Analysis of zz-sudoku-de-692870-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: ..6....217.3..94....2.8.......39.5..6..5.2..4..8.64.......7.6....18..2.742....3.. initial

Autosolve

position: .9643..217.3.294...42.8.9....43985..6.9512..4..876419...5271649961843257427956318 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # B2: 5,8 => CTR => B2: 1
* PRF # B2: 1 => SOL
* DIS # B2: 8 => CTR => B2: 1,5
* PRF # I3: 5,6 => SOL
* DIS # I3: 3 => CTR => I3: 5,6
* DIS # H5: 8 => CTR => H5: 3,7
* DIS # A6: 3,5 => CTR => A6: 2
* PRF # A6: 2 => SOL
* DIS # H3: 6,7 => CTR => H3: 3
* PRF # H3: 3 => SOL
* PRF # H5: 7,8 => SOL
* DIS # H5: 3 => CTR => H5: 7,8
* DIS # A6: 5 => CTR => A6: 2,3
* CNT  13 HDP CHAINS /  16 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 # B2: 5,8 => CTR => B2: 1
* PRF B2: 1 => SOL
* STA B2: 1
* CNT   2 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

..6....217.3..94....2.8.......39.5..6..5.2..4..8.64.......7.6....18..2.742....3.. initial
.9643..217.3.294...42.8.9....43985..6.9512..4..876419...5271649961843257427956318 autosolve
896435721713629485542187936174398562639512874258764193385271649961843257427956318 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (19)
A1: 5,8
A3: 1,5
F1: 5,7
D2: 1,6
D3: 1,6
F3: 5,7
G1: 7,8
H2: 6,8
I2: 5,6
A4: 1,2
B4: 1,7
B5: 3,7
B6: 3,5
H4: 6,7
I4: 2,6
G5: 7,8
I6: 2,3
A7: 3,8
B7: 3,8

