Analysis of xx-top500-398-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: ....1.8...9.....3.2........4..5.3.6.7.1.....4..........5.2.......8...1.....3..... initial

Autosolve

position: 5.3.1.8..19.8...3.28..3..1.429583761731...5848651......5.2.1..8..8...1...123.8... autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # D1: 4,7 => CTR => D1: 6,9
* DIS # F1: 4,7 => CTR => F1: 2,6,9
* DIS # D3: 6,9 => CTR => D3: 4,7
* DIS # D8: 6,9 => CTR => D8: 4,7
* DIS # E2: 4,7 => CTR => E2: 2,5,6
* PRF # E7: 4,7 => SOL
* DIS # E8: 4,7 => CTR => E8: 5,6,9
* DIS # F1: 4,7 => CTR => F1: 2,6,9
* DIS # F8: 4,7 => CTR => F8: 5,6,9
* DIS # H1: 2,9 => CTR => H1: 4,7
* PRF # E7: 4,7 => SOL
* DIS # E8: 4,7 => CTR => E8: 5,6,9
* DIS # F8: 4,7 => CTR => F8: 5,6,9
* DIS # H8: 4,7 => CTR => H8: 2,5,9
* DIS # E9: 6,9 => CTR => E9: 4,5,7
* PRF # G9: 6,9 => SOL
* DIS # G9: 4 => CTR => G9: 6,9
* DIS # I9: 6,9 => CTR => I9: 7
* PRF # I9: 7 => SOL
* CNT  19 HDP CHAINS /  52 HYP OPENED

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

Pair Reduction

Pair Reduction

The following important HDP chains were detected:

* DIS # D1: 4,7 => CTR => D1: 6,9
* DIS D1: 6,9 # F1: 4,7 => CTR => F1: 2,6,9
* DIS D1: 6,9 + F1: 2,6,9 # H1: 2,9 => CTR => H1: 4,7
* DIS D1: 6,9 + F1: 2,6,9 + H1: 4,7 # E2: 4,7 => CTR => E2: 2,5,6
* PRF D1: 6,9 + F1: 2,6,9 + H1: 4,7 + E2: 2,5,6 # E7: 4,7 => SOL
* STA D1: 6,9 + F1: 2,6,9 + H1: 4,7 + E2: 2,5,6 + E7: 4,7
* CNT   5 HDP CHAINS /  13 HYP OPENED

