Analysis of xx-top95-011-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 6..3.2....5.....1..........7.26............543.........8.15........4.2........7.. initial

Autosolve

position: 6..3.25...5.....12.2.5.....7426.5..........543.5....2728.15........4.2........7.. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # G2: 8,9 => SOL
* DIS # I3: 8,9 => CTR => I3: 3,6
* DIS # C1: 8,9 => CTR => C1: 1,4,7
* DIS # I4: 3 => CTR => I4: 8,9
* DIS # G4: 3,9 => CTR => G4: 1,8
* DIS # I4: 3,9 => CTR => I4: 8
* DIS # E4: 1,8 => CTR => E4: 3,9
* PRF # H3: 3,9 => SOL
* DIS # A8: 9 => CTR => A8: 1,5
* DIS # A9: 1,5 => CTR => A9: 4,9
* CNT  10 HDP CHAINS /  26 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 # G2: 8,9 => SOL
* STA G2: 8,9
* CNT   1 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

6..3.2....5.....1..........7.26............543.........8.15........4.2........7.. initial
6..3.25...5.....12.2.5.....7426.5..........543.5....2728.15........4.2........7.. autosolve
614382579953764812827591436742635198168279354395418627286157943579843261431926785 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (4)
I1: 8,9
H4: 3,9
I8: 1,5
I9: 1,5

