Analysis of xx-top95-012-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: .6.5.1.9.1...9..539....7....4.8...7.......5.8.817.5.3.....5.2............76..8... initial

Autosolve

position: .6.5.1.9.12..9..539....7....4.8...7.......5.8.817.5.3.....5.2.7....7.....76..8... autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # C3: 3,5 => CTR => C3: 4,8
* DIS # E3: 2,3 => CTR => E3: 8
* DIS # I3: 2,4 => CTR => I3: 1,6
* DIS # G1: 4 => CTR => G1: 7,8
* DIS # I6: 2,6 => CTR => I6: 4,9
* PRF # H5: 1,6 => SOL
* DIS # E4: 1,6 => CTR => E4: 2,3
* DIS # G8: 1,6 => CTR => G8: 3,4,8,9
* DIS # G9: 1,4 => CTR => G9: 3,9
* DIS # I9: 1,4 => CTR => I9: 5,9
* DIS # D9: 1,4 => CTR => D9: 2,3,9
* DIS # H3: 1,4 => CTR => H3: 2,6,8
* CNT  12 HDP CHAINS /  56 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 # C3: 3,5 => CTR => C3: 4,8
* DIS C3: 4,8 # E3: 2,3 => CTR => E3: 8
* DIS C3: 4,8 + E3: 8 # C4: 3,9 => CTR => C4: 2,5
* DIS C3: 4,8 + E3: 8 + C4: 2,5 # I6: 2,6 => CTR => I6: 9
* PRF C3: 4,8 + E3: 8 + C4: 2,5 + I6: 9 => SOL
* STA C3: 4,8 + E3: 8 + C4: 2,5 + I6: 9
* CNT   5 HDP CHAINS /  17 HYP OPENED

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

Details

Positions

.6.5.1.9.1...9..539....7....4.8...7.......5.8.817.5.3.....5.2............76..8... initial
.6.5.1.9.12..9..539....7....4.8...7.......5.8.817.5.3.....5.2.7....7.....76..8... autosolve
863521794127496853954387621645839172739142568281765439498653217512974386376218945 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (11)
C2: 7,8
B3: 3,5
D2: 4,6
F2: 4,6
D3: 2,3
I1: 2,4
G2: 7,8
B5: 3,9
A6: 2,6
G4: 1,6
H9: 1,4

