Analysis of xx-top500-265-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 6...2..7..4.5....3.........1.5....2....4..8.....3.........1.5..7.....9..........4 initial

Autosolve

position: 6.3.24175.415...935..13..48135...42....45.83.4..3..75.3.4.1.5.775..43912.1...53.4 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # B7: 8,9 => CTR => B7: 2,6
* DIS # A9: 9 => CTR => A9: 2,8
* DIS # D4: 8,9 => CTR => D4: 6,7
* DIS # D7: 8,9 => CTR => D7: 2,6
* DIS # D9: 8,9 => CTR => D9: 2,6,7
* DIS # F4: 6,9 => CTR => F4: 7,8
* DIS # B6: 2,9 => CTR => B6: 6,8
* DIS # C6: 2,9 => CTR => C6: 6,8
* DIS # A9: 2,9 => CTR => A9: 8
* PRF # A9: 8 => SOL
* DIS # F4: 6,9 => CTR => F4: 7,8
* PRF # B6: 6,9 => SOL
* DIS # C6: 6,9 => CTR => C6: 2,8
* DIS # F4: 6,9 => CTR => F4: 7,8
* DIS # B7: 6,8 => CTR => B7: 2,9
* DIS # C9: 6,8 => CTR => C9: 2,9
* DIS # C6: 2,9 => CTR => C6: 6,8
* PRF # D7: 6,8 => SOL
* DIS # D9: 6,8 => CTR => D9: 2,7,9
* DIS # E9: 6,8 => CTR => E9: 7,9
* DIS # D4: 6,8 => CTR => D4: 7,9
* DIS # B7: 6,8 => CTR => B7: 2,9
* PRF # D7: 6,8 => SOL
* DIS # C9: 6,8 => CTR => C9: 2,9
* DIS # D9: 6,8 => CTR => D9: 2,7,9
* DIS # E9: 6,8 => CTR => E9: 7,9
* CNT  26 HDP CHAINS /  65 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 # B7: 8,9 => CTR => B7: 2,6
* PRF B7: 2,6 # B6: 2,6 => SOL
* STA B7: 2,6 + B6: 2,6
* CNT   2 HDP CHAINS /   4 HYP OPENED

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

Details

Positions

6...2..7..4.5....3.........1.5....2....4..8.....3.........1.5..7.....9..........4 initial
6.3.24175.415...935..13..48135...42....45.83.4..3..75.3.4.1.5.775..43912.1...53.4 autosolve
683924175241587693597136248135768429972451836468392751324619587756843912819275364 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (15)
B1: 8,9
A2: 2,8
D1: 8,9
F3: 6,9
G2: 2,6
G3: 2,6
A5: 2,9
F5: 1,2
E6: 6,9
F6: 1,2
I4: 6,9
C8: 6,8
D8: 6,8
H7: 6,8
H9: 6,8

