Analysis of xx-top500-193-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 2...6...7.8..2.........1.4.6.....2.1...4...........3...4.3...5...1............8.. initial

Autosolve

position: 213564987486.2.135...831642654.832.113.4.2568.281563.4.4231.756..16..42336.24.819 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # A3: 7,9 => CTR => A3: 5
* PRF # A3: 5 => SOL
* PRF # C3: 7,9 => SOL
* DIS # C3: 5 => CTR => C3: 7,9
* PRF # C3: 7,9 => SOL
* DIS # C3: 5 => CTR => C3: 7,9
* DIS # A3: 7,9 => CTR => A3: 5
* PRF # A3: 5 => SOL
* PRF # C3: 5,7 => SOL
* DIS # C3: 9 => CTR => C3: 5,7
* CNT  10 HDP CHAINS /  10 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 # A3: 7,9 => CTR => A3: 5
* PRF A3: 5 => SOL
* STA A3: 5
* CNT   2 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

2...6...7.8..2.........1.4.6.....2.1...4...........3...4.3...5...1............8.. initial
213564987486.2.135...831642654.832.113.4.2568.281563.4.4231.756..16..42336.24.819 autosolve
213564987486729135597831642654983271139472568728156394942318756871695423365247819 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (17)
B3: 7,9
D2: 7,9
F2: 7,9
C5: 7,9
A6: 7,9
D4: 7,9
E5: 7,9
H4: 7,9
H6: 7,9
A7: 8,9
A8: 5,8
B8: 7,9
C9: 5,7
F7: 8,9
E8: 7,9
F8: 5,8
F9: 5,7

