Analysis of xx-top500-031-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 3.......4.7.6........1.......8....1......23......3.....5....16.2...74.........8.. initial

Autosolve

position: 3812.76.4.7264...164.1..72.4387..219.6.4.23...2.93.4.6854329167216874...7935..842 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # A5: 5,9 => CTR => A5: 1
* PRF # A5: 1 => SOL
* PRF # E3: 5,9 => SOL
* DIS # E3: 8 => CTR => E3: 5,9
* DIS # C5: 7 => CTR => C5: 5,9
* PRF # E3: 5,9 => SOL
* DIS # E3: 8 => CTR => E3: 5,9
* PRF # F3: 3,8 => SOL
* DIS # F3: 5 => CTR => F3: 3,8
* PRF # H8: 5,9 => SOL
* DIS # H8: 3 => CTR => H8: 5,9
* PRF # F3: 3,8 => SOL
* DIS # F3: 5 => CTR => F3: 3,8
* PRF # A5: 1,5 => SOL
* DIS # A5: 9 => CTR => A5: 1,5
* DIS # C5: 5,7 => CTR => C5: 9
* PRF # C5: 9 => SOL
* DIS # H6: 5,7 => CTR => H6: 8
* PRF # H6: 8 => SOL
* DIS # H5: 5,8 => CTR => H5: 7
* PRF # H8: 5,9 => SOL
* DIS # H8: 3 => CTR => H8: 5,9
* PRF # H8: 3,5 => SOL
* DIS # H8: 9 => CTR => H8: 3,5
* CNT  24 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 # A5: 5,9 => CTR => A5: 1
* PRF A5: 1 => SOL
* STA A5: 1
* CNT   2 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

3.......4.7.6........1.......8....1......23......3.....5....16.2...74.........8.. initial
3812.76.4.7264...164.1..72.4387..219.6.4.23...2.93.4.6854329167216874...7935..842 autosolve
381257694972648531645193728438765219169482375527931486854329167216874953793516842 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (19)
A2: 5,9
C3: 5,9
E1: 5,9
F2: 3,8
H1: 5,9
G2: 5,9
H2: 3,8
I3: 3,8
A6: 1,5
C6: 5,7
E4: 5,6
F4: 5,6
E5: 1,8
F6: 1,8
I5: 5,8
E9: 1,6
F9: 1,6
G8: 5,9
I8: 3,5

