Analysis of xx-top500-162-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: ....29.........1......3......9....2..8...4....5.7........1..8.53..8..6..2........ initial

Autosolve

position: 831.295..92.5781.35...31289..9385.2..8321495..527963.8.9.162835315847692268953... autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # C3: 4,6 => SOL
* DIS # C3: 7 => CTR => C3: 4,6
* DIS # C3: 4,7 => CTR => C3: 6
* PRF # C3: 6 => SOL
* DIS # H1: 4,6 => CTR => H1: 7
* PRF # H1: 7 => SOL
* PRF # C3: 4,6 => SOL
* DIS # C3: 7 => CTR => C3: 4,6
* PRF # H1: 4,7 => SOL
* DIS # H1: 6 => CTR => H1: 4,7
* PRF # I9: 4,7 => SOL
* DIS # I9: 1 => CTR => I9: 4,7
* DIS # H1: 4,6 => CTR => H1: 7
* PRF # H1: 7 => SOL
* PRF # H9: 1,4 => SOL
* DIS # H9: 7 => CTR => H9: 1,4
* DIS # C3: 4,7 => CTR => C3: 6
* PRF # C3: 6 => SOL
* DIS # H9: 4,7 => CTR => H9: 1
* PRF # H9: 1 => SOL
* PRF # I9: 4,7 => SOL
* DIS # I9: 1 => CTR => I9: 4,7
* CNT  22 HDP CHAINS /  22 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 # C3: 4,6 => SOL
* STA C3: 4,6
* CNT   1 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

....29.........1......3......9....2..8...4....5.7........1..8.53..8..6..2........ initial
831.295..92.5781.35...31289..9385.2..8321495..527963.8.9.162835315847692268953... autosolve
831629574924578163576431289649385721783214956152796348497162835315847692268953417 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (17)
C2: 4,6
B3: 4,7
D1: 4,6
D3: 4,6
I1: 4,7
H2: 4,6
A4: 1,6
B4: 4,7
A5: 6,7
A6: 1,4
G4: 4,7
I4: 1,6
I5: 6,7
H6: 1,4
A7: 4,7
C7: 4,7
G9: 4,7