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
F5,F6: 1.. / F5 = 1  => 14 pairs (_) / F6 = 1  => 18 pairs (_)
I5,I6: 1.. / I5 = 1  => 18 pairs (_) / I6 = 1  => 14 pairs (_)
F5,I5: 1.. / F5 = 1  => 14 pairs (_) / I5 = 1  => 18 pairs (_)
F6,I6: 1.. / F6 = 1  => 18 pairs (_) / I6 = 1  => 14 pairs (_)
G2,G3: 2.. / G2 = 2  =>  0 pairs (X) / G3 = 2  =>  0 pairs (_)
F5,F6: 2.. / F5 = 2  => 18 pairs (_) / F6 = 2  => 14 pairs (_)
D7,D9: 2.. / D7 = 2  => 15 pairs (_) / D9 = 2  => 20 pairs (_)
A2,G2: 2.. / A2 = 2  =>  0 pairs (*) / G2 = 2  =>  0 pairs (X)
B7,D7: 2.. / B7 = 2  => 20 pairs (_) / D7 = 2  => 15 pairs (_)
G2,G3: 6.. / G2 = 6  =>  0 pairs (*) / G3 = 6  =>  0 pairs (X)
H7,H9: 6.. / H7 = 6  =>  0 pairs (X) / H9 = 6  => 16 pairs (_)
F3,G3: 6.. / F3 = 6  =>  0 pairs (*) / G3 = 6  =>  0 pairs (X)
C8,D8: 6.. / C8 = 6  =>  0 pairs (*) / D8 = 6  =>  0 pairs (X)
B3,C3: 7.. / B3 = 7  => 16 pairs (_) / C3 = 7  => 16 pairs (_)
E2,F2: 7.. / E2 = 7  => 17 pairs (_) / F2 = 7  => 16 pairs (_)
B5,C5: 7.. / B5 = 7  => 16 pairs (_) / C5 = 7  => 16 pairs (_)
D9,E9: 7.. / D9 = 7  => 15 pairs (_) / E9 = 7  => 18 pairs (_)
B3,B5: 7.. / B3 = 7  => 16 pairs (_) / B5 = 7  => 16 pairs (_)
C3,C5: 7.. / C3 = 7  => 16 pairs (_) / C5 = 7  => 16 pairs (_)
D4,D9: 7.. / D4 = 7  => 18 pairs (_) / D9 = 7  => 15 pairs (_)
F2,F4: 7.. / F2 = 7  => 16 pairs (_) / F4 = 7  => 17 pairs (_)
B1,A2: 8.. / B1 = 8  =>  0 pairs (*) / A2 = 8  =>  0 pairs (X)
B6,C6: 8.. / B6 = 8  =>  0 pairs (X) / C6 = 8  =>  0 pairs (_)
H7,H9: 8.. / H7 = 8  => 16 pairs (_) / H9 = 8  =>  0 pairs (X)
B1,D1: 8.. / B1 = 8  =>  0 pairs (*) / D1 = 8  =>  0 pairs (X)
C8,D8: 8.. / C8 = 8  =>  0 pairs (X) / D8 = 8  =>  0 pairs (_)
A2,A9: 8.. / A2 = 8  =>  0 pairs (X) / A9 = 8  =>  0 pairs (_)
D1,F3: 9.. / D1 = 9  =>  0 pairs (*) / F3 = 9  =>  0 pairs (X)
B1,D1: 9.. / B1 = 9  =>  0 pairs (X) / D1 = 9  =>  0 pairs (_)
A5,A9: 9.. / A5 = 9  => 16 pairs (_) / A9 = 9  =>  0 pairs (X)
* DURATION: 0:00:55.565740  START: 11:55:32.783662  END: 11:56:28.349402 2017-05-04
* CP COUNT: (30)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A2,A5,B1,C8,D1,D8,E6,F3,F5,F6,G2,G3,H7,H9,I4)
* 6.3.24175.415...935..13..48135...42....45.83.4..3..75.3.4.1.5.775..43912.1...53.4
* PAIR B1: 8,9 COL B
B6: 8,9,2,6                              # reduction candidate for 8,9
B6: 8,9                                  # 18 pairs
B7: 8,9,2,6                              # reduction candidate for 8,9
B7: 8,9 => CTR
* 6839241752415..693579136248135...42.9.745.83.4.83..75.39421.5.7756843912.1...53.4
B7: 2,6                                  # 16 pairs
* PAIR A2: 2,8 COL A
A9: 2,8,9                                # reduction candidate for 2,8
A9: 9 => CTR
* 6938241758415672935.21396481357864292..45183.4..3.27513.491.5.775864391291.275384
A9: 2,8                                  # 16 pairs
* PAIR D1: 8,9 COL D
D4: 8,9,6,7                              # reduction candidate for 8,9
D4: 8,9 => CTR
* 6938241758415..2935..1396481359..426...45.83.48.36.75.3642185.7758643912.1.7.53.4
D4: 6,7                                  # 16 pairs
D7: 8,9,2,6                              # reduction candidate for 8,9
D7: 8,9 => CTR
* 6.3.241758415672935.21396481357864292.74518364..3..75.324.1.5.775.643912.16275384
D7: 2,6                                  # 16 pairs
D9: 8,9,2,6,7                            # reduction candidate for 8,9
D9: 8,9 => CTR
* 6.3.241758415672935..139648135786429...45.83.48.39.75.39421.5.7758643912.1..753.4
D9: 2,6,7                                # 15 pairs
* PAIR F3: 6,9 COL F
F4: 6,9,7,8                              # reduction candidate for 6,9
F4: 6,9 => CTR
* 6938241758415672935..139648135786429.6.45.83.48.39.7563.4.18567758643912.16.75384
F4: 7,8                                  # 16 pairs
F7: 6,9,8                                # reduction candidate for 6,9
F7: 6,9                                  # 18 pairs
* PAIR A5: 2,9 BLK 4
B5: 2,9,6,7                              # reduction candidate for 2,9
