  => 15 pairs (_) / H8 = 3  => 13 pairs (_)
F6,F9: 3.. / F6 = 3  => 17 pairs (_) / F9 = 3  =>  0 pairs (*)
B1,C2: 4.. / B1 = 4  =>  0 pairs (*) / C2 = 4  =>  0 pairs (X)
A8,H8: 4.. / A8 = 4  => 13 pairs (_) / H8 = 4  => 15 pairs (_)
G2,G3: 6.. / G2 = 6  =>  0 pairs (*) / G3 = 6  =>  0 pairs (X)
B8,C8: 6.. / B8 = 6  => 15 pairs (_) / C8 = 6  => 11 pairs (_)
H7,I7: 6.. / H7 = 6  => 13 pairs (_) / I7 = 6  => 15 pairs (_)
F2,G2: 6.. / F2 = 6  => 17 pairs (_) / G2 = 6  =>  0 pairs (*)
E3,E5: 6.. / E3 = 6  =>  0 pairs (*) / E5 = 6  =>  0 pairs (X)
H6,H7: 6.. / H6 = 6  => 15 pairs (_) / H7 = 6  => 13 pairs (_)
B1,C2: 9.. / B1 = 9  =>  0 pairs (X) / C2 = 9  =>  0 pairs (_)
F4,F6: 9.. / F4 = 9  => 14 pairs (_) / F6 = 9  =>  0 pairs (X)
A7,A9: 9.. / A7 = 9  => 15 pairs (_) / A9 = 9  => 17 pairs (_)
C2,G2: 9.. / C2 = 9  =>  0 pairs (*) / G2 = 9  =>  0 pairs (X)
A9,H9: 9.. / A9 = 9  => 17 pairs (_) / H9 = 9  => 15 pairs (_)
G2,G5: 9.. / G2 = 9  =>  0 pairs (X) / G5 = 9  =>  0 pairs (_)
* DURATION: 0:00:50.306953  START: 02:39:07.794148  END: 02:39:58.101101 2017-05-04
* CP COUNT: (29)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A8,B1,B8,C2,C8,E5,E7,F2,F4,G3,G5,H8)
* 6.13587..25.71..837389...5157.48.31.8..2.1.751..57.8...178.52.....1975.8.856..1.7
* PAIR B1: 4,9 ROW 1
H1: 4,9,2                                # reduction candidate for 4,9
H1: 4,9                                  # 13 pairs
I1: 4,9,2                                # reduction candidate for 4,9
I1: 4,9                                  # 13 pairs
* PAIR B1: 4,9 COL B
B5: 4,9,6                                # reduction candidate for 4,9
B5: 4,9                                  # 15 pairs
B6: 4,9,2,6                              # reduction candidate for 4,9
B6: 4,9 => SOLVED
* 641358792259714683738962451572489316864231975193576824317845269426197538985623147
B6: 2,6                                  # 15 pairs
* PAIR C2: 4,9 ROW 2
G2: 4,9,6                                # reduction candidate for 4,9
G2: 6 => SOLVED
* 641358792259714683738962451572489316864231975193576824317845269426197538985623147
G2: 4,9                                  # 17 pairs
* PAIR C2: 4,9 COL C
C5: 4,9,3,6                              # reduction candidate for 4,9
C5: 4,9 => SOLVED
* 641358792259714683738962451572489316864231975193576824317845269426197538985623147
C5: 3,6                                  # 15 pairs
C6: 4,9,2,3,6                            # reduction candidate for 4,9
C6: 4,9                                  # 17 pairs
* PAIR F2: 4,6 BLK 2
E3: 4,6,2                                # reduction candidate for 4,6
E3: 4,6                                  # 14 pairs
F3: 4,6,2                                # reduction candidate for 4,6
F3: 4,6                                  # 17 pairs
* PAIR F2: 4,6 ROW 2
G2: 4,6,9                                # reduction candidate for 4,6
G2: 4,6 => SOLVED
* 641358792259714683738962451572489316864231975193576824317845269426197538985623147
G2: 9 => CTR
* 6913587..25.7169837389..65157.48931.8..2614751..5738...178.52.....1975.8.856..1.7
* PAIR G3: 4,6 BLK 3
G2: 4,6,9                                # reduction candidate for 4,6
G2: 4,6 => SOLVED
* 641358792259714683738962451572489316864231975193576824317845269426197538985623147
G2: 9 => CTR
* 6913587..25.7169837389..65157.48931.8..2614751..5738...178.52.....1975.8.856..1.7
* PAIR G3: 4,6 ROW 3
E3: 4,6,2                                # reduction candidate for 4,6
E3: 4,6                                  # 14 pairs
F3: 4,6,2                                # reduction candidate for 4,6
F3: 4,6                                  # 17 pairs
* PAIR F4: 6,9 BLK 5
F6: 6,9,3                                # reduction candidate for 6,9
F6: 6,9 => SOLVED
* 641358792259714683738962451572489316864231975193576824317845269426197538985623147
F6: 3                                    # 17 pairs
* PAIR F4: 6,9 ROW 4
C4: 6,9,2                                # reduction candidate for 6,9
C4: 6,9                                  # 15 pairs
I4: 6,9,2                                # reduction candidate for 6,9
I4: 6,9                                  # 11 pairs
* PAIR E5: 3,6 BLK 5
F6: 3,6,9                                # reduction candidate for 3,6
F6: 9 => CTR
* 6.13587..25.71..8373896245157.48631.8..2319751.35798.4.178452.6...1975.8.856231.7
