Analysis of xx-top500-199-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: ...17....4.......8....3....23.............6.7.......1..5.6..2....7....3...3..8... initial

Autosolve

position: 38917..62471.623.856283.7.1236.1798.81.3..62779.286.131586.327...7..183...37.81.. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # D8: 5,9 => SOL
* DIS # D8: 4 => CTR => D8: 5,9
* DIS # E5: 4,5 => CTR => E5: 9
* PRF # E5: 9 => SOL
* DIS # E5: 4,5 => CTR => E5: 9
* PRF # E5: 9 => SOL
* DIS # D8: 4,5 => CTR => D8: 9
* PRF # D8: 9 => SOL
* PRF # E5: 5,9 => SOL
* DIS # E5: 4 => CTR => E5: 5,9
* PRF # I8: 4,5 => SOL
* DIS # I8: 6,9 => CTR => I8: 4,5
* DIS # I9: 4,5 => CTR => I9: 6,9
* DIS # I8: 6,9 => CTR => I8: 4,5
* PRF # I8: 4,5 => SOL
* DIS # E8: 2,4 => CTR => E8: 5,9
* PRF # E8: 5,9 => SOL
* DIS # I9: 4,5 => CTR => I9: 6,9
* PRF # E9: 2,4 => SOL
* DIS # E9: 5,9 => CTR => E9: 2,4
* DIS # E8: 4,9 => CTR => E8: 2,5
* DIS # E9: 4,9 => CTR => E9: 2,5
* DIS # E5: 5 => CTR => E5: 4,9
* PRF # I8: 4,9 => SOL
* DIS # I9: 4,9 => CTR => I9: 5,6
* PRF # I8: 4,5 => SOL
* DIS # I8: 6,9 => CTR => I8: 4,5
* DIS # I9: 4,5 => CTR => I9: 6,9
* DIS # E9: 4,5 => CTR => E9: 2,9
* CNT  29 HDP CHAINS /  39 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 # D8: 5,9 => SOL
* STA D8: 5,9
* CNT   1 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

...17....4.......8....3....23.............6.7.......1..5.6..2....7....3...3..8... initial
38917..62471.623.856283.7.1236.1798.81.3..62779.286.131586.327...7..183...37.81.. autosolve
389174562471562398562839741236417985814395627795286413158643279627951834943728156 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (19)
F1: 4,5
D2: 5,9
F3: 4,9
G1: 4,5
H2: 5,9
H3: 4,9
C5: 4,5
C6: 4,5
D4: 4,5
F5: 5,9
I4: 4,5
G6: 4,5
A8: 6,9
B8: 2,4
A9: 6,9
B9: 2,4
E7: 4,9
I7: 4,9
H9: 4,5

