Analysis of xx-top500-433-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 9.24........6....1.........76.............54.......2..83..9...7....2..8......5... initial

Autosolve

position: 952431768...6.2951...5.9432764253819...71.54.5..94.27.835194627...327185...865394 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # C3: 7,8 => CTR => C3: 1,6
* DIS # B2: 7,8 => CTR => B2: 4
* PRF # B2: 4 => SOL
* PRF # C2: 7,8 => SOL
* DIS # C2: 3 => CTR => C2: 7,8
* DIS # C3: 7,8 => CTR => C3: 1,6
* PRF # C6: 3 => SOL
* DIS # B9: 7 => CTR => B9: 1,2
* DIS # B9: 1,7 => CTR => B9: 2
* PRF # B9: 2 => SOL
* PRF # C3: 1,7 => SOL
* CNT  11 HDP CHAINS /  19 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 # C3: 7,8 => CTR => C3: 1,6
* DIS C3: 1,6 # B2: 7,8 => CTR => B2: 4
* PRF C3: 1,6 + B2: 4 => SOL
* STA C3: 1,6 + B2: 4
* CNT   3 HDP CHAINS /   3 HYP OPENED

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

Details

Positions

9.24........6....1.........76.............54.......2..83..9...7....2..8......5... initial
952431768...6.2951...5.9432764253819...71.54.5..94.27.835194627...327185...865394 autosolve
952431768348672951671589432764253819289716543513948276835194627496327185127865394 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (15)
A2: 3,4
A3: 1,6
E2: 7,8
E3: 7,8
A5: 2,3
B6: 1,8
F5: 6,8
F6: 6,8
I5: 3,6
I6: 3,6
A8: 4,6
B8: 4,9
C8: 6,9
A9: 1,2
C9: 1,7

