Analysis of zz-sudoku-de-752645-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: .3......7..67.....2.5.84..1.....3.49..4.7.2..19.8.....5..32.8.4.....86..7......5. initial

Autosolve

position: .3......7..673....275.843.16....3.49354.7.2..19.84..3.56.3278.4.....867.7..4...5. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # F1: 1,9 => SOL
* DIS # D1: 6,9 => CTR => D1: 1,2,5
* DIS # F1: 6,9 => CTR => F1: 1,2,5
* DIS # D5: 1 => CTR => D5: 6,9
* DIS # H1: 6,9 => CTR => H1: 2,8
* DIS # C4: 2,8 => CTR => C4: 7
* DIS # C4: 8 => CTR => C4: 2,7
* DIS # D4: 1,5 => CTR => D4: 2
* DIS # G4: 7 => CTR => G4: 1,5
* DIS # E1: 1,5 => CTR => E1: 6,9
* PRF # G4: 5,7 => SOL
* DIS # G4: 1 => CTR => G4: 5,7
* DIS # F6: 2 => CTR => F6: 5,6
* DIS # A1: 4,9 => CTR => A1: 8
* DIS # C9: 2,3 => CTR => C9: 8
* DIS # C9: 3 => CTR => C9: 2,8
* PRF # E9: 1,9 => SOL
* DIS # C9: 2,3 => CTR => C9: 8
* CNT  18 HDP CHAINS /  40 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 /   3 HYP OPENED

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

Details

Positions

.3......7..67.....2.5.84..1.....3.49..4.7.2..19.8.....5..32.8.4.....86..7......5. initial
.3......7..673....275.843.16....3.49354.7.2..19.84..3.56.3278.4.....867.7..4...5. autosolve
839561427416732985275984361687213549354679218192845736561327894943158672728496153 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (21)
C1: 1,9
B2: 1,4
D3: 6,9
I2: 5,8
H3: 6,9
B4: 2,8
C6: 2,7
E4: 1,5
H5: 1,8
I5: 6,8
G6: 5,7
I6: 5,6
C7: 1,9
A8: 4,9
B8: 1,4
C8: 2,3
B9: 2,8
H7: 1,9
I8: 2,3
G9: 1,9
I9: 2,3