F6: 3,6                                  # 14 pairs
* PAIR E5: 3,6 ROW 5
C5: 3,6,4,9                              # reduction candidate for 3,6
C5: 4,9 => SOLVED
* 641358792259714683738962451572489316864231975193576824317845269426197538985623147
C5: 3,6                                  # 15 pairs
* PAIR G5: 4,9 BLK 6
H6: 4,9,2,6                              # reduction candidate for 4,9
H6: 4,9                                  # 17 pairs
I6: 4,9,2,6                              # reduction candidate for 4,9
I6: 4,9                                  # 15 pairs
* PAIR G5: 4,9 ROW 5
B5: 4,9,6                                # reduction candidate for 4,9
B5: 4,9                                  # 15 pairs
C5: 4,9,3,6                              # reduction candidate for 4,9
C5: 4,9 => SOLVED
* 641358792259714683738962451572489316864231975193576824317845269426197538985623147
C5: 3,6                                  # 15 pairs
* PAIR G5: 4,9 COL G
G2: 4,9,6                                # reduction candidate for 4,9
G2: 6 => SOLVED
* 641358792259714683738962451572489316864231975193576824317845269426197538985623147
G2: 4,9                                  # 17 pairs
* PAIR A8: 3,4 BLK 7
A7: 3,4,9                                # reduction candidate for 3,4
A7: 3,4                                  # 17 pairs
A9: 3,4,9                                # reduction candidate for 3,4
A9: 3,4                                  # 15 pairs
* PAIR B8: 2,6 COL B
B6: 2,6,4,9                              # reduction candidate for 2,6
B6: 4,9 => SOLVED
* 641358792259714683738962451572489316864231975193576824317845269426197538985623147
B6: 2,6                                  # 15 pairs
* PAIR C8: 2,6 COL C
C4: 2,6,9                                # reduction candidate for 2,6
C4: 2,6                                  # 13 pairs
C6: 2,6,3,4,9                            # reduction candidate for 2,6
C6: 2,6 => CTR
* 6.13587..2547169837389..65157948.31.8.3261.751..5738...178.52.....1975.8.856..1.7
C6: 3,4,9                                # 12 pairs
* PAIR E7: 3,4 BLK 8
E9: 3,4,2                                # reduction candidate for 3,4
E9: 3,4                                  # 17 pairs
F9: 3,4,2                                # reduction candidate for 3,4
F9: 3,4                                  # 14 pairs
* PAIR E7: 3,4 ROW 7
A7: 3,4,9                                # reduction candidate for 3,4
A7: 3,4                                  # 17 pairs
H7: 3,4,6,9                              # reduction candidate for 3,4
H7: 3,4                                  # 17 pairs
* PAIR H8: 3,4 BLK 9
H7: 3,4,6,9                              # reduction candidate for 3,4
H7: 3,4                                  # 17 pairs
H9: 3,4,9                                # reduction candidate for 3,4
H9: 3,4                                  # 17 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-002-base-pr-000.dot
* REASONING
* PRF # B6: 4,9 => SOL
* PRF # G2: 6 => SOL
* PRF # C5: 4,9 => SOL
* PRF # G2: 4,6 => SOL
* DIS # G2: 9 => CTR => G2: 4,6
* PRF # G2: 4,6 => SOL
* DIS # G2: 9 => CTR => G2: 4,6
* PRF # F6: 6,9 => SOL
* DIS # F6: 9 => CTR => F6: 3,6
* PRF # C5: 4,9 => SOL
* PRF # C5: 4,9 => SOL
* PRF # G2: 6 => SOL
* PRF # B6: 4,9 => SOL
* DIS # C6: 2,6 => CTR => C6: 3,4,9
* CNT  14 HDP CHAINS /  46 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A8,B1,B8,C2,C8,E5,E7,F2,F4,G3,G5,H8)
* 6.13587..25.71..837389...5157.48.31.8..2.1.751..57.8...178.52.....1975.8.856..1.7
* PAIR B1: 4,9 ROW 1
H1: 4,9,2                                # reduction candidate for 4,9
H1: 4,9                                  # 13 pairs
I1: 4,9,2                                # reduction candidate for 4,9
I1: 4,9                                  # 13 pairs
* PAIR B1: 4,9 COL B
B5: 4,9,6                                # reduction candidate for 4,9
B5: 4,9                                  # 15 pairs
B6: 4,9,2,6                              # reduction candidate for 4,9
B6: 4,9 => SOLVED
* 641358792259714683738962451572489316864231975193576824317845269426197538985623147
* DURATION: 0:00:04.851093  START: 02:40:45.152470  END: 02:40:50.003563 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-002-base-pr-001.dot
* REASONING
* PRF # B6: 4,9 => SOL
* STA B6: 4,9
* CNT   1 HDP CHAINS /   4 HYP OPENED