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

Details

Positions

....1.8...9.....3.2........4..5.3.6.7.1.....4..........5.2.......8...1.....3..... initial
5.3.1.8..19.8...3.28..3..1.429583761731...5848651......5.2.1..8..8...1...123.8... autosolve
543912876197864235286735419429583761731629584865147923654271398378496152912358647 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (8)
B1: 4,7
D5: 6,9
E6: 4,7
F6: 4,7
H6: 2,9
C7: 4,7
B8: 4,7
A9: 6,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
E5,F5: 2.. / E5 = 2  =>  9 pairs (_) / F5 = 2  => 12 pairs (_)
H8,I8: 2.. / H8 = 2  => 16 pairs (_) / I8 = 2  => 21 pairs (_)
E2,E5: 2.. / E2 = 2  => 12 pairs (_) / E5 = 2  =>  9 pairs (_)
G2,G6: 2.. / G2 = 2  => 12 pairs (_) / G6 = 2  => 11 pairs (_)
G6,I6: 3.. / G6 = 3  => 20 pairs (_) / I6 = 3  => 10 pairs (_)
A7,A8: 3.. / A7 = 3  => 20 pairs (_) / A8 = 3  => 10 pairs (_)
G7,I8: 3.. / G7 = 3  => 10 pairs (_) / I8 = 3  => 20 pairs (_)
A7,G7: 3.. / A7 = 3  => 20 pairs (_) / G7 = 3  => 10 pairs (_)
A8,I8: 3.. / A8 = 3  => 10 pairs (_) / I8 = 3  => 20 pairs (_)
G6,G7: 3.. / G6 = 3  => 20 pairs (_) / G7 = 3  => 10 pairs (_)
I6,I8: 3.. / I6 = 3  => 10 pairs (_) / I8 = 3  => 20 pairs (_)
E6,F6: 4.. / E6 = 4  =>  0 pairs (*) / F6 = 4  =>  0 pairs (X)
C7,B8: 4.. / C7 = 4  =>  0 pairs (*) / B8 = 4  =>  0 pairs (X)
B1,B8: 4.. / B1 = 4  =>  0 pairs (*) / B8 = 4  =>  0 pairs (X)
I2,I3: 5.. / I2 = 5  =>  8 pairs (_) / I3 = 5  =>  8 pairs (_)
H8,H9: 5.. / H8 = 5  =>  0 pairs (*) / H9 = 5  =>  0 pairs (X)
F3,I3: 5.. / F3 = 5  =>  8 pairs (_) / I3 = 5  =>  8 pairs (_)
E9,H9: 5.. / E9 = 5  =>  0 pairs (*) / H9 = 5  =>  0 pairs (X)
C2,C3: 6.. / C2 = 6  => 10 pairs (_) / C3 = 6  => 10 pairs (_)
E6,F6: 7.. / E6 = 7  =>  0 pairs (X) / F6 = 7  =>  0 pairs (_)
C7,B8: 7.. / C7 = 7  =>  0 pairs (X) / B8 = 7  =>  0 pairs (_)
B1,B8: 7.. / B1 = 7  =>  0 pairs (X) / B8 = 7  =>  0 pairs (_)
* DURATION: 0:00:35.892433  START: 16:25:01.853354  END: 16:25:37.745787 2017-05-04
* CP COUNT: (22)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A9,B1,B8,C7,D5,E6,F6,H6)
* 5.3.1.8..19.8...3.28..3..1.429583761731...5848651......5.2.1..8..8...1...123.8...
* PAIR B1: 4,7 BLK 1
C2: 4,7,6                                # reduction candidate for 4,7
C2: 4,7                                  # 10 pairs
C3: 4,7,6                                # reduction candidate for 4,7
C3: 4,7                                  # 10 pairs
* PAIR B1: 4,7 ROW 1
D1: 4,7,6,9                              # reduction candidate for 4,7
D1: 4,7 => CTR
* 5.3.1.8..19.8...3.28..3..1.429583761731...5848651....3.5.2.13.83.8...1.2.123.8...
D1: 6,9                                  # 11 pairs
F1: 4,7,2,6,9                            # reduction candidate for 4,7
F1: 4,7 => CTR
* 5.3.1.82.19.8...3.28..3..1.429583761731...5848651..293.5.2.13.83.8...1.2.123.8...
F1: 2,6,9                                #  8 pairs
H1: 4,7,2,9                              # reduction candidate for 4,7
H1: 4,7                                  # 12 pairs
* PAIR D5: 6,9 BLK 5
E5: 6,9,2                                # reduction candidate for 6,9
E5: 6,9                                  # 12 pairs
F5: 6,9,2                                # reduction candidate for 6,9
F5: 6,9                                  #  9 pairs
* PAIR D5: 6,9 COL D
D1: 6,9,4,7                              # reduction candidate for 6,9
D1: 6,9                                  # 11 pairs
D3: 6,9,4,7                              # reduction candidate for 6,9
D3: 6,9 => CTR
* 5.3.1.8..19.8...3.28..3..1.429583761731...5848651....3.5.2.13.83.8...152.12358...
D3: 4,7                                  #  9 pairs
D8: 6,9,4,7                              # reduction candidate for 6,9
D8: 6,9 => CTR
* 5.3.1.8..19.8...3.28..3..1.429583761731...5848651....3.5.2.13.83.8...1.2.123.8...
D8: 4,7                                  #  9 pairs
* PAIR E6: 4,7 COL E
E2: 4,7,2,5,6                            # reduction candidate for 4,7