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
C1,B2: 1.. / C1 = 1  =>  0 pairs (X) / B2 = 1  =>  0 pairs (_)
G4,H5: 1.. / G4 = 1  =>  0 pairs (X) / H5 = 1  =>  0 pairs (_)
C7,B8: 1.. / C7 = 1  =>  0 pairs (*) / B8 = 1  =>  0 pairs (X)
H7,G9: 1.. / H7 = 1  =>  0 pairs (X) / G9 = 1  =>  0 pairs (_)
B2,F2: 1.. / B2 = 1  =>  0 pairs (*) / F2 = 1  =>  0 pairs (X)
C7,H7: 1.. / C7 = 1  =>  0 pairs (*) / H7 = 1  =>  0 pairs (X)
B2,B8: 1.. / B2 = 1  =>  0 pairs (*) / B8 = 1  =>  0 pairs (X)
C1,C7: 1.. / C1 = 1  =>  0 pairs (X) / C7 = 1  =>  0 pairs (_)
G4,G9: 1.. / G4 = 1  =>  0 pairs (X) / G9 = 1  =>  0 pairs (_)
H5,H7: 1.. / H5 = 1  =>  0 pairs (*) / H7 = 1  =>  0 pairs (X)
H1,H2: 2.. / H1 = 2  =>  0 pairs (*) / H2 = 2  =>  0 pairs (X)
D4,F6: 2.. / D4 = 2  => 16 pairs (_) / F6 = 2  =>  0 pairs (X)
I8,I9: 2.. / I8 = 2  => 19 pairs (_) / I9 = 2  =>  0 pairs (X)
F2,H2: 2.. / F2 = 2  =>  0 pairs (*) / H2 = 2  =>  0 pairs (X)
C6,F6: 2.. / C6 = 2  => 16 pairs (_) / F6 = 2  =>  0 pairs (X)
C8,I8: 2.. / C8 = 2  =>  0 pairs (X) / I8 = 2  => 19 pairs (_)
B4,B9: 2.. / B4 = 2  =>  0 pairs (X) / B9 = 2  => 17 pairs (_)
D1,D4: 2.. / D1 = 2  =>  0 pairs (X) / D4 = 2  => 16 pairs (_)
C8,C9: 3.. / C8 = 3  => 19 pairs (_) / C9 = 3  =>  0 pairs (X)
I8,I9: 3.. / I8 = 3  =>  0 pairs (X) / I9 = 3  => 19 pairs (_)
C8,I8: 3.. / C8 = 3  => 19 pairs (_) / I8 = 3  =>  0 pairs (X)
C9,I9: 3.. / C9 = 3  =>  0 pairs (X) / I9 = 3  => 19 pairs (_)
G1,G2: 4.. / G1 = 4  => 23 pairs (_) / G2 = 4  =>  0 pairs (X)
A8,B8: 4.. / A8 = 4  =>  0 pairs (X) / B8 = 4  =>  0 pairs (_)
A1,G1: 4.. / A1 = 4  =>  0 pairs (X) / G1 = 4  => 23 pairs (_)
B2,B8: 4.. / B2 = 4  =>  0 pairs (X) / B8 = 4  =>  0 pairs (_)
D8,E8: 5.. / D8 = 5  => 23 pairs (_) / E8 = 5  =>  0 pairs (*)
I2,I6: 5.. / I2 = 5  =>  0 pairs (*) / I6 = 5  =>  0 pairs (X)
H1,H3: 6.. / H1 = 6  =>  0 pairs (X) / H3 = 6  => 22 pairs (_)
I5,I6: 6.. / I5 = 6  =>  0 pairs (X) / I6 = 6  =>  0 pairs (_)
E9,F9: 6.. / E9 = 6  => 22 pairs (_) / F9 = 6  =>  0 pairs (*)
D3,H3: 6.. / D3 = 6  =>  0 pairs (X) / H3 = 6  => 22 pairs (_)
F6,I6: 6.. / F6 = 6  =>  0 pairs (X) / I6 = 6  =>  0 pairs (_)
E1,E9: 6.. / E1 = 6  =>  0 pairs (*) / E9 = 6  =>  0 pairs (X)
C4,C6: 7.. / C4 = 7  => 16 pairs (_) / C6 = 7  =>  0 pairs (X)
G4,G6: 7.. / G4 = 7  =>  0 pairs (X) / G6 = 7  => 16 pairs (_)
C4,G4: 7.. / C4 = 7  => 16 pairs (_) / G4 = 7  =>  0 pairs (X)
C6,G6: 7.. / C6 = 7  =>  0 pairs (X) / G6 = 7  => 16 pairs (_)
A1,A2: 8.. / A1 = 8  => 23 pairs (_) / A2 = 8  =>  0 pairs (X)
B4,C4: 8.. / B4 = 8  => 17 pairs (_) / C4 = 8  =>  0 pairs (X)
H5,I5: 8.. / H5 = 8  =>  0 pairs (X) / I5 = 8  =>  0 pairs (_)
B9,C9: 8.. / B9 = 8  =>  0 pairs (X) / C9 = 8  => 17 pairs (_)
A1,H1: 8.. / A1 = 8  => 23 pairs (_) / H1 = 8  =>  0 pairs (X)
B4,B9: 8.. / B4 = 8  => 17 pairs (_) / B9 = 8  =>  0 pairs (X)
C4,C9: 8.. / C4 = 8  =>  0 pairs (X) / C9 = 8  => 17 pairs (_)
I2,I5: 8.. / I2 = 8  =>  0 pairs (X) / I5 = 8  =>  0 pairs (_)
D5,F5: 9.. / D5 = 9  =>  0 pairs (X) / F5 = 9  => 23 pairs (_)
C7,A8: 9.. / C7 = 9  =>  0 pairs (X) / A8 = 9  =>  0 pairs (_)
H7,G9: 9.. / H7 = 9  =>  0 pairs (*) / G9 = 9  =>  0 pairs (X)
D3,H3: 9.. / D3 = 9  => 22 pairs (_) / H3 = 9  =>  0 pairs (X)
C7,H7: 9.. / C7 = 9  =>  0 pairs (X) / H7 = 9  =>  0 pairs (_)
C1,C7: 9.. / C1 = 9  =>  0 pairs (*) / C7 = 9  =>  0 pairs (X)
