Analysis of xx-top95-014-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 3.6.7...........518.........1.4.5...7.....6.....2......2.....4.....8.3.....5..... initial

Autosolve

position: 356.7.294....4.8518419527...1.4.59..7.4...625...2.741..2....54.....8.3.2...52.1.. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # C2: 7 => CTR => C2: 2,9
* DIS # C2: 7,9 => CTR => C2: 2
* DIS # B8: 7,9 => CTR => B8: 6
* PRF # B8: 6 => SOL
* DIS # B9: 7,9 => CTR => B9: 3,6,8
* DIS # D5: 1,8 => CTR => D5: 3
* PRF # D5: 3 => SOL
* DIS # F5: 3,9 => CTR => F5: 1,8
* DIS # D7: 3,6 => CTR => D7: 1,7
* DIS # B6: 3,9 => CTR => B6: 6,8
* DIS # E5: 3,9 => CTR => E5: 1
* DIS # F5: 3,9 => CTR => F5: 1,8
* PRF # B9: 3,9 => SOL
* DIS # E6: 3,6 => CTR => E6: 9
* PRF # E6: 9 => SOL
* DIS # I4: 3,8 => CTR => I4: 7
* DIS # C6: 3,8 => CTR => C6: 5,9
* DIS # I7: 6,7 => CTR => I7: 8,9
* DIS # I9: 6,7 => CTR => I9: 8,9
* PRF # B8: 6,7 => SOL
* DIS # B8: 9 => CTR => B8: 6,7
* DIS # D8: 6,7 => CTR => D8: 1
* PRF # D8: 1 => SOL
* CNT  23 HDP CHAINS /  42 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: 7 => CTR => C2: 2,9
* DIS C2: 2,9 # D5: 1,8 => CTR => D5: 3
* PRF C2: 2,9 + D5: 3 => SOL
* STA C2: 2,9 + D5: 3
* CNT   3 HDP CHAINS /   3 HYP OPENED

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

Details

Positions

3.6.7...........518.........1.4.5...7.....6.....2......2.....4.....8.3.....5..... initial
356.7.294....4.8518419527...1.4.59..7.4...625...2.741..2....54.....8.3.2...52.1.. autosolve
356871294972643851841952736213465987794318625685297413128736549569184372437529168 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (13)
A2: 2,9
B2: 7,9
D1: 1,8
F1: 1,8
D2: 3,6
F2: 3,6
H3: 3,6
I3: 3,6
A4: 2,6
B5: 3,9
E4: 3,6
I6: 3,8
H8: 6,7

