Analysis of xx-top95-038-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 1....6.8..64..........4...7....9.6...7.4..5..5...7.1...5....32.3....8...4........ initial

Autosolve

position: 1....648..64..........4..67....9.67..7.4..5..5...7.1...5...432.3....87..4.....8.. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # C1: 3,5 => CTR => C1: 2,7,9
* DIS # D1: 3,5 => CTR => D1: 2,7,9
* PRF # A2: 2,9 => SOL
* DIS # F2: 2,9 => CTR => F2: 3,5,7
* DIS # C3: 2,9 => CTR => C3: 3,5,8
* DIS # A5: 2,8 => CTR => A5: 6,9
* DIS # A2: 2,8 => CTR => A2: 7,9
* DIS # D6: 2,3 => CTR => D6: 6,8
* DIS # F2: 2,3 => CTR => F2: 5,7,9
* DIS # F9: 2,3 => CTR => F9: 1,5,7,9
* PRF # D7: 1,6 => SOL
* DIS # C7: 1,6 => CTR => C7: 7,8,9
* CNT  12 HDP CHAINS /  60 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 # C1: 3,5 => CTR => C1: 2,7,9
* DIS C1: 2,7,9 # D1: 3,5 => CTR => D1: 2,7,9
* PRF C1: 2,7,9 + D1: 2,7,9 # A2: 2,9 => SOL
* STA C1: 2,7,9 + D1: 2,7,9 + A2: 2,9
* CNT   3 HDP CHAINS /  12 HYP OPENED

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

Details

Positions

1....6.8..64..........4...7....9.6...7.4..5..5...7.1...5....32.3....8...4........ initial
1....648..64..........4..67....9.67..7.4..5..5...7.1...5...432.3....87..4.....8.. autosolve
137926485964587231825341967241895673673412598589673142758164329396258714412739856 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (7)
I1: 3,5
G2: 2,9
G3: 2,9
A4: 2,8
F6: 2,3
H5: 3,9
E7: 1,6

