Analysis of xx-top500-240-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: .5.2.1.........37....5..6..8.3.4............14............3.48..2.1.............. initial

Autosolve

position: 3562718942814..375.4.583612813.4.2..56.328.414.2.1..381.5.3248..281.4..3.3485.12. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # A9: 7,9 => SOL
* DIS # F9: 6,9 => CTR => F9: 7
* PRF # D6: 7,9 => SOL
* DIS # G6: 7,9 => CTR => G6: 5
* DIS # F4: 7,9 => CTR => F4: 5
* PRF # D6: 7,9 => SOL
* DIS # I4: 6 => CTR => I4: 7,9
* PRF # D7: 6 => SOL
* DIS # G6: 7,9 => CTR => G6: 5
* DIS # G8: 5 => CTR => G8: 7,9
* PRF # A9: 7,9 => SOL
* PRF # I7: 7,9 => SOL
* DIS # F9: 6,9 => CTR => F9: 7
* PRF # A8: 6,9 => SOL
* CNT  14 HDP CHAINS /  36 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 # A9: 7,9 => SOL
* STA A9: 7,9
* CNT   1 HDP CHAINS /   2 HYP OPENED

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

Details

Positions

.5.2.1.........37....5..6..8.3.4............14............3.48..2.1.............. initial
3562718942814..375.4.583612813.4.2..56.328.414.2.1..381.5.3248..281.4..3.3485.12. autosolve
356271894281469375749583612813945267567328941492716538175632489628194753934857126 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (12)
A3: 7,9
C3: 7,9
E2: 6,9
F2: 6,9
C5: 7,9
B6: 7,9
D4: 7,9
H4: 5,6
G5: 7,9
B7: 7,9
E8: 6,9
H8: 5,6

