Analysis of xx-top95-013-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: ..5...987.4..5...1..7......2...48....9.1.....6..2.....3..6..2.......9.7.......5.. initial

Autosolve

position: 1.5...987.4..57..1..7......2...48....9.1.....6..2.....3..6..2.......9.7.......5.. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # D8: 3,4 => CTR => D8: 5,8
* DIS # D9: 3,4 => CTR => D9: 7,8
* DIS # D4: 3,5 => CTR => D4: 7,9
* PRF # D4: 7,9 => SOL
* PRF # F5: 3,5 => SOL
* DIS # D8: 3,8 => CTR => D8: 4,5
* PRF # A5: 4,5 => SOL
* DIS # A5: 7 => CTR => A5: 4,5
* PRF # D9: 3,8 => SOL
* DIS # A5: 4,7 => CTR => A5: 5
* PRF # A5: 5 => SOL
* CNT  11 HDP CHAINS /  38 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 # D8: 3,4 => CTR => D8: 5,8
* DIS D8: 5,8 # D9: 3,4 => CTR => D9: 7,8
* DIS D8: 5,8 + D9: 7,8 # D3: 8,9 => CTR => D3: 3
* PRF D8: 5,8 + D9: 7,8 + D3: 3 # F5: 3,5 => SOL
* STA D8: 5,8 + D9: 7,8 + D3: 3 + F5: 3,5
* CNT   4 HDP CHAINS /  16 HYP OPENED

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

Details

Positions

..5...987.4..5...1..7......2...48....9.1.....6..2.....3..6..2.......9.7.......5.. initial
1.5...987.4..57..1..7......2...48....9.1.....6..2.....3..6..2.......9.7.......5.. autosolve
135426987846957321927381465213748659598163742674295813351674298482539176769812534 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (9)
A2: 8,9
A3: 8,9
D1: 3,4
D2: 8,9
G2: 3,6
C4: 1,3
F6: 3,5
A8: 4,5
A9: 4,7

