Analysis of xx-top500-396-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 34...2....1.....7.....8.6..2...5.......7...1..3.......5.....2..6.......5...1..... initial

Autosolve

position: 347612.5.8165...72952.876.127..51...46.72.51.135...72.5.1...2.76..27.1.572.1.5... autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # F2: 3,4 => CTR => F2: 9
* DIS # D7: 3,4 => CTR => D7: 8,9
* DIS # I4: 8,9 => CTR => I4: 3,4,6
* DIS # I5: 8,9 => CTR => I5: 3
* PRF # I5: 3 => SOL
* PRF # I6: 8,9 => SOL
* DIS # I6: 4 => CTR => I6: 8,9
* DIS # I9: 8,9 => CTR => I9: 3,4,6
* DIS # F2: 3,4 => CTR => F2: 9
* DIS # H4: 3,4 => CTR => H4: 6,8,9
* DIS # H9: 3,4 => CTR => H9: 6,8,9
* DIS # D4: 8,9 => CTR => D4: 3,4
* DIS # I4: 8,9 => CTR => I4: 3,4,6
* PRF # F5: 8,9 => SOL
* DIS # F5: 3 => CTR => F5: 8,9
* DIS # I5: 8,9 => CTR => I5: 3
* PRF # I5: 3 => SOL
* DIS # F7: 8,9 => CTR => F7: 3,4,6
* DIS # E9: 3,4 => CTR => E9: 6,9
* DIS # H9: 3,4 => CTR => H9: 6,8,9
* CNT  20 HDP CHAINS /  50 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 # F2: 3,4 => CTR => F2: 9
* DIS F2: 9 # D7: 3,4 => CTR => D7: 8,9
* DIS F2: 9 + D7: 8,9 # D4: 8,9 => CTR => D4: 3,4
* DIS F2: 9 + D7: 8,9 + D4: 3,4 # I4: 8,9 => CTR => I4: 3,4,6
* DIS F2: 9 + D7: 8,9 + D4: 3,4 + I4: 3,4,6 # I5: 8,9 => CTR => I5: 3
* PRF F2: 9 + D7: 8,9 + D4: 3,4 + I4: 3,4,6 + I5: 3 => SOL
* STA F2: 9 + D7: 8,9 + D4: 3,4 + I4: 3,4,6 + I5: 3
* CNT   6 HDP CHAINS /  10 HYP OPENED

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

Details

Positions

34...2....1.....7.....8.6..2...5.......7...1..3.......5.....2..6.......5...1..... initial
347612.5.8165...72952.876.127..51...46.72.51.135...72.5.1...2.76..27.1.572.1.5... autosolve
347612859816539472952487631278351964469728513135946728591863247683274195724195386 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (11)
D3: 3,4
G1: 8,9
I1: 8,9
G2: 3,4
H3: 3,4
C4: 8,9
C5: 8,9
B7: 8,9
B8: 8,9
C8: 3,4
C9: 3,4

