Analysis of xx-top500-125-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 64...........8.1..2...4....8.......4.....1.3....2......3.7..5.....6..2....1...... initial

Autosolve

position: 6481..32.3...8214621.346.8.823.6..14..64.18321.423865.93271456848.6.32.1.6182.4.3 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # C2: 5,7 => SOL
* DIS # C2: 9 => CTR => C2: 5,7
* PRF # B5: 5,7 => SOL
* DIS # B5: 9 => CTR => B5: 5,7
* PRF # C2: 5,9 => SOL
* DIS # C2: 7 => CTR => C2: 5,9
* PRF # I3: 5,9 => SOL
* DIS # I3: 7 => CTR => I3: 5,9
* DIS # E1: 5,9 => CTR => E1: 7
* PRF # E1: 7 => SOL
* PRF # F1: 5,9 => SOL
* DIS # F1: 7 => CTR => F1: 5,9
* PRF # C2: 5,9 => SOL
* DIS # C2: 7 => CTR => C2: 5,9
* PRF # I3: 5,9 => SOL
* DIS # I3: 7 => CTR => I3: 5,9
* DIS # E1: 5,9 => CTR => E1: 7
* PRF # E1: 7 => SOL
* PRF # F1: 5,9 => SOL
* DIS # F1: 7 => CTR => F1: 5,9
* DIS # I3: 7,9 => CTR => I3: 5
* PRF # I3: 5 => SOL
* PRF # B5: 5,7 => SOL
* DIS # B5: 9 => CTR => B5: 5,7
* DIS # B5: 7,9 => CTR => B5: 5
* PRF # B5: 5 => SOL
* DIS # F4: 5,9 => CTR => F4: 7
* PRF # F4: 7 => SOL
* PRF # F4: 7,9 => SOL
* DIS # F4: 5 => CTR => F4: 7,9
* DIS # B5: 7,9 => CTR => B5: 5
* PRF # B5: 5 => SOL
* PRF # E1: 7,9 => SOL
* DIS # E1: 5 => CTR => E1: 7,9
* PRF # F4: 7,9 => SOL
* DIS # F4: 5 => CTR => F4: 7,9
* DIS # I3: 7,9 => CTR => I3: 5
* PRF # I3: 5 => SOL
* PRF # C2: 5,7 => SOL
* DIS # C2: 9 => CTR => C2: 5,7
* DIS # E1: 5,9 => CTR => E1: 7
* PRF # E1: 7 => SOL
* PRF # F1: 5,9 => SOL
* DIS # F1: 7 => CTR => F1: 5,9
* DIS # F4: 5,9 => CTR => F4: 7
* PRF # F4: 7 => SOL
* CNT  46 HDP CHAINS /  46 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 # C2: 5,7 => SOL
* STA C2: 5,7
* CNT   1 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

64...........8.1..2...4....8.......4.....1.3....2......3.7..5.....6..2....1...... initial
6481..32.3...8214621.346.8.823.6..14..64.18321.423865.93271456848.6.32.1.6182.4.3 autosolve
648175329375982146219346785823567914756491832194238657932714568487653291561829473 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (17)
B2: 5,7
C3: 5,9
D2: 5,9
I1: 5,9
G3: 7,9
A5: 5,7
B6: 7,9
D4: 5,9
E5: 7,9
G4: 7,9
I6: 7,9
C8: 5,7
A9: 5,7
E8: 5,9
F9: 5,9
H8: 7,9
H9: 7,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
I1,I3: 5.. / I1 = 5  =>  0 pairs (X) / I3 = 5  =>  0 pairs (_)
A5,B5: 5.. / A5 = 5  =>  0 pairs (X) / B5 = 5  =>  0 pairs (_)
D4,F4: 5.. / D4 = 5  =>  0 pairs (*) / F4 = 5  =>  0 pairs (X)
C8,A9: 5.. / C8 = 5  =>  0 pairs (X) / A9 = 5  =>  0 pairs (_)
E8,F9: 5.. / E8 = 5  =>  0 pairs (*) / F9 = 5  =>  0 pairs (X)
C3,I3: 5.. / C3 = 5  =>  0 pairs (X) / I3 = 5  =>  0 pairs (_)
C8,E8: 5.. / C8 = 5  =>  0 pairs (X) / E8 = 5  =>  0 pairs (_)
A9,F9: 5.. / A9 = 5  =>  0 pairs (*) / F9 = 5  =>  0 pairs (X)
A5,A9: 5.. / A5 = 5  =>  0 pairs (X) / A9 = 5  =>  0 pairs (_)
B2,B5: 5.. / B2 = 5  =>  0 pairs (X) / B5 = 5  =>  0 pairs (_)
D2,D4: 5.. / D2 = 5  =>  0 pairs (X) / D4 = 5  =>  0 pairs (_)
E1,E8: 5.. / E1 = 5  =>  0 pairs (X) / E8 = 5  =>  0 pairs (_)
B2,C2: 7.. / B2 = 7  =>  0 pairs (*) / C2 = 7  =>  0 pairs (X)