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
E3,F3: 1.. / E3 = 1  => 11 pairs (_) / F3 = 1  => 10 pairs (_)
H5,I5: 2.. / H5 = 2  => 12 pairs (_) / I5 = 2  =>  9 pairs (_)
C2,H2: 2.. / C2 = 2  => 14 pairs (_) / H2 = 2  => 10 pairs (_)
I3,I5: 2.. / I3 = 2  => 12 pairs (_) / I5 = 2  =>  9 pairs (_)
D1,F1: 4.. / D1 = 4  =>  8 pairs (_) / F1 = 4  => 17 pairs (_)
H3,I3: 5.. / H3 = 5  =>  9 pairs (_) / I3 = 5  =>  9 pairs (_)
F7,D8: 5.. / F7 = 5  =>  0 pairs (X) / D8 = 5  =>  0 pairs (_)
B7,F7: 5.. / B7 = 5  =>  0 pairs (*) / F7 = 5  =>  0 pairs (X)
A5,A8: 5.. / A5 = 5  =>  0 pairs (*) / A8 = 5  =>  0 pairs (X)
D4,D8: 5.. / D4 = 5  =>  0 pairs (X) / D8 = 5  =>  0 pairs (_)
E5,F5: 6.. / E5 = 6  =>  0 pairs (*) / F5 = 6  =>  0 pairs (X)
B7,E7: 7.. / B7 = 7  =>  0 pairs (X) / E7 = 7  =>  0 pairs (_)
A5,A9: 7.. / A5 = 7  =>  0 pairs (X) / A9 = 7  =>  0 pairs (_)
D4,D9: 7.. / D4 = 7  =>  0 pairs (*) / D9 = 7  =>  0 pairs (X)
A2,A3: 8.. / A2 = 8  =>  7 pairs (_) / A3 = 8  =>  7 pairs (_)
A2,D2: 8.. / A2 = 8  =>  7 pairs (_) / D2 = 8  =>  7 pairs (_)
A2,A3: 9.. / A2 = 9  =>  7 pairs (_) / A3 = 9  =>  7 pairs (_)
D4,E6: 9.. / D4 = 9  =>  0 pairs (X) / E6 = 9  =>  9 pairs (_)
C7,C9: 9.. / C7 = 9  => 11 pairs (_) / C9 = 9  => 12 pairs (_)
A2,D2: 9.. / A2 = 9  =>  7 pairs (_) / D2 = 9  =>  7 pairs (_)
E3,E6: 9.. / E3 = 9  =>  0 pairs (X) / E6 = 9  =>  9 pairs (_)
* DURATION: 0:00:28.399232  START: 23:07:13.037106  END: 23:07:41.436338 2017-05-03
* CP COUNT: (21)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A2,A3,A8,A9,C4,D1,D2,F6,G2)
* 1.5...987.4..57..1..7......2...48....9.1.....6..2.....3..6..2.......9.7.......5..
* PAIR A3: 8,9 ROW 3
D3: 8,9,3                                # reduction candidate for 8,9
D3: 8,9                                  # 10 pairs
E3: 8,9,1,2,3,6                          # reduction candidate for 8,9
E3: 8,9                                  # 17 pairs
* PAIR D1: 3,4 BLK 2
F1: 3,4,2,6                              # reduction candidate for 3,4
F1: 3,4                                  # 13 pairs
F1: 2,6                                  #  9 pairs
* PAIR D1: 3,4 COL D
D8: 3,4,5,8                              # reduction candidate for 3,4
D8: 3,4 => CTR
* 1.5...987.4..57..1..7......2..548...79.16....6..293...3..6.52.......9.7....7..5..
D8: 5,8                                  # 10 pairs
D9: 3,4,7,8                              # reduction candidate for 3,4
D9: 3,4 => CTR
* 1.53.4987.4..57321.37...4..2..7486..5981..7..67429581335.67.2.84.25391767..482539
D9: 7,8                                  # 10 pairs
* PAIR D2: 8,9 BLK 2
D3: 8,9,3                                # reduction candidate for 8,9
D3: 8,9                                  # 10 pairs
E3: 8,9,1,2,3,6                          # reduction candidate for 8,9
E3: 8,9                                  # 17 pairs
* PAIR G2: 3,6 BLK 3
H2: 3,6,2                                # reduction candidate for 3,6
H2: 3,6                                  # 14 pairs
G3: 3,6,4                                # reduction candidate for 3,6
G3: 3,6                                  # 14 pairs
H3: 3,6,2,4,5                            # reduction candidate for 3,6
H3: 3,6                                  # 11 pairs
I3: 3,6,2,4,5                            # reduction candidate for 3,6
I3: 3,6                                  # 12 pairs
* PAIR G2: 3,6 ROW 2
C2: 3,6,2                                # reduction candidate for 3,6
C2: 2                                    # 14 pairs
C2: 3,6                                  # 10 pairs
* PAIR G2: 3,6 COL G
G4: 3,6,1,7                              # reduction candidate for 3,6
G4: 3,6                                  # 12 pairs
G8: 3,6,1,4,8                            # reduction candidate for 3,6
G8: 3,6                                  # 12 pairs
* PAIR C4: 1,3 BLK 4
B4: 1,3,5,7                              # reduction candidate for 1,3
B4: 1,3                                  # 16 pairs
B6: 1,3,5,7,8                            # reduction candidate for 1,3
B6: 1,3                                  # 15 pairs
C6: 1,3,4,8                              # reduction candidate for 1,3
C6: 1,3                                  # 14 pairs
* PAIR C4: 1,3 ROW 4
G4: 1,3,6,7                              # reduction candidate for 1,3
G4: 1,3                                  # 11 pairs
H4: 1,3,5,6,9                            # reduction candidate for 1,3
H4: 1,3                                  # 12 pairs
* PAIR F6: 3,5 BLK 5
D4: 3,5,7,9                              # reduction candidate for 3,5
D4: 3,5 => CTR
* 1.5...987.4..57..1..7......2...48...79.1.....6..29.7..37.6.52..5....9.7.4..7..5..
D4: 7,9 => SOLVED
* 135426987846957321927381465213748659598163742674295813351674298482539176769812534
F5: 3,5,6                                # reduction candidate for 3,5
