Analysis of xx-top500-067-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 3......21.6.7........4......4.6..5......1...3.........8.1..........2.6........74. initial

Autosolve

position: 3.7.6.4212647.1....1.4.2.761426.35.77...142.3.3.27.1.4871.46..24..3276186231..74. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # C3: 5,9 => SOL
* DIS # E3: 5,9 => CTR => E3: 3,8
* PRF # B5: 5,9 => SOL
* DIS # C6: 5,9 => CTR => C6: 6,8
* DIS # F6: 8 => CTR => F6: 5,9
* PRF # D5: 8,9 => SOL
* DIS # D5: 5 => CTR => D5: 8,9
* DIS # F6: 8,9 => CTR => F6: 5
* PRF # F6: 5 => SOL
* DIS # E3: 8,9 => CTR => E3: 3,5
* DIS # E9: 8,9 => CTR => E9: 5
* PRF # B5: 5,9 => SOL
* PRF # C3: 5,9 => SOL
* DIS # C6: 5,9 => CTR => C6: 6,8
* DIS # F9: 5,9 => CTR => F9: 8
* PRF # D1: 5,9 => SOL
* PRF # G2: 3,9 => SOL
* DIS # F9: 5,9 => CTR => F9: 8
* CNT  18 HDP CHAINS /  43 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 # C3: 5,9 => SOL
* STA C3: 5,9
* CNT   1 HDP CHAINS /   2 HYP OPENED