Header Info

Top 500 Minimum 17 002

solution: 641358792259714683738962451572489316864231975193576824317845269426197538985623147
info: 1305     FNBTWXY  S8.f     35060

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

Solution

position: 641358792259714683738962451572489316864231975193576824317845269426197538985623147 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 # H1: 4,9 => UNS
* INC # I1: 4,9 => UNS
* INC # B5: 4,9 => UNS
* PRF # B6: 4,9 => SOL
* INC # B6: 2,6 => UNS
* INC # G2: 4,9 => UNS
* PRF # G2: 6 => SOL
* PRF # C5: 4,9 => SOL
* INC # C5: 3,6 => UNS
* INC # C6: 4,9 => UNS
* INC # E3: 4,6 => UNS
* INC # F3: 4,6 => UNS
* PRF # G2: 4,6 => SOL
* DIS # G2: 9 => CTR => G2: 4,6
* PRF # G2: 4,6 => SOL
* DIS # G2: 9 => CTR => G2: 4,6
* INC # E3: 4,6 => UNS
* INC # F3: 4,6 => UNS
* PRF # F6: 6,9 => SOL
* INC # F6: 3 => UNS
* INC # C4: 6,9 => UNS
* INC # I4: 6,9 => UNS
* INC # F6: 3,6 => UNS
* DIS # F6: 9 => CTR => F6: 3,6
* INC # C5: 3,6 => UNS
* PRF # C5: 4,9 => SOL
* INC # H6: 4,9 => UNS
* INC # I6: 4,9 => UNS
* INC # B5: 4,9 => UNS
* PRF # C5: 4,9 => SOL
* INC # C5: 3,6 => UNS
* INC # G2: 4,9 => UNS
* PRF # G2: 6 => SOL
* INC # A7: 3,4 => UNS
* INC # A9: 3,4 => UNS
* INC # B6: 2,6 => UNS
* PRF # B6: 4,9 => SOL
* INC # C4: 2,6 => UNS
* DIS # C6: 2,6 => CTR => C6: 3,4,9
* INC # C6: 3,4,9 => UNS
* INC # E9: 3,4 => UNS
* INC # F9: 3,4 => UNS
* INC # A7: 3,4 => UNS
* INC # H7: 3,4 => UNS
* INC # H7: 3,4 => UNS
* INC # H9: 3,4 => UNS
* CNT  46 HDP CHAINS /  46 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # H1: 4,9 => UNS
* INC # I1: 4,9 => UNS
* INC # B5: 4,9 => UNS
* PRF # B6: 4,9 => SOL
* STA B6: 4,9
* CNT   4 HDP CHAINS /   4 HYP OPENED