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
B2,A3: 1.. / B2 = 1  =>  0 pairs (*) / A3 = 1  =>  0 pairs (X)
D2,D3: 1.. / D2 = 1  =>  0 pairs (X) / D3 = 1  =>  0 pairs (_)
A4,B4: 1.. / A4 = 1  =>  0 pairs (*) / B4 = 1  =>  0 pairs (X)
B2,D2: 1.. / B2 = 1  =>  0 pairs (*) / D2 = 1  =>  0 pairs (X)
A3,D3: 1.. / A3 = 1  =>  0 pairs (X) / D3 = 1  =>  0 pairs (_)
A3,A4: 1.. / A3 = 1  =>  0 pairs (X) / A4 = 1  =>  0 pairs (_)
B2,B4: 1.. / B2 = 1  =>  0 pairs (*) / B4 = 1  =>  0 pairs (X)
A4,A6: 2.. / A4 = 2  =>  0 pairs (X) / A6 = 2  =>  0 pairs (_)
I4,I6: 2.. / I4 = 2  =>  0 pairs (*) / I6 = 2  =>  0 pairs (X)
A4,I4: 2.. / A4 = 2  =>  0 pairs (X) / I4 = 2  =>  0 pairs (_)
A6,I6: 2.. / A6 = 2  =>  0 pairs (*) / I6 = 2  =>  0 pairs (X)
H3,I3: 3.. / H3 = 3  =>  0 pairs (*) / I3 = 3  =>  0 pairs (X)
H5,I6: 3.. / H5 = 3  =>  0 pairs (X) / I6 = 3  =>  0 pairs (_)
A7,B7: 3.. / A7 = 3  => 15 pairs (_) / B7 = 3  =>  0 pairs (X)
B5,H5: 3.. / B5 = 3  =>  0 pairs (*) / H5 = 3  =>  0 pairs (X)
A6,A7: 3.. / A6 = 3  =>  0 pairs (X) / A7 = 3  => 15 pairs (_)
H3,H5: 3.. / H3 = 3  =>  0 pairs (*) / H5 = 3  =>  0 pairs (X)
I3,I6: 3.. / I3 = 3  =>  0 pairs (X) / I6 = 3  =>  0 pairs (_)
F1,F3: 5.. / F1 = 5  => 15 pairs (_) / F3 = 5  =>  0 pairs (X)
I2,I3: 5.. / I2 = 5  => 20 pairs (_) / I3 = 5  =>  0 pairs (X)
A6,B6: 5.. / A6 = 5  =>  0 pairs (X) / B6 = 5  => 20 pairs (_)
A1,F1: 5.. / A1 = 5  =>  0 pairs (X) / F1 = 5  => 15 pairs (_)
B2,I2: 5.. / B2 = 5  =>  0 pairs (X) / I2 = 5  => 20 pairs (_)
B2,B6: 5.. / B2 = 5  =>  0 pairs (X) / B6 = 5  => 20 pairs (_)
D2,D3: 6.. / D2 = 6  =>  0 pairs (*) / D3 = 6  =>  0 pairs (X)
H4,I4: 6.. / H4 = 6  =>  0 pairs (*) / I4 = 6  =>  0 pairs (X)
F1,F3: 7.. / F1 = 7  =>  0 pairs (X) / F3 = 7  => 15 pairs (_)
G1,H3: 7.. / G1 = 7  => 15 pairs (_) / H3 = 7  =>  0 pairs (X)
B4,B5: 7.. / B4 = 7  =>  0 pairs (*) / B5 = 7  =>  0 pairs (X)
F1,G1: 7.. / F1 = 7  =>  0 pairs (X) / G1 = 7  => 15 pairs (_)
F3,H3: 7.. / F3 = 7  => 15 pairs (_) / H3 = 7  =>  0 pairs (X)
B4,H4: 7.. / B4 = 7  =>  0 pairs (*) / H4 = 7  =>  0 pairs (X)
G1,G5: 7.. / G1 = 7  => 15 pairs (_) / G5 = 7  =>  0 pairs (X)
A1,B2: 8.. / A1 = 8  => 15 pairs (_) / B2 = 8  =>  0 pairs (X)
G1,H2: 8.. / G1 = 8  =>  0 pairs (X) / H2 = 8  => 15 pairs (_)
G5,H5: 8.. / G5 = 8  => 15 pairs (_) / H5 = 8  =>  0 pairs (X)
A7,B7: 8.. / A7 = 8  =>  0 pairs (X) / B7 = 8  => 15 pairs (_)
A1,G1: 8.. / A1 = 8  => 15 pairs (_) / G1 = 8  =>  0 pairs (X)
B2,H2: 8.. / B2 = 8  =>  0 pairs (X) / H2 = 8  => 15 pairs (_)
A1,A7: 8.. / A1 = 8  => 15 pairs (_) / A7 = 8  =>  0 pairs (X)
B2,B7: 8.. / B2 = 8  =>  0 pairs (X) / B7 = 8  => 15 pairs (_)
G1,G5: 8.. / G1 = 8  =>  0 pairs (X) / G5 = 8  => 15 pairs (_)
H2,H5: 8.. / H2 = 8  => 15 pairs (_) / H5 = 8  =>  0 pairs (X)
* DURATION: 0:01:11.076271  START: 07:53:26.046948  END: 07:54:37.123219 2017-05-01
* CP COUNT: (43)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,A3,A4,A7,B4,B5,B6,B7,D2,D3,F1,F3,G1,G5,H2,H4,I2,I4,I6)
* .9643..217.3.294...42.8.9....43985..6.9512..4..876419...5271649961843257427956318
* PAIR A1: 5,8 BLK 1
B2: 5,8,1                                # reduction candidate for 5,8
B2: 5,8 => CTR
* .9643..217.31294..14268.9..214398576679512834..876419...5271649961843257427956318