E1,F1: 7.. / E1 = 7  =>  0 pairs (*) / F1 = 7  =>  0 pairs (X)
G3,I3: 7.. / G3 = 7  =>  0 pairs (*) / I3 = 7  =>  0 pairs (X)
F4,E5: 7.. / F4 = 7  =>  0 pairs (*) / E5 = 7  =>  0 pairs (X)
G4,I6: 7.. / G4 = 7  =>  0 pairs (X) / I6 = 7  =>  0 pairs (_)
C8,A9: 7.. / C8 = 7  =>  0 pairs (*) / A9 = 7  =>  0 pairs (X)
H8,H9: 7.. / H8 = 7  =>  0 pairs (X) / H9 = 7  =>  0 pairs (_)
F4,G4: 7.. / F4 = 7  =>  0 pairs (*) / G4 = 7  =>  0 pairs (X)
B6,I6: 7.. / B6 = 7  =>  0 pairs (X) / I6 = 7  =>  0 pairs (_)
C8,H8: 7.. / C8 = 7  =>  0 pairs (*) / H8 = 7  =>  0 pairs (X)
A9,H9: 7.. / A9 = 7  =>  0 pairs (X) / H9 = 7  =>  0 pairs (_)
A5,A9: 7.. / A5 = 7  =>  0 pairs (*) / A9 = 7  =>  0 pairs (X)
C2,C8: 7.. / C2 = 7  =>  0 pairs (X) / C8 = 7  =>  0 pairs (_)
E1,E5: 7.. / E1 = 7  =>  0 pairs (*) / E5 = 7  =>  0 pairs (X)
F1,F4: 7.. / F1 = 7  =>  0 pairs (X) / F4 = 7  =>  0 pairs (_)
G3,G4: 7.. / G3 = 7  =>  0 pairs (*) / G4 = 7  =>  0 pairs (X)
I3,I6: 7.. / I3 = 7  =>  0 pairs (X) / I6 = 7  =>  0 pairs (_)
C2,C3: 9.. / C2 = 9  =>  0 pairs (X) / C3 = 9  =>  0 pairs (_)
B5,B6: 9.. / B5 = 9  =>  0 pairs (X) / B6 = 9  =>  0 pairs (_)
G4,I6: 9.. / G4 = 9  =>  0 pairs (*) / I6 = 9  =>  0 pairs (X)
E8,F9: 9.. / E8 = 9  =>  0 pairs (X) / F9 = 9  =>  0 pairs (_)
H8,H9: 9.. / H8 = 9  =>  0 pairs (*) / H9 = 9  =>  0 pairs (X)
C2,D2: 9.. / C2 = 9  =>  0 pairs (X) / D2 = 9  =>  0 pairs (_)
B5,E5: 9.. / B5 = 9  =>  0 pairs (X) / E5 = 9  =>  0 pairs (_)
B6,I6: 9.. / B6 = 9  =>  0 pairs (*) / I6 = 9  =>  0 pairs (X)
E8,H8: 9.. / E8 = 9  =>  0 pairs (X) / H8 = 9  =>  0 pairs (_)
F9,H9: 9.. / F9 = 9  =>  0 pairs (*) / H9 = 9  =>  0 pairs (X)
D2,D4: 9.. / D2 = 9  =>  0 pairs (*) / D4 = 9  =>  0 pairs (X)
G3,G4: 9.. / G3 = 9  =>  0 pairs (X) / G4 = 9  =>  0 pairs (_)
* DURATION: 0:01:11.544357  START: 07:02:06.646875  END: 07:03:18.191232 2017-05-04
* CP COUNT: (41)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A5,A9,B2,B6,C3,C8,D2,D4,E5,E8,F9,G3,G4,H8,H9,I1,I6)
* 6481..32.3...8214621.346.8.823.6..14..64.18321.423865.93271456848.6.32.1.6182.4.3
* PAIR B2: 5,7 BLK 1
C2: 5,7,9                                # reduction candidate for 5,7
C2: 5,7 => SOLVED
* 648175329375982146219346785823567914756491832194238657932714568487653291561829473
C2: 9 => CTR
* 6481..32.379582146215346.8.823965714..64.18321.423865.93271456848.6.32.1.6182.4.3
* PAIR B2: 5,7 COL B
B5: 5,7,9                                # reduction candidate for 5,7
B5: 5,7 => SOLVED
* 648175329375982146219346785823567914756491832194238657932714568487653291561829473
B5: 9 => CTR
* 6481..32.357982146219346785823567914..64.18321.423865.93271456848.6.32.1.6182.4.3
* PAIR C3: 5,9 BLK 1
C2: 5,9,7                                # reduction candidate for 5,9
C2: 5,9 => SOLVED
* 648175329375982146219346785823567914756491832194238657932714568487653291561829473
C2: 7 => CTR
* 6481..32.3.7982146219346785823567914..64918321942386579327145684856.32.1.6182.4.3
* PAIR C3: 5,9 ROW 3
I3: 5,9,7                                # reduction candidate for 5,9
I3: 5,9 => SOLVED
* 648175329375982146219346785823567914756491832194238657932714568487653291561829473
I3: 7 => CTR
