Analysis of zz-sudoku-de-719598-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 3.47...9....36.1..2....5...4......271.5...3.478......9...5....3..3.89....4...36.2 initial

Autosolve

position: 3.471829....36214.2....573.43..518271.58.736478..3.519...5..9.3..3.894.1.4.1736.2 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # C2: 8,9 => CTR => C2: 7
* DIS # A9: 8,9 => CTR => A9: 5
* PRF # A9: 5 => SOL
* PRF # D6: 2,6 => SOL
* DIS # D6: 4 => CTR => D6: 2,6
* PRF # D6: 4,6 => SOL
* DIS # D6: 2 => CTR => D6: 4,6
* PRF # B7: 2,7 => SOL
* DIS # A9: 8,9 => CTR => A9: 5
* PRF # A9: 5 => SOL
* DIS # C2: 8,9 => CTR => C2: 7
* PRF # D6: 2,6 => SOL
* DIS # D6: 4 => CTR => D6: 2,6
* PRF # A9: 5,8 => SOL
* DIS # A9: 9 => CTR => A9: 5,8
* CNT  15 HDP CHAINS /  19 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 # C2: 8,9 => CTR => C2: 7
* DIS C2: 7 # A9: 8,9 => CTR => A9: 5
* PRF C2: 7 + A9: 5 => SOL
* STA C2: 7 + A9: 5
* CNT   3 HDP CHAINS /   2 HYP OPENED

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

Details

Positions

3.47...9....36.1..2....5...4......271.5...3.478......9...5....3..3.89....4...36.2 initial
3.471829....36214.2....573.43..518271.58.736478..3.519...5..9.3..3.894.1.4.1736.2 autosolve
364718295957362148218495736436951827195827364782634519821546973673289451549173682 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (25)
B1: 5,6
A2: 8,9
B3: 1,6
C3: 1,8
D3: 4,9
E3: 4,9
I1: 5,6
I2: 5,8
I3: 6,8
C4: 6,9
B5: 2,9
C6: 2,6
D4: 6,9
E5: 2,9
F6: 4,6
A7: 6,8
A8: 5,6
B8: 2,7
C9: 8,9
E7: 2,4
F7: 4,6
D8: 2,6
H7: 7,8
H8: 5,7
H9: 5,8