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
D3,F3: 1.. / D3 = 1  =>  7 pairs (_) / F3 = 1  => 12 pairs (_)
H2,I2: 1.. / H2 = 1  =>  9 pairs (_) / I2 = 1  =>  9 pairs (_)
G2,G3: 2.. / G2 = 2  => 11 pairs (_) / G3 = 2  =>  6 pairs (_)
B4,B6: 4.. / B4 = 4  =>  7 pairs (_) / B6 = 4  => 12 pairs (_)
H8,I8: 4.. / H8 = 4  => 11 pairs (_) / I8 = 4  =>  7 pairs (_)
B4,I4: 4.. / B4 = 4  =>  7 pairs (_) / I4 = 4  => 12 pairs (_)
H6,H8: 4.. / H6 = 4  =>  7 pairs (_) / H8 = 4  => 11 pairs (_)
C1,C3: 5.. / C1 = 5  =>  0 pairs (X) / C3 = 5  =>  7 pairs (_)
D4,F4: 5.. / D4 = 5  => 12 pairs (_) / F4 = 5  =>  7 pairs (_)
E5,D6: 6.. / E5 = 6  =>  0 pairs (X) / D6 = 6  =>  7 pairs (_)
C6,D6: 6.. / C6 = 6  =>  0 pairs (X) / D6 = 6  =>  7 pairs (_)
A5,A7: 6.. / A5 = 6  =>  7 pairs (_) / A7 = 6  =>  0 pairs (X)
C1,A2: 7.. / C1 = 7  =>  0 pairs (*) / A2 = 7  =>  0 pairs (X)
C1,D1: 7.. / C1 = 7  =>  0 pairs (*) / D1 = 7  =>  0 pairs (X)
A2,A7: 7.. / A2 = 7  =>  0 pairs (X) / A7 = 7  =>  0 pairs (_)
F2,F9: 7.. / F2 = 7  =>  0 pairs (*) / F9 = 7  =>  0 pairs (X)
A7,C7: 8.. / A7 = 8  =>  0 pairs (X) / C7 = 8  =>  7 pairs (_)
E2,E5: 8.. / E2 = 8  =>  7 pairs (_) / E5 = 8  =>  8 pairs (_)
G2,G3: 9.. / G2 = 9  =>  6 pairs (_) / G3 = 9  => 11 pairs (_)
* DURATION: 0:00:22.346687  START: 23:32:34.976692  END: 23:32:57.323379 2017-05-03
* CP COUNT: (19)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A4,E7,F6,G2,G3,H5,I1)
* 1....648..64..........4..67....9.67..7.4..5..5...7.1...5...432.3....87..4.....8..
* PAIR I1: 3,5 BLK 3
H2: 3,5,1                                # reduction candidate for 3,5
H2: 3,5                                  #  9 pairs
I2: 3,5,1                                # reduction candidate for 3,5
I2: 3,5                                  #  9 pairs
* PAIR I1: 3,5 ROW 1
C1: 3,5,2,7,9                            # reduction candidate for 3,5
C1: 3,5 => CTR
* 19.72648.764...2......4.967....9.67..7.4..5..5...7.1..857..432.3....87..4....78..
C1: 2,7,9                                #  7 pairs
D1: 3,5,2,7,9                            # reduction candidate for 3,5
D1: 3,5 => CTR
* 197.2648..64.......35.4..67....9.67..7.4..5..5...7.1..758..432.3....87..4.....8..
D1: 2,7,9                                #  7 pairs
E1: 3,5,2                                # reduction candidate for 3,5
E1: 3,5                                  # 14 pairs
* PAIR G2: 2,9 ROW 2
A2: 2,9,7,8                              # reduction candidate for 2,9
A2: 2,9 => SOLVED
* 137926485964587231825341967241895673673412598589673142758164329396258714412739856
A2: 7,8                                  #  8 pairs
D2: 2,9,3,5,7,8                          # reduction candidate for 2,9
D2: 2,9                                  #  9 pairs
F2: 2,9,3,5,7                            # reduction candidate for 2,9
F2: 2,9 => CTR
* 1....648..64..........4..67....9.67..7.4..5..5...7.1...5...432.3....87..4....78..
F2: 3,5,7                                #  7 pairs
* PAIR G3: 2,9 ROW 3
A3: 2,9,8                                # reduction candidate for 2,9
A3: 2,9                                  # 11 pairs
B3: 2,9,3,8                              # reduction candidate for 2,9
B3: 2,9                                  # 22 pairs
C3: 2,9,3,5,8                            # reduction candidate for 2,9
C3: 2,9 => CTR
* 195726483764...2..832.4.9672...9.67..7.4..5..5...7.1...57..432.3....87..4....78..
C3: 3,5,8                                #  7 pairs
D3: 2,9,1,3,5,8                          # reduction candidate for 2,9
D3: 2,9                                  # 17 pairs
F3: 2,9,1,3,5                            # reduction candidate for 2,9
F3: 2,9                                  # 15 pairs
* PAIR A4: 2,8 BLK 4
B4: 2,8,1,3,4                            # reduction candidate for 2,8
B4: 2,8                                  # 17 pairs