* 6481..3253..582146215346987823965714..64.18321.423865.93271456848.6.32.1.6182.4.3
* PAIR D2: 5,9 BLK 2
E1: 5,9,7                                # reduction candidate for 5,9
E1: 5,9 => CTR
* 6481.732.3...8214621.346.8.823.6.714..647183217423865993271456848.6.32.1761825493
E1: 7 => SOLVED
* 648175329375982146219346785823567914756491832194238657932714568487653291561829473
F1: 5,9,7                                # reduction candidate for 5,9
F1: 5,9 => SOLVED
* 648175329375982146219346785823567914756491832194238657932714568487653291561829473
F1: 7 => CTR
* 6481.732.3...8214621.346.8.823.6.714..647183217423865993271456848.6.32.1761825493
* PAIR D2: 5,9 ROW 2
C2: 5,9,7                                # reduction candidate for 5,9
C2: 5,9 => SOLVED
* 648175329375982146219346785823567914756491832194238657932714568487653291561829473
C2: 7 => CTR
* 6481..32.3.7982146219346785823567914..64918321942386579327145684856.32.1.6182.4.3
* PAIR I1: 5,9 BLK 3
I3: 5,9,7                                # reduction candidate for 5,9
I3: 5,9 => SOLVED
* 648175329375982146219346785823567914756491832194238657932714568487653291561829473
I3: 7 => CTR
* 6481..3253..582146215346987823965714..64.18321.423865.93271456848.6.32.1.6182.4.3
* PAIR I1: 5,9 ROW 1
E1: 5,9,7                                # reduction candidate for 5,9
E1: 5,9 => CTR
* 6481.732.3...8214621.346.8.823.6.714..647183217423865993271456848.6.32.1761825493
E1: 7 => SOLVED
* 648175329375982146219346785823567914756491832194238657932714568487653291561829473
F1: 5,9,7                                # reduction candidate for 5,9
F1: 5,9 => SOLVED
* 648175329375982146219346785823567914756491832194238657932714568487653291561829473
F1: 7 => CTR
* 6481.732.3...8214621.346.8.823.6.714..647183217423865993271456848.6.32.1761825493
* PAIR G3: 7,9 BLK 3
I3: 7,9,5                                # reduction candidate for 7,9
I3: 7,9 => CTR
* 6481..3253..582146215346.8.823965714..64.18321.423865.93271456848.6.32.1.6182.4.3
I3: 5 => SOLVED
* 648175329375982146219346785823567914756491832194238657932714568487653291561829473
* PAIR A5: 5,7 BLK 4
B5: 5,7,9                                # reduction candidate for 5,7
B5: 5,7 => SOLVED
* 648175329375982146219346785823567914756491832194238657932714568487653291561829473
B5: 9 => CTR
* 6481..32.357982146219346785823567914..64.18321.423865.93271456848.6.32.1.6182.4.3
* PAIR B6: 7,9 BLK 4
B5: 7,9,5                                # reduction candidate for 7,9
B5: 7,9 => CTR
* 6481..32.3579821462193467858235679145764918321942386579327145684856.32.1.6182.4.3
B5: 5 => SOLVED
* 648175329375982146219346785823567914756491832194238657932714568487653291561829473
* PAIR D4: 5,9 BLK 5
F4: 5,9,7                                # reduction candidate for 5,9
F4: 5,9 => CTR
* 6481.732.3...8214621.346.8.823.6.714..647183217423865993271456848.6.32.1761825493
F4: 7 => SOLVED
* 648175329375982146219346785823567914756491832194238657932714568487653291561829473
* PAIR E5: 7,9 BLK 5
F4: 7,9,5                                # reduction candidate for 7,9
F4: 7,9 => SOLVED