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

Details

Positions

3......21.6.7........4......4.6..5......1...3.........8.1..........2.6........74. initial
3.7.6.4212647.1....1.4.2.761426.35.77...142.3.3.27.1.4871.46..24..3276186231..74. autosolve
387569421264781935519432876142693587756814293938275164871946352495327618623158749 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (12)
A3: 5,9
H2: 3,5
I2: 5,9
A6: 5,9
E4: 8,9
H4: 8,9
B8: 5,9
C8: 5,9
D7: 5,9
G7: 3,9
H7: 3,5
I9: 5,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
E2,E3: 3.. / E2 = 3  =>  0 pairs (X) / E3 = 3  => 16 pairs (_)
G7,H7: 3.. / G7 = 3  => 16 pairs (_) / H7 = 3  =>  0 pairs (X)
E3,G3: 3.. / E3 = 3  => 16 pairs (_) / G3 = 3  =>  0 pairs (X)
H2,H7: 3.. / H2 = 3  => 16 pairs (_) / H7 = 3  =>  0 pairs (X)
H2,I2: 5.. / H2 = 5  =>  0 pairs (X) / I2 = 5  => 16 pairs (_)
D5,F6: 5.. / D5 = 5  =>  0 pairs (X) / F6 = 5  =>  0 pairs (_)
B8,C8: 5.. / B8 = 5  => 16 pairs (_) / C8 = 5  => 15 pairs (_)
H7,I9: 5.. / H7 = 5  => 16 pairs (_) / I9 = 5  =>  0 pairs (X)
D7,H7: 5.. / D7 = 5  =>  0 pairs (X) / H7 = 5  => 16 pairs (_)
A3,A6: 5.. / A3 = 5  =>  0 pairs (*) / A6 = 5  =>  0 pairs (X)
E3,E9: 5.. / E3 = 5  =>  0 pairs (X) / E9 = 5  => 16 pairs (_)
H2,H7: 5.. / H2 = 5  =>  0 pairs (X) / H7 = 5  => 16 pairs (_)
I2,I9: 5.. / I2 = 5  => 16 pairs (_) / I9 = 5  =>  0 pairs (X)
C5,C6: 6.. / C5 = 6  => 13 pairs (_) / C6 = 6  => 19 pairs (_)
H5,H6: 6.. / H5 = 6  => 19 pairs (_) / H6 = 6  => 13 pairs (_)
C5,H5: 6.. / C5 = 6  => 13 pairs (_) / H5 = 6  => 19 pairs (_)
C6,H6: 6.. / C6 = 6  => 19 pairs (_) / H6 = 6  => 13 pairs (_)
B1,C3: 8.. / B1 = 8  =>  0 pairs (*) / C3 = 8  =>  0 pairs (X)
G2,G3: 8.. / G2 = 8  => 14 pairs (_) / G3 = 8  =>  0 pairs (*)
E9,F9: 8.. / E9 = 8  =>  0 pairs (X) / F9 = 8  => 17 pairs (_)
E2,G2: 8.. / E2 = 8  =>  0 pairs (*) / G2 = 8  =>  0 pairs (X)
E4,H4: 8.. / E4 = 8  => 18 pairs (_) / H4 = 8  => 18 pairs (_)
B1,B5: 8.. / B1 = 8  =>  0 pairs (*) / B5 = 8  =>  0 pairs (X)
D1,D5: 8.. / D1 = 8  => 18 pairs (_) / D5 = 8  =>  0 pairs (*)
B8,C8: 9.. / B8 = 9  => 15 pairs (_) / C8 = 9  => 16 pairs (_)
G7,I9: 9.. / G7 = 9  =>  0 pairs (X) / I9 = 9  => 16 pairs (_)
E4,H4: 9.. / E4 = 9  => 18 pairs (_) / H4 = 9  => 18 pairs (_)
D7,G7: 9.. / D7 = 9  => 16 pairs (_) / G7 = 9  =>  0 pairs (X)
A3,A6: 9.. / A3 = 9  =>  0 pairs (X) / A6 = 9  =>  0 pairs (_)
I2,I9: 9.. / I2 = 9  =>  0 pairs (X) / I9 = 9  => 16 pairs (_)
* DURATION: 0:01:15.544092  START: 04:56:47.455392  END: 04:58:02.999484 2017-05-04
* CP COUNT: (30)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A3,A6,B8,C8,D7,E4,G7,H2,H4,H7,I2,I9)
* 3.7.6.4212647.1....1.4.2.761426.35.77...142.3.3.27.1.4871.46..24..3276186231..74.
* PAIR A3: 5,9 BLK 1
B1: 5,9,8                                # reduction candidate for 5,9
B1: 5,9                                  # 18 pairs
C3: 5,9,8                                # reduction candidate for 5,9
C3: 5,9 => SOLVED
* 387569421264781935519432876142693587756814293938275164871946352495327618623158749
C3: 8                                    # 18 pairs
* PAIR A3: 5,9 ROW 3
E3: 5,9,3,8                              # reduction candidate for 5,9
E3: 5,9 => CTR
* 3.786.421264731859.184523761426.35.778591426393.27.1.48715469324..3276186231..745
E3: 3,8                                  # 16 pairs
* PAIR A6: 5,9 BLK 4
B5: 5,9,8                                # reduction candidate for 5,9
B5: 5,9 => SOLVED
* 387569421264781935519432876142693587756814293938275164871946352495327618623158749
B5: 8                                    # 18 pairs
C5: 5,9,6,8                              # reduction candidate for 5,9
C5: 5,9                                  # 19 pairs
C6: 5,9,6,8                              # reduction candidate for 5,9
C6: 5,9 => CTR
* 3.7.6.4212647.1....184.2.761426.35.7786514293.3.2781648719463524..327618623185749
C6: 6,8                                  # 13 pairs
* PAIR A6: 5,9 ROW 6
F6: 5,9,8                                # reduction candidate for 5,9
F6: 8 => CTR
* 3.7.6.4212647.1....1.4.2.761426.35.77..5142.3.3.2781.48719463524..327618623185749
F6: 5,9                                  # 15 pairs
* PAIR E4: 8,9 BLK 5
D5: 8,9,5                                # reduction candidate for 8,9
D5: 8,9 => SOLVED
* 387569421264781935519432876142693587756814293938275164871946352495327618623158749
D5: 5 => CTR
* 3.786.421264791835.1843297614268359778951426353.27.1.48719463524..3276186231..749
F6: 8,9,5                                # reduction candidate for 8,9
F6: 8,9 => CTR
* 3.786.4212647.1835.184329761426.35.778.5142.39352781.48719463524..3276186231..749
F6: 5 => SOLVED