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
B8,B9: 2.. / B8 = 2  =>  0 pairs (*) / B9 = 2  =>  0 pairs (X)
E8,E9: 2.. / E8 = 2  =>  0 pairs (X) / E9 = 2  =>  0 pairs (_)
B8,E8: 2.. / B8 = 2  =>  0 pairs (*) / E8 = 2  =>  0 pairs (X)
B9,E9: 2.. / B9 = 2  =>  0 pairs (X) / E9 = 2  =>  0 pairs (_)
F1,F3: 4.. / F1 = 4  =>  0 pairs (*) / F3 = 4  =>  0 pairs (X)
G1,H3: 4.. / G1 = 4  =>  0 pairs (X) / H3 = 4  =>  0 pairs (_)
C5,C6: 4.. / C5 = 4  =>  0 pairs (*) / C6 = 4  =>  0 pairs (X)
D4,E5: 4.. / D4 = 4  =>  0 pairs (*) / E5 = 4  =>  0 pairs (X)
I4,G6: 4.. / I4 = 4  =>  0 pairs (X) / G6 = 4  =>  0 pairs (_)
B8,B9: 4.. / B8 = 4  =>  0 pairs (X) / B9 = 4  =>  0 pairs (_)
F1,G1: 4.. / F1 = 4  =>  0 pairs (*) / G1 = 4  =>  0 pairs (X)
F3,H3: 4.. / F3 = 4  =>  0 pairs (X) / H3 = 4  =>  0 pairs (_)
D4,I4: 4.. / D4 = 4  =>  0 pairs (*) / I4 = 4  =>  0 pairs (X)
C5,E5: 4.. / C5 = 4  =>  0 pairs (*) / E5 = 4  =>  0 pairs (X)
C6,G6: 4.. / C6 = 4  =>  0 pairs (X) / G6 = 4  =>  0 pairs (_)
E7,I7: 4.. / E7 = 4  =>  0 pairs (*) / I7 = 4  =>  0 pairs (X)
D4,D8: 4.. / D4 = 4  =>  0 pairs (*) / D8 = 4  =>  0 pairs (X)
G1,G6: 4.. / G1 = 4  =>  0 pairs (X) / G6 = 4  =>  0 pairs (_)
H3,H9: 4.. / H3 = 4  =>  0 pairs (*) / H9 = 4  =>  0 pairs (X)
F1,D2: 5.. / F1 = 5  =>  0 pairs (X) / D2 = 5  =>  0 pairs (_)
G1,H2: 5.. / G1 = 5  =>  0 pairs (*) / H2 = 5  =>  0 pairs (X)
C5,C6: 5.. / C5 = 5  =>  0 pairs (X) / C6 = 5  =>  0 pairs (_)
I4,G6: 5.. / I4 = 5  =>  0 pairs (*) / G6 = 5  =>  0 pairs (X)
F1,G1: 5.. / F1 = 5  =>  0 pairs (X) / G1 = 5  =>  0 pairs (_)
D2,H2: 5.. / D2 = 5  =>  0 pairs (*) / H2 = 5  =>  0 pairs (X)
D4,I4: 5.. / D4 = 5  =>  0 pairs (X) / I4 = 5  =>  0 pairs (_)
C6,G6: 5.. / C6 = 5  =>  0 pairs (*) / G6 = 5  =>  0 pairs (X)
F1,F5: 5.. / F1 = 5  =>  0 pairs (X) / F5 = 5  =>  0 pairs (_)
G1,G6: 5.. / G1 = 5  =>  0 pairs (*) / G6 = 5  =>  0 pairs (X)
H2,H9: 5.. / H2 = 5  =>  0 pairs (X) / H9 = 5  =>  0 pairs (_)
A8,A9: 6.. / A8 = 6  => 17 pairs (_) / A9 = 6  =>  0 pairs (X)
I8,I9: 6.. / I8 = 6  =>  0 pairs (X) / I9 = 6  => 17 pairs (_)
A8,I8: 6.. / A8 = 6  => 17 pairs (_) / I8 = 6  =>  0 pairs (X)
A9,I9: 6.. / A9 = 6  =>  0 pairs (X) / I9 = 6  => 17 pairs (_)
D2,F3: 9.. / D2 = 9  =>  0 pairs (X) / F3 = 9  =>  0 pairs (_)
H2,H3: 9.. / H2 = 9  =>  0 pairs (*) / H3 = 9  =>  0 pairs (X)
E5,F5: 9.. / E5 = 9  =>  0 pairs (*) / F5 = 9  =>  0 pairs (X)
A8,A9: 9.. / A8 = 9  =>  0 pairs (X) / A9 = 9  => 17 pairs (_)
D2,H2: 9.. / D2 = 9  =>  0 pairs (X) / H2 = 9  =>  0 pairs (_)
F3,H3: 9.. / F3 = 9  =>  0 pairs (*) / H3 = 9  =>  0 pairs (X)
E7,I7: 9.. / E7 = 9  =>  0 pairs (X) / I7 = 9  =>  0 pairs (_)
D2,D8: 9.. / D2 = 9  =>  0 pairs (X) / D8 = 9  =>  0 pairs (_)
F3,F5: 9.. / F3 = 9  =>  0 pairs (*) / F5 = 9  =>  0 pairs (X)
* DURATION: 0:01:10.231686  START: 09:32:13.308500  END: 09:33:23.540186 2017-05-04
* CP COUNT: (43)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A8,A9,B8,B9,C5,C6,D2,D4,E7,F1,F3,F5,G1,G6,H2,H3,H9,I4,I7)
* 38917..62471.623.856283.7.1236.1798.81.3..62779.286.131586.327...7..183...37.81..
* PAIR D2: 5,9 COL D
D8: 5,9,4                                # reduction candidate for 5,9
D8: 5,9 => SOLVED
* 389174562471562398562839741236417985814395627795286413158643279627951834943728156
D8: 4 => CTR
* 38917..6247196235856283479123651798481534962779428651315869327...7..183...37.81..
* PAIR C5: 4,5 ROW 5
E5: 4,5,9                                # reduction candidate for 4,5
E5: 4,5 => CTR
* 389175462471962358562834791236.1798481.34962779428651315869327...7..183...37.81..
E5: 9 => SOLVED
* 389174562471562398562839741236417985814395627795286413158643279627951834943728156
* PAIR D4: 4,5 BLK 5
E5: 4,5,9                                # reduction candidate for 4,5
E5: 4,5 => CTR
* 389175462471962358562834791236.1798481.34962779428651315869327...7..183...37.81..
E5: 9 => SOLVED
* 389174562471562398562839741236417985814395627795286413158643279627951834943728156
* PAIR D4: 4,5 COL D
D8: 4,5,9                                # reduction candidate for 4,5
D8: 4,5 => CTR
* 38917546247196235856283479123651798481534962779428651315869327...7..183...37.814.
D8: 9 => SOLVED
* 389174562471562398562839741236417985814395627795286413158643279627951834943728156
* PAIR F5: 5,9 BLK 5
E5: 5,9,4                                # reduction candidate for 5,9
E5: 5,9 => SOLVED
* 389174562471562398562839741236417985814395627795286413158643279627951834943728156
E5: 4 => CTR
* 38917..62471.623.856283.7.1236.1798.81.349627794286513158693274..7..183...37.81..
* PAIR I4: 4,5 COL I
I8: 4,5,6,9                              # reduction candidate for 4,5
I8: 4,5 => SOLVED
* 389174562471562398562839741236417985814395627795286413158643279627951834943728156
I8: 6,9 => CTR
* 389175462471962358562834791236.1798481.34962779428651315869327...7..183...37.81..
I9: 4,5,6,9                              # reduction candidate for 4,5
I9: 4,5 => CTR