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
B6,C6: 1.. / B6 = 1  => 18 pairs (_) / C6 = 1  => 16 pairs (_)
A3,A9: 1.. / A3 = 1  =>  0 pairs (X) / A9 = 1  =>  0 pairs (_)
A5,B5: 2.. / A5 = 2  =>  0 pairs (*) / B5 = 2  =>  0 pairs (X)
A9,B9: 2.. / A9 = 2  =>  0 pairs (X) / B9 = 2  =>  0 pairs (_)
A5,A9: 2.. / A5 = 2  =>  0 pairs (*) / A9 = 2  =>  0 pairs (X)
B5,B9: 2.. / B5 = 2  =>  0 pairs (X) / B9 = 2  =>  0 pairs (_)
A2,C2: 3.. / A2 = 3  =>  0 pairs (*) / C2 = 3  =>  0 pairs (X)
I5,I6: 3.. / I5 = 3  =>  0 pairs (*) / I6 = 3  =>  0 pairs (X)
C6,I6: 3.. / C6 = 3  =>  0 pairs (*) / I6 = 3  =>  0 pairs (X)
A2,A5: 3.. / A2 = 3  =>  0 pairs (*) / A5 = 3  =>  0 pairs (X)
A2,B2: 4.. / A2 = 4  =>  0 pairs (X) / B2 = 4  =>  0 pairs (_)
A8,B8: 4.. / A8 = 4  =>  0 pairs (*) / B8 = 4  =>  0 pairs (X)
A2,A8: 4.. / A2 = 4  =>  0 pairs (X) / A8 = 4  =>  0 pairs (_)
B2,B8: 4.. / B2 = 4  =>  0 pairs (*) / B8 = 4  =>  0 pairs (X)
A3,C3: 6.. / A3 = 6  =>  0 pairs (*) / C3 = 6  =>  0 pairs (X)
F5,F6: 6.. / F5 = 6  =>  0 pairs (*) / F6 = 6  =>  0 pairs (X)
I5,I6: 6.. / I5 = 6  => 14 pairs (_) / I6 = 6  =>  0 pairs (*)
A8,C8: 6.. / A8 = 6  =>  0 pairs (X) / C8 = 6  =>  0 pairs (_)
F5,I5: 6.. / F5 = 6  =>  0 pairs (*) / I5 = 6  =>  0 pairs (X)
F6,I6: 6.. / F6 = 6  => 14 pairs (_) / I6 = 6  =>  0 pairs (*)
A3,A8: 6.. / A3 = 6  =>  0 pairs (*) / A8 = 6  =>  0 pairs (X)
C3,C8: 6.. / C3 = 6  =>  0 pairs (X) / C8 = 6  =>  0 pairs (_)
E2,E3: 7.. / E2 = 7  => 16 pairs (_) / E3 = 7  => 18 pairs (_)
B9,C9: 7.. / B9 = 7  =>  0 pairs (X) / C9 = 7  => 16 pairs (_)
E2,E3: 8.. / E2 = 8  => 18 pairs (_) / E3 = 8  => 16 pairs (_)
F5,F6: 8.. / F5 = 8  => 14 pairs (_) / F6 = 8  =>  0 pairs (*)
B5,C5: 9.. / B5 = 9  =>  0 pairs (X) / C5 = 9  =>  0 pairs (_)
B8,C8: 9.. / B8 = 9  =>  0 pairs (*) / C8 = 9  =>  0 pairs (X)
B5,B8: 9.. / B5 = 9  =>  0 pairs (X) / B8 = 9  =>  0 pairs (_)
C5,C8: 9.. / C5 = 9  =>  0 pairs (*) / C8 = 9  =>  0 pairs (X)
* DURATION: 0:00:53.576106  START: 17:33:30.200715  END: 17:34:23.776821 2017-05-04
* CP COUNT: (30)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A2,A3,A5,A8,A9,B6,B8,C8,C9,E2,E3,F5,F6,I5,I6)
* 952431768...6.2951...5.9432764253819...71.54.5..94.27.835194627...327185...865394
* PAIR A3: 1,6 BLK 1
C3: 1,6,7,8                              # reduction candidate for 1,6
C3: 7,8 => CTR
* 952431768...6.295161.5.9432764253819...71.54.58194627383519462749632718512.865394
C3: 1,6                                  # 17 pairs
* PAIR E2: 7,8 ROW 2
B2: 7,8,4                                # reduction candidate for 7,8
B2: 7,8 => CTR
* 9524317684.36.2951...5.94327642538193297185465..9462738351946276..327185...865394
B2: 4 => SOLVED
* 952431768348672951671589432764253819289716543513948276835194627496327185127865394
C2: 7,8,3                                # reduction candidate for 7,8
C2: 7,8 => SOLVED
* 952431768348672951671589432764253819289716543513948276835194627496327185127865394
C2: 3 => CTR
* 952431768..36.2951...5.94327642538193297185465..946273835194627.963271852..865394
* PAIR E3: 7,8 ROW 3
B3: 7,8,1                                # reduction candidate for 7,8
B3: 7,8                                  # 17 pairs
C3: 7,8,1,6                              # reduction candidate for 7,8
C3: 7,8 => CTR
* 952431768...6.295161.5.9432764253819...71.54.58194627383519462749632718512.865394
C3: 1,6                                  # 17 pairs
* PAIR B6: 1,8 BLK 4
C6: 1,8,3                                # reduction candidate for 1,8
C6: 3 => SOLVED
* 952431768348672951671589432764253819289716543513948276835194627496327185127865394
C6: 1,8                                  # 14 pairs
* PAIR B6: 1,8 COL B
B3: 1,8,7                                # reduction candidate for 1,8
B3: 1,8                                  # 19 pairs
B3: 7                                    # 16 pairs
* PAIR A9: 1,2 BLK 7
B9: 1,2,7                                # reduction candidate for 1,2
B9: 7 => CTR
* 952431768...6.2951...5.9432764253819.297185465..946273835194627.96327185271865394
B9: 1,2                                  # 16 pairs
* PAIR C9: 1,7 BLK 7
B9: 1,7,2                                # reduction candidate for 1,7
B9: 1,7 => CTR
* 952431768...6.2951...5.9432764253819.297185465..946273835194627.963271852..865394
B9: 2 => SOLVED
* 952431768348672951671589432764253819289716543513948276835194627496327185127865394
* PAIR C9: 1,7 COL C
C3: 1,7,6,8                              # reduction candidate for 1,7
C3: 1,7 => SOLVED
* 952431768348672951671589432764253819289716543513948276835194627496327185127865394
C3: 6,8                                  # 16 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-433-base-pr-000.dot
* REASONING
* DIS # C3: 7,8 => CTR => C3: 1,6
* DIS # B2: 7,8 => CTR => B2: 4
* PRF # B2: 4 => SOL
* PRF # C2: 7,8 => SOL
* DIS # C2: 3 => CTR => C2: 7,8
* DIS # C3: 7,8 => CTR => C3: 1,6
* PRF # C6: 3 => SOL
* DIS # B9: 7 => CTR => B9: 1,2
* DIS # B9: 1,7 => CTR => B9: 2
* PRF # B9: 2 => SOL
* PRF # C3: 1,7 => SOL
* CNT  11 HDP CHAINS /  19 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A2,A3,A5,A8,A9,B6,B8,C8,C9,E2,E3,F5,F6,I5,I6)
* 952431768...6.2951...5.9432764253819...71.54.5..94.27.835194627...327185...865394
* PAIR A3: 1,6 BLK 1
C3: 1,6,7,8                              # reduction candidate for 1,6
C3: 7,8 => CTR
* 952431768...6.295161.5.9432764253819...71.54.58194627383519462749632718512.865394
* PAIR E2: 7,8 ROW 2
B2: 7,8,4                                # reduction candidate for 7,8
B2: 7,8 => CTR
* 9524317684.36.2951...5.94327642538193297185465.89462738351946276..327185...865394
B2: 4 => SOLVED
* 952431768348672951671589432764253819289716543513948276835194627496327185127865394
* DURATION: 0:00:04.049416  START: 17:34:46.286396  END: 17:34:50.335812 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-433-base-pr-001.dot
* REASONING
* DIS # C3: 7,8 => CTR => C3: 1,6
* DIS C3: 1,6 # B2: 7,8 => CTR => B2: 4
* PRF C3: 1,6 + B2: 4 => SOL
* STA C3: 1,6 + B2: 4
* CNT   3 HDP CHAINS /   3 HYP OPENED