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
I8,I9: 1.. / I8 = 1  =>  2 pairs (_) / I9 = 1  =>  0 pairs (X)
E4,G4: 1.. / E4 = 1  =>  0 pairs (X) / G4 = 1  =>  4 pairs (_)
D5,E5: 2.. / D5 = 2  =>  5 pairs (_) / E5 = 2  =>  5 pairs (_)
D9,E9: 2.. / D9 = 2  =>  5 pairs (_) / E9 = 2  =>  5 pairs (_)
D5,D9: 2.. / D5 = 2  =>  5 pairs (_) / D9 = 2  =>  5 pairs (_)
E5,E9: 2.. / E5 = 2  =>  5 pairs (_) / E9 = 2  =>  5 pairs (_)
C2,C3: 3.. / C2 = 3  =>  0 pairs (*) / C3 = 3  =>  0 pairs (X)
B8,B9: 3.. / B8 = 3  =>  0 pairs (X) / B9 = 3  =>  4 pairs (_)
C2,G2: 3.. / C2 = 3  =>  0 pairs (*) / G2 = 3  =>  0 pairs (X)
D6,F6: 4.. / D6 = 4  =>  4 pairs (_) / F6 = 4  =>  6 pairs (_)
C1,H1: 4.. / C1 = 4  =>  4 pairs (_) / H1 = 4  =>  0 pairs (X)
D2,D6: 4.. / D2 = 4  =>  6 pairs (_) / D6 = 4  =>  4 pairs (_)
A8,A9: 5.. / A8 = 5  =>  2 pairs (_) / A9 = 5  =>  0 pairs (X)
I8,I9: 5.. / I8 = 5  =>  0 pairs (X) / I9 = 5  =>  2 pairs (_)
A8,I8: 5.. / A8 = 5  =>  2 pairs (_) / I8 = 5  =>  0 pairs (X)
A9,I9: 5.. / A9 = 5  =>  0 pairs (X) / I9 = 5  =>  2 pairs (_)
E2,F2: 6.. / E2 = 6  =>  4 pairs (_) / F2 = 6  =>  0 pairs (X)
H3,I3: 6.. / H3 = 6  =>  0 pairs (X) / I3 = 6  =>  5 pairs (_)
G5,G6: 6.. / G5 = 6  =>  0 pairs (X) / G6 = 6  =>  5 pairs (_)
B6,G6: 6.. / B6 = 6  =>  0 pairs (X) / G6 = 6  =>  5 pairs (_)
E2,E9: 6.. / E2 = 6  =>  4 pairs (_) / E9 = 6  =>  0 pairs (X)
I3,I7: 6.. / I3 = 6  =>  5 pairs (_) / I7 = 6  =>  0 pairs (X)
H1,H3: 7.. / H1 = 7  =>  0 pairs (*) / H3 = 7  =>  0 pairs (X)
C7,F7: 7.. / C7 = 7  =>  0 pairs (X) / F7 = 7  =>  7 pairs (_)
B1,B8: 7.. / B1 = 7  =>  0 pairs (X) / B8 = 7  =>  0 pairs (_)
A5,C5: 8.. / A5 = 8  =>  5 pairs (_) / C5 = 8  =>  5 pairs (_)
H8,H9: 8.. / H8 = 8  =>  5 pairs (_) / H9 = 8  =>  5 pairs (_)
* DURATION: 0:00:40.948072  START: 23:04:12.367592  END: 23:04:53.315664 2017-05-03
* CP COUNT: (27)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (H4,I1,I8,I9)
* 6..3.25...5.....12.2.5.....7426.5..........543.5....2728.15........4.2........7..
* PAIR I1: 8,9 BLK 3
G2: 8,9,3,4                              # reduction candidate for 8,9
G2: 8,9 => SOLVED
* 614382579953764812827591436742635198168279354395418627286157943579843261431926785
G2: 3,4                                  #  5 pairs
G3: 8,9,3,4                              # reduction candidate for 8,9
G3: 8,9                                  #  8 pairs
I3: 8,9,3,6                              # reduction candidate for 8,9
I3: 8,9 => CTR
* 6.43.257..5.....12.2.5...6.7426.5.93....3..543.5....27289157..6.7..4328.43....7..
I3: 3,6                                  #  5 pairs
* PAIR I1: 8,9 ROW 1
C1: 8,9,1,4,7                            # reduction candidate for 8,9
C1: 8,9 => CTR
* 61.37254..57.6.312.235...767426.5..........543.5....2728.1574...7..4.2...34.2.7..
C1: 1,4,7                                #  4 pairs
E1: 8,9,1,7                              # reduction candidate for 8,9
E1: 8,9                                  #  7 pairs
* PAIR I1: 8,9 COL I
I4: 8,9,3                                # reduction candidate for 8,9
I4: 3 => CTR
* 6..3.25...57.6.312.235.....7426.5.93.......543.5....2728.157.3..7..432........7..
I4: 8,9                                  #  7 pairs
* PAIR H4: 3,9 BLK 6
G4: 3,9,1,8                              # reduction candidate for 3,9
G4: 3,9 => CTR
* 6..3.25.9.57.6.312.235.18.6742615938.......543.5....2728.1574.3.7..432........7..
G4: 1,8                                  #  5 pairs
I4: 3,9,8                                # reduction candidate for 3,9
I4: 3,9 => CTR
* 6..3.25...57.6.312.235.....7426.5..........543.5....2728.157....7..4.2...3..2.7..
I4: 8                                    #  7 pairs
G5: 3,9,1,6                              # reduction candidate for 3,9
G5: 3,9                                  # 10 pairs
* PAIR H4: 3,9 ROW 4
E4: 3,9,1,8                              # reduction candidate for 3,9
E4: 1,8 => CTR
* 6..3.25...57.6.312.235.....7426.5..........543.5....2728.157....7..4.2...3..2.7..
E4: 3,9                                  #  9 pairs
* PAIR H4: 3,9 COL H
H3: 3,9,4,6,7                            # reduction candidate for 3,9
H3: 3,9 => SOLVED
* 614382579953764812827591436742635198168279354395418627286157943579843261431926785
H3: 4,6,7                                #  4 pairs
H7: 3,9,4,6                              # reduction candidate for 3,9
H7: 3,9                                  #  8 pairs
H8: 3,9,6,8                              # reduction candidate for 3,9
H8: 3,9                                  #  9 pairs
H9: 3,9,4,6,8                            # reduction candidate for 3,9
H9: 3,9                                  #  9 pairs
* PAIR I8: 1,5 ROW 8
A8: 1,5,9                                # reduction candidate for 1,5
A8: 9 => CTR
* 6..37254..57.6.312.235...767426.5..........543.5....272861574..97184.2.5534.2.781
A8: 1,5                                  #  5 pairs
* PAIR I9: 1,5 ROW 9
A9: 1,5,4,9                              # reduction candidate for 1,5
A9: 1,5 => CTR
* 6..37254..57.6.312.235...767426.5..........543.5....2728.1574...7..4.2...34.2.7..
A9: 4,9                                  #  3 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top95-011-base-pr-000.dot
* REASONING
* PRF # G2: 8,9 => SOL
* DIS # I3: 8,9 => CTR => I3: 3,6
* DIS # C1: 8,9 => CTR => C1: 1,4,7
* DIS # I4: 3 => CTR => I4: 8,9
* DIS # G4: 3,9 => CTR => G4: 1,8
* DIS # I4: 3,9 => CTR => I4: 8
* DIS # E4: 1,8 => CTR => E4: 3,9
* PRF # H3: 3,9 => SOL
* DIS # A8: 9 => CTR => A8: 1,5
* DIS # A9: 1,5 => CTR => A9: 4,9
* CNT  10 HDP CHAINS /  26 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (H4,I1,I8,I9)
* 6..3.25...5.....12.2.5.....7426.5..........543.5....2728.15........4.2........7..
* PAIR I1: 8,9 BLK 3
G2: 8,9,3,4                              # reduction candidate for 8,9
G2: 8,9 => SOLVED
* 614382579953764812827591436742635198168279354395418627286157943579843261431926785
* DURATION: 0:00:02.729172  START: 23:05:15.724247  END: 23:05:18.453419 2017-05-03
* SOLUTION FOUND
* SAVE PR GRAPH xx-top95-011-base-pr-001.dot
* REASONING
* PRF # G2: 8,9 => SOL
* STA G2: 8,9
* CNT   1 HDP CHAINS /   1 HYP OPENED