C4: 2,8,1,3                              # reduction candidate for 2,8
C4: 2,8                                  # 19 pairs
A5: 2,8,6,9                              # reduction candidate for 2,8
A5: 2,8 => CTR
* 1....648..64..........4..67....9.67..7.4..5..5...7.1..6587143293....87..4.7...8..
A5: 6,9                                  #  8 pairs
C5: 2,8,1,3,6,9                          # reduction candidate for 2,8
C5: 2,8                                  # 14 pairs
B6: 2,8,3,4,9                            # reduction candidate for 2,8
B6: 2,8                                  # 10 pairs
C6: 2,8,3,6,9                            # reduction candidate for 2,8
C6: 2,8                                  # 14 pairs
* PAIR A4: 2,8 ROW 4
D4: 2,8,1,3,5                            # reduction candidate for 2,8
D4: 2,8                                  # 13 pairs
I4: 2,8,3,4                              # reduction candidate for 2,8
I4: 2,8                                  # 11 pairs
* PAIR A4: 2,8 COL A
A2: 2,8,7,9                              # reduction candidate for 2,8
A2: 2,8 => CTR
* 1.79.648.864..79..93584126724139567.67.41.5.858.67.1..75816432939...87..4..7398..
A2: 7,9                                  #  8 pairs
A3: 2,8,9                                # reduction candidate for 2,8
A3: 2,8                                  # 10 pairs
* PAIR F6: 2,3 BLK 5
D4: 2,3,1,5,8                            # reduction candidate for 2,3
D4: 2,3                                  # 10 pairs
F4: 2,3,1,5                              # reduction candidate for 2,3
F4: 2,3                                  # 13 pairs
E5: 2,3,1,6,8                            # reduction candidate for 2,3
E5: 2,3                                  # 15 pairs
F5: 2,3,1                                # reduction candidate for 2,3
F5: 2,3                                  # 10 pairs
D6: 2,3,6,8                              # reduction candidate for 2,3
D6: 2,3 => CTR
* 1....648..64..........4..67....9.67..7.46.5..5.6.7.1..6587143293....87..4.7...8..
D6: 6,8                                  #  8 pairs
* PAIR F6: 2,3 ROW 6
B6: 2,3,4,8,9                            # reduction candidate for 2,3
B6: 2,3                                  # 14 pairs
C6: 2,3,6,8,9                            # reduction candidate for 2,3
C6: 2,3                                  #  9 pairs
I6: 2,3,4,8,9                            # reduction candidate for 2,3
I6: 2,3                                  # 10 pairs
* PAIR F6: 2,3 COL F
F2: 2,3,5,7,9                            # reduction candidate for 2,3
F2: 2,3 => CTR
* 1.7..648..64...9..8351492672...9567..7.4.15..5...7.1...58..432.3....87..4....78..
F2: 5,7,9                                #  7 pairs
F3: 2,3,1,5,9                            # reduction candidate for 2,3
F3: 2,3                                  # 10 pairs
F9: 2,3,1,5,7,9                          # reduction candidate for 2,3
F9: 2,3 => CTR
* 1.7..648..64..79..8...49267....9567..7.4.15..5...7.1..758..432.3....87..4..7..8..
F9: 1,5,7,9                              #  7 pairs
* PAIR H5: 3,9 BLK 6
I5: 3,9,2,8                              # reduction candidate for 3,9
I5: 3,9                                  # 14 pairs
H6: 3,9,4                                # reduction candidate for 3,9
H6: 3,9                                  # 11 pairs
I6: 3,9,2,4,8                            # reduction candidate for 3,9
I6: 3,9                                  # 13 pairs
* PAIR H5: 3,9 ROW 5
C5: 3,9,1,2,6,8                          # reduction candidate for 3,9
C5: 3,9                                  # 10 pairs
C5: 1,2,6,8                              #  7 pairs
* PAIR E7: 1,6 BLK 8
D7: 1,6,7,9                              # reduction candidate for 1,6
D7: 1,6 => SOLVED