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
G2,H3: 3.. / G2 = 3  =>  0 pairs (X) / H3 = 3  =>  0 pairs (_)
D4,F5: 3.. / D4 = 3  =>  0 pairs (*) / F5 = 3  =>  0 pairs (X)
C8,C9: 3.. / C8 = 3  =>  0 pairs (*) / C9 = 3  =>  0 pairs (X)
D3,H3: 3.. / D3 = 3  =>  0 pairs (X) / H3 = 3  =>  0 pairs (_)
F5,I5: 3.. / F5 = 3  =>  0 pairs (X) / I5 = 3  =>  0 pairs (_)
G2,H3: 4.. / G2 = 4  =>  0 pairs (*) / H3 = 4  =>  0 pairs (X)
C8,C9: 4.. / C8 = 4  =>  0 pairs (X) / C9 = 4  =>  0 pairs (_)
D3,H3: 4.. / D3 = 4  =>  0 pairs (*) / H3 = 4  =>  0 pairs (X)
E6,F6: 6.. / E6 = 6  => 17 pairs (_) / F6 = 6  => 12 pairs (_)
H4,I4: 6.. / H4 = 6  => 19 pairs (_) / I4 = 6  => 11 pairs (_)
F6,F7: 6.. / F6 = 6  => 12 pairs (_) / F7 = 6  => 17 pairs (_)
I4,I9: 6.. / I4 = 6  => 11 pairs (_) / I9 = 6  => 19 pairs (_)
G1,I1: 8.. / G1 = 8  => 13 pairs (_) / I1 = 8  => 13 pairs (_)
C4,C5: 8.. / C4 = 8  => 13 pairs (_) / C5 = 8  => 13 pairs (_)
B7,B8: 8.. / B7 = 8  => 13 pairs (_) / B8 = 8  => 11 pairs (_)
B8,F8: 8.. / B8 = 8  => 11 pairs (_) / F8 = 8  => 13 pairs (_)
H4,H9: 8.. / H4 = 8  => 17 pairs (_) / H9 = 8  => 11 pairs (_)
E2,F2: 9.. / E2 = 9  =>  0 pairs (X) / F2 = 9  => 13 pairs (_)
G1,I1: 9.. / G1 = 9  => 13 pairs (_) / I1 = 9  => 13 pairs (_)
C4,C5: 9.. / C4 = 9  => 13 pairs (_) / C5 = 9  => 13 pairs (_)
B7,B8: 9.. / B7 = 9  => 11 pairs (_) / B8 = 9  => 13 pairs (_)
* DURATION: 0:00:38.378449  START: 16:21:50.756307  END: 16:22:29.134756 2017-05-04
* CP COUNT: (21)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B7,B8,C4,C5,C8,C9,D3,G1,G2,H3,I1)
* 347612.5.8165...72952.876.127..51...46.72.51.135...72.5.1...2.76..27.1.572.1.5...
* PAIR D3: 3,4 BLK 2
E2: 3,4,9                                # reduction candidate for 3,4
E2: 3,4                                  # 13 pairs
F2: 3,4,9                                # reduction candidate for 3,4
F2: 3,4 => CTR
* 347612.5.81659..72952.8764127..514.646.72.513135.4672.5.143.2676.427.135723165..4
F2: 9                                    # 13 pairs
* PAIR D3: 3,4 COL D
D4: 3,4,8,9                              # reduction candidate for 3,4
D4: 3,4                                  # 14 pairs
D7: 3,4,8,9                              # reduction candidate for 3,4
D7: 3,4 => CTR
* 347612.5.8165...72952.876.127..51...46.72351.135...72.5.1...2.76..27.1.572.1.5...
D7: 8,9                                  # 12 pairs
* PAIR G1: 8,9 COL G
G4: 8,9,3,4                              # reduction candidate for 8,9
G4: 8,9                                  # 19 pairs
G9: 8,9,3,4                              # reduction candidate for 8,9
G9: 8,9                                  # 13 pairs
* PAIR I1: 8,9 COL I
I4: 8,9,3,4,6                            # reduction candidate for 8,9
I4: 8,9 => CTR
* 347612.5.8165...72952.876.127..51.6.46.72.513135...7245.1...2.76..27.1.572.1.5.86
I4: 3,4,6                                # 11 pairs
I5: 8,9,3                                # reduction candidate for 8,9
I5: 8,9 => CTR
* 347612.5.8165..37295238764127.451...46.72351.135...7245.1...2.76.427.135723195486
I5: 3 => SOLVED
* 347612859816539472952487631278351964469728513135946728591863247683274195724195386
I6: 8,9,4                                # reduction candidate for 8,9
I6: 8,9 => SOLVED
* 347612859816539472952487631278351964469728513135946728591863247683274195724195386
I6: 4 => CTR
* 347612.5.8165..37295238764127.451..346.72351.135...7245.1.342676.427.1357231654..
I9: 8,9,3,4,6                            # reduction candidate for 8,9
I9: 8,9 => CTR
* 347612.5.8165...72952.876.127..51..646.72.513135...7245.1...2.76..27.1.572.1.5...