* 38917..62471962358562834791236.1798.81.3.962779.2865131586432799475.18366.37981..
I9: 6,9                                  # 20 pairs
* PAIR A8: 6,9 ROW 8
I8: 6,9,4,5                              # reduction candidate for 6,9
I8: 6,9 => CTR
* 389175462471962358562834791236.1798481.34962779428651315869327...7..183...37.81..
I8: 4,5 => SOLVED
* 389174562471562398562839741236417985814395627795286413158643279627951834943728156
* PAIR B8: 2,4 ROW 8
E8: 2,4,5,9                              # reduction candidate for 2,4
E8: 2,4 => CTR
* 38917..62471.623.856283.7.12364179858143..6277952864131586.327...75.183...37.815.
E8: 5,9 => SOLVED
* 389174562471562398562839741236417985814395627795286413158643279627951834943728156
* PAIR A9: 6,9 ROW 9
I9: 6,9,4,5                              # reduction candidate for 6,9
I9: 4,5 => CTR
* 38917..62471962358562834791236.1798.81.3.962779.2865131586432799475.18366.37981..
I9: 6,9                                  # 20 pairs
* PAIR B9: 2,4 ROW 9
E9: 2,4,5,9                              # reduction candidate for 2,4
E9: 2,4 => SOLVED
* 389174562471562398562839741236417985814395627795286413158643279627951834943728156
E9: 5,9 => CTR
* 38917..62471.623.856283.7.12364179858143..627795286413158643279.47521836623798154
* PAIR E7: 4,9 BLK 8
D8: 4,9,5                                # reduction candidate for 4,9
D8: 4,9                                  # 24 pairs
E8: 4,9,2,5                              # reduction candidate for 4,9
E8: 4,9 => CTR
* 38917.56247156239856283974123641798.81.3..62779.286.131586.327..27..183..4372815.
E8: 2,5                                  # 20 pairs
E9: 4,9,2,5                              # reduction candidate for 4,9
E9: 4,9 => CTR
* 38917..62471.623.856283.7.1236.1798.81.3596277952864131586.327..4752183..237.81..
E9: 2,5                                  # 21 pairs
* PAIR E7: 4,9 COL E
E5: 4,9,5                                # reduction candidate for 4,9
E5: 5 => CTR
* 38917..62471.623.856283.7.12364179858143596277952864131586.327...75.183...37.815.
E5: 4,9                                  # 24 pairs
* PAIR I7: 4,9 BLK 9
I8: 4,9,5,6                              # reduction candidate for 4,9
I8: 4,9 => SOLVED
* 389174562471562398562839741236417985814395627795286413158643279627951834943728156
I8: 5,6                                  # 20 pairs
I9: 4,9,5,6                              # reduction candidate for 4,9
I9: 4,9 => CTR
* 38917.562471562398562839741236417985814395627795286413158643279..7..18366.37.815.
I9: 5,6                                  # 20 pairs
* PAIR H9: 4,5 BLK 9
I8: 4,5,6,9                              # reduction candidate for 4,5
I8: 4,5 => SOLVED
* 389174562471562398562839741236417985814395627795286413158643279627951834943728156
I8: 6,9 => CTR
* 389175462471962358562834791236.1798481.34962779428651315869327...7..183...37.81..
I9: 4,5,6,9                              # reduction candidate for 4,5
I9: 4,5 => CTR
* 38917..62471962358562834791236.1798.81.3.962779.2865131586432799475.18366.37981..
I9: 6,9                                  # 20 pairs
* PAIR H9: 4,5 ROW 9
E9: 4,5,2,9                              # reduction candidate for 4,5
E9: 4,5 => CTR
* 38917..62471.623.856283.7.12364179858143..6277952864131586.327..4752183..2374815.
E9: 2,9                                  # 20 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-199-base-pr-000.dot
* REASONING
* PRF # D8: 5,9 => SOL
* DIS # D8: 4 => CTR => D8: 5,9
* DIS # E5: 4,5 => CTR => E5: 9
* PRF # E5: 9 => SOL
* DIS # E5: 4,5 => CTR => E5: 9
* PRF # E5: 9 => SOL
* DIS # D8: 4,5 => CTR => D8: 9
* PRF # D8: 9 => SOL
* PRF # E5: 5,9 => SOL
* DIS # E5: 4 => CTR => E5: 5,9
* PRF # I8: 4,5 => SOL
* DIS # I8: 6,9 => CTR => I8: 4,5
* DIS # I9: 4,5 => CTR => I9: 6,9
* DIS # I8: 6,9 => CTR => I8: 4,5
* PRF # I8: 4,5 => SOL
* DIS # E8: 2,4 => CTR => E8: 5,9
* PRF # E8: 5,9 => SOL
* DIS # I9: 4,5 => CTR => I9: 6,9
* PRF # E9: 2,4 => SOL
* DIS # E9: 5,9 => CTR => E9: 2,4
* DIS # E8: 4,9 => CTR => E8: 2,5
* DIS # E9: 4,9 => CTR => E9: 2,5
* DIS # E5: 5 => CTR => E5: 4,9
* PRF # I8: 4,9 => SOL
* DIS # I9: 4,9 => CTR => I9: 5,6
* PRF # I8: 4,5 => SOL
* DIS # I8: 6,9 => CTR => I8: 4,5
* DIS # I9: 4,5 => CTR => I9: 6,9
* DIS # E9: 4,5 => CTR => E9: 2,9
* CNT  29 HDP CHAINS /  39 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A8,A9,B8,B9,C5,C6,D2,D4,E7,F1,F3,F5,G1,G6,H2,H3,H9,I4,I7)
* 38917..62471.623.856283.7.1236.1798.81.3..62779.286.131586.327...7..183...37.81..
* PAIR D2: 5,9 COL D
D8: 5,9,4                                # reduction candidate for 5,9
D8: 5,9 => SOLVED
* 389174562471562398562839741236417985814395627795286413158643279627951834943728156
* DURATION: 0:00:01.921929  START: 09:34:04.979948  END: 09:34:06.901877 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-199-base-pr-001.dot
* REASONING
* PRF # D8: 5,9 => SOL
* STA D8: 5,9
* CNT   1 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 199