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
B3,C3: 1.. / B3 = 1  =>  0 pairs (*) / C3 = 1  =>  0 pairs (X)
B7,C7: 1.. / B7 = 1  => 21 pairs (_) / C7 = 1  =>  0 pairs (*)
B3,B7: 1.. / B3 = 1  =>  0 pairs (*) / B7 = 1  =>  0 pairs (X)
C3,C7: 1.. / C3 = 1  => 21 pairs (_) / C7 = 1  =>  0 pairs (*)
B5,C6: 2.. / B5 = 2  =>  0 pairs (X) / C6 = 2  =>  0 pairs (_)
E5,D6: 2.. / E5 = 2  =>  0 pairs (*) / D6 = 2  =>  0 pairs (X)
E7,D8: 2.. / E7 = 2  =>  0 pairs (X) / D8 = 2  =>  0 pairs (_)
B5,E5: 2.. / B5 = 2  =>  0 pairs (X) / E5 = 2  =>  0 pairs (_)
C6,D6: 2.. / C6 = 2  =>  0 pairs (*) / D6 = 2  =>  0 pairs (X)
B8,D8: 2.. / B8 = 2  =>  0 pairs (X) / D8 = 2  =>  0 pairs (_)
C6,C7: 2.. / C6 = 2  =>  0 pairs (*) / C7 = 2  =>  0 pairs (X)
D6,D8: 2.. / D6 = 2  =>  0 pairs (X) / D8 = 2  =>  0 pairs (_)
E5,E7: 2.. / E5 = 2  =>  0 pairs (*) / E7 = 2  =>  0 pairs (X)
D3,E3: 4.. / D3 = 4  =>  0 pairs (*) / E3 = 4  =>  0 pairs (X)
D6,F6: 4.. / D6 = 4  =>  0 pairs (X) / F6 = 4  =>  0 pairs (_)
E7,F7: 4.. / E7 = 4  =>  0 pairs (*) / F7 = 4  =>  0 pairs (X)
D3,D6: 4.. / D3 = 4  =>  0 pairs (*) / D6 = 4  =>  0 pairs (X)
E3,E7: 4.. / E3 = 4  =>  0 pairs (X) / E7 = 4  =>  0 pairs (_)
F6,F7: 4.. / F6 = 4  =>  0 pairs (*) / F7 = 4  =>  0 pairs (X)
B1,B2: 5.. / B1 = 5  => 21 pairs (_) / B2 = 5  =>  0 pairs (*)
I1,I2: 5.. / I1 = 5  =>  0 pairs (*) / I2 = 5  =>  0 pairs (X)
A8,A9: 5.. / A8 = 5  =>  0 pairs (X) / A9 = 5  =>  0 pairs (_)
H8,H9: 5.. / H8 = 5  =>  0 pairs (*) / H9 = 5  =>  0 pairs (X)
B1,I1: 5.. / B1 = 5  => 21 pairs (_) / I1 = 5  =>  0 pairs (*)
B2,I2: 5.. / B2 = 5  =>  0 pairs (*) / I2 = 5  =>  0 pairs (X)
A8,H8: 5.. / A8 = 5  =>  0 pairs (X) / H8 = 5  =>  0 pairs (_)
A9,H9: 5.. / A9 = 5  =>  0 pairs (*) / H9 = 5  =>  0 pairs (X)
B1,B3: 6.. / B1 = 6  =>  0 pairs (*) / B3 = 6  =>  0 pairs (X)
I1,I3: 6.. / I1 = 6  => 21 pairs (_) / I3 = 6  =>  0 pairs (*)
C4,C6: 6.. / C4 = 6  =>  0 pairs (*) / C6 = 6  =>  0 pairs (X)
A7,A8: 6.. / A7 = 6  =>  0 pairs (X) / A8 = 6  =>  0 pairs (_)
F7,D8: 6.. / F7 = 6  =>  0 pairs (*) / D8 = 6  =>  0 pairs (X)
B1,I1: 6.. / B1 = 6  =>  0 pairs (*) / I1 = 6  =>  0 pairs (X)
B3,I3: 6.. / B3 = 6  => 21 pairs (_) / I3 = 6  =>  0 pairs (*)
C4,D4: 6.. / C4 = 6  =>  0 pairs (*) / D4 = 6  =>  0 pairs (X)
A7,F7: 6.. / A7 = 6  =>  0 pairs (X) / F7 = 6  =>  0 pairs (_)
A8,D8: 6.. / A8 = 6  =>  0 pairs (*) / D8 = 6  =>  0 pairs (X)
F6,F7: 6.. / F6 = 6  =>  0 pairs (X) / F7 = 6  =>  0 pairs (_)
B2,C2: 7.. / B2 = 7  =>  0 pairs (X) / C2 = 7  => 27 pairs (_)
H7,H8: 7.. / H7 = 7  =>  0 pairs (*) / H8 = 7  =>  0 pairs (X)
B8,H8: 7.. / B8 = 7  =>  0 pairs (*) / H8 = 7  =>  0 pairs (X)
C2,C7: 7.. / C2 = 7  => 27 pairs (_) / C7 = 7  =>  0 pairs (X)
I2,I3: 8.. / I2 = 8  =>  0 pairs (*) / I3 = 8  =>  0 pairs (X)
H7,H9: 8.. / H7 = 8  =>  0 pairs (X) / H9 = 8  =>  0 pairs (_)
C3,I3: 8.. / C3 = 8  =>  0 pairs (*) / I3 = 8  =>  0 pairs (X)
A7,H7: 8.. / A7 = 8  =>  0 pairs (*) / H7 = 8  =>  0 pairs (X)
D3,E3: 9.. / D3 = 9  =>  0 pairs (X) / E3 = 9  =>  0 pairs (_)
C4,B5: 9.. / C4 = 9  =>  0 pairs (X) / B5 = 9  =>  0 pairs (_)
D4,E5: 9.. / D4 = 9  =>  0 pairs (*) / E5 = 9  =>  0 pairs (X)
A9,C9: 9.. / A9 = 9  =>  0 pairs (X) / C9 = 9  =>  0 pairs (_)
C4,D4: 9.. / C4 = 9  =>  0 pairs (X) / D4 = 9  =>  0 pairs (_)
B5,E5: 9.. / B5 = 9  =>  0 pairs (*) / E5 = 9  =>  0 pairs (X)
A2,A9: 9.. / A2 = 9  =>  0 pairs (*) / A9 = 9  =>  0 pairs (X)
B2,B5: 9.. / B2 = 9  =>  0 pairs (X) / B5 = 9  =>  0 pairs (_)
D3,D4: 9.. / D3 = 9  =>  0 pairs (X) / D4 = 9  =>  0 pairs (_)
E3,E5: 9.. / E3 = 9  =>  0 pairs (*) / E5 = 9  =>  0 pairs (X)
* DURATION: 0:01:38.688606  START: 08:15:03.348109  END: 08:16:42.036715 2017-05-01
* CP COUNT: (56)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A2,A7,A8,B1,B3,B5,B8,C3,C4,C6,C9,D3,D4,D8,E3,E5,E7,F6,F7,H7,H8,H9,I1,I2,I3)
* 3.471829....36214.2....573.43..518271.58.736478..3.519...5..9.3..3.894.1.4.1736.2
* PAIR A2: 8,9 BLK 1
C2: 8,9,7                                # reduction candidate for 8,9
C2: 8,9 => CTR