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
F4,F6: 5.. / F4 = 5  => 12 pairs (_) / F6 = 5  =>  0 pairs (X)
H4,G6: 5.. / H4 = 5  =>  0 pairs (X) / G6 = 5  => 12 pairs (_)
G8,H8: 5.. / G8 = 5  =>  0 pairs (X) / H8 = 5  => 12 pairs (_)
F4,H4: 5.. / F4 = 5  => 12 pairs (_) / H4 = 5  =>  0 pairs (X)
F6,G6: 5.. / F6 = 5  =>  0 pairs (X) / G6 = 5  => 12 pairs (_)
G6,G8: 5.. / G6 = 5  => 12 pairs (_) / G8 = 5  =>  0 pairs (X)
H4,H8: 5.. / H4 = 5  =>  0 pairs (X) / H8 = 5  => 12 pairs (_)
E2,F2: 6.. / E2 = 6  => 15 pairs (_) / F2 = 6  => 14 pairs (_)
D6,F6: 6.. / D6 = 6  => 15 pairs (_) / F6 = 6  =>  0 pairs (*)
H4,I4: 6.. / H4 = 6  => 12 pairs (_) / I4 = 6  =>  0 pairs (X)
A8,A9: 6.. / A8 = 6  =>  0 pairs (*) / A9 = 6  =>  0 pairs (X)
D7,I7: 6.. / D7 = 6  =>  0 pairs (*) / I7 = 6  =>  0 pairs (X)
D6,D7: 6.. / D6 = 6  => 15 pairs (_) / D7 = 6  =>  0 pairs (*)
E2,E8: 6.. / E2 = 6  => 15 pairs (_) / E8 = 6  => 14 pairs (_)
H4,H8: 6.. / H4 = 6  => 12 pairs (_) / H8 = 6  =>  0 pairs (X)
A3,C3: 7.. / A3 = 7  =>  0 pairs (*) / C3 = 7  =>  0 pairs (X)
C5,B6: 7.. / C5 = 7  =>  0 pairs (*) / B6 = 7  =>  0 pairs (X)
D7,F9: 7.. / D7 = 7  =>  0 pairs (X) / F9 = 7  => 16 pairs (_)
C5,G5: 7.. / C5 = 7  =>  0 pairs (*) / G5 = 7  =>  0 pairs (X)
A8,G8: 7.. / A8 = 7  => 16 pairs (_) / G8 = 7  =>  0 pairs (*)
B6,B7: 7.. / B6 = 7  => 16 pairs (_) / B7 = 7  =>  0 pairs (*)
C3,C5: 7.. / C3 = 7  => 16 pairs (_) / C5 = 7  =>  0 pairs (*)
A3,C3: 9.. / A3 = 9  => 16 pairs (_) / C3 = 9  =>  0 pairs (*)
E2,F2: 9.. / E2 = 9  => 14 pairs (_) / F2 = 9  => 15 pairs (_)
C5,B6: 9.. / C5 = 9  => 16 pairs (_) / B6 = 9  =>  0 pairs (*)
C5,G5: 9.. / C5 = 9  => 16 pairs (_) / G5 = 9  =>  0 pairs (*)
B6,B7: 9.. / B6 = 9  =>  0 pairs (*) / B7 = 9  =>  0 pairs (X)
C3,C5: 9.. / C3 = 9  =>  0 pairs (*) / C5 = 9  =>  0 pairs (X)
E2,E8: 9.. / E2 = 9  => 14 pairs (_) / E8 = 9  => 15 pairs (_)
* DURATION: 0:00:57.211893  START: 11:00:20.058345  END: 11:01:17.270238 2017-05-04
* CP COUNT: (29)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A3,B6,B7,C3,C5,D4,E2,E8,F2,G5,H4,H8)
* 3562718942814..375.4.583612813.4.2..56.328.414.2.1..381.5.3248..281.4..3.3485.12.
* PAIR A3: 7,9 COL A
A8: 7,9,6                                # reduction candidate for 7,9
A8: 7,9                                  # 15 pairs
A9: 7,9,6                                # reduction candidate for 7,9
A9: 7,9 => SOLVED
* 356271894281469375749583612813945267567328941492716538175632489628194753934857126
A9: 6                                    # 15 pairs
* PAIR F2: 6,9 COL F
F6: 6,9,5,7                              # reduction candidate for 6,9
F6: 6,9                                  # 16 pairs
F9: 6,9,7                                # reduction candidate for 6,9
F9: 6,9 => CTR
* 3562718942814..375.4.583612813945267567328941492.1..381.5732486.281.4.53.3485.12.
F9: 7                                    # 16 pairs
* PAIR B6: 7,9 ROW 6
D6: 7,9,6                                # reduction candidate for 7,9
D6: 7,9 => SOLVED
* 356271894281469375749583612813945267567328941492716538175632489628194753934857126
D6: 6                                    # 15 pairs
F6: 7,9,5,6                              # reduction candidate for 7,9
F6: 7,9                                  # 15 pairs
G6: 7,9,5                                # reduction candidate for 7,9
G6: 7,9 => CTR
* 3562718942814..375.4.583612813.4.25656.328.414.2.15.381.563248..2819456363485712.
G6: 5                                    # 12 pairs
* PAIR D4: 7,9 BLK 5
F4: 7,9,5                                # reduction candidate for 7,9
F4: 7,9 => CTR
* 3562718942814..375.4.583612813.4.25656.328.414.2.15.381.563248..2819456363485712.
F4: 5                                    # 12 pairs
D6: 7,9,6                                # reduction candidate for 7,9
D6: 7,9 => SOLVED
* 356271894281469375749583612813945267567328941492716538175632489628194753934857126
D6: 6                                    # 15 pairs
F6: 7,9,5,6                              # reduction candidate for 7,9
F6: 7,9                                  # 15 pairs
* PAIR D4: 7,9 ROW 4
I4: 7,9,6                                # reduction candidate for 7,9
I4: 6 => CTR
* 356271894281469375947583612813.4.2.656.328.414.2.1..381.563248..28194.63634857129
I4: 7,9                                  # 12 pairs
* PAIR D4: 7,9 COL D
D7: 7,9,6                                # reduction candidate for 7,9
D7: 6 => SOLVED
* 356271894281469375749583612813945267567328941492716538175632489628194753934857126
D7: 7,9                                  # 15 pairs
* PAIR G5: 7,9 BLK 6
I4: 7,9,6                                # reduction candidate for 7,9
I4: 7,9                                  # 12 pairs
G6: 7,9,5                                # reduction candidate for 7,9
G6: 7,9 => CTR
* 3562718942814..375.4.583612813.4.25656.328.414.2.15.381.563248..2819456363485712.
G6: 5                                    # 12 pairs
* PAIR G5: 7,9 COL G
G8: 7,9,5                                # reduction candidate for 7,9
G8: 5 => CTR
* 356271894281469375.4.583612813.4.2..56.328.414.2.1..381.5.3248.728194563634857129
G8: 7,9                                  # 12 pairs
* PAIR B7: 7,9 BLK 7
A8: 7,9,6                                # reduction candidate for 7,9
A8: 7,9                                  # 15 pairs
A9: 7,9,6                                # reduction candidate for 7,9
A9: 7,9 => SOLVED
* 356271894281469375749583612813945267567328941492716538175632489628194753934857126
A9: 6                                    # 15 pairs
* PAIR B7: 7,9 ROW 7
D7: 7,9,6                                # reduction candidate for 7,9
D7: 7,9                                  # 15 pairs
I7: 7,9,6                                # reduction candidate for 7,9
I7: 7,9 => SOLVED
* 356271894281469375749583612813945267567328941492716538175632489628194753934857126
I7: 6                                    # 15 pairs
* PAIR E8: 6,9 BLK 8
D7: 6,9,7                                # reduction candidate for 6,9
D7: 6,9                                  # 16 pairs
F9: 6,9,7                                # reduction candidate for 6,9
F9: 6,9 => CTR
* 3562718942814..375.4.583612813945267567328941492.1..381.5732486.281.4.53.3485.12.
F9: 7                                    # 16 pairs
* PAIR E8: 6,9 ROW 8
A8: 6,9,7                                # reduction candidate for 6,9
A8: 6,9 => SOLVED
* 356271894281469375749583612813945267567328941492716538175632489628194753934857126
A8: 7                                    # 16 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-240-base-pr-000.dot
* REASONING
* PRF # A9: 7,9 => SOL
* DIS # F9: 6,9 => CTR => F9: 7
* PRF # D6: 7,9 => SOL
* DIS # G6: 7,9 => CTR => G6: 5
* DIS # F4: 7,9 => CTR => F4: 5
* PRF # D6: 7,9 => SOL
* DIS # I4: 6 => CTR => I4: 7,9
* PRF # D7: 6 => SOL
* DIS # G6: 7,9 => CTR => G6: 5
* DIS # G8: 5 => CTR => G8: 7,9
* PRF # A9: 7,9 => SOL
* PRF # I7: 7,9 => SOL
* DIS # F9: 6,9 => CTR => F9: 7
* PRF # A8: 6,9 => SOL
* CNT  14 HDP CHAINS /  36 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A3,B6,B7,C3,C5,D4,E2,E8,F2,G5,H4,H8)
* 3562718942814..375.4.583612813.4.2..56.328.414.2.1..381.5.3248..281.4..3.3485.12.
* PAIR A3: 7,9 COL A
A8: 7,9,6                                # reduction candidate for 7,9
A8: 7,9                                  # 15 pairs
A9: 7,9,6                                # reduction candidate for 7,9
A9: 7,9 => SOLVED
* 356271894281469375749583612813945267567328941492716538175632489628194753934857126
* DURATION: 0:00:03.135529  START: 11:01:59.961400  END: 11:02:03.096929 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-240-base-pr-001.dot
* REASONING
* PRF # A9: 7,9 => SOL
* STA A9: 7,9
* CNT   1 HDP CHAINS /   2 HYP OPENED