* DURATION: 0:01:37.668617  START: 08:27:29.163065  END: 08:29:06.831682 2017-05-01
* CP COUNT: (52)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A8,B2,B4,B8,B9,C1,C6,C7,C8,D3,E4,G6,G9,H3,H5,H7,I2,I5,I6,I8,I9)
* .3......7..673....275.843.16....3.49354.7.2..19.84..3.56.3278.4.....867.7..4...5.
* PAIR C1: 1,9 ROW 1
D1: 1,9,2,5,6                            # reduction candidate for 1,9
D1: 1,9                                  # 22 pairs
E1: 1,9,5,6                              # reduction candidate for 1,9
E1: 1,9                                  # 25 pairs
F1: 1,9,2,5,6                            # reduction candidate for 1,9
F1: 1,9 => SOLVED
* 839561427416732985275984361687213549354679218192845736561327894943158672728496153
F1: 2,5,6                                # 21 pairs
* PAIR D3: 6,9 BLK 2
D1: 6,9,1,2,5                            # reduction candidate for 6,9
D1: 6,9 => CTR
* .3......7..673....275.843.16872.3.4935417928619284673556.327814.13598672728461953
D1: 1,2,5                                # 21 pairs
E1: 6,9,1,5                              # reduction candidate for 6,9
E1: 6,9                                  # 22 pairs
F1: 6,9,1,2,5                            # reduction candidate for 6,9
F1: 6,9 => CTR
* .3......7.1673....275.843.16....3.49354.7.2..19.84..365613278949....867.7..4...5.
F1: 1,2,5                                # 21 pairs
* PAIR D3: 6,9 COL D
D5: 6,9,1                                # reduction candidate for 6,9
D5: 1 => CTR
* .3......7..673....275.843.16....3.4935417928619.846.3556.327814.1...867.7..46195.
D5: 6,9                                  # 23 pairs
* PAIR H3: 6,9 BLK 3
H1: 6,9,2,8                              # reduction candidate for 6,9
H1: 6,9 => CTR
* 83....4.7..673..28275.843.16....3.49354.7.28619.846.3556.327814.1...867.7..46195.
H1: 2,8                                  # 23 pairs
* PAIR B4: 2,8 BLK 4
C4: 2,8,7                                # reduction candidate for 2,8
C4: 2,8 => CTR
* .392..4.741673....275.843.16....3749354.7.21819784253656132789494...867.7..4..15.
C4: 7                                    # 16 pairs
* PAIR C6: 2,7 BLK 4
C4: 2,7,8                                # reduction candidate for 2,7
C4: 8 => CTR
* .392..4.741673....275.843.16.8..3749354.7.21819784253656132789494...867.78.4..15.
C4: 2,7                                  # 17 pairs
* PAIR E4: 1,5 BLK 5
D4: 1,5,2                                # reduction candidate for 1,5
D4: 1,5 => CTR
* .3.2.5.878.673..25275.843616....374935467921819784253656132789494...867.7..49..5.
D4: 2                                    # 16 pairs
* PAIR E4: 1,5 ROW 4
G4: 1,5,7                                # reduction candidate for 1,5
G4: 7 => CTR
* .392..4.741673....275.843.16....3749354.7.21819784253656132789494...867.7..4..15.
G4: 1,5                                  # 16 pairs
* PAIR E4: 1,5 COL E
E1: 1,5,6,9                              # reduction candidate for 1,5
E1: 1,5 => CTR
* .3......7.1673....275.843.16....314935417928619.84673556.3278.4....9867.7..46195.
E1: 6,9                                  # 22 pairs
E8: 1,5,9                                # reduction candidate for 1,5
E8: 1,5                                  # 24 pairs
* PAIR G6: 5,7 BLK 6
G4: 5,7,1                                # reduction candidate for 5,7
G4: 5,7 => SOLVED
* 839561427416732985275984361687213549354679218192845736561327894943158672728496153
