Analysis of xx-top500-381-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: ...9...329.18............4..3...2...6.....1......4.....2..8.......7..6..7........ initial

Autosolve

position: 5..914832941823...283...94143.1.2.8.6.23.81.481..4.2.312.48.3..3.47.16287.823.41. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # E3: 7 => SOL
* DIS # I4: 5,7 => CTR => I4: 6,9
* CNT   2 HDP CHAINS /  32 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 # E3: 7 => SOL
* STA E3: 7
* CNT   1 HDP CHAINS /   2 HYP OPENED

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

Details

Positions

...9...329.18............4..3...2...6.....1......4.....2..8.......7..6..7........ initial
5..914832941823...283...94143.1.2.8.6.23.81.481..4.2.312.48.3..3.47.16287.823.41. autosolve
576914832941823756283675941437162589652398174819547263125486397394751628768239415 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (10)
B1: 6,7
C1: 6,7
D3: 5,6
F3: 5,7
G2: 5,7
D6: 5,6
G4: 5,7
B8: 5,9
E8: 5,9
I9: 5,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
B8,E8: 5.. / B8 = 5  => 15 pairs (_) / E8 = 5  => 17 pairs (_)
D3,D6: 5.. / D3 = 5  => 10 pairs (_) / D6 = 5  => 13 pairs (_)
G2,G4: 5.. / G2 = 5  => 12 pairs (_) / G4 = 5  => 12 pairs (_)
B1,C1: 6.. / B1 = 6  => 16 pairs (_) / C1 = 6  => 11 pairs (_)
D3,E3: 6.. / D3 = 6  => 13 pairs (_) / E3 = 6  => 10 pairs (_)
H2,I2: 6.. / H2 = 6  => 10 pairs (_) / I2 = 6  => 13 pairs (_)
E4,D6: 6.. / E4 = 6  => 13 pairs (_) / D6 = 6  => 10 pairs (_)
I4,H6: 6.. / I4 = 6  => 10 pairs (_) / H6 = 6  => 13 pairs (_)
C7,B9: 6.. / C7 = 6  => 16 pairs (_) / B9 = 6  => 11 pairs (_)
F7,F9: 6.. / F7 = 6  => 11 pairs (_) / F9 = 6  => 16 pairs (_)
E4,I4: 6.. / E4 = 6  => 13 pairs (_) / I4 = 6  => 10 pairs (_)
D6,H6: 6.. / D6 = 6  => 10 pairs (_) / H6 = 6  => 13 pairs (_)
C7,F7: 6.. / C7 = 6  => 16 pairs (_) / F7 = 6  => 11 pairs (_)
B9,F9: 6.. / B9 = 6  => 11 pairs (_) / F9 = 6  => 16 pairs (_)
B1,B9: 6.. / B1 = 6  => 16 pairs (_) / B9 = 6  => 11 pairs (_)
C1,C7: 6.. / C1 = 6  => 11 pairs (_) / C7 = 6  => 16 pairs (_)
D3,D6: 6.. / D3 = 6  => 13 pairs (_) / D6 = 6  => 10 pairs (_)
E3,E4: 6.. / E3 = 6  => 10 pairs (_) / E4 = 6  => 13 pairs (_)
H2,H6: 6.. / H2 = 6  => 10 pairs (_) / H6 = 6  => 13 pairs (_)
I2,I4: 6.. / I2 = 6  => 13 pairs (_) / I4 = 6  => 10 pairs (_)
B1,C1: 7.. / B1 = 7  => 11 pairs (_) / C1 = 7  => 16 pairs (_)
E3,F3: 7.. / E3 = 7  =>  0 pairs (*) / F3 = 7  =>  0 pairs (X)
H7,I7: 7.. / H7 = 7  => 16 pairs (_) / I7 = 7  => 12 pairs (_)
B1,B5: 7.. / B1 = 7  => 11 pairs (_) / B5 = 7  => 16 pairs (_)
F3,F6: 7.. / F3 = 7  => 11 pairs (_) / F6 = 7  =>  0 pairs (*)
G2,G4: 7.. / G2 = 7  => 12 pairs (_) / G4 = 7  => 12 pairs (_)
B8,E8: 9.. / B8 = 9  => 17 pairs (_) / E8 = 9  => 15 pairs (_)
* DURATION: 0:00:45.601564  START: 15:53:28.224748  END: 15:54:13.826312 2017-05-04
* CP COUNT: (27)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B1,B8,C1,D3,D6,E8,F3,G2,G4,I9)
* 5..914832941823...283...94143.1.2.8.6.23.81.481..4.2.312.48.3..3.47.16287.823.41.
* PAIR D3: 5,6 BLK 2
E3: 5,6,7                                # reduction candidate for 5,6
E3: 7 => SOLVED
* 576914832941823756283675941437162589652398174819547263125486397394751628768239415
E3: 5,6                                  # 11 pairs
* PAIR F3: 5,7 BLK 2
E3: 5,7,6                                # reduction candidate for 5,7
E3: 5,7                                  # 13 pairs
E3: 6                                    # 10 pairs
* PAIR F3: 5,7 COL F
F6: 5,7,9                                # reduction candidate for 5,7
F6: 5,7                                  # 17 pairs
F6: 9                                    # 15 pairs
* PAIR G2: 5,7 BLK 3
H2: 5,7,6                                # reduction candidate for 5,7
H2: 5,7                                  # 13 pairs
I2: 5,7,6                                # reduction candidate for 5,7
I2: 5,7                                  # 10 pairs
* PAIR D6: 5,6 BLK 5
E4: 5,6,7,9                              # reduction candidate for 5,6
E4: 5,6                                  # 13 pairs
E4: 7,9                                  # 11 pairs
* PAIR D6: 5,6 ROW 6
H6: 5,6,7,9                              # reduction candidate for 5,6
H6: 5,6                                  # 13 pairs
H6: 7,9                                  # 11 pairs
* PAIR G4: 5,7 BLK 6
I4: 5,7,6,9                              # reduction candidate for 5,7
I4: 5,7 => CTR
* 5..914832941823..62836..941439162.8.6523.81948175492631254863..3.47.16287.823.41.
I4: 6,9                                  # 11 pairs
H5: 5,7,9                                # reduction candidate for 5,7
H5: 5,7                                  # 13 pairs
H6: 5,7,6,9                              # reduction candidate for 5,7
H6: 5,7                                  # 14 pairs
* PAIR G4: 5,7 ROW 4
C4: 5,7,9                                # reduction candidate for 5,7
C4: 5,7                                  # 13 pairs
E4: 5,7,6,9                              # reduction candidate for 5,7
E4: 5,7                                  # 14 pairs
* PAIR B8: 5,9 BLK 7
C7: 5,9,6                                # reduction candidate for 5,9
C7: 5,9                                  # 11 pairs
B9: 5,9,6                                # reduction candidate for 5,9
B9: 5,9                                  # 16 pairs
* PAIR B8: 5,9 COL B
B5: 5,9,7                                # reduction candidate for 5,9
B5: 7                                    # 16 pairs
B5: 5,9                                  # 11 pairs
* PAIR E8: 5,9 BLK 8
F7: 5,9,6                                # reduction candidate for 5,9
F7: 5,9                                  # 16 pairs
F9: 5,9,6                                # reduction candidate for 5,9
F9: 5,9                                  # 11 pairs
* PAIR E8: 5,9 COL E
E4: 5,9,6,7                              # reduction candidate for 5,9
E4: 5,9                                  # 13 pairs
E5: 5,9,7                                # reduction candidate for 5,9
E5: 5,9                                  # 13 pairs
* PAIR I9: 5,9 BLK 9
H7: 5,9,7                                # reduction candidate for 5,9
H7: 5,9                                  # 12 pairs
I7: 5,9,7                                # reduction candidate for 5,9
I7: 5,9                                  # 16 pairs
* PAIR I9: 5,9 ROW 9
B9: 5,9,6                                # reduction candidate for 5,9
B9: 5,9                                  # 16 pairs
F9: 5,9,6                                # reduction candidate for 5,9
F9: 5,9                                  # 11 pairs
* PAIR I9: 5,9 COL I
I4: 5,9,6,7                              # reduction candidate for 5,9
I4: 5,9                                  # 15 pairs
I4: 6,7                                  # 12 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-381-base-pr-000.dot
* REASONING
* PRF # E3: 7 => SOL
* DIS # I4: 5,7 => CTR => I4: 6,9
* CNT   2 HDP CHAINS /  32 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B1,B8,C1,D3,D6,E8,F3,G2,G4,I9)
* 5..914832941823...283...94143.1.2.8.6.23.81.481..4.2.312.48.3..3.47.16287.823.41.
* PAIR D3: 5,6 BLK 2
E3: 5,6,7                                # reduction candidate for 5,6
E3: 7 => SOLVED
* 576914832941823756283675941437162589652398174819547263125486397394751628768239415
* DURATION: 0:00:02.934968  START: 15:54:43.753397  END: 15:54:46.688365 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-381-base-pr-001.dot
* REASONING
* PRF # E3: 7 => SOL
* STA E3: 7
* CNT   1 HDP CHAINS /   2 HYP OPENED