* 137926485964587231825341967241895673673412598589673142758164329396258714412739856
D7: 7,9                                  #  8 pairs
D8: 1,6,2,5,9                            # reduction candidate for 1,6
D8: 1,6                                  # 11 pairs
E8: 1,6,2,5                              # reduction candidate for 1,6
E8: 1,6                                  #  9 pairs
D9: 1,6,2,3,5,7,9                        # reduction candidate for 1,6
D9: 1,6                                  # 11 pairs
E9: 1,6,2,3,5                            # reduction candidate for 1,6
E9: 1,6                                  # 10 pairs
* PAIR E7: 1,6 ROW 7
C7: 1,6,7,8,9                            # reduction candidate for 1,6
C7: 1,6 => CTR
* 1....648..64..........4..67....9.67..7.4..5..5...7.1..85.7.43293....87..4.7...8..
C7: 7,8,9                                #  7 pairs
I7: 1,6,9                                # reduction candidate for 1,6
I7: 1,6                                  #  9 pairs
* PAIR E7: 1,6 COL E
E5: 1,6,2,3,8                            # reduction candidate for 1,6
E5: 1,6                                  #  9 pairs
E5: 2,3,8                                #  8 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top95-038-base-pr-000.dot
* REASONING
* DIS # C1: 3,5 => CTR => C1: 2,7,9
* DIS # D1: 3,5 => CTR => D1: 2,7,9
* PRF # A2: 2,9 => SOL
* DIS # F2: 2,9 => CTR => F2: 3,5,7
* DIS # C3: 2,9 => CTR => C3: 3,5,8
* DIS # A5: 2,8 => CTR => A5: 6,9
* DIS # A2: 2,8 => CTR => A2: 7,9
* DIS # D6: 2,3 => CTR => D6: 6,8
* DIS # F2: 2,3 => CTR => F2: 5,7,9
* DIS # F9: 2,3 => CTR => F9: 1,5,7,9
* PRF # D7: 1,6 => SOL
* DIS # C7: 1,6 => CTR => C7: 7,8,9
* CNT  12 HDP CHAINS /  60 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A4,E7,F6,G2,G3,H5,I1)
* 1....648..64..........4..67....9.67..7.4..5..5...7.1...5...432.3....87..4.....8..
* PAIR I1: 3,5 BLK 3
H2: 3,5,1                                # reduction candidate for 3,5
H2: 3,5                                  #  9 pairs
I2: 3,5,1                                # reduction candidate for 3,5
I2: 3,5                                  #  9 pairs
* PAIR I1: 3,5 ROW 1
C1: 3,5,2,7,9                            # reduction candidate for 3,5
C1: 3,5 => CTR
* 19.72648.764...2......4.967....9.67..7.4..5..5...7.1..857..432.3....87..4....78..
D1: 3,5,2,7,9                            # reduction candidate for 3,5
D1: 3,5 => CTR
* 197.2648..64.......35.4..67....9.67..7.4..5..5...7.1..758..432.3....87..4.....8..
E1: 3,5,2                                # reduction candidate for 3,5
E1: 3,5                                  # 14 pairs
* RESTART
* PAIR I1: 3,5 ROW 1
E1: 3,5,2                                # reduction candidate for 3,5
E1: 2                                    # 16 pairs
E1: 3,5                                  # 14 pairs
* PAIR RESTART
* PAIR I1: 3,5 BLK 3
H2: 3,5,1                                # reduction candidate for 3,5
H2: 3,5                                  #  9 pairs
I2: 3,5,1                                # reduction candidate for 3,5
I2: 3,5                                  #  9 pairs
* PAIR I1: 3,5 ROW 1
E1: 3,5,2                                # reduction candidate for 3,5
E1: 2                                    # 16 pairs
E1: 3,5                                  # 14 pairs
* PAIR G2: 2,9 ROW 2
A2: 2,9,7,8                              # reduction candidate for 2,9
A2: 2,9 => SOLVED
* 137926485964587231825341967241895673673412598589673142758164329396258714412739856
* DURATION: 0:00:10.323933  START: 23:33:37.344789  END: 23:33:47.668722 2017-05-03
* SOLUTION FOUND
* SAVE PR GRAPH xx-top95-038-base-pr-001.dot
* REASONING
* DIS # C1: 3,5 => CTR => C1: 2,7,9
* DIS C1: 2,7,9 # D1: 3,5 => CTR => D1: 2,7,9
* PRF C1: 2,7,9 + D1: 2,7,9 # A2: 2,9 => SOL
* STA C1: 2,7,9 + D1: 2,7,9 + A2: 2,9
* CNT   3 HDP CHAINS /  12 HYP OPENED