I9: 3,4,6                                # 11 pairs
* PAIR G2: 3,4 ROW 2
E2: 3,4,9                                # reduction candidate for 3,4
E2: 3,4                                  # 13 pairs
F2: 3,4,9                                # reduction candidate for 3,4
F2: 3,4 => CTR
* 347612.5.81659..72952.8764127..514.646.72.513135.4672.5.143.2676.427.135723165..4
F2: 9                                    # 13 pairs
* PAIR G2: 3,4 COL G
G4: 3,4,8,9                              # reduction candidate for 3,4
G4: 3,4                                  # 13 pairs
G9: 3,4,8,9                              # reduction candidate for 3,4
G9: 3,4                                  # 19 pairs
* PAIR H3: 3,4 COL H
H4: 3,4,6,8,9                            # reduction candidate for 3,4
H4: 3,4 => CTR
* 347612.5.8165...72952.876.127..51..646.72.51.135...72.5.1...2676..27.19572.1.5.8.
H4: 6,8,9                                # 11 pairs
H7: 3,4,6,9                              # reduction candidate for 3,4
H7: 3,4                                  # 16 pairs
H8: 3,4,9                                # reduction candidate for 3,4
H8: 3,4                                  # 15 pairs
H9: 3,4,6,8,9                            # reduction candidate for 3,4
H9: 3,4 => CTR
* 347612.5.8165...72952.876.127..51.8646872.51.135...72.5.1...2676..27.19572.1.5...
H9: 6,8,9                                # 11 pairs
* PAIR C4: 8,9 ROW 4
D4: 8,9,3,4                              # reduction candidate for 8,9
D4: 8,9 => CTR
* 347612.5.8165...72952.876.127..51...46.72351.135...72.5.1...2.76..27.1.572.1.5...
D4: 3,4                                  # 14 pairs
G4: 8,9,3,4                              # reduction candidate for 8,9
G4: 8,9                                  # 19 pairs
H4: 8,9,3,4,6                            # reduction candidate for 8,9
H4: 8,9                                  # 17 pairs
I4: 8,9,3,4,6                            # reduction candidate for 8,9
I4: 8,9 => CTR
* 347612.5.8165...72952.876.127..51.6.46.72.513135...7245.1...2.76..27.1.572.1.5.86
I4: 3,4,6                                # 11 pairs
* PAIR C5: 8,9 ROW 5
F5: 8,9,3                                # reduction candidate for 8,9
F5: 8,9 => SOLVED
* 347612859816539472952487631278351964469728513135946728591863247683274195724195386
F5: 3 => CTR
* 347612.5.8165..37295238764127.451...46.72351.135...7245.1...2.76.427.135723195486
I5: 8,9,3                                # reduction candidate for 8,9
I5: 8,9 => CTR
* 347612.5.8165..37295238764127.451...46.72351.135...7245.1...2.76.427.135723195486
I5: 3 => SOLVED
* 347612859816539472952487631278351964469728513135946728591863247683274195724195386
* PAIR B7: 8,9 ROW 7
D7: 8,9,3,4                              # reduction candidate for 8,9
D7: 8,9                                  # 12 pairs
F7: 8,9,3,4,6                            # reduction candidate for 8,9
F7: 8,9 => CTR
* 347612.5.8165...72952.876.127..51...46.72351.135.4672.5.1...2.76..27.1.572.1.5...
F7: 3,4,6                                # 11 pairs
* PAIR B8: 8,9 ROW 8
F8: 8,9,3,4                              # reduction candidate for 8,9
F8: 3,4                                  # 16 pairs
F8: 8,9                                  # 15 pairs
* PAIR C8: 3,4 ROW 8
F8: 3,4,8,9                              # reduction candidate for 3,4
F8: 3,4                                  # 16 pairs
H8: 3,4,9                                # reduction candidate for 3,4
H8: 3,4                                  # 15 pairs
* PAIR C9: 3,4 ROW 9
E9: 3,4,6,9                              # reduction candidate for 3,4
E9: 3,4 => CTR