solution: 389174562471562398562839741236417985814395627795286413158643279627951834943728156
info: 1887     FNBTHWX  S8.f     7342

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

Solution

position: 389174562471562398562839741236417985814395627795286413158643279627951834943728156 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 # D8: 5,9 => SOL
* DIS # D8: 4 => CTR => D8: 5,9
* DIS # E5: 4,5 => CTR => E5: 9
* PRF # E5: 9 => SOL
* DIS # E5: 4,5 => CTR => E5: 9
* PRF # E5: 9 => SOL
* DIS # D8: 4,5 => CTR => D8: 9
* PRF # D8: 9 => SOL
* PRF # E5: 5,9 => SOL
* DIS # E5: 4 => CTR => E5: 5,9
* PRF # I8: 4,5 => SOL
* DIS # I8: 6,9 => CTR => I8: 4,5
* DIS # I9: 4,5 => CTR => I9: 6,9
* INC # I9: 6,9 => UNS
* DIS # I8: 6,9 => CTR => I8: 4,5
* PRF # I8: 4,5 => SOL
* DIS # E8: 2,4 => CTR => E8: 5,9
* PRF # E8: 5,9 => SOL
* INC # I9: 6,9 => UNS
* DIS # I9: 4,5 => CTR => I9: 6,9
* PRF # E9: 2,4 => SOL
* DIS # E9: 5,9 => CTR => E9: 2,4
* INC # D8: 4,9 => UNS
* DIS # E8: 4,9 => CTR => E8: 2,5
* INC # E8: 2,5 => UNS
* DIS # E9: 4,9 => CTR => E9: 2,5
* INC # E9: 2,5 => UNS
* INC # E5: 4,9 => UNS
* DIS # E5: 5 => CTR => E5: 4,9
* PRF # I8: 4,9 => SOL
* INC # I8: 5,6 => UNS
* DIS # I9: 4,9 => CTR => I9: 5,6
* INC # I9: 5,6 => UNS
* PRF # I8: 4,5 => SOL
* DIS # I8: 6,9 => CTR => I8: 4,5
* DIS # I9: 4,5 => CTR => I9: 6,9
* INC # I9: 6,9 => UNS
* DIS # E9: 4,5 => CTR => E9: 2,9
* INC # E9: 2,9 => UNS
* CNT  39 HDP CHAINS /  39 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* PRF # D8: 5,9 => SOL
* STA D8: 5,9
* CNT   1 HDP CHAINS /   1 HYP OPENED