Header Info

Top 500 Minimum 17 433

solution: 952431768348672951671589432764253819289716543513948276835194627496327185127865394
info: 95227    FNBTYK   S8.f     44431

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

Solution

position: 952431768348672951671589432764253819289716543513948276835194627496327185127865394 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 # C3: 1,6 => UNS
* DIS # C3: 7,8 => CTR => C3: 1,6
* DIS # B2: 7,8 => CTR => B2: 4
* PRF # B2: 4 => SOL
* PRF # C2: 7,8 => SOL
* DIS # C2: 3 => CTR => C2: 7,8
* INC # B3: 7,8 => UNS
* DIS # C3: 7,8 => CTR => C3: 1,6
* INC # C3: 1,6 => UNS
* INC # C6: 1,8 => UNS
* PRF # C6: 3 => SOL
* INC # B3: 1,8 => UNS
* INC # B3: 7 => UNS
* INC # B9: 1,2 => UNS
* DIS # B9: 7 => CTR => B9: 1,2
* DIS # B9: 1,7 => CTR => B9: 2
* PRF # B9: 2 => SOL
* PRF # C3: 1,7 => SOL
* INC # C3: 6,8 => UNS
* CNT  19 HDP CHAINS /  19 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # C3: 1,6 => UNS
* DIS # C3: 7,8 => CTR => C3: 1,6
* DIS C3: 1,6 # B2: 7,8 => CTR => B2: 4
* PRF C3: 1,6 + B2: 4 => SOL
* STA C3: 1,6 + B2: 4
* CNT   4 HDP CHAINS /   3 HYP OPENED