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
A5,A6: 1.. / A5 = 1  =>  0 pairs (*) / A6 = 1  =>  0 pairs (X)
E5,F6: 1.. / E5 = 1  =>  0 pairs (X) / F6 = 1  =>  0 pairs (_)
E9,F9: 1.. / E9 = 1  =>  0 pairs (*) / F9 = 1  =>  0 pairs (X)
A5,E5: 1.. / A5 = 1  =>  0 pairs (*) / E5 = 1  =>  0 pairs (X)
A6,F6: 1.. / A6 = 1  =>  0 pairs (X) / F6 = 1  =>  0 pairs (_)
E5,E9: 1.. / E5 = 1  =>  0 pairs (X) / E9 = 1  =>  0 pairs (_)
F6,F9: 1.. / F6 = 1  =>  0 pairs (*) / F9 = 1  =>  0 pairs (X)
F2,F3: 3.. / F2 = 3  =>  0 pairs (X) / F3 = 3  =>  0 pairs (_)
H2,I3: 3.. / H2 = 3  =>  0 pairs (*) / I3 = 3  =>  0 pairs (X)
H8,I8: 3.. / H8 = 3  =>  0 pairs (X) / I8 = 3  =>  0 pairs (_)
F2,H2: 3.. / F2 = 3  =>  0 pairs (X) / H2 = 3  =>  0 pairs (_)
F3,I3: 3.. / F3 = 3  =>  0 pairs (*) / I3 = 3  =>  0 pairs (X)
H2,H8: 3.. / H2 = 3  =>  0 pairs (*) / H8 = 3  =>  0 pairs (X)
I3,I8: 3.. / I3 = 3  =>  0 pairs (X) / I8 = 3  =>  0 pairs (_)
A2,C3: 5.. / A2 = 5  =>  0 pairs (X) / C3 = 5  =>  0 pairs (_)
H1,G2: 5.. / H1 = 5  =>  0 pairs (X) / G2 = 5  =>  0 pairs (_)
E4,F4: 5.. / E4 = 5  =>  0 pairs (X) / F4 = 5  =>  0 pairs (_)
E1,H1: 5.. / E1 = 5  =>  0 pairs (*) / H1 = 5  =>  0 pairs (X)
A2,G2: 5.. / A2 = 5  =>  0 pairs (X) / G2 = 5  =>  0 pairs (_)
F3,F4: 5.. / F3 = 5  =>  0 pairs (X) / F4 = 5  =>  0 pairs (_)
G2,G8: 5.. / G2 = 5  =>  0 pairs (*) / G8 = 5  =>  0 pairs (X)
I5,I8: 5.. / I5 = 5  =>  0 pairs (*) / I8 = 5  =>  0 pairs (X)
E4,F4: 6.. / E4 = 6  =>  0 pairs (*) / F4 = 6  =>  0 pairs (X)
E9,F9: 6.. / E9 = 6  =>  0 pairs (X) / F9 = 6  =>  0 pairs (_)
E4,E9: 6.. / E4 = 6  =>  0 pairs (*) / E9 = 6  =>  0 pairs (X)
F4,F9: 6.. / F4 = 6  =>  0 pairs (X) / F9 = 6  =>  0 pairs (_)
C5,C6: 7.. / C5 = 7  =>  0 pairs (X) / C6 = 7  => 20 pairs (_)
H5,H6: 7.. / H5 = 7  => 20 pairs (_) / H6 = 7  =>  0 pairs (X)
C5,H5: 7.. / C5 = 7  =>  0 pairs (X) / H5 = 7  => 20 pairs (_)
C6,H6: 7.. / C6 = 7  => 20 pairs (_) / H6 = 7  =>  0 pairs (X)
H2,I3: 8.. / H2 = 8  =>  0 pairs (X) / I3 = 8  =>  0 pairs (_)
E5,F6: 8.. / E5 = 8  =>  0 pairs (*) / F6 = 8  =>  0 pairs (X)
F2,H2: 8.. / F2 = 8  =>  0 pairs (*) / H2 = 8  =>  0 pairs (X)
F6,H6: 8.. / F6 = 8  =>  0 pairs (X) / H6 = 8  =>  0 pairs (_)
E3,E5: 8.. / E3 = 8  =>  0 pairs (X) / E5 = 8  =>  0 pairs (_)
I3,I5: 8.. / I3 = 8  =>  0 pairs (*) / I5 = 8  =>  0 pairs (X)
A2,C3: 9.. / A2 = 9  =>  0 pairs (*) / C3 = 9  =>  0 pairs (X)
E1,E3: 9.. / E1 = 9  =>  0 pairs (X) / E3 = 9  =>  0 pairs (_)
H1,G2: 9.. / H1 = 9  =>  0 pairs (*) / G2 = 9  =>  0 pairs (X)
A5,C5: 9.. / A5 = 9  =>  0 pairs (X) / C5 = 9  =>  0 pairs (_)
G8,H8: 9.. / G8 = 9  =>  0 pairs (*) / H8 = 9  =>  0 pairs (X)
E1,H1: 9.. / E1 = 9  =>  0 pairs (X) / H1 = 9  =>  0 pairs (_)
A2,G2: 9.. / A2 = 9  =>  0 pairs (*) / G2 = 9  =>  0 pairs (X)
C3,E3: 9.. / C3 = 9  =>  0 pairs (X) / E3 = 9  =>  0 pairs (_)
A2,A5: 9.. / A2 = 9  =>  0 pairs (*) / A5 = 9  =>  0 pairs (X)
C3,C5: 9.. / C3 = 9  =>  0 pairs (X) / C5 = 9  =>  0 pairs (_)
G2,G8: 9.. / G2 = 9  =>  0 pairs (X) / G8 = 9  =>  0 pairs (_)
H1,H8: 9.. / H1 = 9  =>  0 pairs (*) / H8 = 9  =>  0 pairs (X)
* DURATION: 0:02:00.293388  START: 03:41:42.092530  END: 03:43:42.385918 2017-05-04
* CP COUNT: (48)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A2,A6,C3,C6,E1,E4,E5,E9,F2,F4,F6,F9,G2,G8,H1,H2,I3,I5,I8)
* 3812.76.4.7264...164.1..72.4387..219.6.4.23...2.93.4.6854329167216874...7935..842
* PAIR A2: 5,9 COL A
A5: 5,9,1                                # reduction candidate for 5,9
A5: 5,9 => CTR
* 3812.76.4.72643.8164.185723438756219.6.4123.812.9384.6854329167216874.35793561842
A5: 1 => SOLVED
* 381257694972648531645193728438765219169482375527931486854329167216874953793516842
* PAIR C3: 5,9 ROW 3
E3: 5,9,8                                # reduction candidate for 5,9
E3: 5,9 => SOLVED
* 381257694972648531645193728438765219169482375527931486854329167216874953793516842
E3: 8 => CTR
* 38129765457264.9.16491857234387..219.6.4.23...2.93.4.6854329167216874...7935..842
* PAIR C3: 5,9 COL C
C5: 5,9,7                                # reduction candidate for 5,9
C5: 7 => CTR
* 3812976545726439816491..72.4387..2199674123..125938476854329167216874...793561842
C5: 5,9                                  # 20 pairs
* PAIR E1: 5,9 BLK 2
E3: 5,9,8                                # reduction candidate for 5,9
E3: 5,9 => SOLVED
* 381257694972648531645193728438765219169482375527931486854329167216874953793516842