Header Info

Top 500 Minimum 17 240

solution: 356271894281469375749583612813945267567328941492716538175632489628194753934857126
info: 2069     FNBWXY   S8.f     20163

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

Solution

position: 356271894281469375749583612813945267567328941492716538175632489628194753934857126 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 # A8: 7,9 => UNS
* PRF # A9: 7,9 => SOL
* INC # A9: 6 => UNS
* INC # F6: 6,9 => UNS
* DIS # F9: 6,9 => CTR => F9: 7
* INC # F9: 7 => UNS
* PRF # D6: 7,9 => SOL
* INC # D6: 6 => UNS
* INC # F6: 7,9 => UNS
* DIS # G6: 7,9 => CTR => G6: 5
* INC # G6: 5 => UNS
* DIS # F4: 7,9 => CTR => F4: 5
* INC # F4: 5 => UNS
* PRF # D6: 7,9 => SOL
* INC # D6: 6 => UNS
* INC # F6: 7,9 => UNS
* INC # I4: 7,9 => UNS
* DIS # I4: 6 => CTR => I4: 7,9
* INC # D7: 7,9 => UNS
* PRF # D7: 6 => SOL
* INC # I4: 7,9 => UNS
* DIS # G6: 7,9 => CTR => G6: 5
* INC # G6: 5 => UNS
* INC # G8: 7,9 => UNS
* DIS # G8: 5 => CTR => G8: 7,9
* INC # A8: 7,9 => UNS
* PRF # A9: 7,9 => SOL
* INC # A9: 6 => UNS
* INC # D7: 7,9 => UNS
* PRF # I7: 7,9 => SOL
* INC # I7: 6 => UNS
* INC # D7: 6,9 => UNS
* DIS # F9: 6,9 => CTR => F9: 7
* INC # F9: 7 => UNS
* PRF # A8: 6,9 => SOL
* INC # A8: 7 => UNS
* CNT  36 HDP CHAINS /  36 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # A8: 7,9 => UNS
* PRF # A9: 7,9 => SOL
* STA A9: 7,9
* CNT   2 HDP CHAINS /   2 HYP OPENED