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
B7,B8: 1.. / B7 = 1  => 11 pairs (_) / B8 = 1  => 11 pairs (_)
E1,I1: 2.. / E1 = 2  => 12 pairs (_) / I1 = 2  =>  0 pairs (X)
H3,H5: 2.. / H3 = 2  => 13 pairs (_) / H5 = 2  =>  0 pairs (X)
G8,G9: 3.. / G8 = 3  => 11 pairs (_) / G9 = 3  => 11 pairs (_)
D2,F2: 4.. / D2 = 4  =>  9 pairs (_) / F2 = 4  =>  9 pairs (_)
B3,C3: 5.. / B3 = 5  => 10 pairs (_) / C3 = 5  =>  0 pairs (X)
A4,C4: 5.. / A4 = 5  => 11 pairs (_) / C4 = 5  => 10 pairs (_)
I8,I9: 5.. / I8 = 5  =>  0 pairs (X) / I9 = 5  => 11 pairs (_)
A9,I9: 5.. / A9 = 5  =>  0 pairs (X) / I9 = 5  => 11 pairs (_)
B3,B8: 5.. / B3 = 5  => 10 pairs (_) / B8 = 5  =>  0 pairs (X)
D2,F2: 6.. / D2 = 6  =>  9 pairs (_) / F2 = 6  =>  9 pairs (_)
G1,G2: 7.. / G1 = 7  =>  9 pairs (_) / G2 = 7  => 10 pairs (_)
A5,C5: 7.. / A5 = 7  => 11 pairs (_) / C5 = 7  => 12 pairs (_)
C2,G2: 7.. / C2 = 7  =>  9 pairs (_) / G2 = 7  => 10 pairs (_)
A1,A5: 7.. / A1 = 7  => 12 pairs (_) / A5 = 7  => 11 pairs (_)
E1,E3: 8.. / E1 = 8  =>  0 pairs (X) / E3 = 8  => 13 pairs (_)
C2,G2: 8.. / C2 = 8  => 10 pairs (_) / G2 = 8  =>  9 pairs (_)
G6,I6: 9.. / G6 = 9  => 13 pairs (_) / I6 = 9  => 14 pairs (_)
C4,F4: 9.. / C4 = 9  =>  0 pairs (X) / F4 = 9  => 11 pairs (_)
* DURATION: 0:00:23.654789  START: 23:05:33.591546  END: 23:05:57.246335 2017-05-03
* CP COUNT: (19)
* CLUE FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A6,B3,B5,C2,D2,D3,F2,G2,G4,H9,I1)
* .6.5.1.9.12..9..539....7....4.8...7.......5.8.817.5.3.....5.2.7....7.....76..8...
* PAIR C2: 7,8 BLK 1
A1: 7,8,3,4                              # reduction candidate for 7,8
A1: 7,8                                  # 13 pairs
C1: 7,8,3,4                              # reduction candidate for 7,8
C1: 7,8                                  # 13 pairs
* PAIR B3: 3,5 BLK 1
C3: 3,5,4,8                              # reduction candidate for 3,5
C3: 3,5 => CTR
* .6.531.9212..9..539..287....4.82..7.6.7...528281765.3.....5.2.7..2.7.....76..8...
C3: 4,8                                  # 12 pairs
* PAIR B3: 3,5 COL B
B8: 3,5,1,9                              # reduction candidate for 3,5
B8: 3,5                                  # 11 pairs
B8: 1,9                                  # 11 pairs
* PAIR D2: 4,6 COL D
D7: 4,6,1,3,9                            # reduction candidate for 4,6
D7: 4,6                                  # 12 pairs
D8: 4,6,1,2,3,9                          # reduction candidate for 4,6
D8: 4,6                                  # 12 pairs
* PAIR F2: 4,6 COL F
F7: 4,6,3,9                              # reduction candidate for 4,6
F7: 4,6                                  # 12 pairs
F8: 4,6,2,3,9                            # reduction candidate for 4,6
F8: 4,6                                  # 14 pairs
* PAIR D3: 2,3 BLK 2
E1: 2,3,8                                # reduction candidate for 2,3
E1: 2,3                                  # 13 pairs
E3: 2,3,8                                # reduction candidate for 2,3
E3: 2,3 => CTR
* .6.581.9212..9..5395...7....4.8.9.7.6.7...528281765.3...9.5.2.7..2.7.....762.8...
E3: 8                                    # 13 pairs
* PAIR D3: 2,3 COL D
D5: 2,3,1,4,9                            # reduction candidate for 2,3
D5: 2,3                                  # 12 pairs
D8: 2,3,1,4,6,9                          # reduction candidate for 2,3
D8: 2,3                                  # 12 pairs
D9: 2,3,1,4,9                            # reduction candidate for 2,3
D9: 2,3                                  # 12 pairs
* PAIR I1: 2,4 BLK 3
H3: 2,4,1,6,8                            # reduction candidate for 2,4
H3: 2,4                                  # 16 pairs
I3: 2,4,1,6                              # reduction candidate for 2,4
I3: 2,4 => CTR
* 763521894128.9.753954387..2.4.832.7.637...528281765439....5.2.7..2.7.3..3762.89.5
I3: 1,6                                  # 12 pairs
* PAIR I1: 2,4 COL I
I6: 2,4,6,9                              # reduction candidate for 2,4
I6: 2,4                                  # 22 pairs