E2: 4,7 => CTR
* 5.3.1.8..19.8...3.28..3..1.429583761731.2.5848651......5.2.1..8..8...1...123.8...
E2: 2,5,6                                #  8 pairs
E7: 4,7,6,9                              # reduction candidate for 4,7
E7: 4,7 => SOLVED
* 543912876197864235286735419429583761731629584865147923654271398378496152912358647
E7: 6,9                                  #  9 pairs
E8: 4,7,5,6,9                            # reduction candidate for 4,7
E8: 4,7 => CTR
* 5.3.1.8..19.8...3.28..3..1.429583761731...5848651......5.2.1..8..8...1...123.8...
E8: 5,6,9                                #  8 pairs
E9: 4,7,5,6,9                            # reduction candidate for 4,7
E9: 4,7                                  # 10 pairs
* PAIR F6: 4,7 COL F
F1: 4,7,2,6,9                            # reduction candidate for 4,7
F1: 4,7 => CTR
* 5.3.1.82.19.8...3.28..3..1.429583761731...5848651..293.5.2.13.83.8...1.2.123.8...
F1: 2,6,9                                #  8 pairs
F2: 4,7,2,5,6                            # reduction candidate for 4,7
F2: 4,7                                  #  9 pairs
F3: 4,7,5,6,9                            # reduction candidate for 4,7
F3: 4,7                                  #  9 pairs
F8: 4,7,5,6,9                            # reduction candidate for 4,7
F8: 4,7 => CTR
* 5.3.1.8..19.8...3.28..3..1.429583761731...5848651....3.5.2.13.83.8...152.12358...
F8: 5,6,9                                #  8 pairs
* PAIR H6: 2,9 BLK 6
G6: 2,9,3                                # reduction candidate for 2,9
G6: 2,9                                  # 10 pairs
I6: 2,9,3                                # reduction candidate for 2,9
I6: 2,9                                  # 20 pairs
* PAIR H6: 2,9 COL H
H1: 2,9,4,7                              # reduction candidate for 2,9
H1: 2,9 => CTR
* 5.3.1.8..19.8...3.28..3..1.429583761731...5848651......5.2.1..8..8...1...123.8...
H1: 4,7                                  # 12 pairs
H8: 2,9,4,5,7                            # reduction candidate for 2,9
H8: 2,9                                  # 16 pairs
* PAIR C7: 4,7 ROW 7
E7: 4,7,6,9                              # reduction candidate for 4,7
E7: 4,7 => SOLVED
* 543912876197864235286735419429583761731629584865147923654271398378496152912358647
E7: 6,9                                  #  9 pairs
H7: 4,7,9                                # reduction candidate for 4,7
H7: 4,7                                  # 10 pairs
* PAIR C7: 4,7 COL C
C2: 4,7,6                                # reduction candidate for 4,7
C2: 4,7                                  # 10 pairs
C3: 4,7,6                                # reduction candidate for 4,7
C3: 4,7                                  # 10 pairs
* PAIR B8: 4,7 ROW 8
D8: 4,7,6,9                              # reduction candidate for 4,7
D8: 4,7                                  #  9 pairs
E8: 4,7,5,6,9                            # reduction candidate for 4,7
E8: 4,7 => CTR
* 5.3.1.8..19.8...3.28..3..1.429583761731...5848651......5.2.1..8..8...1...123.8...
E8: 5,6,9                                #  8 pairs
F8: 4,7,5,6,9                            # reduction candidate for 4,7
F8: 4,7 => CTR
* 5.3.1.8..19.8...3.28..3..1.429583761731...5848651....3.5.2.13.83.8...152.12358...
F8: 5,6,9                                #  8 pairs
H8: 4,7,2,5,9                            # reduction candidate for 4,7
H8: 4,7 => CTR
* 5.3.128..19.8..23.28..3..1.429583761731.2.5848651..92365.2.13983.8.951.29123.8.5.
H8: 2,5,9                                #  8 pairs
* PAIR A9: 6,9 BLK 7
A7: 6,9,3                                # reduction candidate for 6,9
A7: 6,9                                  # 10 pairs
A8: 6,9,3                                # reduction candidate for 6,9
A8: 6,9                                  # 20 pairs
* PAIR A9: 6,9 ROW 9
E9: 6,9,4,5,7                            # reduction candidate for 6,9
E9: 6,9 => CTR
