Analysis of xx-top500-013-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 5...92...1.....6...............1..928..6............5..2.4..3...7.3.......9...... initial

Autosolve

position: 56.79214.1.25..6799.71..2.57568134928946257..2..9..85662.4.93.747.3..92.3.92..564 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # E2: 4,8 => CTR => E2: 3
* PRF # F3: 4,8 => SOL
* DIS # B2: 3 => CTR => B2: 4,8
* PRF # C8: 1,8 => SOL
* DIS # F9: 7 => CTR => F9: 1,8
* PRF # E8: 5,8 => SOL
* PRF # C7: 5,8 => SOL
* DIS # C7: 1 => CTR => C7: 5,8
* DIS # F9: 7,8 => CTR => F9: 1
* PRF # F9: 1 => SOL
* PRF # C7: 5 => SOL
* PRF # C8: 1,8 => SOL
* CNT  12 HDP CHAINS /  27 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 # E2: 4,8 => CTR => E2: 3
* PRF E2: 3 # F3: 4,8 => SOL
* STA E2: 3 + F3: 4,8
* CNT   2 HDP CHAINS /   5 HYP OPENED

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

Details

Positions

5...92...1.....6...............1..928..6............5..2.4..3...7.3.......9...... initial
56.79214.1.25..6799.71..2.57568134928946257..2..9..85662.4.93.747.3..92.3.92..564 autosolve
568792143142538679937164285756813492894625731213947856625489317471356928389271564 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (15)
C1: 3,8
F2: 4,8
I1: 3,8
H3: 3,8
B6: 1,3
C6: 1,3
E6: 4,7
F6: 4,7
H5: 1,3
I5: 1,3
B9: 1,8
E7: 5,8
E9: 7,8
H7: 1,8
I8: 1,8