I6: 6,9                                  # 12 pairs
* PAIR G2: 7,8 BLK 3
G1: 7,8,4                                # reduction candidate for 7,8
G1: 4 => CTR
* .6.581492128.9.753954..7....4.8.9.7.6.7...528281765934..9.5.2.7..2.7.....762.83.9
G1: 7,8                                  # 12 pairs
* PAIR B5: 3,9 BLK 4
C4: 3,9,2,5                              # reduction candidate for 3,9
C4: 3,9                                  # 13 pairs
C5: 3,9,2,7                              # reduction candidate for 3,9
C5: 3,9                                  # 23 pairs
* PAIR B5: 3,9 ROW 5
D5: 3,9,1,2,4                            # reduction candidate for 3,9
D5: 3,9                                  # 15 pairs
F5: 3,9,2,4                              # reduction candidate for 3,9
F5: 3,9                                  # 14 pairs
* PAIR B5: 3,9 COL B
B7: 3,9,1                                # reduction candidate for 3,9
B7: 3,9                                  # 11 pairs
B8: 3,9,1,5                              # reduction candidate for 3,9
B8: 3,9                                  # 11 pairs
* PAIR A6: 2,6 BLK 4
A4: 2,6,3,5                              # reduction candidate for 2,6
A4: 2,6                                  # 23 pairs
A5: 2,6,3,7                              # reduction candidate for 2,6
A5: 2,6                                  # 15 pairs
* PAIR A6: 2,6 ROW 6
E6: 2,6,4                                # reduction candidate for 2,6
E6: 2,6                                  # 14 pairs
I6: 2,6,4,9                              # reduction candidate for 2,6
I6: 2,6 => CTR
* 763521894128.9.7539543876213458691726.7.1.548281745936....5.2.7..2.7.3..576238419
I6: 4,9                                  # 12 pairs
* PAIR G4: 1,6 BLK 6
I4: 1,6,2                                # reduction candidate for 1,6
I4: 1,6                                  # 19 pairs
H5: 1,6,2,4                              # reduction candidate for 1,6
H5: 1,6 => SOLVED
* 863521794127496853954387621645839172739142568281765439498653217512974386376218945
H5: 2,4                                  # 12 pairs
* PAIR G4: 1,6 ROW 4
E4: 1,6,2,3                              # reduction candidate for 1,6
E4: 1,6 => CTR
* 763521894128.9.753954387.2.3458.9.72697.325.82817.5936..9.5.2.7..297.4.55762483.9
E4: 2,3                                  # 16 pairs
* PAIR G4: 1,6 COL G
G3: 1,6,4,8                              # reduction candidate for 1,6
G3: 1,6                                  # 13 pairs
G8: 1,6,3,4,8,9                          # reduction candidate for 1,6
G8: 1,6 => CTR
* 76.5.1.92128.9.7539..3278...4.832.7.637...528281765934....5.2.7..2.7...55762.83.9
G8: 3,4,8,9                              # 11 pairs
* PAIR H9: 1,4 BLK 9
H7: 1,4,6,8                              # reduction candidate for 1,4
H7: 1,4                                  # 21 pairs
G8: 1,4,3,6,8,9                          # reduction candidate for 1,4
G8: 1,4                                  # 16 pairs
H8: 1,4,6,8                              # reduction candidate for 1,4
H8: 1,4                                  # 21 pairs
I8: 1,4,5,6,9                            # reduction candidate for 1,4
I8: 1,4                                  # 17 pairs
G9: 1,4,3,9                              # reduction candidate for 1,4
G9: 1,4 => CTR
* 76.521894128.9.7539.4387621.45869172697...5.82817.5936....5.2.7..2.7.3...76..8...
G9: 3,9                                  # 12 pairs
I9: 1,4,5,9                              # reduction candidate for 1,4
I9: 1,4 => CTR
* .6.521.9412..9..53954387.26.458.9.72.....25.82817.5.39....5.2.7..2.7.3.5576238941
I9: 5,9                                  # 12 pairs
* PAIR H9: 1,4 ROW 9
D9: 1,4,2,3,9                            # reduction candidate for 1,4
D9: 1,4 => CTR
* 76.5.1.9.128.9.7539....7.2..4.8...726.7...5.82817.5.3.....5.2.7..2.7.....76.28...
D9: 2,3,9                                # 11 pairs
E9: 1,4,2,3                              # reduction candidate for 1,4