* 5.3.1.87.19.8...3.28..3..1.429583761731...5848651......5.2.1..8.78...1...123.8457
E9: 4,5,7                                #  8 pairs
G9: 6,9,4                                # reduction candidate for 6,9
G9: 6,9 => SOLVED
* 543912876197864235286735419429583761731629584865147923654271398378496152912358647
G9: 4 => CTR
* 573.1.84.1948...3.28643.91.429583761731...584865174.29657241398.487..1...123.8476
I9: 6,9,7                                # reduction candidate for 6,9
I9: 6,9 => CTR
* 573.1.84.1948...3.28643.91.429583761731...584865174.29657241398.487..1..912358476
I9: 7 => SOLVED
* 543912876197864235286735419429583761731629584865147923654271398378496152912358647
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-398-base-pr-000.dot
* REASONING
* DIS # D1: 4,7 => CTR => D1: 6,9
* DIS # F1: 4,7 => CTR => F1: 2,6,9
* DIS # D3: 6,9 => CTR => D3: 4,7
* DIS # D8: 6,9 => CTR => D8: 4,7
* DIS # E2: 4,7 => CTR => E2: 2,5,6
* PRF # E7: 4,7 => SOL
* DIS # E8: 4,7 => CTR => E8: 5,6,9
* DIS # F1: 4,7 => CTR => F1: 2,6,9
* DIS # F8: 4,7 => CTR => F8: 5,6,9
* DIS # H1: 2,9 => CTR => H1: 4,7
* PRF # E7: 4,7 => SOL
* DIS # E8: 4,7 => CTR => E8: 5,6,9
* DIS # F8: 4,7 => CTR => F8: 5,6,9
* DIS # H8: 4,7 => CTR => H8: 2,5,9
* DIS # E9: 6,9 => CTR => E9: 4,5,7
* PRF # G9: 6,9 => SOL
* DIS # G9: 4 => CTR => G9: 6,9
* DIS # I9: 6,9 => CTR => I9: 7
* PRF # I9: 7 => SOL
* CNT  19 HDP CHAINS /  52 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A9,B1,B8,C7,D5,E6,F6,H6)
* 5.3.1.8..19.8...3.28..3..1.429583761731...5848651......5.2.1..8..8...1...123.8...
* PAIR B1: 4,7 BLK 1
C2: 4,7,6                                # reduction candidate for 4,7
C2: 4,7                                  # 10 pairs
C3: 4,7,6                                # reduction candidate for 4,7
C3: 4,7                                  # 10 pairs
* PAIR B1: 4,7 ROW 1
D1: 4,7,6,9                              # reduction candidate for 4,7
D1: 4,7 => CTR
* 5.3.1.8..19.8...3.28..3..1.429583761731...5848651....3.5.2.13.83.8...1.2.123.8...
F1: 4,7,2,6,9                            # reduction candidate for 4,7
F1: 4,7 => CTR
* 5.3.1.82.19.8...3.28..3..1.429583761731...5848651..293.5.2.13.83.8...152.123.8...
H1: 4,7,2,9                              # reduction candidate for 4,7
H1: 4,7                                  # 12 pairs
* RESTART
* PAIR B1: 4,7 ROW 1
H1: 4,7,2,9                              # reduction candidate for 4,7
H1: 2,9 => CTR
* 543.1.8.719.8...3.28..3..1.429583761731...5848651......542.1..8.784..1...123.8.4.
* PAIR RESTART
* PAIR B1: 4,7 BLK 1
C2: 4,7,6                                # reduction candidate for 4,7
C2: 4,7                                  # 14 pairs
C3: 4,7,6                                # reduction candidate for 4,7
C3: 4,7                                  # 17 pairs
* PAIR D5: 6,9 BLK 5
E5: 6,9,2                                # reduction candidate for 6,9
E5: 6,9                                  # 20 pairs
F5: 6,9,2                                # reduction candidate for 6,9
F5: 6,9                                  # 14 pairs
* PAIR E6: 4,7 COL E
E2: 4,7,2,5,6                            # reduction candidate for 4,7
E2: 4,7 => CTR
* 5.3.1.8..19.8...3.28..3..1.429583761731.2.5848651......5.2.1..8..8...1...123.8...
E7: 4,7,6,9                              # reduction candidate for 4,7
E7: 4,7 => SOLVED
* 543912876197864235286735419429583761731629584865147923654271398378496152912358647
* DURATION: 0:00:13.635604  START: 16:26:21.372450  END: 16:26:35.008054 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-398-base-pr-001.dot
* REASONING
* DIS # D1: 4,7 => CTR => D1: 6,9
* DIS D1: 6,9 # F1: 4,7 => CTR => F1: 2,6,9
* DIS D1: 6,9 + F1: 2,6,9 # H1: 2,9 => CTR => H1: 4,7
* DIS D1: 6,9 + F1: 2,6,9 + H1: 4,7 # E2: 4,7 => CTR => E2: 2,5,6
* PRF D1: 6,9 + F1: 2,6,9 + H1: 4,7 + E2: 2,5,6 # E7: 4,7 => SOL
* STA D1: 6,9 + F1: 2,6,9 + H1: 4,7 + E2: 2,5,6 + E7: 4,7
* CNT   5 HDP CHAINS /  13 HYP OPENED