* 387569421264781935519432876142693587756814293938275164871946352495327618623158749
* PAIR E4: 8,9 COL E
E2: 8,9,3                                # reduction candidate for 8,9
E2: 8,9                                  # 16 pairs
E3: 8,9,3,5                              # reduction candidate for 8,9
E3: 8,9 => CTR
* 3.7.6.421264731859.1.4.23761426.35.77...142.3.3.27.1.48715469324..3276186231..745
E3: 3,5                                  # 13 pairs
E9: 8,9,5                                # reduction candidate for 8,9
E9: 8,9 => CTR
* 3.7.6.4212647.1....1.4523761426.35.77...142.353.27.1.4871.469324.53276186231.574.
E9: 5                                    # 16 pairs
* PAIR H4: 8,9 BLK 6
H5: 8,9,6                                # reduction candidate for 8,9
H5: 8,9                                  # 13 pairs
H6: 8,9,6                                # reduction candidate for 8,9
H6: 8,9                                  # 19 pairs
* PAIR B8: 5,9 COL B
B1: 5,9,8                                # reduction candidate for 5,9
B1: 5,9                                  # 18 pairs
B5: 5,9,8                                # reduction candidate for 5,9
B5: 5,9 => SOLVED
* 387569421264781935519432876142693587756814293938275164871946352495327618623158749
B5: 8                                    # 18 pairs
* PAIR C8: 5,9 COL C
C3: 5,9,8                                # reduction candidate for 5,9
C3: 5,9 => SOLVED
* 387569421264781935519432876142693587756814293938275164871946352495327618623158749
C3: 8                                    # 18 pairs
C5: 5,9,6,8                              # reduction candidate for 5,9
C5: 5,9                                  # 19 pairs
C6: 5,9,6,8                              # reduction candidate for 5,9
C6: 5,9 => CTR
* 3.7.6.4212647.1....184.2.761426.35.7786514293.3.2781648719463524..327618623185749
C6: 6,8                                  # 13 pairs
* PAIR D7: 5,9 BLK 8
E9: 5,9,8                                # reduction candidate for 5,9
E9: 5,9                                  # 17 pairs
F9: 5,9,8                                # reduction candidate for 5,9
F9: 5,9 => CTR
* 3.7.6.4212647.18...1845237614269358778.5142.353.2781.4871946..24..32761862318.74.
F9: 8                                    # 17 pairs
* PAIR D7: 5,9 COL D
D1: 5,9,8                                # reduction candidate for 5,9
D1: 5,9 => SOLVED
* 387569421264781935519432876142693587756814293938275164871946352495327618623158749
D1: 8                                    # 18 pairs
D5: 5,9,8                                # reduction candidate for 5,9
D5: 5,9                                  # 18 pairs
* PAIR G7: 3,9 COL G
G2: 3,9,8                                # reduction candidate for 3,9
G2: 3,9 => SOLVED
* 387569421264781935519432876142693587756814293938275164871946352495327618623158749
G2: 8                                    # 14 pairs
G3: 3,9,8                                # reduction candidate for 3,9
G3: 3,9                                  # 14 pairs
* PAIR I9: 5,9 ROW 9
E9: 5,9,8                                # reduction candidate for 5,9
E9: 5,9                                  # 17 pairs
F9: 5,9,8                                # reduction candidate for 5,9
F9: 5,9 => CTR
* 3.7.6.4212647.18...1845237614269358778.5142.353.2781.4871946..24..32761862318.74.
F9: 8                                    # 17 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-067-base-pr-000.dot
* REASONING
* PRF # C3: 5,9 => SOL
* DIS # E3: 5,9 => CTR => E3: 3,8
* PRF # B5: 5,9 => SOL
* DIS # C6: 5,9 => CTR => C6: 6,8
* DIS # F6: 8 => CTR => F6: 5,9
* PRF # D5: 8,9 => SOL
* DIS # D5: 5 => CTR => D5: 8,9
* DIS # F6: 8,9 => CTR => F6: 5
* PRF # F6: 5 => SOL
* DIS # E3: 8,9 => CTR => E3: 3,5
* DIS # E9: 8,9 => CTR => E9: 5
* PRF # B5: 5,9 => SOL
* PRF # C3: 5,9 => SOL
* DIS # C6: 5,9 => CTR => C6: 6,8
* DIS # F9: 5,9 => CTR => F9: 8
* PRF # D1: 5,9 => SOL
* PRF # G2: 3,9 => SOL
* DIS # F9: 5,9 => CTR => F9: 8
* CNT  18 HDP CHAINS /  43 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A3,A6,B8,C8,D7,E4,G7,H2,H4,H7,I2,I9)
* 3.7.6.4212647.1....1.4.2.761426.35.77...142.3.3.27.1.4871.46..24..3276186231..74.
* PAIR A3: 5,9 BLK 1
B1: 5,9,8                                # reduction candidate for 5,9
B1: 5,9                                  # 18 pairs
C3: 5,9,8                                # reduction candidate for 5,9
C3: 5,9 => SOLVED
* 387569421264781935519432876142693587756814293938275164871946352495327618623158749
* DURATION: 0:00:03.712569  START: 04:59:02.911588  END: 04:59:06.624157 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-067-base-pr-001.dot
* REASONING
* PRF # C3: 5,9 => SOL
* STA C3: 5,9
* CNT   1 HDP CHAINS /   2 HYP OPENED