Header Info

Top 500 Minimum 17 381

solution: 576914832941823756283675941437162589652398174819547263125486397394751628768239415
info: 33306    FNBTYO   S8.f     12538

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

Solution

position: 576914832941823756283675941437162589652398174819547263125486397394751628768239415 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 # E3: 5,6 => UNS
* PRF # E3: 7 => SOL
* INC # E3: 5,7 => UNS
* INC # E3: 6 => UNS
* INC # F6: 5,7 => UNS
* INC # F6: 9 => UNS
* INC # H2: 5,7 => UNS
* INC # I2: 5,7 => UNS
* INC # E4: 5,6 => UNS
* INC # E4: 7,9 => UNS
* INC # H6: 5,6 => UNS
* INC # H6: 7,9 => UNS
* DIS # I4: 5,7 => CTR => I4: 6,9
* INC # I4: 6,9 => UNS
* INC # H5: 5,7 => UNS
* INC # H6: 5,7 => UNS
* INC # C4: 5,7 => UNS
* INC # E4: 5,7 => UNS
* INC # C7: 5,9 => UNS
* INC # B9: 5,9 => UNS
* INC # B5: 5,9 => UNS
* INC # B5: 7 => UNS
* INC # F7: 5,9 => UNS
* INC # F9: 5,9 => UNS
* INC # E4: 5,9 => UNS
* INC # E5: 5,9 => UNS
* INC # H7: 5,9 => UNS
* INC # I7: 5,9 => UNS
* INC # B9: 5,9 => UNS
* INC # F9: 5,9 => UNS
* INC # I4: 5,9 => UNS
* INC # I4: 6,7 => UNS
* CNT  32 HDP CHAINS /  32 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # E3: 5,6 => UNS
* PRF # E3: 7 => SOL
* STA E3: 7
* CNT   2 HDP CHAINS /   2 HYP OPENED