* 3.471829..7.3621452....573843..51827195827364782.3.519.2.5..9.3..3.894.1.4.1736.2
C2: 7                                    # 27 pairs
* PAIR A2: 8,9 COL A
A9: 8,9,5                                # reduction candidate for 8,9
A9: 8,9 => CTR
* 3.471829....36214.2....573.43695182719582736478243.519...5..9.35.3689471.4.173652
A9: 5 => SOLVED
* 364718295957362148218495736436951827195827364782634519821546973673289451549173682
* PAIR C6: 2,6 ROW 6
D6: 2,6,4                                # reduction candidate for 2,6
D6: 2,6 => SOLVED
* 364718295957362148218495736436951827195827364782634519821546973673289451549173682
D6: 4 => CTR
* 3.471829....36214.2....573.43..518271.582736478243651962154.9.3..3.894.1.4.1736.2
* PAIR F6: 4,6 BLK 5
D6: 4,6,2                                # reduction candidate for 4,6
D6: 4,6 => SOLVED
* 364718295957362148218495736436951827195827364782634519821546973673289451549173682
D6: 2 => CTR
* 3.471829....36214.2..49573.43.95182719582736478..3.519...5..9.3..3.894.1.4.1736.2
* PAIR B8: 2,7 BLK 7
B7: 2,7,1                                # reduction candidate for 2,7
B7: 2,7 => SOLVED
* 364718295957362148218495736436951827195827364782634519821546973673289451549173682
B7: 1                                    # 21 pairs
C7: 2,7,1                                # reduction candidate for 2,7
C7: 2,7                                  # 21 pairs
* PAIR C9: 8,9 BLK 7
A9: 8,9,5                                # reduction candidate for 8,9
A9: 8,9 => CTR
* 3.471829....36214.2....573.43695182719582736478243.519...5..9.35.3689471.4.173652
A9: 5 => SOLVED
* 364718295957362148218495736436951827195827364782634519821546973673289451549173682
* PAIR C9: 8,9 COL C
C2: 8,9,7                                # reduction candidate for 8,9
C2: 8,9 => CTR
* 3.471829..7.3621452....573843..51827195827364782.3.519.2.5..9.3..3.894.1.4.1736.2
C2: 7                                    # 27 pairs
* PAIR D8: 2,6 COL D
D6: 2,6,4                                # reduction candidate for 2,6
D6: 2,6 => SOLVED
* 364718295957362148218495736436951827195827364782634519821546973673289451549173682
D6: 4 => CTR
* 3.471829....36214.2....573.43..518271.582736478243651962154.9.3..3.894.1.4.1736.2
* PAIR H9: 5,8 ROW 9
A9: 5,8,9                                # reduction candidate for 5,8
A9: 5,8 => SOLVED
* 364718295957362148218495736436951827195827364782634519821546973673289451549173682
A9: 9 => CTR
* 3.471829.8..3621452.1..573843695182719582736478243.519...5..9.35.3689471948173652
* INCONCLUSIVE
* SAVE PR GRAPH zz-sudoku-de-719598-base-pr-000.dot
* REASONING
* DIS # C2: 8,9 => CTR => C2: 7
* DIS # A9: 8,9 => CTR => A9: 5
* PRF # A9: 5 => SOL
* PRF # D6: 2,6 => SOL
* DIS # D6: 4 => CTR => D6: 2,6
* PRF # D6: 4,6 => SOL
* DIS # D6: 2 => CTR => D6: 4,6
* PRF # B7: 2,7 => SOL
* DIS # A9: 8,9 => CTR => A9: 5
* PRF # A9: 5 => SOL
* DIS # C2: 8,9 => CTR => C2: 7
* PRF # D6: 2,6 => SOL
* DIS # D6: 4 => CTR => D6: 2,6
* PRF # A9: 5,8 => SOL
* DIS # A9: 9 => CTR => A9: 5,8
* CNT  15 HDP CHAINS /  19 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A2,A7,A8,B1,B3,B5,B8,C3,C4,C6,C9,D3,D4,D8,E3,E5,E7,F6,F7,H7,H8,H9,I1,I2,I3)
* 3.471829....36214.2....573.43..518271.58.736478..3.519...5..9.3..3.894.1.4.1736.2
* PAIR A2: 8,9 BLK 1
C2: 8,9,7                                # reduction candidate for 8,9
C2: 8,9 => CTR
* 3.471829..7.3621452....573843..51827195827364782.3.519.2.5..9.3..3.894.1.4.1736.2
* PAIR A2: 8,9 COL A
A9: 8,9,5                                # reduction candidate for 8,9
A9: 8,9 => CTR
* 3.471829...736214.2....573.43695182719582736478243.519...5..9.35.3689471.4.173652
A9: 5 => SOLVED
* 364718295957362148218495736436951827195827364782634519821546973673289451549173682
* DURATION: 0:00:05.116408  START: 08:17:04.491660  END: 08:17:09.608068 2017-05-01
* SOLUTION FOUND
* SAVE PR GRAPH zz-sudoku-de-719598-base-pr-001.dot
* REASONING
* DIS # C2: 8,9 => CTR => C2: 7
* DIS C2: 7 # A9: 8,9 => CTR => A9: 5
* PRF C2: 7 + A9: 5 => SOL
* STA C2: 7 + A9: 5
* CNT   3 HDP CHAINS /   2 HYP OPENED