G4: 1 => CTR
* .3......7..673....275.843.16.7..3149354.7.28619284673556.327814.13..8672728461953
* PAIR I6: 5,6 ROW 6
F6: 5,6,2                                # reduction candidate for 5,6
F6: 2 => CTR
* .3.2.5.878.673..25275.843616....374935467921819784253656132789494...867.7..49..5.
F6: 5,6                                  # 16 pairs
* PAIR A8: 4,9 COL A
A1: 4,9,8                                # reduction candidate for 4,9
A1: 4,9 => CTR
* 439....878.673..25275.843616....3.49354.7.21819.84..3656132789494...867.7..4..15.
A1: 8                                    # 23 pairs
A2: 4,9,8                                # reduction candidate for 4,9
A2: 4,9                                  # 23 pairs
* PAIR C8: 2,3 BLK 7
C9: 2,3,8                                # reduction candidate for 2,3
C9: 2,3 => CTR
* .392..4.741673....275.843.16.8..3749354.7.21819784253656132789494...867.78.4..15.
C9: 8                                    # 17 pairs
* PAIR B9: 2,8 BLK 7
C9: 2,8,3                                # reduction candidate for 2,8
C9: 3 => CTR
* .392..4.741673....275.843.16.8..3749354.7.218197842536561327894942..86737834..152
C9: 2,8                                  # 19 pairs
* PAIR G9: 1,9 ROW 9
E9: 1,9,6                                # reduction candidate for 1,9
E9: 1,9 => SOLVED
* 839561427416732985275984361687213549354679218192845736561327894943158672728496153
E9: 6                                    # 22 pairs
F9: 1,9,6                                # reduction candidate for 1,9
F9: 1,9                                  # 22 pairs
* PAIR I9: 2,3 ROW 9
C9: 2,3,8                                # reduction candidate for 2,3
C9: 2,3 => CTR
* .392..4.741673....275.843.16.8..3749354.7.21819784253656132789494...867.78.4..15.
C9: 8                                    # 17 pairs
* INCONCLUSIVE
* SAVE PR GRAPH zz-sudoku-de-752645-base-pr-000.dot
* REASONING
* PRF # F1: 1,9 => SOL
* DIS # D1: 6,9 => CTR => D1: 1,2,5
* DIS # F1: 6,9 => CTR => F1: 1,2,5
* DIS # D5: 1 => CTR => D5: 6,9
* DIS # H1: 6,9 => CTR => H1: 2,8
* DIS # C4: 2,8 => CTR => C4: 7
* DIS # C4: 8 => CTR => C4: 2,7
* DIS # D4: 1,5 => CTR => D4: 2
* DIS # G4: 7 => CTR => G4: 1,5
* DIS # E1: 1,5 => CTR => E1: 6,9
* PRF # G4: 5,7 => SOL
* DIS # G4: 1 => CTR => G4: 5,7
* DIS # F6: 2 => CTR => F6: 5,6
* DIS # A1: 4,9 => CTR => A1: 8
* DIS # C9: 2,3 => CTR => C9: 8
* DIS # C9: 3 => CTR => C9: 2,8
* PRF # E9: 1,9 => SOL
* DIS # C9: 2,3 => CTR => C9: 8
* CNT  18 HDP CHAINS /  40 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A8,B2,B4,B8,B9,C1,C6,C7,C8,D3,E4,G6,G9,H3,H5,H7,I2,I5,I6,I8,I9)
* .3......7..673....275.843.16....3.49354.7.2..19.84..3.56.3278.4.....867.7..4...5.
* PAIR C1: 1,9 ROW 1
D1: 1,9,2,5,6                            # reduction candidate for 1,9
D1: 1,9                                  # 22 pairs
E1: 1,9,5,6                              # reduction candidate for 1,9
E1: 1,9                                  # 25 pairs
F1: 1,9,2,5,6                            # reduction candidate for 1,9
F1: 1,9 => SOLVED
* 839561427416732985275984361687213549354679218192845736561327894943158672728496153
* DURATION: 0:00:04.603304  START: 08:29:46.267824  END: 08:29:50.871128 2017-05-01
* SOLUTION FOUND
* SAVE PR GRAPH zz-sudoku-de-752645-base-pr-001.dot
* REASONING
* PRF # F1: 1,9 => SOL
* STA F1: 1,9
* CNT   1 HDP CHAINS /   3 HYP OPENED