* 347612.5.8165...72952.876.127..51...46.72.51.135...72.5.1...2.76..27.1.572.1.5...
E9: 6,9                                  # 12 pairs
G9: 3,4,8,9                              # reduction candidate for 3,4
G9: 3,4                                  # 19 pairs
H9: 3,4,6,8,9                            # reduction candidate for 3,4
H9: 3,4 => CTR
* 347612.5.8165...72952.876.127..51.8646872.51.135...72.5.1...2676..27.19572.1.5...
H9: 6,8,9                                # 11 pairs
I9: 3,4,6,8,9                            # reduction candidate for 3,4
I9: 3,4                                  # 15 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-396-base-pr-000.dot
* REASONING
* DIS # F2: 3,4 => CTR => F2: 9
* DIS # D7: 3,4 => CTR => D7: 8,9
* DIS # I4: 8,9 => CTR => I4: 3,4,6
* DIS # I5: 8,9 => CTR => I5: 3
* PRF # I5: 3 => SOL
* PRF # I6: 8,9 => SOL
* DIS # I6: 4 => CTR => I6: 8,9
* DIS # I9: 8,9 => CTR => I9: 3,4,6
* DIS # F2: 3,4 => CTR => F2: 9
* DIS # H4: 3,4 => CTR => H4: 6,8,9
* DIS # H9: 3,4 => CTR => H9: 6,8,9
* DIS # D4: 8,9 => CTR => D4: 3,4
* DIS # I4: 8,9 => CTR => I4: 3,4,6
* PRF # F5: 8,9 => SOL
* DIS # F5: 3 => CTR => F5: 8,9
* DIS # I5: 8,9 => CTR => I5: 3
* PRF # I5: 3 => SOL
* DIS # F7: 8,9 => CTR => F7: 3,4,6
* DIS # E9: 3,4 => CTR => E9: 6,9
* DIS # H9: 3,4 => CTR => H9: 6,8,9
* CNT  20 HDP CHAINS /  50 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B7,B8,C4,C5,C8,C9,D3,G1,G2,H3,I1)
* 347612.5.8165...72952.876.127..51...46.72.51.135...72.5.1...2.76..27.1.572.1.5...
* PAIR D3: 3,4 BLK 2
E2: 3,4,9                                # reduction candidate for 3,4
E2: 3,4                                  # 13 pairs
F2: 3,4,9                                # reduction candidate for 3,4
F2: 3,4 => CTR
* 347612.5.81659..72952.8764127..514.646.72.513135.4672.5.143.2676.427.135723165..4
* RESTART
* PAIR D3: 3,4 COL D
D4: 3,4,8,9                              # reduction candidate for 3,4
D4: 3,4                                  # 17 pairs
D7: 3,4,8,9                              # reduction candidate for 3,4
D7: 3,4 => CTR
* 347612.5.8165.9.72952.876.127..51...46.72351.135...72.5.1...2.76..27.1.572.1.5...
* RESTART
* PAIR D3: 3,4 COL D
D4: 3,4,8,9                              # reduction candidate for 3,4
D4: 8,9 => CTR
* 347612.5.81654937295238764127.851..34687235191354..72.5.1..42.76.42781357231.5...
* PAIR RESTART
* PAIR G1: 8,9 COL G
G4: 8,9,3,4                              # reduction candidate for 8,9
G4: 8,9                                  # 19 pairs
G9: 8,9,3,4                              # reduction candidate for 8,9
G9: 8,9                                  # 19 pairs
* PAIR I1: 8,9 COL I
I4: 8,9,3,4,6                            # reduction candidate for 8,9
I4: 8,9 => CTR
* 347612.5.8165.9.72952.876.127..51.6.46.72.513135...7245.1...2.76..27.19572.195.86
I5: 8,9,3                                # reduction candidate for 8,9
I5: 8,9 => CTR
* 347612.5.81654937295238764127.451..346.72351.1358967245819342676942781357231654..
I5: 3 => SOLVED
* 347612859816539472952487631278351964469728513135946728591863247683274195724195386
* DURATION: 0:00:11.532183  START: 16:23:16.679128  END: 16:23:28.211311 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-396-base-pr-001.dot
* REASONING
* DIS # F2: 3,4 => CTR => F2: 9
* DIS F2: 9 # D7: 3,4 => CTR => D7: 8,9
* DIS F2: 9 + D7: 8,9 # D4: 8,9 => CTR => D4: 3,4
* DIS F2: 9 + D7: 8,9 + D4: 3,4 # I4: 8,9 => CTR => I4: 3,4,6
* DIS F2: 9 + D7: 8,9 + D4: 3,4 + I4: 3,4,6 # I5: 8,9 => CTR => I5: 3
* PRF F2: 9 + D7: 8,9 + D4: 3,4 + I4: 3,4,6 + I5: 3 => SOL
* STA F2: 9 + D7: 8,9 + D4: 3,4 + I4: 3,4,6 + I5: 3
* CNT   6 HDP CHAINS /  10 HYP OPENED