E9: 1,4                                  # 14 pairs
* PAIR H9: 1,4 COL H
H3: 1,4,2,6,8                            # reduction candidate for 1,4
H3: 1,4 => CTR
* 7635.1.9.128.9.7539543.7....4.832.7.637...528281765.3.....5.2.7..2.7.....762.8...
H3: 2,6,8                                # 11 pairs
H5: 1,4,2,6                              # reduction candidate for 1,4
H5: 1,4                                  # 16 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top95-012-base-pr-000.dot
* REASONING
* DIS # C3: 3,5 => CTR => C3: 4,8
* DIS # E3: 2,3 => CTR => E3: 8
* DIS # I3: 2,4 => CTR => I3: 1,6
* DIS # G1: 4 => CTR => G1: 7,8
* DIS # I6: 2,6 => CTR => I6: 4,9
* PRF # H5: 1,6 => SOL
* DIS # E4: 1,6 => CTR => E4: 2,3
* DIS # G8: 1,6 => CTR => G8: 3,4,8,9
* DIS # G9: 1,4 => CTR => G9: 3,9
* DIS # I9: 1,4 => CTR => I9: 5,9
* DIS # D9: 1,4 => CTR => D9: 2,3,9
* DIS # H3: 1,4 => CTR => H3: 2,6,8
* CNT  12 HDP CHAINS /  56 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A6,B3,B5,C2,D2,D3,F2,G2,G4,H9,I1)
* .6.5.1.9.12..9..539....7....4.8...7.......5.8.817.5.3.....5.2.7....7.....76..8...
* PAIR C2: 7,8 BLK 1
A1: 7,8,3,4                              # reduction candidate for 7,8
A1: 7,8                                  # 13 pairs
C1: 7,8,3,4                              # reduction candidate for 7,8
C1: 7,8                                  # 13 pairs
* PAIR B3: 3,5 BLK 1
C3: 3,5,4,8                              # reduction candidate for 3,5
C3: 3,5 => CTR
* .6.531.9212..9..539..287....4.82..7.6.7...528281765.3.....5.2.7..2.7.....76..8...
* PAIR D2: 4,6 COL D
D7: 4,6,1,3,9                            # reduction candidate for 4,6
D7: 4,6                                  # 13 pairs
D8: 4,6,1,2,3,9                          # reduction candidate for 4,6
D8: 4,6                                  # 13 pairs
* PAIR F2: 4,6 COL F
F7: 4,6,3,9                              # reduction candidate for 4,6
F7: 4,6                                  # 13 pairs
F8: 4,6,2,3,9                            # reduction candidate for 4,6
F8: 4,6                                  # 15 pairs
* PAIR D3: 2,3 BLK 2
E3: 2,3,8                                # reduction candidate for 2,3
E3: 2,3 => CTR
* .6.581.9212..9..5395...7....4.8.9.7.6.7...528281765.3...9.5.2.7..2.7.....762.8...
* PAIR B5: 3,9 BLK 4
C4: 3,9,2,5                              # reduction candidate for 3,9
C4: 3,9 => CTR
* .6.521.9412..9..53954387.2.54.8.2.7.7.21.9548681745932.9..5.217..5.7...9.769.8..5
C5: 3,9,7                                # reduction candidate for 3,9
C5: 3,9                                  # 23 pairs
* RESTART
* PAIR B5: 3,9 BLK 4
C5: 3,9,7                                # reduction candidate for 3,9
C5: 3,9                                  # 23 pairs
C5: 7                                    # 15 pairs
* PAIR B5: 3,9 COL B
B7: 3,9,1                                # reduction candidate for 3,9
B7: 3,9                                  # 16 pairs
B8: 3,9,1                                # reduction candidate for 3,9
B8: 3,9                                  # 16 pairs
* PAIR A6: 2,6 BLK 4
A4: 2,6,3,5                              # reduction candidate for 2,6
A4: 2,6                                  # 23 pairs
A4: 3,5                                  # 16 pairs
* PAIR A6: 2,6 ROW 6
I6: 2,6,9                                # reduction candidate for 2,6
I6: 2,6 => CTR
* .6.521.9412..9..53954387.2.3458.9.72.97..3548281745936..9.5.2.7..2.7.3..576238419
I6: 9 => SOLVED
* 863521794127496853954387621645839172739142568281765439498653217512974386376218945
* DURATION: 0:00:19.078164  START: 23:06:38.828031  END: 23:06:57.906195 2017-05-03
* SOLUTION FOUND
* SAVE PR GRAPH xx-top95-012-base-pr-001.dot
* REASONING
* DIS # C3: 3,5 => CTR => C3: 4,8
* DIS C3: 4,8 # E3: 2,3 => CTR => E3: 8
* DIS C3: 4,8 + E3: 8 # C4: 3,9 => CTR => C4: 2,5
* DIS C3: 4,8 + E3: 8 + C4: 2,5 # I6: 2,6 => CTR => I6: 9
* PRF C3: 4,8 + E3: 8 + C4: 2,5 + I6: 9 => SOL
* STA C3: 4,8 + E3: 8 + C4: 2,5 + I6: 9
* CNT   5 HDP CHAINS /  17 HYP OPENED