Header Info

http://www.sudokus.de/752645.html
sehr schwierig

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

* PAIR REDUCTION ..
* ROUND 1: .3......7..673....275.843.16....3.49354.7.2..19.84..3.56.3278.4.....867.7..4...5.
C1: 1,9
D1: 1,2,5,6,9                            # reduction candidate for 1,9
E1: 1,5,6,9                              # reduction candidate for 1,9
F1: 1,2,5,6,9                            # reduction candidate for 1,9
F1: 1,9 => SOLVED
* 839561427416732985275984361687213549354679218192845736561327894943158672728496153
* SOLVED!
--------------------------------------------------

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

highlight 3
C8: 2,3
I8: 2,3
C9: 2,3,8
I9: 2,3
=> C9 = 8 # pair quad

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

E9: 1,6,9
F9: 1,6,9
G9: 1,9
=>  E9 = 6 or F9 = 6

* DISABLE VALUE:: E9 != 6
* SOLVED!

|:step:| reasoning
--------------------------------------------------

highlight 6
D3 = 6 => coloring =>
D5: 1,9
F5: 1,6,9
F9: 1,9
=> F5 = 6 => finish coloring
=> analysis
=> CTR

* DISABLE VALUE:: D3 != 6
D3: 9                 # naked single
H3: 6..               # hidden single

Solution

position: 839561427416732985275984361687213549354679218192845736561327894943158672728496153 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 # D1: 1,9 => UNS
* INC # E1: 1,9 => UNS
* PRF # F1: 1,9 => SOL
* INC # F1: 2,5,6 => UNS
* DIS # D1: 6,9 => CTR => D1: 1,2,5
* INC # D1: 1,2,5 => UNS
* INC # E1: 6,9 => UNS
* DIS # F1: 6,9 => CTR => F1: 1,2,5
* INC # F1: 1,2,5 => UNS
* INC # D5: 6,9 => UNS
* DIS # D5: 1 => CTR => D5: 6,9
* DIS # H1: 6,9 => CTR => H1: 2,8
* INC # H1: 2,8 => UNS
* DIS # C4: 2,8 => CTR => C4: 7
* INC # C4: 7 => UNS
* INC # C4: 2,7 => UNS
* DIS # C4: 8 => CTR => C4: 2,7
* DIS # D4: 1,5 => CTR => D4: 2
* INC # D4: 2 => UNS
* INC # G4: 1,5 => UNS
* DIS # G4: 7 => CTR => G4: 1,5
* DIS # E1: 1,5 => CTR => E1: 6,9
* INC # E1: 6,9 => UNS
* INC # E8: 1,5 => UNS
* PRF # G4: 5,7 => SOL
* DIS # G4: 1 => CTR => G4: 5,7
* INC # F6: 5,6 => UNS
* DIS # F6: 2 => CTR => F6: 5,6
* DIS # A1: 4,9 => CTR => A1: 8
* INC # A1: 8 => UNS
* INC # A2: 4,9 => UNS
* DIS # C9: 2,3 => CTR => C9: 8
* INC # C9: 8 => UNS
* INC # C9: 2,8 => UNS
* DIS # C9: 3 => CTR => C9: 2,8
* PRF # E9: 1,9 => SOL
* INC # E9: 6 => UNS
* INC # F9: 1,9 => UNS
* DIS # C9: 2,3 => CTR => C9: 8
* INC # C9: 8 => UNS
* CNT  40 HDP CHAINS /  40 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # D1: 1,9 => UNS
* INC # E1: 1,9 => UNS
* PRF # F1: 1,9 => SOL
* STA F1: 1,9
* CNT   3 HDP CHAINS /   3 HYP OPENED