Header Info

Top 500 Minimum 17 396

solution: 347612859816539472952487631278351964469728513135946728591863247683274195724195386
info: 67103    FNBXYK   S8.f     29984

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

Solution

position: 347612859816539472952487631278351964469728513135946728591863247683274195724195386 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 # E2: 3,4 => UNS
* DIS # F2: 3,4 => CTR => F2: 9
* INC # F2: 9 => UNS
* INC # D4: 3,4 => UNS
* DIS # D7: 3,4 => CTR => D7: 8,9
* INC # D7: 8,9 => UNS
* INC # G4: 8,9 => UNS
* INC # G9: 8,9 => UNS
* DIS # I4: 8,9 => CTR => I4: 3,4,6
* INC # I4: 3,4,6 => UNS
* DIS # I5: 8,9 => CTR => I5: 3
* PRF # I5: 3 => SOL
* PRF # I6: 8,9 => SOL
* DIS # I6: 4 => CTR => I6: 8,9
* DIS # I9: 8,9 => CTR => I9: 3,4,6
* INC # I9: 3,4,6 => UNS
* INC # E2: 3,4 => UNS
* DIS # F2: 3,4 => CTR => F2: 9
* INC # F2: 9 => UNS
* INC # G4: 3,4 => UNS
* INC # G9: 3,4 => UNS
* DIS # H4: 3,4 => CTR => H4: 6,8,9
* INC # H4: 6,8,9 => UNS
* INC # H7: 3,4 => UNS
* INC # H8: 3,4 => UNS
* DIS # H9: 3,4 => CTR => H9: 6,8,9
* INC # H9: 6,8,9 => UNS
* DIS # D4: 8,9 => CTR => D4: 3,4
* INC # D4: 3,4 => UNS
* INC # G4: 8,9 => UNS
* INC # H4: 8,9 => UNS
* DIS # I4: 8,9 => CTR => I4: 3,4,6
* INC # I4: 3,4,6 => UNS
* PRF # F5: 8,9 => SOL
* DIS # F5: 3 => CTR => F5: 8,9
* DIS # I5: 8,9 => CTR => I5: 3
* PRF # I5: 3 => SOL
* INC # D7: 8,9 => UNS
* DIS # F7: 8,9 => CTR => F7: 3,4,6
* INC # F7: 3,4,6 => UNS
* INC # F8: 8,9 => UNS
* INC # F8: 3,4 => UNS
* INC # F8: 3,4 => UNS
* INC # H8: 3,4 => UNS
* DIS # E9: 3,4 => CTR => E9: 6,9
* INC # E9: 6,9 => UNS
* INC # G9: 3,4 => UNS
* DIS # H9: 3,4 => CTR => H9: 6,8,9
* INC # H9: 6,8,9 => UNS
* INC # I9: 3,4 => UNS
* CNT  50 HDP CHAINS /  50 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # E2: 3,4 => UNS
* DIS # F2: 3,4 => CTR => F2: 9
* INC F2: 9 # D4: 3,4 => UNS
* DIS F2: 9 # D7: 3,4 => CTR => D7: 8,9
* INC F2: 9 + D7: 8,9 # D4: 3,4 => UNS
* DIS F2: 9 + D7: 8,9 # D4: 8,9 => CTR => D4: 3,4
* INC F2: 9 + D7: 8,9 + D4: 3,4 # G4: 8,9 => UNS
* INC F2: 9 + D7: 8,9 + D4: 3,4 # G9: 8,9 => UNS
* DIS F2: 9 + D7: 8,9 + D4: 3,4 # I4: 8,9 => CTR => I4: 3,4,6
* DIS F2: 9 + D7: 8,9 + D4: 3,4 + I4: 3,4,6 # I5: 8,9 => CTR => I5: 3
* PRF F2: 9 + D7: 8,9 + D4: 3,4 + I4: 3,4,6 + I5: 3 => SOL
* STA F2: 9 + D7: 8,9 + D4: 3,4 + I4: 3,4,6 + I5: 3
* CNT  11 HDP CHAINS /  10 HYP OPENED