Analysis of zz-sudoku-de-741856-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: ....5.23.2.64.....4....8.9...3.7..2.7..2.5..9.5..8.4...8.1....3.....35.2.21.6.... initial

Autosolve

position: .78.5.2342.643.857435728.9.8.3.74.25764215389.5238.47.589142763647893512321567948 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # F1: 1,9 => SOL
* DIS # F1: 6 => CTR => F1: 1,9
* PRF # F1: 6,9 => SOL
* DIS # F1: 1 => CTR => F1: 6,9
* PRF # F1: 1,9 => SOL
* DIS # F1: 6 => CTR => F1: 1,9
* PRF # F1: 6,9 => SOL
* DIS # F1: 1 => CTR => F1: 6,9
* CNT   8 HDP CHAINS /   8 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 # F1: 1,9 => SOL
* STA F1: 1,9
* CNT   1 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

....5.23.2.64.....4....8.9...3.7..2.7..2.5..9.5..8.4...8.1....3.....35.2.21.6.... initial
.78.5.2342.643.857435728.9.8.3.74.25764215389.5238.47.589142763647893512321567948 autosolve
178659234296431857435728196813974625764215389952386471589142763647893512321567948 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (12)
A1: 1,9
B2: 1,9
D1: 6,9
F2: 1,9
G3: 1,6
I3: 1,6
B4: 1,9
A6: 1,9
D4: 6,9
F6: 6,9
G4: 1,6
I6: 1,6

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
A1,B2: 1.. / A1 = 1  =>  0 pairs (*) / B2 = 1  =>  0 pairs (X)
F1,F2: 1.. / F1 = 1  =>  0 pairs (X) / F2 = 1  =>  0 pairs (_)
G3,I3: 1.. / G3 = 1  =>  0 pairs (*) / I3 = 1  =>  0 pairs (X)
B4,A6: 1.. / B4 = 1  =>  0 pairs (*) / A6 = 1  =>  0 pairs (X)
G4,I6: 1.. / G4 = 1  =>  0 pairs (X) / I6 = 1  =>  0 pairs (_)
A1,F1: 1.. / A1 = 1  =>  0 pairs (*) / F1 = 1  =>  0 pairs (X)
B2,F2: 1.. / B2 = 1  =>  0 pairs (X) / F2 = 1  =>  0 pairs (_)
B4,G4: 1.. / B4 = 1  =>  0 pairs (*) / G4 = 1  =>  0 pairs (X)
A6,I6: 1.. / A6 = 1  =>  0 pairs (X) / I6 = 1  =>  0 pairs (_)
A1,A6: 1.. / A1 = 1  =>  0 pairs (*) / A6 = 1  =>  0 pairs (X)
B2,B4: 1.. / B2 = 1  =>  0 pairs (X) / B4 = 1  =>  0 pairs (_)
G3,G4: 1.. / G3 = 1  =>  0 pairs (*) / G4 = 1  =>  0 pairs (X)
I3,I6: 1.. / I3 = 1  =>  0 pairs (X) / I6 = 1  =>  0 pairs (_)
D1,F1: 6.. / D1 = 6  =>  0 pairs (*) / F1 = 6  =>  0 pairs (X)
G3,I3: 6.. / G3 = 6  =>  0 pairs (X) / I3 = 6  =>  0 pairs (_)
D4,F6: 6.. / D4 = 6  =>  0 pairs (X) / F6 = 6  =>  0 pairs (_)
G4,I6: 6.. / G4 = 6  =>  0 pairs (*) / I6 = 6  =>  0 pairs (X)
D4,G4: 6.. / D4 = 6  =>  0 pairs (X) / G4 = 6  =>  0 pairs (_)
F6,I6: 6.. / F6 = 6  =>  0 pairs (*) / I6 = 6  =>  0 pairs (X)
D1,D4: 6.. / D1 = 6  =>  0 pairs (*) / D4 = 6  =>  0 pairs (X)
F1,F6: 6.. / F1 = 6  =>  0 pairs (X) / F6 = 6  =>  0 pairs (_)
G3,G4: 6.. / G3 = 6  =>  0 pairs (X) / G4 = 6  =>  0 pairs (_)
I3,I6: 6.. / I3 = 6  =>  0 pairs (*) / I6 = 6  =>  0 pairs (X)
A1,B2: 9.. / A1 = 9  =>  0 pairs (X) / B2 = 9  =>  0 pairs (_)
B4,A6: 9.. / B4 = 9  =>  0 pairs (X) / A6 = 9  =>  0 pairs (_)
D4,F6: 9.. / D4 = 9  =>  0 pairs (*) / F6 = 9  =>  0 pairs (X)
B2,F2: 9.. / B2 = 9  =>  0 pairs (*) / F2 = 9  =>  0 pairs (X)
B4,D4: 9.. / B4 = 9  =>  0 pairs (X) / D4 = 9  =>  0 pairs (_)
A6,F6: 9.. / A6 = 9  =>  0 pairs (*) / F6 = 9  =>  0 pairs (X)
A1,A6: 9.. / A1 = 9  =>  0 pairs (X) / A6 = 9  =>  0 pairs (_)
B2,B4: 9.. / B2 = 9  =>  0 pairs (*) / B4 = 9  =>  0 pairs (X)
D1,D4: 9.. / D1 = 9  =>  0 pairs (X) / D4 = 9  =>  0 pairs (_)
* DURATION: 0:00:54.397165  START: 08:26:07.686697  END: 08:27:02.083862 2017-05-01
* CP COUNT: (32)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,A6,B2,B4,D1,D4,F2,F6,G3,G4,I3,I6)
* .78.5.2342.643.857435728.9.8.3.74.25764215389.5238.47.589142763647893512321567948
* PAIR A1: 1,9 ROW 1
F1: 1,9,6                                # reduction candidate for 1,9
F1: 1,9 => SOLVED
* 178659234296431857435728196813974625764215389952386471589142763647893512321567948
F1: 6 => CTR
* 17895623429643.857435728.9.8.3.74.25764215389.5238.47.589142763647893512321567948
* PAIR D1: 6,9 BLK 2
F1: 6,9,1                                # reduction candidate for 6,9
F1: 6,9 => SOLVED
* 178659234296431857435728196813974625764215389952386471589142763647893512321567948
F1: 1 => CTR
* .78651234216439857435728.9.893.74.25764215389.5238.47.589142763647893512321567948
* PAIR F2: 1,9 BLK 2
F1: 1,9,6                                # reduction candidate for 1,9
F1: 1,9 => SOLVED
* 178659234296431857435728196813974625764215389952386471589142763647893512321567948
F1: 6 => CTR
* 17895623429643.857435728.9.8.3.74.25764215389.5238.47.589142763647893512321567948
* PAIR F6: 6,9 COL F
F1: 6,9,1                                # reduction candidate for 6,9
F1: 6,9 => SOLVED
* 178659234296431857435728196813974625764215389952386471589142763647893512321567948
F1: 1 => CTR
* .78651234216439857435728.9.893.74.25764215389.5238.47.589142763647893512321567948
* INCONCLUSIVE
* SAVE PR GRAPH zz-sudoku-de-741856-base-pr-000.dot
* REASONING
* PRF # F1: 1,9 => SOL
* DIS # F1: 6 => CTR => F1: 1,9
* PRF # F1: 6,9 => SOL
* DIS # F1: 1 => CTR => F1: 6,9
* PRF # F1: 1,9 => SOL
* DIS # F1: 6 => CTR => F1: 1,9
* PRF # F1: 6,9 => SOL
* DIS # F1: 1 => CTR => F1: 6,9
* CNT   8 HDP CHAINS /   8 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,A6,B2,B4,D1,D4,F2,F6,G3,G4,I3,I6)
* .78.5.2342.643.857435728.9.8.3.74.25764215389.5238.47.589142763647893512321567948
* PAIR A1: 1,9 ROW 1
F1: 1,9,6                                # reduction candidate for 1,9
F1: 1,9 => SOLVED
* 178659234296431857435728196813974625764215389952386471589142763647893512321567948
* DURATION: 0:00:01.773153  START: 08:27:12.519745  END: 08:27:14.292898 2017-05-01
* SOLUTION FOUND
* SAVE PR GRAPH zz-sudoku-de-741856-base-pr-001.dot
* REASONING
* PRF # F1: 1,9 => SOL
* STA F1: 1,9
* CNT   1 HDP CHAINS /   1 HYP OPENED