* 648175329375982146219346785823567914756491832194238657932714568487653291561829473
F4: 5 => CTR
* 6481.732.3...8214621.346.8.823.65714..647183217423865993271456848.653291.6182.4.3
* PAIR E5: 7,9 ROW 5
B5: 7,9,5                                # reduction candidate for 7,9
B5: 7,9 => CTR
* 6481..32.3579821462193467858235679145764918321942386579327145684856.32.1.6182.4.3
B5: 5 => SOLVED
* 648175329375982146219346785823567914756491832194238657932714568487653291561829473
* PAIR E5: 7,9 COL E
E1: 7,9,5                                # reduction candidate for 7,9
E1: 7,9 => SOLVED
* 648175329375982146219346785823567914756491832194238657932714568487653291561829473
E1: 5 => CTR
* 6481573293..98214621934678.823.6..14..64.18321.423865.93271456848.6.32.1.6182.4.3
* PAIR G4: 7,9 ROW 4
F4: 7,9,5                                # reduction candidate for 7,9
F4: 7,9 => SOLVED
* 648175329375982146219346785823567914756491832194238657932714568487653291561829473
F4: 5 => CTR
* 6481.732.3...8214621.346.8.823.65714..647183217423865993271456848.653291.6182.4.3
* PAIR I6: 7,9 COL I
I3: 7,9,5                                # reduction candidate for 7,9
I3: 7,9 => CTR
* 6481..3253..582146215346.8.823965714..64.18321.423865.93271456848.6.32.1.6182.4.3
I3: 5 => SOLVED
* 648175329375982146219346785823567914756491832194238657932714568487653291561829473
* PAIR C8: 5,7 COL C
C2: 5,7,9                                # reduction candidate for 5,7
C2: 5,7 => SOLVED
* 648175329375982146219346785823567914756491832194238657932714568487653291561829473
C2: 9 => CTR
* 6481..32.379582146215346.8.823965714..64.18321.423865.93271456848.6.32.1.6182.4.3
* PAIR E8: 5,9 COL E
E1: 5,9,7                                # reduction candidate for 5,9
E1: 5,9 => CTR
* 6481.732.3...8214621.346.8.823.6.714..647183217423865993271456848.6.32.1761825493
E1: 7 => SOLVED
* 648175329375982146219346785823567914756491832194238657932714568487653291561829473
* PAIR F9: 5,9 COL F
F1: 5,9,7                                # reduction candidate for 5,9
F1: 5,9 => SOLVED
* 648175329375982146219346785823567914756491832194238657932714568487653291561829473
F1: 7 => CTR
* 6481.732.3...8214621.346.8.823.6.714..647183217423865993271456848.6.32.1761825493
F4: 5,9,7                                # reduction candidate for 5,9
F4: 5,9 => CTR
* 6481.732.3...8214621.346.8.823.6.714..647183217423865993271456848.6.32.1761825493
F4: 7 => SOLVED
* 648175329375982146219346785823567914756491832194238657932714568487653291561829473
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-125-base-pr-000.dot
* REASONING
* PRF # C2: 5,7 => SOL
* DIS # C2: 9 => CTR => C2: 5,7
* PRF # B5: 5,7 => SOL
* DIS # B5: 9 => CTR => B5: 5,7
* PRF # C2: 5,9 => SOL
* DIS # C2: 7 => CTR => C2: 5,9
* PRF # I3: 5,9 => SOL
* DIS # I3: 7 => CTR => I3: 5,9
* DIS # E1: 5,9 => CTR => E1: 7
* PRF # E1: 7 => SOL
* PRF # F1: 5,9 => SOL
* DIS # F1: 7 => CTR => F1: 5,9
* PRF # C2: 5,9 => SOL
* DIS # C2: 7 => CTR => C2: 5,9
* PRF # I3: 5,9 => SOL
* DIS # I3: 7 => CTR => I3: 5,9
* DIS # E1: 5,9 => CTR => E1: 7
* PRF # E1: 7 => SOL
* PRF # F1: 5,9 => SOL
* DIS # F1: 7 => CTR => F1: 5,9