Header Info

Top 95 Sudokus 011
[sudoku:top95] “95 Hard Puzzles”, http://magictour.free.fr/top95, or http://norvig.com/top95.txt

Solution

position: 614382579953764812827591436742635198168279354395418627286157943579843261431926785 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 # G2: 8,9 => SOL
* INC # G2: 3,4 => UNS
* INC # G3: 8,9 => UNS
* DIS # I3: 8,9 => CTR => I3: 3,6
* INC # I3: 3,6 => UNS
* DIS # C1: 8,9 => CTR => C1: 1,4,7
* INC # C1: 1,4,7 => UNS
* INC # E1: 8,9 => UNS
* INC # I4: 8,9 => UNS
* DIS # I4: 3 => CTR => I4: 8,9
* DIS # G4: 3,9 => CTR => G4: 1,8
* INC # G4: 1,8 => UNS
* DIS # I4: 3,9 => CTR => I4: 8
* INC # I4: 8 => UNS
* INC # G5: 3,9 => UNS
* INC # E4: 3,9 => UNS
* DIS # E4: 1,8 => CTR => E4: 3,9
* PRF # H3: 3,9 => SOL
* INC # H3: 4,6,7 => UNS
* INC # H7: 3,9 => UNS
* INC # H8: 3,9 => UNS
* INC # H9: 3,9 => UNS
* INC # A8: 1,5 => UNS
* DIS # A8: 9 => CTR => A8: 1,5
* DIS # A9: 1,5 => CTR => A9: 4,9
* INC # A9: 4,9 => UNS
* CNT  26 HDP CHAINS /  26 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* PRF # G2: 8,9 => SOL
* STA G2: 8,9
* CNT   1 HDP CHAINS /   1 HYP OPENED