Analysis of xx-top500-367-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 3.41.....5....76.....2.....6...3.....8......7.......1.72...........8.3...1....... initial

Autosolve

position: 3741682..5923476811682..7436.173.82.28..16437.3782..1672.4.31.8....81372813.72..4 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # F4: 5,9 => SOL
* DIS # F4: 4 => CTR => F4: 5,9
* DIS # F6: 5,9 => CTR => F6: 4
* PRF # F6: 4 => SOL
* DIS # F4: 9 => CTR => F4: 4,5
* DIS # F6: 5 => CTR => F6: 4,9
* PRF # F4: 5,9 => SOL
* DIS # F4: 4 => CTR => F4: 5,9
* DIS # F6: 5,9 => CTR => F6: 4
* PRF # F6: 4 => SOL
* PRF # F4: 5,9 => SOL
* DIS # F4: 4 => CTR => F4: 5,9
* DIS # F6: 5,9 => CTR => F6: 4
* PRF # F6: 4 => SOL
* CNT  14 HDP CHAINS /  30 HYP OPENED

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

Pair Reduction

Pair Reduction

The following important HDP chains were detected:

* PRF # F4: 5,9 => SOL
* STA F4: 5,9
* CNT   1 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

3.41.....5....76.....2.....6...3.....8......7.......1.72...........8.3...1....... initial
3741682..5923476811682..7436.173.82.28..16437.3782..1672.4.31.8....81372813.72..4 autosolve
374168295592347681168259743641735829285916437937824516726493158459681372813572964 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (14)
E3: 5,9
F3: 5,9
H1: 5,9
I1: 5,9
B4: 4,5
C5: 5,9
A6: 4,9
D5: 5,9
I4: 5,9
G6: 5,9
A8: 4,9
B8: 4,5
E7: 5,9
G9: 5,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
B4,A6: 4.. / B4 = 4  =>  0 pairs (*) / A6 = 4  =>  0 pairs (X)
F4,F6: 4.. / F4 = 4  =>  0 pairs (X) / F6 = 4  =>  0 pairs (_)
A8,B8: 4.. / A8 = 4  =>  0 pairs (*) / B8 = 4  =>  0 pairs (X)
B4,F4: 4.. / B4 = 4  =>  0 pairs (*) / F4 = 4  =>  0 pairs (X)
A6,F6: 4.. / A6 = 4  =>  0 pairs (X) / F6 = 4  =>  0 pairs (_)
A6,A8: 4.. / A6 = 4  =>  0 pairs (X) / A8 = 4  =>  0 pairs (_)
B4,B8: 4.. / B4 = 4  =>  0 pairs (*) / B8 = 4  =>  0 pairs (X)
E3,F3: 5.. / E3 = 5  =>  0 pairs (*) / F3 = 5  =>  0 pairs (X)
H1,I1: 5.. / H1 = 5  =>  0 pairs (X) / I1 = 5  => 14 pairs (_)
B4,C5: 5.. / B4 = 5  =>  0 pairs (X) / C5 = 5  =>  0 pairs (_)
I4,G6: 5.. / I4 = 5  =>  0 pairs (X) / G6 = 5  => 14 pairs (_)
C5,D5: 5.. / C5 = 5  =>  0 pairs (*) / D5 = 5  =>  0 pairs (X)
F6,G6: 5.. / F6 = 5  =>  0 pairs (X) / G6 = 5  => 14 pairs (_)
B4,B8: 5.. / B4 = 5  =>  0 pairs (X) / B8 = 5  =>  0 pairs (_)
E3,E7: 5.. / E3 = 5  =>  0 pairs (*) / E7 = 5  =>  0 pairs (X)
G6,G9: 5.. / G6 = 5  => 14 pairs (_) / G9 = 5  =>  0 pairs (X)
I1,I4: 5.. / I1 = 5  => 14 pairs (_) / I4 = 5  =>  0 pairs (X)
C7,C8: 6.. / C7 = 6  => 17 pairs (_) / C8 = 6  => 17 pairs (_)
D8,D9: 6.. / D8 = 6  => 17 pairs (_) / D9 = 6  => 17 pairs (_)
H7,H9: 6.. / H7 = 6  => 17 pairs (_) / H9 = 6  => 17 pairs (_)
C7,H7: 6.. / C7 = 6  => 17 pairs (_) / H7 = 6  => 17 pairs (_)
C8,D8: 6.. / C8 = 6  => 17 pairs (_) / D8 = 6  => 17 pairs (_)
D9,H9: 6.. / D9 = 6  => 17 pairs (_) / H9 = 6  => 17 pairs (_)
E3,F3: 9.. / E3 = 9  =>  0 pairs (X) / F3 = 9  =>  0 pairs (_)
H1,I1: 9.. / H1 = 9  => 14 pairs (_) / I1 = 9  =>  0 pairs (X)
C5,A6: 9.. / C5 = 9  =>  0 pairs (X) / A6 = 9  =>  0 pairs (_)
I4,G6: 9.. / I4 = 9  => 14 pairs (_) / G6 = 9  =>  0 pairs (X)
F4,I4: 9.. / F4 = 9  =>  0 pairs (X) / I4 = 9  => 14 pairs (_)
C5,D5: 9.. / C5 = 9  =>  0 pairs (X) / D5 = 9  =>  0 pairs (_)
A6,A8: 9.. / A6 = 9  =>  0 pairs (*) / A8 = 9  =>  0 pairs (X)
E3,E7: 9.. / E3 = 9  =>  0 pairs (X) / E7 = 9  =>  0 pairs (_)
G6,G9: 9.. / G6 = 9  =>  0 pairs (X) / G9 = 9  => 14 pairs (_)
I1,I4: 9.. / I1 = 9  =>  0 pairs (X) / I4 = 9  => 14 pairs (_)
* DURATION: 0:00:55.276558  START: 15:23:32.074147  END: 15:24:27.350705 2017-05-04
* CP COUNT: (33)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A6,A8,B4,B8,C5,D5,E3,E7,F3,G6,G9,H1,I1,I4)
* 3741682..5923476811682..7436.173.82.28..16437.3782..1672.4.31.8....81372813.72..4
* PAIR F3: 5,9 COL F
F4: 5,9,4                                # reduction candidate for 5,9
F4: 5,9 => SOLVED
* 374168295592347681168259743641735829285916437937824516726493158459681372813572964
F4: 4 => CTR
* 3741682..5923476811682..7436.173482928..1643743782951672.4.31.894..81372813972..4
F6: 5,9,4                                # reduction candidate for 5,9
F6: 5,9 => CTR
* 3741682..5923476811682..7436.173482928..1643743782951672.4.31.894..81372813972..4
F6: 4 => SOLVED
* 374168295592347681168259743641735829285916437937824516726493158459681372813572964
* PAIR H1: 5,9 COL H
H7: 5,9,6                                # reduction candidate for 5,9