* DIS # I3: 7,9 => CTR => I3: 5
* PRF # I3: 5 => SOL
* PRF # B5: 5,7 => SOL
* DIS # B5: 9 => CTR => B5: 5,7
* DIS # B5: 7,9 => CTR => B5: 5
* PRF # B5: 5 => SOL
* DIS # F4: 5,9 => CTR => F4: 7
* PRF # F4: 7 => SOL
* PRF # F4: 7,9 => SOL
* DIS # F4: 5 => CTR => F4: 7,9
* DIS # B5: 7,9 => CTR => B5: 5
* PRF # B5: 5 => SOL
* PRF # E1: 7,9 => SOL
* DIS # E1: 5 => CTR => E1: 7,9
* PRF # F4: 7,9 => SOL
* DIS # F4: 5 => CTR => F4: 7,9
* DIS # I3: 7,9 => CTR => I3: 5
* PRF # I3: 5 => SOL
* PRF # C2: 5,7 => SOL
* DIS # C2: 9 => CTR => C2: 5,7
* DIS # E1: 5,9 => CTR => E1: 7
* PRF # E1: 7 => SOL
* PRF # F1: 5,9 => SOL
* DIS # F1: 7 => CTR => F1: 5,9
* DIS # F4: 5,9 => CTR => F4: 7
* PRF # F4: 7 => SOL
* CNT  46 HDP CHAINS /  46 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A5,A9,B2,B6,C3,C8,D2,D4,E5,E8,F9,G3,G4,H8,H9,I1,I6)
* 6481..32.3...8214621.346.8.823.6..14..64.18321.423865.93271456848.6.32.1.6182.4.3
* PAIR B2: 5,7 BLK 1
C2: 5,7,9                                # reduction candidate for 5,7
C2: 5,7 => SOLVED
* 648175329375982146219346785823567914756491832194238657932714568487653291561829473
* DURATION: 0:00:01.902153  START: 07:04:10.177535  END: 07:04:12.079688 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-125-base-pr-001.dot
* REASONING
* PRF # C2: 5,7 => SOL
* STA C2: 5,7
* CNT   1 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 125

solution: 648175329375982146219346785823567914756491832194238657932714568487653291561829473
info: 1808     FNBWY    S8.f     35874

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

Solution

position: 648175329375982146219346785823567914756491832194238657932714568487653291561829473 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 # C2: 5,7 => SOL
* DIS # C2: 9 => CTR => C2: 5,7
* PRF # B5: 5,7 => SOL
* DIS # B5: 9 => CTR => B5: 5,7
* PRF # C2: 5,9 => SOL
* DIS # C2: 7 => CTR => C2: 5,9
* PRF # I3: 5,9 => SOL
* DIS # I3: 7 => CTR => I3: 5,9
* DIS # E1: 5,9 => CTR => E1: 7
* PRF # E1: 7 => SOL
* PRF # F1: 5,9 => SOL
* DIS # F1: 7 => CTR => F1: 5,9
* PRF # C2: 5,9 => SOL
* DIS # C2: 7 => CTR => C2: 5,9
* PRF # I3: 5,9 => SOL
* DIS # I3: 7 => CTR => I3: 5,9
* DIS # E1: 5,9 => CTR => E1: 7
* PRF # E1: 7 => SOL
* PRF # F1: 5,9 => SOL
* DIS # F1: 7 => CTR => F1: 5,9
* DIS # I3: 7,9 => CTR => I3: 5
* PRF # I3: 5 => SOL
* PRF # B5: 5,7 => SOL
* DIS # B5: 9 => CTR => B5: 5,7
* DIS # B5: 7,9 => CTR => B5: 5
* PRF # B5: 5 => SOL
* DIS # F4: 5,9 => CTR => F4: 7
* PRF # F4: 7 => SOL
* PRF # F4: 7,9 => SOL
* DIS # F4: 5 => CTR => F4: 7,9
* DIS # B5: 7,9 => CTR => B5: 5
* PRF # B5: 5 => SOL
* PRF # E1: 7,9 => SOL
* DIS # E1: 5 => CTR => E1: 7,9
* PRF # F4: 7,9 => SOL
* DIS # F4: 5 => CTR => F4: 7,9
* DIS # I3: 7,9 => CTR => I3: 5
* PRF # I3: 5 => SOL
* PRF # C2: 5,7 => SOL
* DIS # C2: 9 => CTR => C2: 5,7
* DIS # E1: 5,9 => CTR => E1: 7
* PRF # E1: 7 => SOL
* PRF # F1: 5,9 => SOL
* DIS # F1: 7 => CTR => F1: 5,9
* DIS # F4: 5,9 => CTR => F4: 7
* PRF # F4: 7 => SOL
* CNT  46 HDP CHAINS /  46 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* PRF # C2: 5,7 => SOL
* STA C2: 5,7
* CNT   1 HDP CHAINS /   1 HYP OPENED