B5: 2,9                                  # 16 pairs
C5: 2,9,6,7                              # reduction candidate for 2,9
C5: 2,9                                  # 16 pairs
B6: 2,9,6,8                              # reduction candidate for 2,9
B6: 2,9 => CTR
* 6839241752415..6935..136248135...42.9674528314283.175.394.1.5.7756843912.1...53.4
B6: 6,8                                  # 16 pairs
C6: 2,9,6,8                              # reduction candidate for 2,9
C6: 2,9 => CTR
* 6938241758415672935..1396481357864292.945.83.48.3..75.3.491.5.7758643912.1.275384
C6: 6,8                                  # 17 pairs
* PAIR A5: 2,9 COL A
A9: 2,9,8                                # reduction candidate for 2,9
A9: 2,9 => CTR
* 6938241758415672935..1396481357864292.94518364863..75.3.491.5.7758643912.1.275384
A9: 8 => SOLVED
* 683924175241587693597136248135768429972451836468392751324619587756843912819275364
* PAIR E6: 6,9 BLK 5
D4: 6,9,7,8                              # reduction candidate for 6,9
D4: 6,9                                  # 18 pairs
E4: 6,9,7,8                              # reduction candidate for 6,9
E4: 6,9                                  # 21 pairs
F4: 6,9,7,8                              # reduction candidate for 6,9
F4: 6,9 => CTR
* 6938241758415672935..139648135786429.6.45.83.48.39.7563.4.18567758643912.16.75384
F4: 7,8                                  # 16 pairs
* PAIR E6: 6,9 ROW 6
B6: 6,9,2,8                              # reduction candidate for 6,9
B6: 6,9 => SOLVED
* 683924175241587693597136248135768429972451836468392751324619587756843912819275364
B6: 2,8                                  # 16 pairs
C6: 6,9,2,8                              # reduction candidate for 6,9
C6: 6,9 => CTR
* 6938241758415672935..1396481357864292.94518364863.27513.491.5.7758643912.1.275384
C6: 2,8                                  # 16 pairs
I6: 6,9,1                                # reduction candidate for 6,9
I6: 6,9                                  # 18 pairs
* PAIR E6: 6,9 COL E
E9: 6,9,7,8                              # reduction candidate for 6,9
E9: 6,9                                  # 19 pairs
E9: 7,8                                  # 16 pairs
* PAIR I4: 6,9 BLK 6
I5: 6,9,1                                # reduction candidate for 6,9
I5: 6,9                                  # 14 pairs
I6: 6,9,1                                # reduction candidate for 6,9
I6: 6,9                                  # 18 pairs
* PAIR I4: 6,9 ROW 4
D4: 6,9,7,8                              # reduction candidate for 6,9
D4: 6,9                                  # 18 pairs
E4: 6,9,7,8                              # reduction candidate for 6,9
E4: 6,9                                  # 21 pairs
F4: 6,9,7,8                              # reduction candidate for 6,9
F4: 6,9 => CTR
* 6938241758415672935..139648135786429.6.45.83.48.39.7563.4.18567758643912.16.75384
F4: 7,8                                  # 16 pairs
* PAIR C8: 6,8 BLK 7
B7: 6,8,2,9                              # reduction candidate for 6,8
B7: 6,8 => CTR
* 6839241752415..6935..136248135...42.9..45.83.4.83..75.3.42195.775..43912.1...53.4
B7: 2,9                                  # 16 pairs
C9: 6,8,2,9                              # reduction candidate for 6,8
C9: 6,8 => CTR
* 6938241758415..2935..139648135.8.42..6745.83.489362751324918567758643912916275384
C9: 2,9                                  # 16 pairs
* PAIR C8: 6,8 COL C
C6: 6,8,2,9                              # reduction candidate for 6,8
C6: 2,9 => CTR
* 6938241758415672935..1396481357864292.945.83.48.3..75.3.491.5.7758643912.1.275384
C6: 6,8                                  # 17 pairs
* PAIR D8: 6,8 BLK 8
D7: 6,8,2,9                              # reduction candidate for 6,8
D7: 6,8 => SOLVED
* 683924175241587693597136248135768429972451836468392751324619587756843912819275364
D7: 2,9                                  # 16 pairs
F7: 6,8,9                                # reduction candidate for 6,8