Header Info

http://www.sudokus.de/741856.html
sehr schwierig

--------------------------------------------------
level: medium

* PAIR REDUCTION ..
* ROUND 1: .78.5.2342.643.857435728.9.8.3.74.25764215389.5238.47.589142763647893512321567948
A1: 1,9
F1: 1,6,9                                # reduction candidate for 1,9
F1: 1,9 => SOLVED
* 178659234296431857435728196813974625764215389952386471589142763647893512321567948
* SOLVED!
--------------------------------------------------

|:step:| 00
--------------------------------------------------

highlight 1
A1: 1,9
B4: 1,9
F2: 1,9
A1 != 1 => A1,B4,F2 = 9 => D1,D4,F6 = 6 => CTR
=> A1 = 1

|:step:| 01
--------------------------------------------------

Solution

position: 178659234296431857435728196813974625764215389952386471589142763647893512321567948 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 # F1: 1,9 => SOL
* DIS # F1: 6 => CTR => F1: 1,9
* PRF # F1: 6,9 => SOL
* DIS # F1: 1 => CTR => F1: 6,9
* PRF # F1: 1,9 => SOL
* DIS # F1: 6 => CTR => F1: 1,9
* PRF # F1: 6,9 => SOL
* DIS # F1: 1 => CTR => F1: 6,9
* CNT   8 HDP CHAINS /   8 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* PRF # F1: 1,9 => SOL
* STA F1: 1,9
* CNT   1 HDP CHAINS /   1 HYP OPENED