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
D1,F1: 1.. / D1 = 1  =>  0 pairs (X) / F1 = 1  => 13 pairs (_)
A7,A8: 1.. / A7 = 1  => 15 pairs (_) / A8 = 1  =>  0 pairs (X)
E5,E7: 1.. / E5 = 1  => 15 pairs (_) / E7 = 1  =>  0 pairs (X)
A2,C2: 2.. / A2 = 2  =>  0 pairs (X) / C2 = 2  => 15 pairs (_)
A4,C4: 2.. / A4 = 2  => 15 pairs (_) / C4 = 2  =>  0 pairs (X)
A2,A4: 2.. / A2 = 2  =>  0 pairs (X) / A4 = 2  => 15 pairs (_)
C2,C4: 2.. / C2 = 2  => 15 pairs (_) / C4 = 2  =>  0 pairs (X)
D2,F2: 3.. / D2 = 3  =>  0 pairs (X) / F2 = 3  => 12 pairs (_)
H3,I3: 3.. / H3 = 3  => 12 pairs (_) / I3 = 3  =>  0 pairs (X)
H3,H4: 3.. / H3 = 3  => 12 pairs (_) / H4 = 3  =>  0 pairs (X)
A8,A9: 4.. / A8 = 4  => 16 pairs (_) / A9 = 4  => 14 pairs (_)
F8,F9: 4.. / F8 = 4  => 14 pairs (_) / F9 = 4  => 16 pairs (_)
A8,F8: 4.. / A8 = 4  => 16 pairs (_) / F8 = 4  => 14 pairs (_)
A9,F9: 4.. / A9 = 4  => 14 pairs (_) / F9 = 4  => 16 pairs (_)
A6,C6: 5.. / A6 = 5  => 13 pairs (_) / C6 = 5  =>  0 pairs (*)
A8,C8: 5.. / A8 = 5  =>  0 pairs (*) / C8 = 5  =>  0 pairs (X)
A6,A8: 5.. / A6 = 5  => 13 pairs (_) / A8 = 5  =>  0 pairs (*)
C6,C8: 5.. / C6 = 5  =>  0 pairs (*) / C8 = 5  =>  0 pairs (X)
D2,F2: 6.. / D2 = 6  => 12 pairs (_) / F2 = 6  =>  0 pairs (X)
H3,I3: 6.. / H3 = 6  =>  0 pairs (X) / I3 = 6  => 12 pairs (_)
E4,E6: 6.. / E4 = 6  => 15 pairs (_) / E6 = 6  =>  0 pairs (X)
A4,E4: 6.. / A4 = 6  =>  0 pairs (X) / E4 = 6  => 15 pairs (_)
B2,C2: 7.. / B2 = 7  => 14 pairs (_) / C2 = 7  =>  0 pairs (X)
H4,I4: 7.. / H4 = 7  =>  0 pairs (X) / I4 = 7  => 14 pairs (_)
D7,D8: 7.. / D7 = 7  => 14 pairs (_) / D8 = 7  =>  0 pairs (X)
D1,F1: 8.. / D1 = 8  => 13 pairs (_) / F1 = 8  =>  0 pairs (X)
D5,F5: 8.. / D5 = 8  =>  0 pairs (X) / F5 = 8  => 13 pairs (_)
C7,I7: 8.. / C7 = 8  =>  0 pairs (*) / I7 = 8  =>  0 pairs (X)
B6,B9: 8.. / B6 = 8  => 18 pairs (_) / B9 = 8  =>  0 pairs (X)
D1,D5: 8.. / D1 = 8  => 13 pairs (_) / D5 = 8  =>  0 pairs (X)
F1,F5: 8.. / F1 = 8  =>  0 pairs (X) / F5 = 8  => 13 pairs (_)
H4,H9: 8.. / H4 = 8  => 15 pairs (_) / H9 = 8  =>  0 pairs (X)
I7,I9: 9.. / I7 = 9  =>  0 pairs (*) / I9 = 9  =>  0 pairs (X)
* DURATION: 0:01:01.810366  START: 23:08:39.652601  END: 23:09:41.462967 2017-05-03
* CP COUNT: (33)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A2,A4,B2,B5,D1,D2,E4,F1,F2,H3,H8,I3,I6)
* 356.7.294....4.8518419527...1.4.59..7.4...625...2.741..2....54.....8.3.2...52.1..
* PAIR A2: 2,9 BLK 1
C2: 2,9,7                                # reduction candidate for 2,9
C2: 7 => CTR
* 356.7.294297.4.8518419527366124359..734...625.8.267413.2....54.....8.3.2...52.1..
C2: 2,9                                  # 14 pairs
* PAIR B2: 7,9 BLK 1
C2: 7,9,2                                # reduction candidate for 7,9
C2: 7,9 => CTR
* 356.7.2942...4.8518419527366124359..734...625...267413.2....54....78.362.6352.1..
C2: 2                                    # 15 pairs
* PAIR B2: 7,9 COL B
B8: 7,9,6                                # reduction candidate for 7,9
B8: 7,9 => CTR
* 356.7.294972.4.8518419527..2184659..734...625569237418.2....54..95.8.3.2.8.52.1..
B8: 6 => SOLVED
* 356871294972643851841952736213465987794318625685297413128736549569184372437529168
B9: 7,9,3,6,8                            # reduction candidate for 7,9
B9: 7,9 => CTR
* 356.7.294....4.851841952736.1.4.5987734...625.8.2.7413.2.7.654..6.18.372...52.1..
B9: 3,6,8                                # 13 pairs
* PAIR D1: 1,8 COL D
D5: 1,8,3                                # reduction candidate for 1,8
D5: 1,8 => CTR
* 356.7.294972.4.8518419527..2184659..734...625569237418.2....54..95.8.3.2.8.52.1..
D5: 3 => SOLVED
* 356871294972643851841952736213465987794318625685297413128736549569184372437529168
* PAIR F1: 1,8 COL F
F5: 1,8,3,9                              # reduction candidate for 1,8
F5: 3,9 => CTR
* 356178294972.4.8518419527..2184659..734819625569237418.2..9.54..95.8.3.2.8.52.1.9
F5: 1,8                                  # 15 pairs
* PAIR D2: 3,6 COL D
D7: 3,6,1,7                              # reduction candidate for 3,6
D7: 3,6 => CTR
* 356.7.294972.4.851841952736218465973734...625569237418.2....54..9578.362.8.52.1..
D7: 1,7                                  # 14 pairs
* PAIR F2: 3,6 COL F
F7: 3,6,1,9                              # reduction candidate for 3,6
F7: 3,6                                  # 15 pairs
F9: 3,6,4,9                              # reduction candidate for 3,6
F9: 3,6                                  # 16 pairs
* PAIR B5: 3,9 BLK 4
B6: 3,9,6,8                              # reduction candidate for 3,9
B6: 3,9 => CTR
* 356.7.294.7.346851841952736.1.4.5987734...625598267413.23...548.65.8.372.87523169
B6: 6,8                                  # 14 pairs
C6: 3,9,5,8                              # reduction candidate for 3,9