E3: 8 => CTR
* 38129765457264.9.16491857234387..219.6.4.23...2.93.4.6854329167216874...7935..842
* PAIR F2: 3,8 BLK 2
F3: 3,8,5                                # reduction candidate for 3,8
F3: 3,8 => SOLVED
* 381257694972648531645193728438765219169482375527931486854329167216874953793516842
F3: 5 => CTR
* 3812.76.4.72643.8164.185723438756219.6.4123.812.9384.6854329167216874.35793561842
* PAIR H1: 5,9 COL H
H8: 5,9,3                                # reduction candidate for 5,9
H8: 5,9 => SOLVED
* 381257694972648531645193728438765219169482375527931486854329167216874953793516842
H8: 3 => CTR
* 3812.769497264.5.164519.72.4387.5219.69482375.2.93.4.6854329167216874...7935..842
* PAIR I3: 3,8 ROW 3
F3: 3,8,5                                # reduction candidate for 3,8
F3: 3,8 => SOLVED
* 381257694972648531645193728438765219169482375527931486854329167216874953793516842
F3: 5 => CTR
* 3812.76.4.72643.8164.185723438756219.6.4123.812.9384.6854329167216874.35793561842
* PAIR A6: 1,5 BLK 4
A5: 1,5,9                                # reduction candidate for 1,5
A5: 1,5 => SOLVED
* 381257694972648531645193728438765219169482375527931486854329167216874953793516842
A5: 9 => CTR
* 3812.76.457264398164.1..72.4387..21996.4123..12.9384.6854329167216874...793561842
* PAIR C6: 5,7 BLK 4
C5: 5,7,9                                # reduction candidate for 5,7
C5: 5,7 => CTR
* 3812976545726439816491..72.4387..21996.4123..12.9384.6854329167216874...793561842
C5: 9 => SOLVED
* 381257694972648531645193728438765219169482375527931486854329167216874953793516842
* PAIR C6: 5,7 ROW 6
H6: 5,7,8                                # reduction candidate for 5,7
H6: 5,7 => CTR
* 3812.76.4.72643.8164.185723438756219.6.4123.812.9384.6854329167216874.35793561842
H6: 8 => SOLVED
* 381257694972648531645193728438765219169482375527931486854329167216874953793516842
* PAIR I5: 5,8 BLK 6
H5: 5,8,7                                # reduction candidate for 5,8
H5: 5,8 => CTR
* 3812.76.457264.9.16491..72.4387..2199674123..125938476854329167216874593793561842
H5: 7                                    # 20 pairs
H6: 5,8,7                                # reduction candidate for 5,8
H6: 5,8                                  # 20 pairs
* PAIR G8: 5,9 BLK 9
H8: 5,9,3                                # reduction candidate for 5,9
H8: 5,9 => SOLVED
* 381257694972648531645193728438765219169482375527931486854329167216874953793516842
H8: 3 => CTR
* 3812.769497264.5.164519.72.4387.5219.69482375.2.93.4.6854329167216874...7935..842
* PAIR I8: 3,5 BLK 9
H8: 3,5,9                                # reduction candidate for 3,5
H8: 3,5 => SOLVED
* 381257694972648531645193728438765219169482375527931486854329167216874953793516842
H8: 9 => CTR
* 38129765457264..3164.1.37284387.5219.6.4823.5.2.931486854329167216874593793516842
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-031-base-pr-000.dot
* REASONING
* DIS # A5: 5,9 => CTR => A5: 1
* PRF # A5: 1 => SOL
* PRF # E3: 5,9 => SOL
* DIS # E3: 8 => CTR => E3: 5,9
* DIS # C5: 7 => CTR => C5: 5,9
* PRF # E3: 5,9 => SOL
* DIS # E3: 8 => CTR => E3: 5,9
* PRF # F3: 3,8 => SOL
* DIS # F3: 5 => CTR => F3: 3,8
* PRF # H8: 5,9 => SOL
* DIS # H8: 3 => CTR => H8: 5,9
* PRF # F3: 3,8 => SOL
* DIS # F3: 5 => CTR => F3: 3,8
* PRF # A5: 1,5 => SOL
* DIS # A5: 9 => CTR => A5: 1,5
* DIS # C5: 5,7 => CTR => C5: 9
* PRF # C5: 9 => SOL
* DIS # H6: 5,7 => CTR => H6: 8
* PRF # H6: 8 => SOL
* DIS # H5: 5,8 => CTR => H5: 7
* PRF # H8: 5,9 => SOL
* DIS # H8: 3 => CTR => H8: 5,9
* PRF # H8: 3,5 => SOL
* DIS # H8: 9 => CTR => H8: 3,5
* CNT  24 HDP CHAINS /  27 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A2,A6,C3,C6,E1,E4,E5,E9,F2,F4,F6,F9,G2,G8,H1,H2,I3,I5,I8)
* 3812.76.4.7264...164.1..72.4387..219.6.4.23...2.93.4.6854329167216874...7935..842
* PAIR A2: 5,9 COL A
A5: 5,9,1                                # reduction candidate for 5,9
A5: 5,9 => CTR
* 3812.76.4.72643.8164.185723438756219.6.4123.812.9384.6854329167216874.35793561842
A5: 1 => SOLVED
* 381257694972648531645193728438765219169482375527931486854329167216874953793516842
* DURATION: 0:00:04.003070  START: 03:44:26.787005  END: 03:44:30.790075 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-031-base-pr-001.dot
* REASONING
* DIS # A5: 5,9 => CTR => A5: 1
* PRF A5: 1 => SOL
* STA A5: 1
* CNT   2 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 031