Header Info

Top 500 Minimum 17 398

solution: 543912876197864235286735419429583761731629584865147923654271398378496152912358647
info: 90173    FNBX     S8.f     2973

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

Solution

position: 543912876197864235286735419429583761731629584865147923654271398378496152912358647 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 # C2: 4,7 => UNS
* INC # C3: 4,7 => UNS
* DIS # D1: 4,7 => CTR => D1: 6,9
* INC # D1: 6,9 => UNS
* DIS # F1: 4,7 => CTR => F1: 2,6,9
* INC # F1: 2,6,9 => UNS
* INC # H1: 4,7 => UNS
* INC # E5: 6,9 => UNS
* INC # F5: 6,9 => UNS
* INC # D1: 6,9 => UNS
* DIS # D3: 6,9 => CTR => D3: 4,7
* INC # D3: 4,7 => UNS
* DIS # D8: 6,9 => CTR => D8: 4,7
* INC # D8: 4,7 => UNS
* DIS # E2: 4,7 => CTR => E2: 2,5,6
* INC # E2: 2,5,6 => UNS
* PRF # E7: 4,7 => SOL
* INC # E7: 6,9 => UNS
* DIS # E8: 4,7 => CTR => E8: 5,6,9
* INC # E8: 5,6,9 => UNS
* INC # E9: 4,7 => UNS
* DIS # F1: 4,7 => CTR => F1: 2,6,9
* INC # F1: 2,6,9 => UNS
* INC # F2: 4,7 => UNS
* INC # F3: 4,7 => UNS
* DIS # F8: 4,7 => CTR => F8: 5,6,9
* INC # F8: 5,6,9 => UNS
* INC # G6: 2,9 => UNS
* INC # I6: 2,9 => UNS
* DIS # H1: 2,9 => CTR => H1: 4,7
* INC # H1: 4,7 => UNS
* INC # H8: 2,9 => UNS
* PRF # E7: 4,7 => SOL
* INC # E7: 6,9 => UNS
* INC # H7: 4,7 => UNS
* INC # C2: 4,7 => UNS
* INC # C3: 4,7 => UNS
* INC # D8: 4,7 => UNS
* DIS # E8: 4,7 => CTR => E8: 5,6,9
* INC # E8: 5,6,9 => UNS
* DIS # F8: 4,7 => CTR => F8: 5,6,9
* INC # F8: 5,6,9 => UNS
* DIS # H8: 4,7 => CTR => H8: 2,5,9
* INC # H8: 2,5,9 => UNS
* INC # A7: 6,9 => UNS
* INC # A8: 6,9 => UNS
* DIS # E9: 6,9 => CTR => E9: 4,5,7
* INC # E9: 4,5,7 => UNS
* PRF # G9: 6,9 => SOL
* DIS # G9: 4 => CTR => G9: 6,9
* DIS # I9: 6,9 => CTR => I9: 7
* PRF # I9: 7 => SOL
* CNT  52 HDP CHAINS /  52 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # C2: 4,7 => UNS
* INC # C3: 4,7 => UNS
* DIS # D1: 4,7 => CTR => D1: 6,9
* DIS D1: 6,9 # F1: 4,7 => CTR => F1: 2,6,9
* INC D1: 6,9 + F1: 2,6,9 # H1: 4,7 => UNS
* INC D1: 6,9 + F1: 2,6,9 # H1: 4,7 => UNS
* DIS D1: 6,9 + F1: 2,6,9 # H1: 2,9 => CTR => H1: 4,7
* INC D1: 6,9 + F1: 2,6,9 + H1: 4,7 # C2: 4,7 => UNS
* INC D1: 6,9 + F1: 2,6,9 + H1: 4,7 # C3: 4,7 => UNS
* INC D1: 6,9 + F1: 2,6,9 + H1: 4,7 # E5: 6,9 => UNS
* INC D1: 6,9 + F1: 2,6,9 + H1: 4,7 # F5: 6,9 => UNS
* DIS D1: 6,9 + F1: 2,6,9 + H1: 4,7 # E2: 4,7 => CTR => E2: 2,5,6
* PRF D1: 6,9 + F1: 2,6,9 + H1: 4,7 + E2: 2,5,6 # E7: 4,7 => SOL
* STA D1: 6,9 + F1: 2,6,9 + H1: 4,7 + E2: 2,5,6 + E7: 4,7
* CNT  13 HDP CHAINS /  13 HYP OPENED