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
A4,A6: 1.. / A4 = 1  =>  0 pairs (X) / A6 = 1  =>  0 pairs (_)
I4,H6: 1.. / I4 = 1  =>  0 pairs (*) / H6 = 1  =>  0 pairs (X)
H9,I9: 1.. / H9 = 1  =>  0 pairs (*) / I9 = 1  =>  0 pairs (X)
A4,I4: 1.. / A4 = 1  =>  0 pairs (X) / I4 = 1  =>  0 pairs (_)
A6,H6: 1.. / A6 = 1  =>  0 pairs (*) / H6 = 1  =>  0 pairs (X)
H6,H9: 1.. / H6 = 1  =>  0 pairs (X) / H9 = 1  =>  0 pairs (_)
I4,I9: 1.. / I4 = 1  =>  0 pairs (*) / I9 = 1  =>  0 pairs (X)
D1,D3: 4.. / D1 = 4  =>  0 pairs (X) / D3 = 4  =>  0 pairs (_)
B4,A6: 4.. / B4 = 4  =>  0 pairs (*) / A6 = 4  =>  0 pairs (X)
G4,H6: 4.. / G4 = 4  =>  0 pairs (X) / H6 = 4  =>  0 pairs (_)
A7,C7: 4.. / A7 = 4  =>  0 pairs (*) / C7 = 4  =>  0 pairs (X)
C2,H2: 4.. / C2 = 4  =>  0 pairs (*) / H2 = 4  =>  0 pairs (X)
B4,G4: 4.. / B4 = 4  =>  0 pairs (*) / G4 = 4  =>  0 pairs (X)
A6,H6: 4.. / A6 = 4  =>  0 pairs (X) / H6 = 4  =>  0 pairs (_)
A6,A7: 4.. / A6 = 4  =>  0 pairs (X) / A7 = 4  =>  0 pairs (_)
B3,B4: 4.. / B3 = 4  =>  0 pairs (X) / B4 = 4  =>  0 pairs (_)
G4,G9: 4.. / G4 = 4  =>  0 pairs (X) / G9 = 4  =>  0 pairs (_)
I1,I9: 4.. / I1 = 4  =>  0 pairs (*) / I9 = 4  =>  0 pairs (X)
C2,C3: 6.. / C2 = 6  =>  0 pairs (X) / C3 = 6  =>  0 pairs (_)
D1,D3: 6.. / D1 = 6  =>  0 pairs (*) / D3 = 6  =>  0 pairs (X)
H1,H2: 6.. / H1 = 6  =>  0 pairs (X) / H2 = 6  =>  0 pairs (_)
A4,A5: 6.. / A4 = 6  =>  0 pairs (*) / A5 = 6  =>  0 pairs (X)
I4,I5: 6.. / I4 = 6  =>  0 pairs (X) / I5 = 6  =>  0 pairs (_)
D1,H1: 6.. / D1 = 6  =>  0 pairs (*) / H1 = 6  =>  0 pairs (X)
C2,H2: 6.. / C2 = 6  =>  0 pairs (X) / H2 = 6  =>  0 pairs (_)
C3,D3: 6.. / C3 = 6  =>  0 pairs (*) / D3 = 6  =>  0 pairs (X)
A4,I4: 6.. / A4 = 6  =>  0 pairs (*) / I4 = 6  =>  0 pairs (X)
A5,I5: 6.. / A5 = 6  =>  0 pairs (X) / I5 = 6  =>  0 pairs (_)
B3,C3: 7.. / B3 = 7  =>  0 pairs (*) / C3 = 7  =>  0 pairs (X)
H1,I1: 7.. / H1 = 7  =>  0 pairs (*) / I1 = 7  =>  0 pairs (X)
B4,A5: 7.. / B4 = 7  =>  0 pairs (X) / A5 = 7  =>  0 pairs (_)
G4,I5: 7.. / G4 = 7  =>  0 pairs (*) / I5 = 7  =>  0 pairs (X)
A7,C7: 7.. / A7 = 7  =>  0 pairs (X) / C7 = 7  =>  0 pairs (_)
B4,G4: 7.. / B4 = 7  =>  0 pairs (X) / G4 = 7  =>  0 pairs (_)
A5,I5: 7.. / A5 = 7  =>  0 pairs (*) / I5 = 7  =>  0 pairs (X)
A5,A7: 7.. / A5 = 7  =>  0 pairs (*) / A7 = 7  =>  0 pairs (X)
B3,B4: 7.. / B3 = 7  =>  0 pairs (*) / B4 = 7  =>  0 pairs (X)
C3,C7: 7.. / C3 = 7  =>  0 pairs (X) / C7 = 7  =>  0 pairs (_)
G4,G9: 7.. / G4 = 7  =>  0 pairs (*) / G9 = 7  =>  0 pairs (X)
H1,H9: 7.. / H1 = 7  =>  0 pairs (*) / H9 = 7  =>  0 pairs (X)
* DURATION: 0:01:06.710634  START: 08:17:16.807018  END: 08:18:23.517652 2017-05-04
* CP COUNT: (40)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A4,A5,A6,A7,B3,B4,C2,C7,D1,D3,G4,G9,H2,H6,I1,I4,I5)
* 831.295..92.5781.35...31289..9385.2..8321495..527963.8.9.162835315847692268953...
* PAIR C2: 4,6 BLK 1
C3: 4,6,7                                # reduction candidate for 4,6
C3: 4,6 => SOLVED
* 831629574924578163576431289649385721783214956152796348497162835315847692268953417
C3: 7 => CTR
* 831.295..926578143547631289.7938542.683214957.527963.8.9.162835315847692268953...
* PAIR B3: 4,7 BLK 1
C3: 4,7,6                                # reduction candidate for 4,7
C3: 4,7 => CTR
* 831.295..9265781435..631289..938542..83214957.527963.8.9.162835315847692268953...
C3: 6 => SOLVED
* 831629574924578163576431289649385721783214956152796348497162835315847692268953417
* PAIR D1: 4,6 ROW 1
H1: 4,6,7                                # reduction candidate for 4,6
H1: 4,6 => CTR
* 831.295.792.5781.35...31289..938572.783214956.527963484971628353158476922689534..
H1: 7 => SOLVED
* 831629574924578163576431289649385721783214956152796348497162835315847692268953417
* PAIR D3: 4,6 ROW 3
C3: 4,6,7                                # reduction candidate for 4,6
C3: 4,6 => SOLVED
* 831629574924578163576431289649385721783214956152796348497162835315847692268953417
C3: 7 => CTR
* 831.295..926578143547631289.7938542.683214957.527963.8.9.162835315847692268953...
* PAIR I1: 4,7 BLK 3
H1: 4,7,6                                # reduction candidate for 4,7
H1: 4,7 => SOLVED
* 831629574924578163576431289649385721783214956152796348497162835315847692268953417
H1: 6 => CTR
* 831.295679265781435..631289..9385.2..8321495..527963.8.9.162835315847692268953...
* PAIR I1: 4,7 COL I
I9: 4,7,1                                # reduction candidate for 4,7
I9: 4,7 => SOLVED
* 831629574924578163576431289649385721783214956152796348497162835315847692268953417
I9: 1 => CTR
* 831.295.4924578163576431289.4938572.783214956152796348.9.162835315847692268953...
* PAIR H2: 4,6 BLK 3
H1: 4,6,7                                # reduction candidate for 4,6
H1: 4,6 => CTR
* 831.295.792.5781.35...31289..938572.783214956.527963484971628353158476922689534..
H1: 7 => SOLVED
* 831629574924578163576431289649385721783214956152796348497162835315847692268953417
* PAIR H6: 1,4 COL H
H9: 1,4,7                                # reduction candidate for 1,4
H9: 1,4 => SOLVED
* 831629574924578163576431289649385721783214956152796348497162835315847692268953417
H9: 7 => CTR
* 831.295..92.5781.35...31289..9385.2..8321495..52796318.9.162835315847692268953.71
* PAIR C7: 4,7 COL C
C3: 4,7,6                                # reduction candidate for 4,7
C3: 4,7 => CTR
* 831.295..9265781435..631289..938542..83214957.527963.8.9.162835315847692268953...
C3: 6 => SOLVED
* 831629574924578163576431289649385721783214956152796348497162835315847692268953417
* PAIR G9: 4,7 BLK 9
H9: 4,7,1                                # reduction candidate for 4,7
H9: 4,7 => CTR
* 831.295.49245781635764312891.9385.2..8321495..52796318.9.162835315847692268953..1
H9: 1 => SOLVED
* 831629574924578163576431289649385721783214956152796348497162835315847692268953417
I9: 4,7,1                                # reduction candidate for 4,7
I9: 4,7 => SOLVED
* 831629574924578163576431289649385721783214956152796348497162835315847692268953417
I9: 1 => CTR
* 831.295.4924578163576431289.4938572.783214956152796348.9.162835315847692268953...
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-162-base-pr-000.dot
* REASONING
* PRF # C3: 4,6 => SOL
* DIS # C3: 7 => CTR => C3: 4,6
* DIS # C3: 4,7 => CTR => C3: 6
* PRF # C3: 6 => SOL
* DIS # H1: 4,6 => CTR => H1: 7
* PRF # H1: 7 => SOL
* PRF # C3: 4,6 => SOL
* DIS # C3: 7 => CTR => C3: 4,6
* PRF # H1: 4,7 => SOL
* DIS # H1: 6 => CTR => H1: 4,7
* PRF # I9: 4,7 => SOL
* DIS # I9: 1 => CTR => I9: 4,7
* DIS # H1: 4,6 => CTR => H1: 7
* PRF # H1: 7 => SOL
* PRF # H9: 1,4 => SOL
* DIS # H9: 7 => CTR => H9: 1,4
* DIS # C3: 4,7 => CTR => C3: 6
* PRF # C3: 6 => SOL
* DIS # H9: 4,7 => CTR => H9: 1
* PRF # H9: 1 => SOL
* PRF # I9: 4,7 => SOL
* DIS # I9: 1 => CTR => I9: 4,7
* CNT  22 HDP CHAINS /  22 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A4,A5,A6,A7,B3,B4,C2,C7,D1,D3,G4,G9,H2,H6,I1,I4,I5)
* 831.295..92.5781.35...31289..9385.2..8321495..527963.8.9.162835315847692268953...
* PAIR C2: 4,6 BLK 1
C3: 4,6,7                                # reduction candidate for 4,6
C3: 4,6 => SOLVED
* 831629574924578163576431289649385721783214956152796348497162835315847692268953417
* DURATION: 0:00:01.894408  START: 08:18:49.544597  END: 08:18:51.439005 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-162-base-pr-001.dot
* REASONING
* PRF # C3: 4,6 => SOL
* STA C3: 4,6
* CNT   1 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 162