F7: 6,8                                  # 19 pairs
D9: 6,8,2,7,9                            # reduction candidate for 6,8
D9: 6,8 => CTR
* 6839241752415876935..1362481357.842.9..45.83.4.83..75.3.42195.775..43912.1..753.4
D9: 2,7,9                                # 15 pairs
E9: 6,8,7,9                              # reduction candidate for 6,8
E9: 6,8 => CTR
* 6839241752415..6935..136248135...42.9..45.83.4.83..75.3.42195.775..43912.1.7.53.4
E9: 7,9                                  # 16 pairs
* PAIR D8: 6,8 COL D
D4: 6,8,7,9                              # reduction candidate for 6,8
D4: 6,8 => CTR
* 6839241752415..6935..136248135...42.9..45.83.4.83..75.3.421.5.77568439128127.53.4
D4: 7,9                                  # 17 pairs
* PAIR H7: 6,8 ROW 7
B7: 6,8,2,9                              # reduction candidate for 6,8
B7: 6,8 => CTR
* 6839241752415..6935..136248135...42.9..45.83.4.83..75.3.42195.775..43912.1...53.4
B7: 2,9                                  # 16 pairs
D7: 6,8,2,9                              # reduction candidate for 6,8
D7: 6,8 => SOLVED
* 683924175241587693597136248135768429972451836468392751324619587756843912819275364
D7: 2,9                                  # 16 pairs
F7: 6,8,9                                # reduction candidate for 6,8
F7: 6,8                                  # 19 pairs
* PAIR H9: 6,8 ROW 9
C9: 6,8,2,9                              # reduction candidate for 6,8
C9: 6,8 => CTR
* 6938241758415..2935..139648135.8.42..6745.83.489362751324918567758643912916275384
C9: 2,9                                  # 16 pairs
D9: 6,8,2,7,9                            # reduction candidate for 6,8
D9: 6,8 => CTR
* 6839241752415876935..1362481357.842.9..45.83.4.83..75.3.42195.775..43912.1..753.4
D9: 2,7,9                                # 15 pairs
E9: 6,8,7,9                              # reduction candidate for 6,8
E9: 6,8 => CTR
* 6839241752415..6935..136248135...42.9..45.83.4.83..75.3.42195.775..43912.1.7.53.4
E9: 7,9                                  # 16 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-265-base-pr-000.dot
* REASONING
* DIS # B7: 8,9 => CTR => B7: 2,6
* DIS # A9: 9 => CTR => A9: 2,8
* DIS # D4: 8,9 => CTR => D4: 6,7
* DIS # D7: 8,9 => CTR => D7: 2,6
* DIS # D9: 8,9 => CTR => D9: 2,6,7
* DIS # F4: 6,9 => CTR => F4: 7,8
* DIS # B6: 2,9 => CTR => B6: 6,8
* DIS # C6: 2,9 => CTR => C6: 6,8
* DIS # A9: 2,9 => CTR => A9: 8
* PRF # A9: 8 => SOL
* DIS # F4: 6,9 => CTR => F4: 7,8
* PRF # B6: 6,9 => SOL
* DIS # C6: 6,9 => CTR => C6: 2,8
* DIS # F4: 6,9 => CTR => F4: 7,8
* DIS # B7: 6,8 => CTR => B7: 2,9
* DIS # C9: 6,8 => CTR => C9: 2,9
* DIS # C6: 2,9 => CTR => C6: 6,8
* PRF # D7: 6,8 => SOL
* DIS # D9: 6,8 => CTR => D9: 2,7,9
* DIS # E9: 6,8 => CTR => E9: 7,9
* DIS # D4: 6,8 => CTR => D4: 7,9
* DIS # B7: 6,8 => CTR => B7: 2,9
* PRF # D7: 6,8 => SOL
* DIS # C9: 6,8 => CTR => C9: 2,9
* DIS # D9: 6,8 => CTR => D9: 2,7,9
* DIS # E9: 6,8 => CTR => E9: 7,9
* CNT  26 HDP CHAINS /  65 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A2,A5,B1,C8,D1,D8,E6,F3,F5,F6,G2,G3,H7,H9,I4)
* 6.3.24175.415...935..13..48135...42....45.83.4..3..75.3.4.1.5.775..43912.1...53.4
* PAIR B1: 8,9 COL B
B6: 8,9,2,6                              # reduction candidate for 8,9
B6: 8,9                                  # 18 pairs
B7: 8,9,2,6                              # reduction candidate for 8,9
B7: 8,9 => CTR
* 6839241752415..693579136248135...42.9.745.83.4.83..75.39421.5.7756843912.1...53.4
* RESTART
* PAIR B1: 8,9 COL B
B6: 8,9,2,6                              # reduction candidate for 8,9
B6: 2,6 => SOLVED
* 683924175241587693597136248135768429972451836468392751324619587756843912819275364
* DURATION: 0:00:05.598630  START: 11:57:34.273951  END: 11:57:39.872581 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-265-base-pr-001.dot
* REASONING
* DIS # B7: 8,9 => CTR => B7: 2,6
* PRF B7: 2,6 # B6: 2,6 => SOL
* STA B7: 2,6 + B6: 2,6
* CNT   2 HDP CHAINS /   4 HYP OPENED