solution: 381257694972648531645193728438765219169482375527931486854329167216874953793516842
info: 1331     FNBTWXY  S8.f     28638

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

Solution

position: 381257694972648531645193728438765219169482375527931486854329167216874953793516842 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 # A5: 5,9 => CTR => A5: 1
* PRF # A5: 1 => SOL
* PRF # E3: 5,9 => SOL
* DIS # E3: 8 => CTR => E3: 5,9
* INC # C5: 5,9 => UNS
* DIS # C5: 7 => CTR => C5: 5,9
* PRF # E3: 5,9 => SOL
* DIS # E3: 8 => CTR => E3: 5,9
* PRF # F3: 3,8 => SOL
* DIS # F3: 5 => CTR => F3: 3,8
* PRF # H8: 5,9 => SOL
* DIS # H8: 3 => CTR => H8: 5,9
* PRF # F3: 3,8 => SOL
* DIS # F3: 5 => CTR => F3: 3,8
* PRF # A5: 1,5 => SOL
* DIS # A5: 9 => CTR => A5: 1,5
* DIS # C5: 5,7 => CTR => C5: 9
* PRF # C5: 9 => SOL
* DIS # H6: 5,7 => CTR => H6: 8
* PRF # H6: 8 => SOL
* DIS # H5: 5,8 => CTR => H5: 7
* INC # H5: 7 => UNS
* INC # H6: 5,8 => UNS
* PRF # H8: 5,9 => SOL
* DIS # H8: 3 => CTR => H8: 5,9
* PRF # H8: 3,5 => SOL
* DIS # H8: 9 => CTR => H8: 3,5
* CNT  27 HDP CHAINS /  27 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # A5: 5,9 => CTR => A5: 1
* PRF A5: 1 => SOL
* STA A5: 1
* CNT   2 HDP CHAINS /   1 HYP OPENED