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
B6,C6: 1.. / B6 = 1  =>  0 pairs (*) / C6 = 1  =>  0 pairs (X)
H5,I5: 1.. / H5 = 1  =>  0 pairs (X) / I5 = 1  =>  0 pairs (_)
F8,F9: 1.. / F8 = 1  =>  0 pairs (X) / F9 = 1  =>  0 pairs (_)
H7,I8: 1.. / H7 = 1  =>  0 pairs (*) / I8 = 1  =>  0 pairs (X)
C7,H7: 1.. / C7 = 1  =>  0 pairs (X) / H7 = 1  =>  0 pairs (_)
B9,F9: 1.. / B9 = 1  =>  0 pairs (X) / F9 = 1  =>  0 pairs (_)
B6,B9: 1.. / B6 = 1  =>  0 pairs (*) / B9 = 1  =>  0 pairs (X)
H5,H7: 1.. / H5 = 1  =>  0 pairs (X) / H7 = 1  =>  0 pairs (_)
I5,I8: 1.. / I5 = 1  =>  0 pairs (*) / I8 = 1  =>  0 pairs (X)
E2,E3: 3.. / E2 = 3  => 16 pairs (_) / E3 = 3  =>  0 pairs (X)
I1,H3: 3.. / I1 = 3  =>  0 pairs (*) / H3 = 3  =>  0 pairs (X)
B6,C6: 3.. / B6 = 3  =>  0 pairs (X) / C6 = 3  =>  0 pairs (_)
H5,I5: 3.. / H5 = 3  =>  0 pairs (*) / I5 = 3  =>  0 pairs (X)
C1,I1: 3.. / C1 = 3  =>  0 pairs (X) / I1 = 3  =>  0 pairs (_)
B2,E2: 3.. / B2 = 3  =>  0 pairs (X) / E2 = 3  => 16 pairs (_)
C1,C6: 3.. / C1 = 3  =>  0 pairs (X) / C6 = 3  =>  0 pairs (_)
H3,H5: 3.. / H3 = 3  =>  0 pairs (X) / H5 = 3  =>  0 pairs (_)
I1,I5: 3.. / I1 = 3  =>  0 pairs (*) / I5 = 3  =>  0 pairs (X)
B2,B3: 4.. / B2 = 4  => 19 pairs (_) / B3 = 4  => 17 pairs (_)
E6,F6: 4.. / E6 = 4  => 14 pairs (_) / F6 = 4  =>  0 pairs (X)
C7,C8: 5.. / C7 = 5  =>  0 pairs (*) / C8 = 5  =>  0 pairs (X)
E7,E8: 5.. / E7 = 5  => 16 pairs (_) / E8 = 5  =>  0 pairs (*)
C7,E7: 5.. / C7 = 5  =>  0 pairs (*) / E7 = 5  =>  0 pairs (X)
C8,E8: 5.. / C8 = 5  => 16 pairs (_) / E8 = 5  =>  0 pairs (*)
E3,F3: 6.. / E3 = 6  =>  0 pairs (*) / F3 = 6  =>  0 pairs (X)
E8,F8: 6.. / E8 = 6  => 16 pairs (_) / F8 = 6  =>  0 pairs (*)
E3,E8: 6.. / E3 = 6  =>  0 pairs (*) / E8 = 6  =>  0 pairs (X)
F3,F8: 6.. / F3 = 6  => 16 pairs (_) / F8 = 6  =>  0 pairs (*)
E6,F6: 7.. / E6 = 7  =>  0 pairs (X) / F6 = 7  => 14 pairs (_)
E9,F9: 7.. / E9 = 7  => 14 pairs (_) / F9 = 7  =>  0 pairs (X)
E6,E9: 7.. / E6 = 7  =>  0 pairs (X) / E9 = 7  => 14 pairs (_)
F6,F9: 7.. / F6 = 7  => 14 pairs (_) / F9 = 7  =>  0 pairs (X)
I1,H3: 8.. / I1 = 8  =>  0 pairs (X) / H3 = 8  =>  0 pairs (_)
H7,I8: 8.. / H7 = 8  =>  0 pairs (X) / I8 = 8  =>  0 pairs (_)
C1,I1: 8.. / C1 = 8  =>  0 pairs (*) / I1 = 8  =>  0 pairs (X)
H3,H7: 8.. / H3 = 8  =>  0 pairs (*) / H7 = 8  =>  0 pairs (X)
I1,I8: 8.. / I1 = 8  =>  0 pairs (X) / I8 = 8  =>  0 pairs (_)
* DURATION: 0:01:07.141198  START: 03:02:08.782291  END: 03:03:15.923489 2017-05-04
* CP COUNT: (37)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B6,B9,C1,C6,E6,E7,E9,F2,F6,H3,H5,H7,I1,I5,I8)
* 56.79214.1.25..6799.71..2.57568134928946257..2..9..85662.4.93.747.3..92.3.92..564
* PAIR C1: 3,8 BLK 1
B2: 3,8,4                                # reduction candidate for 3,8
B2: 3,8                                  # 17 pairs
B3: 3,8,4                                # reduction candidate for 3,8
B3: 3,8                                  # 19 pairs
* PAIR F2: 4,8 BLK 2
E2: 4,8,3                                # reduction candidate for 4,8
E2: 4,8 => CTR
* 56.79214.1325..6799471362857568134928946257312139..85662.4.93174713..92.3.92..564
E2: 3                                    # 16 pairs
E3: 4,8,3,6                              # reduction candidate for 4,8
E3: 4,8                                  # 18 pairs
F3: 4,8,6                                # reduction candidate for 4,8
F3: 4,8 => SOLVED
* 568792143142538679937164285756813492894625731213947856625489317471356928389271564
F3: 6                                    # 16 pairs
* PAIR F2: 4,8 ROW 2
B2: 4,8,3                                # reduction candidate for 4,8
B2: 3 => CTR
* 56.79214.1325..6799471362857568134928946257312139..85662.4.93174713..92.3.92..564
B2: 4,8                                  # 16 pairs
* PAIR H3: 3,8 ROW 3
B3: 3,8,4                                # reduction candidate for 3,8
B3: 3,8                                  # 19 pairs
E3: 3,8,4,6                              # reduction candidate for 3,8
E3: 3,8                                  # 18 pairs
* PAIR B9: 1,8 BLK 7
C7: 1,8,5                                # reduction candidate for 1,8
C7: 1,8                                  # 16 pairs
C8: 1,8,5                                # reduction candidate for 1,8
C8: 1,8 => SOLVED
* 568792143142538679937164285756813492894625731213947856625489317471356928389271564
C8: 5                                    # 16 pairs
* PAIR B9: 1,8 ROW 9
F9: 1,8,7                                # reduction candidate for 1,8
F9: 7 => CTR
* 5687921431.25.86799.71.628575681349289462573123.9..85662.4.93.747.3.1928319287564
F9: 1,8                                  # 14 pairs
* PAIR E7: 5,8 BLK 8
E8: 5,8,6                                # reduction candidate for 5,8
E8: 5,8 => SOLVED
* 568792143142538679937164285756813492894625731213947856625489317471356928389271564
E8: 6                                    # 16 pairs
* PAIR E7: 5,8 ROW 7
C7: 5,8,1                                # reduction candidate for 5,8
C7: 5,8 => SOLVED
* 568792143142538679937164285756813492894625731213947856625489317471356928389271564
C7: 1 => CTR
* 5687921431.25..6799.71..2.57568134928946257..2..9..8566214593874753..921389271564
* PAIR E9: 7,8 BLK 8
F9: 7,8,1                                # reduction candidate for 7,8
F9: 7,8 => CTR
* 5687921431.25..6799.71.628575681349289462573123.9..85662.4.93.747.3.19283192..564
F9: 1 => SOLVED
* 568792143142538679937164285756813492894625731213947856625489317471356928389271564
* PAIR H7: 1,8 ROW 7
C7: 1,8,5                                # reduction candidate for 1,8
C7: 5 => SOLVED
* 568792143142538679937164285756813492894625731213947856625489317471356928389271564
C7: 1,8                                  # 16 pairs
* PAIR I8: 1,8 ROW 8
C8: 1,8,5                                # reduction candidate for 1,8
C8: 1,8 => SOLVED
* 568792143142538679937164285756813492894625731213947856625489317471356928389271564
C8: 5                                    # 16 pairs
F8: 1,8,6                                # reduction candidate for 1,8
F8: 1,8                                  # 16 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-013-base-pr-000.dot
* REASONING
* DIS # E2: 4,8 => CTR => E2: 3
* PRF # F3: 4,8 => SOL
* DIS # B2: 3 => CTR => B2: 4,8
* PRF # C8: 1,8 => SOL
* DIS # F9: 7 => CTR => F9: 1,8
* PRF # E8: 5,8 => SOL
* PRF # C7: 5,8 => SOL
* DIS # C7: 1 => CTR => C7: 5,8
* DIS # F9: 7,8 => CTR => F9: 1
* PRF # F9: 1 => SOL
* PRF # C7: 5 => SOL
* PRF # C8: 1,8 => SOL
* CNT  12 HDP CHAINS /  27 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B6,B9,C1,C6,E6,E7,E9,F2,F6,H3,H5,H7,I1,I5,I8)
* 56.79214.1.25..6799.71..2.57568134928946257..2..9..85662.4.93.747.3..92.3.92..564
* PAIR C1: 3,8 BLK 1
B2: 3,8,4                                # reduction candidate for 3,8
B2: 3,8                                  # 17 pairs
B3: 3,8,4                                # reduction candidate for 3,8
B3: 3,8                                  # 19 pairs
* PAIR F2: 4,8 BLK 2
E2: 4,8,3                                # reduction candidate for 4,8
E2: 4,8 => CTR
* 56.79214.1325..6799471362857568134928946257312139..85662.4.93174713..92.3.92..564
E3: 4,8,6                                # reduction candidate for 4,8
E3: 4,8                                  # 18 pairs
F3: 4,8,6                                # reduction candidate for 4,8
F3: 4,8 => SOLVED
* 568792143142538679937164285756813492894625731213947856625489317471356928389271564
* DURATION: 0:00:06.028763  START: 03:03:45.648831  END: 03:03:51.677594 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-013-base-pr-001.dot
* REASONING
* DIS # E2: 4,8 => CTR => E2: 3
* PRF E2: 3 # F3: 4,8 => SOL
* STA E2: 3 + F3: 4,8
* CNT   2 HDP CHAINS /   5 HYP OPENED