solution: 831629574924578163576431289649385721783214956152796348497162835315847692268953417
info: 1821     FNBTWY   S8.f     3648

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

Solution

position: 831629574924578163576431289649385721783214956152796348497162835315847692268953417 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 # C3: 4,6 => SOL
* DIS # C3: 7 => CTR => C3: 4,6
* DIS # C3: 4,7 => CTR => C3: 6
* PRF # C3: 6 => SOL
* DIS # H1: 4,6 => CTR => H1: 7
* PRF # H1: 7 => SOL
* PRF # C3: 4,6 => SOL
* DIS # C3: 7 => CTR => C3: 4,6
* PRF # H1: 4,7 => SOL
* DIS # H1: 6 => CTR => H1: 4,7
* PRF # I9: 4,7 => SOL
* DIS # I9: 1 => CTR => I9: 4,7
* DIS # H1: 4,6 => CTR => H1: 7
* PRF # H1: 7 => SOL
* PRF # H9: 1,4 => SOL
* DIS # H9: 7 => CTR => H9: 1,4
* DIS # C3: 4,7 => CTR => C3: 6
* PRF # C3: 6 => SOL
* DIS # H9: 4,7 => CTR => H9: 1
* PRF # H9: 1 => SOL
* PRF # I9: 4,7 => SOL
* DIS # I9: 1 => CTR => I9: 4,7
* CNT  22 HDP CHAINS /  22 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* PRF # C3: 4,6 => SOL
* STA C3: 4,6
* CNT   1 HDP CHAINS /   1 HYP OPENED