H7: 5,9                                  # 17 pairs
H9: 5,9,6                                # reduction candidate for 5,9
H9: 5,9                                  # 17 pairs
* PAIR B4: 4,5 ROW 4
F4: 4,5,9                                # reduction candidate for 4,5
F4: 9 => CTR
* 3741682..5923476811682..74364173982528..16437.3782..1672.4.31.8....81372813.72..4
F4: 4,5                                  # 14 pairs
* PAIR C5: 5,9 COL C
C7: 5,9,6                                # reduction candidate for 5,9
C7: 5,9                                  # 17 pairs
C8: 5,9,6                                # reduction candidate for 5,9
C8: 5,9                                  # 17 pairs
* PAIR A6: 4,9 ROW 6
F6: 4,9,5                                # reduction candidate for 4,9
F6: 5 => CTR
* 3741682..5923476811682..7436.173482928.916437.3782..1672.4.31.8....81372813.72..4
F6: 4,9                                  # 14 pairs
* PAIR D5: 5,9 BLK 5
F4: 5,9,4                                # reduction candidate for 5,9
F4: 5,9 => SOLVED
* 374168295592347681168259743641735829285916437937824516726493158459681372813572964
F4: 4 => CTR
* 3741682..5923476811682..7436.173482928..1643743782951672.4.31.894..81372813972..4
F6: 5,9,4                                # reduction candidate for 5,9
F6: 5,9 => CTR
* 3741682..5923476811682..7436.173482928..1643743782951672.4.31.894..81372813972..4
F6: 4 => SOLVED
* 374168295592347681168259743641735829285916437937824516726493158459681372813572964
* PAIR D5: 5,9 COL D
D8: 5,9,6                                # reduction candidate for 5,9
D8: 5,9                                  # 17 pairs
D9: 5,9,6                                # reduction candidate for 5,9
D9: 5,9                                  # 17 pairs
* PAIR I4: 5,9 ROW 4
F4: 5,9,4                                # reduction candidate for 5,9
F4: 5,9 => SOLVED
* 374168295592347681168259743641735829285916437937824516726493158459681372813572964
F4: 4 => CTR
* 3741682..5923476811682..7436.173482928..1643743782951672.4.31.894..81372813972..4
* PAIR G6: 5,9 ROW 6
F6: 5,9,4                                # reduction candidate for 5,9
F6: 5,9 => CTR
* 3741682..5923476811682..7436.173482928..1643743782951672.4.31.894..81372813972..4
F6: 4 => SOLVED
* 374168295592347681168259743641735829285916437937824516726493158459681372813572964
* PAIR E7: 5,9 BLK 8
D8: 5,9,6                                # reduction candidate for 5,9
D8: 5,9                                  # 17 pairs
D9: 5,9,6                                # reduction candidate for 5,9
D9: 5,9                                  # 17 pairs
* PAIR E7: 5,9 ROW 7
C7: 5,9,6                                # reduction candidate for 5,9
C7: 5,9                                  # 17 pairs
H7: 5,9,6                                # reduction candidate for 5,9
H7: 5,9                                  # 17 pairs
* PAIR G9: 5,9 BLK 9
H7: 5,9,6                                # reduction candidate for 5,9
H7: 5,9                                  # 17 pairs
H9: 5,9,6                                # reduction candidate for 5,9
H9: 5,9                                  # 17 pairs
* PAIR G9: 5,9 ROW 9
D9: 5,9,6                                # reduction candidate for 5,9
D9: 6                                    # 17 pairs
D9: 5,9                                  # 17 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-367-base-pr-000.dot
* REASONING
* PRF # F4: 5,9 => SOL
* DIS # F4: 4 => CTR => F4: 5,9
* DIS # F6: 5,9 => CTR => F6: 4
* PRF # F6: 4 => SOL
* DIS # F4: 9 => CTR => F4: 4,5
* DIS # F6: 5 => CTR => F6: 4,9
* PRF # F4: 5,9 => SOL
* DIS # F4: 4 => CTR => F4: 5,9
* DIS # F6: 5,9 => CTR => F6: 4
* PRF # F6: 4 => SOL
* PRF # F4: 5,9 => SOL
* DIS # F4: 4 => CTR => F4: 5,9
* DIS # F6: 5,9 => CTR => F6: 4
* PRF # F6: 4 => SOL
* CNT  14 HDP CHAINS /  30 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A6,A8,B4,B8,C5,D5,E3,E7,F3,G6,G9,H1,I1,I4)
* 3741682..5923476811682..7436.173.82.28..16437.3782..1672.4.31.8....81372813.72..4
* PAIR F3: 5,9 COL F
F4: 5,9,4                                # reduction candidate for 5,9
F4: 5,9 => SOLVED
* 374168295592347681168259743641735829285916437937824516726493158459681372813572964
* DURATION: 0:00:01.947626  START: 15:24:57.434816  END: 15:24:59.382442 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-367-base-pr-001.dot
* REASONING
* PRF # F4: 5,9 => SOL
* STA F4: 5,9
* CNT   1 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 367