C6: 3,9                                  # 16 pairs
* PAIR B5: 3,9 ROW 5
E5: 3,9,1                                # reduction candidate for 3,9
E5: 3,9 => CTR
* 356.7.294972.4.8518419527..21.4659..734.9.625569237418628.1.54.195.843.24..52.1..
E5: 1                                    # 15 pairs
F5: 3,9,1,8                              # reduction candidate for 3,9
F5: 3,9 => CTR
* 356178294972.4.8518419527..2184659..734819625569237418.2..9.54..95.8.3.2.8.52.1.9
F5: 1,8                                  # 15 pairs
* PAIR B5: 3,9 COL B
B9: 3,9,6,7,8                            # reduction candidate for 3,9
B9: 3,9 => SOLVED
* 356871294972643851841952736213465987794318625685297413128736549569184372437529168
B9: 6,7,8                                # 14 pairs
* PAIR E4: 3,6 BLK 5
E6: 3,6,9                                # reduction candidate for 3,6
E6: 3,6 => CTR
* 356.7.294972.4.8518419527..2184659..734...625569237418.2....54..95.8.3.2.8.52.1..
E6: 9 => SOLVED
* 356871294972643851841952736213465987794318625685297413128736549569184372437529168
* PAIR I6: 3,8 BLK 6
H4: 3,8,7                                # reduction candidate for 3,8
H4: 3,8                                  # 14 pairs
I4: 3,8,7                                # reduction candidate for 3,8
I4: 3,8 => CTR
* 356.7.294....4.851841952736.12435978734...625.8.267413.287..54.....8.362.6352.187
I4: 7                                    # 14 pairs
* PAIR I6: 3,8 ROW 6
B6: 3,8,6,9                              # reduction candidate for 3,8
B6: 3,8                                  # 18 pairs
C6: 3,8,5,9                              # reduction candidate for 3,8
C6: 3,8 => CTR
* 356.7.294.7..4.8518419527..612435987734...625598267413.237..548.6518.372..752.1..
C6: 5,9                                  # 14 pairs
* PAIR H8: 6,7 BLK 9
I7: 6,7,8,9                              # reduction candidate for 6,7
I7: 6,7 => CTR
* 356.7.294....4.851841952736.1.4.59787.4...625.8.2.7413.28...547...78.362.6.52.189
I7: 8,9                                  # 14 pairs
H9: 6,7,8                                # reduction candidate for 6,7
H9: 6,7                                  # 15 pairs
I9: 6,7,8,9                              # reduction candidate for 6,7
I9: 6,7 => CTR
* 356.7.294...643851841952736.12435978734...625.8.2674131287..549....8.362.6352.187
I9: 8,9                                  # 14 pairs
* PAIR H8: 6,7 ROW 8
B8: 6,7,9                                # reduction candidate for 6,7
B8: 6,7 => SOLVED
* 356871294972643851841952736213465987794318625685297413128736549569184372437529168
B8: 9 => CTR
* 356.7.294.7..4.8518419527...184.59..734...625569237418.2....54..95.8.3.2.8.52.1..
D8: 6,7,1                                # reduction candidate for 6,7
D8: 6,7 => CTR
* 356.7.294972.4.8518419527..2184659..734...625569237418.2....54..95.8.3.2.8.52.1..
D8: 1 => SOLVED
* 356871294972643851841952736213465987794318625685297413128736549569184372437529168
* INCONCLUSIVE
* SAVE PR GRAPH xx-top95-014-base-pr-000.dot
* REASONING
* DIS # C2: 7 => CTR => C2: 2,9
* DIS # C2: 7,9 => CTR => C2: 2
* DIS # B8: 7,9 => CTR => B8: 6
* PRF # B8: 6 => SOL
* DIS # B9: 7,9 => CTR => B9: 3,6,8
* DIS # D5: 1,8 => CTR => D5: 3
* PRF # D5: 3 => SOL
* DIS # F5: 3,9 => CTR => F5: 1,8
* DIS # D7: 3,6 => CTR => D7: 1,7
* DIS # B6: 3,9 => CTR => B6: 6,8
* DIS # E5: 3,9 => CTR => E5: 1
* DIS # F5: 3,9 => CTR => F5: 1,8
* PRF # B9: 3,9 => SOL
* DIS # E6: 3,6 => CTR => E6: 9
* PRF # E6: 9 => SOL
* DIS # I4: 3,8 => CTR => I4: 7
* DIS # C6: 3,8 => CTR => C6: 5,9
* DIS # I7: 6,7 => CTR => I7: 8,9
* DIS # I9: 6,7 => CTR => I9: 8,9
* PRF # B8: 6,7 => SOL
* DIS # B8: 9 => CTR => B8: 6,7
* DIS # D8: 6,7 => CTR => D8: 1
* PRF # D8: 1 => SOL
* CNT  23 HDP CHAINS /  42 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A2,A4,B2,B5,D1,D2,E4,F1,F2,H3,H8,I3,I6)
* 356.7.294....4.8518419527...1.4.59..7.4...625...2.741..2....54.....8.3.2...52.1..
* PAIR A2: 2,9 BLK 1
C2: 2,9,7                                # reduction candidate for 2,9
C2: 7 => CTR
* 356.7.294297.4.8518419527366124359..734...625.8.267413.2....54.....8.3.2...52.1..
* PAIR D1: 1,8 COL D
D5: 1,8,3                                # reduction candidate for 1,8
D5: 1,8 => CTR
* 356.7.294972.4.8518419527..2184659..734...625569237418.2....54..95.8.3.2.8.52.1..
D5: 3 => SOLVED
* 356871294972643851841952736213465987794318625685297413128736549569184372437529168
* DURATION: 0:00:05.599317  START: 23:10:27.741258  END: 23:10:33.340575 2017-05-03
* SOLUTION FOUND
* SAVE PR GRAPH xx-top95-014-base-pr-001.dot
* REASONING
* DIS # C2: 7 => CTR => C2: 2,9
* DIS C2: 2,9 # D5: 1,8 => CTR => D5: 3
* PRF C2: 2,9 + D5: 3 => SOL
* STA C2: 2,9 + D5: 3
* CNT   3 HDP CHAINS /   3 HYP OPENED