Header Info

Top 95 Sudokus 012
[sudoku:top95] “95 Hard Puzzles”, http://magictour.free.fr/top95, or http://norvig.com/top95.txt

Solution

position: 863521794127496853954387621645839172739142568281765439498653217512974386376218945 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 # A1: 7,8 => UNS
* INC # C1: 7,8 => UNS
* DIS # C3: 3,5 => CTR => C3: 4,8
* INC # C3: 4,8 => UNS
* INC # B8: 3,5 => UNS
* INC # B8: 1,9 => UNS
* INC # D7: 4,6 => UNS
* INC # D8: 4,6 => UNS
* INC # F7: 4,6 => UNS
* INC # F8: 4,6 => UNS
* INC # E1: 2,3 => UNS
* DIS # E3: 2,3 => CTR => E3: 8
* INC # E3: 8 => UNS
* INC # D5: 2,3 => UNS
* INC # D8: 2,3 => UNS
* INC # D9: 2,3 => UNS
* INC # H3: 2,4 => UNS
* DIS # I3: 2,4 => CTR => I3: 1,6
* INC # I3: 1,6 => UNS
* INC # I6: 2,4 => UNS
* INC # I6: 6,9 => UNS
* INC # G1: 7,8 => UNS
* DIS # G1: 4 => CTR => G1: 7,8
* INC # C4: 3,9 => UNS
* INC # C5: 3,9 => UNS
* INC # D5: 3,9 => UNS
* INC # F5: 3,9 => UNS
* INC # B7: 3,9 => UNS
* INC # B8: 3,9 => UNS
* INC # A4: 2,6 => UNS
* INC # A5: 2,6 => UNS
* INC # E6: 2,6 => UNS
* DIS # I6: 2,6 => CTR => I6: 4,9
* INC # I6: 4,9 => UNS
* INC # I4: 1,6 => UNS
* PRF # H5: 1,6 => SOL
* INC # H5: 2,4 => UNS
* DIS # E4: 1,6 => CTR => E4: 2,3
* INC # E4: 2,3 => UNS
* INC # G3: 1,6 => UNS
* DIS # G8: 1,6 => CTR => G8: 3,4,8,9
* INC # G8: 3,4,8,9 => UNS
* INC # H7: 1,4 => UNS
* INC # G8: 1,4 => UNS
* INC # H8: 1,4 => UNS
* INC # I8: 1,4 => UNS
* DIS # G9: 1,4 => CTR => G9: 3,9
* INC # G9: 3,9 => UNS
* DIS # I9: 1,4 => CTR => I9: 5,9
* INC # I9: 5,9 => UNS
* DIS # D9: 1,4 => CTR => D9: 2,3,9
* INC # D9: 2,3,9 => UNS
* INC # E9: 1,4 => UNS
* DIS # H3: 1,4 => CTR => H3: 2,6,8
* INC # H3: 2,6,8 => UNS
* INC # H5: 1,4 => UNS
* CNT  56 HDP CHAINS /  56 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # A1: 7,8 => UNS
* INC # C1: 7,8 => UNS
* DIS # C3: 3,5 => CTR => C3: 4,8
* INC C3: 4,8 # D7: 4,6 => UNS
* INC C3: 4,8 # D8: 4,6 => UNS
* INC C3: 4,8 # F7: 4,6 => UNS
* INC C3: 4,8 # F8: 4,6 => UNS
* DIS C3: 4,8 # E3: 2,3 => CTR => E3: 8
* DIS C3: 4,8 + E3: 8 # C4: 3,9 => CTR => C4: 2,5
* INC C3: 4,8 + E3: 8 + C4: 2,5 # C5: 3,9 => UNS
* INC C3: 4,8 + E3: 8 + C4: 2,5 # C5: 3,9 => UNS
* INC C3: 4,8 + E3: 8 + C4: 2,5 # C5: 7 => UNS
* INC C3: 4,8 + E3: 8 + C4: 2,5 # B7: 3,9 => UNS
* INC C3: 4,8 + E3: 8 + C4: 2,5 # B8: 3,9 => UNS
* INC C3: 4,8 + E3: 8 + C4: 2,5 # A4: 2,6 => UNS
* INC C3: 4,8 + E3: 8 + C4: 2,5 # A4: 3,5 => UNS
* DIS C3: 4,8 + E3: 8 + C4: 2,5 # I6: 2,6 => CTR => I6: 9
* PRF C3: 4,8 + E3: 8 + C4: 2,5 + I6: 9 => SOL
* STA C3: 4,8 + E3: 8 + C4: 2,5 + I6: 9
* CNT  18 HDP CHAINS /  17 HYP OPENED