solution: 374168295592347681168259743641735829285916437937824516726493158459681372813572964
info: 5144     FNWX     S8.f     45272

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

Solution

position: 374168295592347681168259743641735829285916437937824516726493158459681372813572964 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:

* PRF # F4: 5,9 => SOL
* DIS # F4: 4 => CTR => F4: 5,9
* DIS # F6: 5,9 => CTR => F6: 4
* PRF # F6: 4 => SOL
* INC # H7: 5,9 => UNS
* INC # H9: 5,9 => UNS
* INC # F4: 4,5 => UNS
* DIS # F4: 9 => CTR => F4: 4,5
* INC # C7: 5,9 => UNS
* INC # C8: 5,9 => UNS
* INC # F6: 4,9 => UNS
* DIS # F6: 5 => CTR => F6: 4,9
* PRF # F4: 5,9 => SOL
* DIS # F4: 4 => CTR => F4: 5,9
* DIS # F6: 5,9 => CTR => F6: 4
* PRF # F6: 4 => SOL
* INC # D8: 5,9 => UNS
* INC # D9: 5,9 => UNS
* PRF # F4: 5,9 => SOL
* DIS # F4: 4 => CTR => F4: 5,9
* DIS # F6: 5,9 => CTR => F6: 4
* PRF # F6: 4 => SOL
* INC # D8: 5,9 => UNS
* INC # D9: 5,9 => UNS
* INC # C7: 5,9 => UNS
* INC # H7: 5,9 => UNS
* INC # H7: 5,9 => UNS
* INC # H9: 5,9 => UNS
* INC # D9: 5,9 => UNS
* INC # D9: 6 => UNS
* CNT  30 HDP CHAINS /  30 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* PRF # F4: 5,9 => SOL
* STA F4: 5,9
* CNT   1 HDP CHAINS /   1 HYP OPENED