Header Info

Top 500 Minimum 17 067

solution: 387569421264781935519432876142693587756814293938275164871946352495327618623158749
info: 1444     FNBTHWX  S8.f     28710

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

Solution

position: 387569421264781935519432876142693587756814293938275164871946352495327618623158749 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: 5,9 => UNS
* PRF # C3: 5,9 => SOL
* INC # C3: 8 => UNS
* DIS # E3: 5,9 => CTR => E3: 3,8
* INC # E3: 3,8 => UNS
* PRF # B5: 5,9 => SOL
* INC # B5: 8 => UNS
* INC # C5: 5,9 => UNS
* DIS # C6: 5,9 => CTR => C6: 6,8
* INC # C6: 6,8 => UNS
* INC # F6: 5,9 => UNS
* DIS # F6: 8 => CTR => F6: 5,9
* PRF # D5: 8,9 => SOL
* DIS # D5: 5 => CTR => D5: 8,9
* DIS # F6: 8,9 => CTR => F6: 5
* PRF # F6: 5 => SOL
* INC # E2: 8,9 => UNS
* DIS # E3: 8,9 => CTR => E3: 3,5
* INC # E3: 3,5 => UNS
* DIS # E9: 8,9 => CTR => E9: 5
* INC # E9: 5 => UNS
* INC # H5: 8,9 => UNS
* INC # H6: 8,9 => UNS
* INC # B1: 5,9 => UNS
* PRF # B5: 5,9 => SOL
* INC # B5: 8 => UNS
* PRF # C3: 5,9 => SOL
* INC # C3: 8 => UNS
* INC # C5: 5,9 => UNS
* DIS # C6: 5,9 => CTR => C6: 6,8
* INC # C6: 6,8 => UNS
* INC # E9: 5,9 => UNS
* DIS # F9: 5,9 => CTR => F9: 8
* INC # F9: 8 => UNS
* PRF # D1: 5,9 => SOL
* INC # D1: 8 => UNS
* INC # D5: 5,9 => UNS
* PRF # G2: 3,9 => SOL
* INC # G2: 8 => UNS
* INC # G3: 3,9 => UNS
* INC # E9: 5,9 => UNS
* DIS # F9: 5,9 => CTR => F9: 8
* INC # F9: 8 => UNS
* CNT  43 HDP CHAINS /  43 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # B1: 5,9 => UNS
* PRF # C3: 5,9 => SOL
* STA C3: 5,9
* CNT   2 HDP CHAINS /   2 HYP OPENED