Header Info

Top 500 Minimum 17 013

solution: 568792143142538679937164285756813492894625731213947856625489317471356928389271564
info: 1309     FNBWXY   S8.f     32644

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

Solution

position: 568792143142538679937164285756813492894625731213947856625489317471356928389271564 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 # B2: 3,8 => UNS
* INC # B3: 3,8 => UNS
* DIS # E2: 4,8 => CTR => E2: 3
* INC # E2: 3 => UNS
* INC # E3: 4,8 => UNS
* PRF # F3: 4,8 => SOL
* INC # F3: 6 => UNS
* INC # B2: 4,8 => UNS
* DIS # B2: 3 => CTR => B2: 4,8
* INC # B3: 3,8 => UNS
* INC # E3: 3,8 => UNS
* INC # C7: 1,8 => UNS
* PRF # C8: 1,8 => SOL
* INC # C8: 5 => UNS
* INC # F9: 1,8 => UNS
* DIS # F9: 7 => CTR => F9: 1,8
* PRF # E8: 5,8 => SOL
* INC # E8: 6 => UNS
* PRF # C7: 5,8 => SOL
* DIS # C7: 1 => CTR => C7: 5,8
* DIS # F9: 7,8 => CTR => F9: 1
* PRF # F9: 1 => SOL
* INC # C7: 1,8 => UNS
* PRF # C7: 5 => SOL
* PRF # C8: 1,8 => SOL
* INC # C8: 5 => UNS
* INC # F8: 1,8 => UNS
* CNT  27 HDP CHAINS /  27 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # B2: 3,8 => UNS
* INC # B3: 3,8 => UNS
* DIS # E2: 4,8 => CTR => E2: 3
* INC E2: 3 # E3: 4,8 => UNS
* PRF E2: 3 # F3: 4,8 => SOL
* STA E2: 3 + F3: 4,8
* CNT   5 HDP CHAINS /   5 HYP OPENED