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
A3,C3: 5.. / A3 = 5  =>  0 pairs (*) / C3 = 5  =>  0 pairs (X)
A8,C9: 5.. / A8 = 5  =>  0 pairs (X) / C9 = 5  =>  0 pairs (_)
F8,F9: 5.. / F8 = 5  =>  0 pairs (*) / F9 = 5  =>  0 pairs (X)
A8,F8: 5.. / A8 = 5  =>  0 pairs (X) / F8 = 5  =>  0 pairs (_)
C9,F9: 5.. / C9 = 5  =>  0 pairs (*) / F9 = 5  =>  0 pairs (X)
A3,A8: 5.. / A3 = 5  =>  0 pairs (*) / A8 = 5  =>  0 pairs (X)
C3,C9: 5.. / C3 = 5  =>  0 pairs (X) / C9 = 5  =>  0 pairs (_)
D2,F2: 7.. / D2 = 7  =>  0 pairs (*) / F2 = 7  =>  0 pairs (X)
C5,A6: 7.. / C5 = 7  =>  0 pairs (X) / A6 = 7  =>  0 pairs (_)
D4,E5: 7.. / D4 = 7  =>  0 pairs (X) / E5 = 7  =>  0 pairs (_)
H4,H6: 7.. / H4 = 7  =>  0 pairs (*) / H6 = 7  =>  0 pairs (X)
B8,C9: 7.. / B8 = 7  =>  0 pairs (*) / C9 = 7  =>  0 pairs (X)
E8,F9: 7.. / E8 = 7  =>  0 pairs (X) / F9 = 7  =>  0 pairs (_)
D4,H4: 7.. / D4 = 7  =>  0 pairs (X) / H4 = 7  =>  0 pairs (_)
C5,E5: 7.. / C5 = 7  =>  0 pairs (X) / E5 = 7  =>  0 pairs (_)
A6,H6: 7.. / A6 = 7  =>  0 pairs (*) / H6 = 7  =>  0 pairs (X)
B8,E8: 7.. / B8 = 7  =>  0 pairs (*) / E8 = 7  =>  0 pairs (X)
C9,F9: 7.. / C9 = 7  =>  0 pairs (X) / F9 = 7  =>  0 pairs (_)
A3,A6: 7.. / A3 = 7  =>  0 pairs (X) / A6 = 7  =>  0 pairs (_)
B3,B8: 7.. / B3 = 7  =>  0 pairs (X) / B8 = 7  =>  0 pairs (_)
D2,D4: 7.. / D2 = 7  =>  0 pairs (*) / D4 = 7  =>  0 pairs (X)
E5,E8: 7.. / E5 = 7  =>  0 pairs (*) / E8 = 7  =>  0 pairs (X)
F2,F9: 7.. / F2 = 7  =>  0 pairs (X) / F9 = 7  =>  0 pairs (_)
A7,A8: 8.. / A7 = 8  =>  0 pairs (X) / A8 = 8  =>  0 pairs (_)
F7,F8: 8.. / F7 = 8  =>  0 pairs (*) / F8 = 8  =>  0 pairs (X)
A7,F7: 8.. / A7 = 8  =>  0 pairs (X) / F7 = 8  =>  0 pairs (_)
A8,F8: 8.. / A8 = 8  =>  0 pairs (*) / F8 = 8  =>  0 pairs (X)
D2,F2: 9.. / D2 = 9  =>  0 pairs (X) / F2 = 9  =>  0 pairs (_)
C5,A6: 9.. / C5 = 9  =>  0 pairs (*) / A6 = 9  =>  0 pairs (X)
D4,E5: 9.. / D4 = 9  =>  0 pairs (*) / E5 = 9  =>  0 pairs (X)
H4,H6: 9.. / H4 = 9  =>  0 pairs (X) / H6 = 9  =>  0 pairs (_)
A7,B8: 9.. / A7 = 9  =>  0 pairs (*) / B8 = 9  =>  0 pairs (X)
F7,E8: 9.. / F7 = 9  =>  0 pairs (X) / E8 = 9  =>  0 pairs (_)
D4,H4: 9.. / D4 = 9  =>  0 pairs (*) / H4 = 9  =>  0 pairs (X)
C5,E5: 9.. / C5 = 9  =>  0 pairs (*) / E5 = 9  =>  0 pairs (X)
A6,H6: 9.. / A6 = 9  =>  0 pairs (X) / H6 = 9  =>  0 pairs (_)
A7,F7: 9.. / A7 = 9  =>  0 pairs (*) / F7 = 9  =>  0 pairs (X)
B8,E8: 9.. / B8 = 9  =>  0 pairs (X) / E8 = 9  =>  0 pairs (_)
B3,B8: 9.. / B3 = 9  =>  0 pairs (*) / B8 = 9  =>  0 pairs (X)
C3,C5: 9.. / C3 = 9  =>  0 pairs (X) / C5 = 9  =>  0 pairs (_)
D2,D4: 9.. / D2 = 9  =>  0 pairs (X) / D4 = 9  =>  0 pairs (_)
E5,E8: 9.. / E5 = 9  =>  0 pairs (X) / E8 = 9  =>  0 pairs (_)
F2,F7: 9.. / F2 = 9  =>  0 pairs (*) / F7 = 9  =>  0 pairs (X)
* DURATION: 0:01:32.587323  START: 09:20:24.954696  END: 09:21:57.542019 2017-05-04
* CP COUNT: (43)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A6,A7,A8,B3,B8,C5,C9,D2,D4,E5,E8,F2,F7,F8,F9,H4,H6)
* 213564987486.2.135...831642654.832.113.4.2568.281563.4.4231.756..16..42336.24.819
* PAIR B3: 7,9 BLK 1
A3: 7,9,5                                # reduction candidate for 7,9
A3: 7,9 => CTR
* 213564987486.2.135..5831642654.832.1139472568728156394.4231.7565716..42336.24.819
A3: 5 => SOLVED
* 213564987486729135597831642654983271139472568728156394942318756871695423365247819
C3: 7,9,5                                # reduction candidate for 7,9
C3: 7,9 => SOLVED
* 213564987486729135597831642654983271139472568728156394942318756871695423365247819
C3: 5 => CTR
* 213564987486.2.135..5831642654.832.1139472568728156394.4231.7565716..42336.24.819
* PAIR C5: 7,9 COL C
C3: 7,9,5                                # reduction candidate for 7,9
C3: 7,9 => SOLVED
* 213564987486729135597831642654983271139472568728156394942318756871695423365247819
C3: 5 => CTR
* 213564987486.2.135..5831642654.832.1139472568728156394.4231.7565716..42336.24.819
* PAIR A6: 7,9 COL A
A3: 7,9,5                                # reduction candidate for 7,9
A3: 7,9 => CTR
* 213564987486.2.135..5831642654.832.1139472568728156394.4231.7565716..42336.24.819
A3: 5 => SOLVED
* 213564987486729135597831642654983271139472568728156394942318756871695423365247819
* PAIR C9: 5,7 COL C
C3: 5,7,9                                # reduction candidate for 5,7
C3: 5,7 => SOLVED
* 213564987486729135597831642654983271139472568728156394942318756871695423365247819
C3: 9 => CTR
* 213564987486.2.135579831642654.832.113.4.2568.281563.4.4231.756..16..42336.24.819
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-193-base-pr-000.dot
* REASONING
* DIS # A3: 7,9 => CTR => A3: 5
* PRF # A3: 5 => SOL
* PRF # C3: 7,9 => SOL
* DIS # C3: 5 => CTR => C3: 7,9
* PRF # C3: 7,9 => SOL
* DIS # C3: 5 => CTR => C3: 7,9
* DIS # A3: 7,9 => CTR => A3: 5
* PRF # A3: 5 => SOL
* PRF # C3: 5,7 => SOL
* DIS # C3: 9 => CTR => C3: 5,7
* CNT  10 HDP CHAINS /  10 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A6,A7,A8,B3,B8,C5,C9,D2,D4,E5,E8,F2,F7,F8,F9,H4,H6)
* 213564987486.2.135...831642654.832.113.4.2568.281563.4.4231.756..16..42336.24.819
* PAIR B3: 7,9 BLK 1
A3: 7,9,5                                # reduction candidate for 7,9
A3: 7,9 => CTR
* 213564987486.2.135..5831642654.832.1139472568728156394.4231.7565716..42336.24.819
A3: 5 => SOLVED
* 213564987486729135597831642654983271139472568728156394942318756871695423365247819
* DURATION: 0:00:01.834059  START: 09:22:13.378545  END: 09:22:15.212604 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-193-base-pr-001.dot
* REASONING
* DIS # A3: 7,9 => CTR => A3: 5
* PRF A3: 5 => SOL
* STA A3: 5
* CNT   2 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 193

solution: 213564987486729135597831642654983271139472568728156394942318756871695423365247819
info: 1849     FNBTWX   S8.f     46313

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

Solution

position: 213564987486729135597831642654983271139472568728156394942318756871695423365247819 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:

* DIS # A3: 7,9 => CTR => A3: 5
* PRF # A3: 5 => SOL
* PRF # C3: 7,9 => SOL
* DIS # C3: 5 => CTR => C3: 7,9
* PRF # C3: 7,9 => SOL
* DIS # C3: 5 => CTR => C3: 7,9
* DIS # A3: 7,9 => CTR => A3: 5
* PRF # A3: 5 => SOL
* PRF # C3: 5,7 => SOL
* DIS # C3: 9 => CTR => C3: 5,7
* CNT  10 HDP CHAINS /  10 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # A3: 7,9 => CTR => A3: 5
* PRF A3: 5 => SOL
* STA A3: 5
* CNT   2 HDP CHAINS /   1 HYP OPENED