Header Info

http://www.sudokus.de/719598.html
sehr schwierig

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

* PAIR REDUCTION ..
* ROUND 1: 3.471829....36214.2....573.43..518271.58.736478..3.519...5..9.3..3.894.1.4.1736.2
B1: 5,6
A2: 8,9
C2: 7,8,9                                # reduction candidate for 8,9
C2: 8,9 => CTR
* 3.471829..7.3621452....573843..51827195827364782.3.519.2.5..9.3..3.894.1.4.1736.2
A9: 5,8,9                                # reduction candidate for 8,9
A9: 8,9 => CTR
* 3.471829...736214.2....573.43695182719582736478243.519...5..9.35.3689471.4.173652
A9: 5 => SOLVED
* 364718295957362148218495736436951827195827364782634519821546973673289451549173682
* SOLVED!
--------------------------------------------------

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

* FORCE VALUE:: D6 = 2
D6 = 2                # set value
E5: 9                 # naked single
D8: 6                 # naked single
C6: 6                 # naked single
B5: 2..               # hidden single
F6: 4..               # hidden single
E7: 2..               # hidden single
B8: 2..               # hidden single
C7: 2..               # hidden single
D3: 4..               # hidden single
* AUTO ..
D3 = 4                # set value
E3: 9                 # naked single
E3 = 9                # set value
E5 = 0 => CTR
* CTR!

* DISABLE VALUE:: D6 != 2
E5: 2..               # hidden single
C6: 2..               # hidden single
D8: 2..               # hidden single
* SOLVED!

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

Solution

position: 364718295957362148218495736436951827195827364782634519821546973673289451549173682 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 # C2: 8,9 => CTR => C2: 7
* INC # C2: 7 => UNS
* DIS # A9: 8,9 => CTR => A9: 5
* PRF # A9: 5 => SOL
* PRF # D6: 2,6 => SOL
* DIS # D6: 4 => CTR => D6: 2,6
* PRF # D6: 4,6 => SOL
* DIS # D6: 2 => CTR => D6: 4,6
* PRF # B7: 2,7 => SOL
* INC # B7: 1 => UNS
* INC # C7: 2,7 => UNS
* DIS # A9: 8,9 => CTR => A9: 5
* PRF # A9: 5 => SOL
* DIS # C2: 8,9 => CTR => C2: 7
* INC # C2: 7 => UNS
* PRF # D6: 2,6 => SOL
* DIS # D6: 4 => CTR => D6: 2,6
* PRF # A9: 5,8 => SOL
* DIS # A9: 9 => CTR => A9: 5,8
* CNT  19 HDP CHAINS /  19 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # C2: 8,9 => CTR => C2: 7
* DIS C2: 7 # A9: 8,9 => CTR => A9: 5
* PRF C2: 7 + A9: 5 => SOL
* STA C2: 7 + A9: 5
* CNT   3 HDP CHAINS /   2 HYP OPENED