Header Info

Top 500 Minimum 17 265

solution: 683924175241587693597136248135768429972451836468392751324619587756843912819275364
info: 2132     FNBHWXY  S8.f     34538

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

Solution

position: 683924175241587693597136248135768429972451836468392751324619587756843912819275364 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 # B6: 8,9 => UNS
* DIS # B7: 8,9 => CTR => B7: 2,6
* INC # B7: 2,6 => UNS
* INC # A9: 2,8 => UNS
* DIS # A9: 9 => CTR => A9: 2,8
* DIS # D4: 8,9 => CTR => D4: 6,7
* INC # D4: 6,7 => UNS
* DIS # D7: 8,9 => CTR => D7: 2,6
* INC # D7: 2,6 => UNS
* DIS # D9: 8,9 => CTR => D9: 2,6,7
* INC # D9: 2,6,7 => UNS
* DIS # F4: 6,9 => CTR => F4: 7,8
* INC # F4: 7,8 => UNS
* INC # F7: 6,9 => UNS
* INC # B5: 2,9 => UNS
* INC # C5: 2,9 => UNS
* DIS # B6: 2,9 => CTR => B6: 6,8
* INC # B6: 6,8 => UNS
* DIS # C6: 2,9 => CTR => C6: 6,8
* INC # C6: 6,8 => UNS
* DIS # A9: 2,9 => CTR => A9: 8
* PRF # A9: 8 => SOL
* INC # D4: 6,9 => UNS
* INC # E4: 6,9 => UNS
* DIS # F4: 6,9 => CTR => F4: 7,8
* INC # F4: 7,8 => UNS
* PRF # B6: 6,9 => SOL
* INC # B6: 2,8 => UNS
* DIS # C6: 6,9 => CTR => C6: 2,8
* INC # C6: 2,8 => UNS
* INC # I6: 6,9 => UNS
* INC # E9: 6,9 => UNS
* INC # E9: 7,8 => UNS
* INC # I5: 6,9 => UNS
* INC # I6: 6,9 => UNS
* INC # D4: 6,9 => UNS
* INC # E4: 6,9 => UNS
* DIS # F4: 6,9 => CTR => F4: 7,8
* INC # F4: 7,8 => UNS
* DIS # B7: 6,8 => CTR => B7: 2,9
* INC # B7: 2,9 => UNS
* DIS # C9: 6,8 => CTR => C9: 2,9
* INC # C9: 2,9 => UNS
* INC # C6: 6,8 => UNS
* DIS # C6: 2,9 => CTR => C6: 6,8
* PRF # D7: 6,8 => SOL
* INC # D7: 2,9 => UNS
* INC # F7: 6,8 => UNS
* DIS # D9: 6,8 => CTR => D9: 2,7,9
* INC # D9: 2,7,9 => UNS
* DIS # E9: 6,8 => CTR => E9: 7,9
* INC # E9: 7,9 => UNS
* DIS # D4: 6,8 => CTR => D4: 7,9
* INC # D4: 7,9 => UNS
* DIS # B7: 6,8 => CTR => B7: 2,9
* INC # B7: 2,9 => UNS
* PRF # D7: 6,8 => SOL
* INC # D7: 2,9 => UNS
* INC # F7: 6,8 => UNS
* DIS # C9: 6,8 => CTR => C9: 2,9
* INC # C9: 2,9 => UNS
* DIS # D9: 6,8 => CTR => D9: 2,7,9
* INC # D9: 2,7,9 => UNS
* DIS # E9: 6,8 => CTR => E9: 7,9
* INC # E9: 7,9 => UNS
* CNT  65 HDP CHAINS /  65 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # B6: 8,9 => UNS
* DIS # B7: 8,9 => CTR => B7: 2,6
* INC B7: 2,6 # B6: 8,9 => UNS
* PRF B7: 2,6 # B6: 2,6 => SOL
* STA B7: 2,6 + B6: 2,6
* CNT   4 HDP CHAINS /   4 HYP OPENED