F5: 3,5 => SOLVED
* 135426987846957321927381465213748659598163742674295813351674298482539176769812534
F5: 6                                    # 10 pairs
* PAIR F6: 3,5 ROW 6
B6: 3,5,1,7,8                            # reduction candidate for 3,5
B6: 3,5                                  # 11 pairs
H6: 3,5,1,4,9                            # reduction candidate for 3,5
H6: 3,5                                  # 11 pairs
I6: 3,5,4,8,9                            # reduction candidate for 3,5
I6: 3,5                                  # 11 pairs
* PAIR A8: 4,5 ROW 8
D8: 4,5,3,8                              # reduction candidate for 4,5
D8: 3,8 => CTR
* 1.5...987.4..57..1..7......2..548....9.1.....6..293...3..6.52.......9.7....7.45..
D8: 4,5                                  # 10 pairs
* PAIR A8: 4,5 COL A
A5: 4,5,7                                # reduction candidate for 4,5
A5: 4,5 => SOLVED
* 135426987846957321927381465213748659598163742674295813351674298482539176769812534
A5: 7 => CTR
* 1.5...987.4..57..1..7......2..5487..79.1.....65.2.....3..6..2..5....9.7.4.....5..
* PAIR A9: 4,7 ROW 9
D9: 4,7,3,8                              # reduction candidate for 4,7
D9: 3,8 => SOLVED
* 135426987846957321927381465213748659598163742674295813351674298482539176769812534
D9: 4,7                                  # 10 pairs
* PAIR A9: 4,7 COL A
A5: 4,7,5                                # reduction candidate for 4,7
A5: 4,7 => CTR
* 1.5...987.4..57..1..7......27.548...49.1.....65.2937..3..6.52..5....9.7....7..5..
A5: 5 => SOLVED
* 135426987846957321927381465213748659598163742674295813351674298482539176769812534
* INCONCLUSIVE
* SAVE PR GRAPH xx-top95-013-base-pr-000.dot
* REASONING
* DIS # D8: 3,4 => CTR => D8: 5,8
* DIS # D9: 3,4 => CTR => D9: 7,8
* DIS # D4: 3,5 => CTR => D4: 7,9
* PRF # D4: 7,9 => SOL
* PRF # F5: 3,5 => SOL
* DIS # D8: 3,8 => CTR => D8: 4,5
* PRF # A5: 4,5 => SOL
* DIS # A5: 7 => CTR => A5: 4,5
* PRF # D9: 3,8 => SOL
* DIS # A5: 4,7 => CTR => A5: 5
* PRF # A5: 5 => SOL
* CNT  11 HDP CHAINS /  38 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A2,A3,A8,A9,C4,D1,D2,F6,G2)
* 1.5...987.4..57..1..7......2...48....9.1.....6..2.....3..6..2.......9.7.......5..
* PAIR A3: 8,9 ROW 3
D3: 8,9,3                                # reduction candidate for 8,9
D3: 8,9                                  # 10 pairs
E3: 8,9,1,2,3,6                          # reduction candidate for 8,9
E3: 8,9                                  # 17 pairs
* PAIR D1: 3,4 BLK 2
F1: 3,4,2,6                              # reduction candidate for 3,4
F1: 3,4                                  # 13 pairs
F1: 2,6                                  #  9 pairs
* PAIR D1: 3,4 COL D
D8: 3,4,5,8                              # reduction candidate for 3,4
D8: 3,4 => CTR
* 1.5...987.4..57..1..7......2..548...79.16....6..293...3..6.52.......9.7....7..5..
D9: 3,4,7,8                              # reduction candidate for 3,4
D9: 3,4 => CTR
* 1.53.4987.4..57321.37...4..2..7486..5981..7..67429581335.67.2.84.25391767..482539
* PAIR RESTART
* PAIR D2: 8,9 BLK 2
D3: 8,9,3                                # reduction candidate for 8,9
D3: 8,9 => CTR
* 1.54..987.4..57..1..7......2..348....9.1.....6..295...35.67.2..4..5.9.7.7..8..5..
* RESTART
* PAIR G2: 3,6 BLK 3
H2: 3,6,2                                # reduction candidate for 3,6
H2: 3,6                                  # 17 pairs
H2: 2                                    # 14 pairs
* PAIR G2: 3,6 COL G
G4: 3,6,1,7                              # reduction candidate for 3,6
G4: 3,6                                  # 19 pairs
G8: 3,6,1,4,8                            # reduction candidate for 3,6
G8: 3,6                                  # 19 pairs
* PAIR C4: 1,3 BLK 4
C6: 1,3,4,8                              # reduction candidate for 1,3
C6: 1,3                                  # 20 pairs
C6: 4,8                                  # 18 pairs
* PAIR C4: 1,3 ROW 4
G4: 1,3,6,7                              # reduction candidate for 1,3
G4: 1,3                                  # 19 pairs
H4: 1,3,5,6,9                            # reduction candidate for 1,3
H4: 1,3                                  # 20 pairs
* PAIR F6: 3,5 BLK 5
F5: 3,5,6                                # reduction candidate for 3,5
F5: 3,5 => SOLVED
* 135426987846957321927381465213748659598163742674295813351674298482539176769812534
* DURATION: 0:00:13.777384  START: 23:08:10.587814  END: 23:08:24.365198 2017-05-03
* SOLUTION FOUND
* SAVE PR GRAPH xx-top95-013-base-pr-001.dot
* REASONING
* DIS # D8: 3,4 => CTR => D8: 5,8
* DIS D8: 5,8 # D9: 3,4 => CTR => D9: 7,8
* DIS D8: 5,8 + D9: 7,8 # D3: 8,9 => CTR => D3: 3
* PRF D8: 5,8 + D9: 7,8 + D3: 3 # F5: 3,5 => SOL
* STA D8: 5,8 + D9: 7,8 + D3: 3 + F5: 3,5
* CNT   4 HDP CHAINS /  16 HYP OPENED