Header Info

Top 95 Sudokus 014
[sudoku:top95] “95 Hard Puzzles”, http://magictour.free.fr/top95, or http://norvig.com/top95.txt

Solution

position: 356871294972643851841952736213465987794318625685297413128736549569184372437529168 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 # C2: 2,9 => UNS
* DIS # C2: 7 => CTR => C2: 2,9
* DIS # C2: 7,9 => CTR => C2: 2
* INC # C2: 2 => UNS
* DIS # B8: 7,9 => CTR => B8: 6
* PRF # B8: 6 => SOL
* DIS # B9: 7,9 => CTR => B9: 3,6,8
* INC # B9: 3,6,8 => UNS
* DIS # D5: 1,8 => CTR => D5: 3
* PRF # D5: 3 => SOL
* INC # F5: 1,8 => UNS
* DIS # F5: 3,9 => CTR => F5: 1,8
* DIS # D7: 3,6 => CTR => D7: 1,7
* INC # D7: 1,7 => UNS
* INC # F7: 3,6 => UNS
* INC # F9: 3,6 => UNS
* DIS # B6: 3,9 => CTR => B6: 6,8
* INC # B6: 6,8 => UNS
* INC # C6: 3,9 => UNS
* DIS # E5: 3,9 => CTR => E5: 1
* INC # E5: 1 => UNS
* DIS # F5: 3,9 => CTR => F5: 1,8
* INC # F5: 1,8 => UNS
* PRF # B9: 3,9 => SOL
* INC # B9: 6,7,8 => UNS
* DIS # E6: 3,6 => CTR => E6: 9
* PRF # E6: 9 => SOL
* INC # H4: 3,8 => UNS
* DIS # I4: 3,8 => CTR => I4: 7
* INC # I4: 7 => UNS
* INC # B6: 3,8 => UNS
* DIS # C6: 3,8 => CTR => C6: 5,9
* INC # C6: 5,9 => UNS
* DIS # I7: 6,7 => CTR => I7: 8,9
* INC # I7: 8,9 => UNS
* INC # H9: 6,7 => UNS
* DIS # I9: 6,7 => CTR => I9: 8,9
* INC # I9: 8,9 => UNS
* PRF # B8: 6,7 => SOL
* DIS # B8: 9 => CTR => B8: 6,7
* DIS # D8: 6,7 => CTR => D8: 1
* PRF # D8: 1 => SOL
* CNT  42 HDP CHAINS /  42 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # C2: 2,9 => UNS
* DIS # C2: 7 => CTR => C2: 2,9
* DIS C2: 2,9 # D5: 1,8 => CTR => D5: 3
* PRF C2: 2,9 + D5: 3 => SOL
* STA C2: 2,9 + D5: 3
* CNT   4 HDP CHAINS /   3 HYP OPENED