B2: 1 => SOLVED
* 896435721713629485542187936174398562639512874258764193385271649961843257427956318
* PAIR A3: 1,5 BLK 1
B2: 1,5,8                                # reduction candidate for 1,5
B2: 8 => CTR
* .9643..2178312946514268597...43985..6.9512..4..876419...5271649961843257427956318
B2: 1,5                                  # 15 pairs
* PAIR I2: 5,6 BLK 3
I3: 5,6,3                                # reduction candidate for 5,6
I3: 5,6 => SOLVED
* 896435721713629485542187936174398562639512874258764193385271649961843257427956318
I3: 3 => CTR
* .9643..21783129465142685973..43985.66.9512.34.58764192.35271649961843257427956318
* PAIR B5: 3,7 ROW 5
H5: 3,7,8                                # reduction candidate for 3,7
H5: 8 => CTR
* .9643..217.3.294...42.8.93...43985766.9512..4..876419...5271649961843257427956318
H5: 3,7                                  # 15 pairs
* PAIR B6: 3,5 BLK 4
A6: 3,5,2                                # reduction candidate for 3,5
A6: 3,5 => CTR
* 896435721753.294...42.8.9..214398576679512834..8764192..5271649961843257427956318
A6: 2 => SOLVED
* 896435721713629485542187936174398562639512874258764193385271649961843257427956318
* PAIR H4: 6,7 COL H
H3: 6,7,3                                # reduction candidate for 6,7
H3: 6,7 => CTR
* .9643..217.3.29485.42.8.9632143985..6.9512.34..8764192..5271649961843257427956318
H3: 3 => SOLVED
* 896435721713629485542187936174398562639512874258764193385271649961843257427956318
* PAIR G5: 7,8 BLK 6
H5: 7,8,3                                # reduction candidate for 7,8
H5: 7,8 => SOLVED
* 896435721713629485542187936174398562639512874258764193385271649961843257427956318
H5: 3 => CTR
* 8964357217.3.2948..42.87963214398576679512834.38764192385271649961843257427956318
* PAIR I6: 2,3 ROW 6
A6: 2,3,5                                # reduction candidate for 2,3
A6: 5 => CTR
* .9643..217.3.294...42.8.9..214398576679512834538764192385271649961843257427956318
A6: 2,3                                  # 20 pairs
* INCONCLUSIVE
* SAVE PR GRAPH zz-sudoku-de-692870-base-pr-000.dot
* REASONING
* DIS # B2: 5,8 => CTR => B2: 1
* PRF # B2: 1 => SOL
* DIS # B2: 8 => CTR => B2: 1,5
* PRF # I3: 5,6 => SOL
* DIS # I3: 3 => CTR => I3: 5,6
* DIS # H5: 8 => CTR => H5: 3,7
* DIS # A6: 3,5 => CTR => A6: 2
* PRF # A6: 2 => SOL
* DIS # H3: 6,7 => CTR => H3: 3
* PRF # H3: 3 => SOL
* PRF # H5: 7,8 => SOL
* DIS # H5: 3 => CTR => H5: 7,8
* DIS # A6: 5 => CTR => A6: 2,3
* CNT  13 HDP CHAINS /  16 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,A3,A4,A7,B4,B5,B6,B7,D2,D3,F1,F3,G1,G5,H2,H4,I2,I4,I6)
* .9643..217.3.294...42.8.9....43985..6.9512..4..876419...5271649961843257427956318
* PAIR A1: 5,8 BLK 1
B2: 5,8,1                                # reduction candidate for 5,8
B2: 5,8 => CTR
* .9643..217.31294..14268.9..214398576679512834..876419...5271649961843257427956318
B2: 1 => SOLVED
* 896435721713629485542187936174398562639512874258764193385271649961843257427956318
* DURATION: 0:00:02.746510  START: 07:54:54.845467  END: 07:54:57.591977 2017-05-01
* SOLUTION FOUND
* SAVE PR GRAPH zz-sudoku-de-692870-base-pr-001.dot
* REASONING
* DIS # B2: 5,8 => CTR => B2: 1
* PRF B2: 1 => SOL
* STA B2: 1
* CNT   2 HDP CHAINS /   1 HYP OPENED