Header Info

Top 95 Sudokus 013
[sudoku:top95] “95 Hard Puzzles”, http://magictour.free.fr/top95, or http://norvig.com/top95.txt

Solution

position: 135426987846957321927381465213748659598163742674295813351674298482539176769812534 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 # D3: 8,9 => UNS
* INC # E3: 8,9 => UNS
* INC # F1: 3,4 => UNS
* INC # F1: 2,6 => UNS
* DIS # D8: 3,4 => CTR => D8: 5,8
* INC # D8: 5,8 => UNS
* DIS # D9: 3,4 => CTR => D9: 7,8
* INC # D9: 7,8 => UNS
* INC # D3: 8,9 => UNS
* INC # E3: 8,9 => UNS
* INC # H2: 3,6 => UNS
* INC # G3: 3,6 => UNS
* INC # H3: 3,6 => UNS
* INC # I3: 3,6 => UNS
* INC # C2: 3,6 => UNS
* INC # C2: 2 => UNS
* INC # G4: 3,6 => UNS
* INC # G8: 3,6 => UNS
* INC # B4: 1,3 => UNS
* INC # B6: 1,3 => UNS
* INC # C6: 1,3 => UNS
* INC # G4: 1,3 => UNS
* INC # H4: 1,3 => UNS
* DIS # D4: 3,5 => CTR => D4: 7,9
* PRF # D4: 7,9 => SOL
* PRF # F5: 3,5 => SOL
* INC # F5: 6 => UNS
* INC # B6: 3,5 => UNS
* INC # H6: 3,5 => UNS
* INC # I6: 3,5 => UNS
* INC # D8: 4,5 => UNS
* DIS # D8: 3,8 => CTR => D8: 4,5
* PRF # A5: 4,5 => SOL
* DIS # A5: 7 => CTR => A5: 4,5
* INC # D9: 4,7 => UNS
* PRF # D9: 3,8 => SOL
* DIS # A5: 4,7 => CTR => A5: 5
* PRF # A5: 5 => SOL
* CNT  38 HDP CHAINS /  38 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # D3: 8,9 => UNS
* INC # E3: 8,9 => UNS
* INC # F1: 3,4 => UNS
* INC # F1: 2,6 => UNS
* DIS # D8: 3,4 => CTR => D8: 5,8
* DIS D8: 5,8 # D9: 3,4 => CTR => D9: 7,8
* DIS D8: 5,8 + D9: 7,8 # D3: 8,9 => CTR => D3: 3
* INC D8: 5,8 + D9: 7,8 + D3: 3 # H2: 3,6 => UNS
* INC D8: 5,8 + D9: 7,8 + D3: 3 # H2: 2 => UNS
* INC D8: 5,8 + D9: 7,8 + D3: 3 # G4: 3,6 => UNS
* INC D8: 5,8 + D9: 7,8 + D3: 3 # G8: 3,6 => UNS
* INC D8: 5,8 + D9: 7,8 + D3: 3 # C6: 1,3 => UNS
* INC D8: 5,8 + D9: 7,8 + D3: 3 # C6: 4,8 => UNS
* INC D8: 5,8 + D9: 7,8 + D3: 3 # G4: 1,3 => UNS
* INC D8: 5,8 + D9: 7,8 + D3: 3 # H4: 1,3 => UNS
* PRF D8: 5,8 + D9: 7,8 + D3: 3 # F5: 3,5 => SOL
* STA D8: 5,8 + D9: 7,8 + D3: 3 + F5: 3,5
* CNT  16 HDP CHAINS /  16 HYP OPENED