Header Info

Top 95 Sudokus 038
[sudoku:top95] “95 Hard Puzzles”, http://magictour.free.fr/top95, or http://norvig.com/top95.txt

Solution

position: 137926485964587231825341967241895673673412598589673142758164329396258714412739856 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 # H2: 3,5 => UNS
* INC # I2: 3,5 => UNS
* DIS # C1: 3,5 => CTR => C1: 2,7,9
* INC # C1: 2,7,9 => UNS
* DIS # D1: 3,5 => CTR => D1: 2,7,9
* INC # D1: 2,7,9 => UNS
* INC # E1: 3,5 => UNS
* PRF # A2: 2,9 => SOL
* INC # A2: 7,8 => UNS
* INC # D2: 2,9 => UNS
* DIS # F2: 2,9 => CTR => F2: 3,5,7
* INC # F2: 3,5,7 => UNS
* INC # A3: 2,9 => UNS
* INC # B3: 2,9 => UNS
* DIS # C3: 2,9 => CTR => C3: 3,5,8
* INC # C3: 3,5,8 => UNS
* INC # D3: 2,9 => UNS
* INC # F3: 2,9 => UNS
* INC # B4: 2,8 => UNS
* INC # C4: 2,8 => UNS
* DIS # A5: 2,8 => CTR => A5: 6,9
* INC # A5: 6,9 => UNS
* INC # C5: 2,8 => UNS
* INC # B6: 2,8 => UNS
* INC # C6: 2,8 => UNS
* INC # D4: 2,8 => UNS
* INC # I4: 2,8 => UNS
* DIS # A2: 2,8 => CTR => A2: 7,9
* INC # A2: 7,9 => UNS
* INC # A3: 2,8 => UNS
* INC # D4: 2,3 => UNS
* INC # F4: 2,3 => UNS
* INC # E5: 2,3 => UNS
* INC # F5: 2,3 => UNS
* DIS # D6: 2,3 => CTR => D6: 6,8
* INC # D6: 6,8 => UNS
* INC # B6: 2,3 => UNS
* INC # C6: 2,3 => UNS
* INC # I6: 2,3 => UNS
* DIS # F2: 2,3 => CTR => F2: 5,7,9
* INC # F2: 5,7,9 => UNS
* INC # F3: 2,3 => UNS
* DIS # F9: 2,3 => CTR => F9: 1,5,7,9
* INC # F9: 1,5,7,9 => UNS
* INC # I5: 3,9 => UNS
* INC # H6: 3,9 => UNS
* INC # I6: 3,9 => UNS
* INC # C5: 3,9 => UNS
* INC # C5: 1,2,6,8 => UNS
* PRF # D7: 1,6 => SOL
* INC # D7: 7,9 => UNS
* INC # D8: 1,6 => UNS
* INC # E8: 1,6 => UNS
* INC # D9: 1,6 => UNS
* INC # E9: 1,6 => UNS
* DIS # C7: 1,6 => CTR => C7: 7,8,9
* INC # C7: 7,8,9 => UNS
* INC # I7: 1,6 => UNS
* INC # E5: 1,6 => UNS
* INC # E5: 2,3,8 => UNS
* CNT  60 HDP CHAINS /  60 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # H2: 3,5 => UNS
* INC # I2: 3,5 => UNS
* DIS # C1: 3,5 => CTR => C1: 2,7,9
* DIS C1: 2,7,9 # D1: 3,5 => CTR => D1: 2,7,9
* INC C1: 2,7,9 + D1: 2,7,9 # E1: 3,5 => UNS
* INC C1: 2,7,9 + D1: 2,7,9 # E1: 3,5 => UNS
* INC C1: 2,7,9 + D1: 2,7,9 # E1: 2 => UNS
* INC C1: 2,7,9 + D1: 2,7,9 # H2: 3,5 => UNS
* INC C1: 2,7,9 + D1: 2,7,9 # I2: 3,5 => UNS
* INC C1: 2,7,9 + D1: 2,7,9 # E1: 3,5 => UNS
* INC C1: 2,7,9 + D1: 2,7,9 # E1: 2 => UNS
* PRF C1: 2,7,9 + D1: 2,7,9 # A2: 2,9 => SOL
* STA C1: 2,7,9 + D1: 2,7,9 + A2: 2,9
* CNT  12 HDP CHAINS /  12 HYP OPENED