Header Info

http://www.sudokus.de/692870.html
sehr schwierig

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

* PAIR REDUCTION ..
* ROUND 1: .9643..217.3.294...42.8.9....43985..6.9512..4..876419...5271649961843257427956318
A1: 5,8
B2: 1,5,8                                # reduction candidate for 5,8
B2: 5,8 => CTR
* .9643..217.31294..14268.9..214398576679512834..876419...5271649961843257427956318
B2: 1 => SOLVED
* 896435721713629485542187936174398562639512874258764193385271649961843257427956318
* SOLVED!
--------------------------------------------------

--------------------------------------------------
* AUTO ..
E2 = 2                # set value
C4 = 4                # set value
F4 = 8                # set value
E5 = 1                # set value
D6: 7                 # naked single
E9: 5                 # naked single
D6 = 7                # set value
D1: 4                 # naked single
D7 = 2                # set value
B8 = 6                # set value
C9 = 7                # set value
C5: 9                 # naked single
E9 = 5                # set value
F8: 3                 # naked single
E8: 4..               # hidden single
D9: 9..               # hidden single
H7: 4..               # hidden single
C7: 5..               # hidden single
G6: 1..               # hidden single
D1 = 4                # set value
E1: 3                 # naked single
E1 = 3                # set value
E8: 4                 # naked single
C5 = 9                # set value
C7: 5                 # naked single
G6 = 1                # set value
C7 = 5                # set value
H7 = 4                # set value
E8 = 4                # set value
F8 = 3                # set value
F7: 1                 # naked single
A8: 9                 # naked single
D9 = 9                # set value
I9: 8                 # naked single
I9 = 8                # set value
I7: 9                 # naked single
H9: 1                 # naked single
B3: 4..               # hidden single
F9: 6..               # hidden single
H8: 5..               # hidden single
B3 = 4                # set value
F7 = 1                # set value
F9: 6                 # naked single
I7 = 9                # set value
H8: 5                 # naked single
A8 = 9                # set value
H8 = 5                # set value
F9 = 6                # set value
H9 = 1                # set value
B1: 9..               # hidden single
H6: 9..               # hidden single
B1 = 9                # set value
H6 = 9                # set value
G3: 9..               # hidden single
G3 = 9                # set value
* UNSOLVED!

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

* FORCE VALUE:: I3 = 3
I3 = 3                # set value
I6: 2                 # naked single
I2: 5..               # hidden single
H5: 3..               # hidden single
=> CTR

* DISABLE VALUE:: I3 != 3
H3: 3..               # hidden single
I6: 3..               # hidden single
* SOLVED!

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

Solution

position: 896435721713629485542187936174398562639512874258764193385271649961843257427956318 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:

* DIS # B2: 5,8 => CTR => B2: 1
* PRF # B2: 1 => SOL
* INC # B2: 1,5 => UNS
* DIS # B2: 8 => CTR => B2: 1,5
* PRF # I3: 5,6 => SOL
* DIS # I3: 3 => CTR => I3: 5,6
* INC # H5: 3,7 => UNS
* DIS # H5: 8 => CTR => H5: 3,7
* DIS # A6: 3,5 => CTR => A6: 2
* PRF # A6: 2 => SOL
* DIS # H3: 6,7 => CTR => H3: 3
* PRF # H3: 3 => SOL
* PRF # H5: 7,8 => SOL
* DIS # H5: 3 => CTR => H5: 7,8
* INC # A6: 2,3 => UNS
* DIS # A6: 5 => CTR => A6: 2,3
* CNT  16 HDP CHAINS /  16 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # B2: 5,8 => CTR => B2: 1
* PRF B2: 1 => SOL
* STA B2: 1
* CNT   2 HDP CHAINS /   1 HYP OPENED