Analysis of xx-top500-361-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: ...6..3...24.......5......73..2........5....4.......1.5.....28.7...4........1.... initial

Autosolve

position: 1..65.342.24173.5..5342.1.73152.47.....531.244.27.65135493672817.1.42.3523..1547. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # B1: 7,8 => SOL
* DIS # B1: 9 => CTR => B1: 7,8
* PRF # A3: 6,9 => SOL
* DIS # A3: 8 => CTR => A3: 6,9
* DIS # G2: 6,9 => CTR => G2: 8
* PRF # G2: 8 => SOL
* PRF # I2: 6,9 => SOL
* DIS # I2: 8 => CTR => I2: 6,9
* DIS # B1: 8,9 => CTR => B1: 7
* PRF # B1: 7 => SOL
* DIS # A3: 8,9 => CTR => A3: 6
* PRF # A3: 6 => SOL
* DIS # G2: 6,9 => CTR => G2: 8
* PRF # G2: 8 => SOL
* PRF # I2: 6,9 => SOL
* DIS # I2: 8 => CTR => I2: 6,9
* PRF # A3: 6,9 => SOL
* DIS # A3: 8 => CTR => A3: 6,9
* DIS # A3: 8,9 => CTR => A3: 6
* PRF # A3: 6 => SOL
* DIS # B1: 8,9 => CTR => B1: 7
* PRF # B1: 7 => SOL
* PRF # I4: 8,9 => SOL
* DIS # I4: 6 => CTR => I4: 8,9
* DIS # I4: 6,9 => CTR => I4: 8
* PRF # I4: 8 => SOL
* PRF # I4: 8,9 => SOL
* DIS # I4: 6 => CTR => I4: 8,9
* PRF # G2: 8,9 => SOL
* DIS # G2: 6 => CTR => G2: 8,9
* DIS # G2: 6,9 => CTR => G2: 8
* PRF # G2: 8 => SOL
* PRF # I2: 6,9 => SOL
* DIS # I2: 8 => CTR => I2: 6,9
* DIS # I4: 6,9 => CTR => I4: 8
* PRF # I4: 8 => SOL
* CNT  36 HDP CHAINS /  36 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 # B1: 7,8 => SOL
* STA B1: 7,8
* CNT   1 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

...6..3...24.......5......73..2........5....4.......1.5.....28.7...4........1.... initial
1..65.342.24173.5..5342.1.73152.47.....531.244.27.65135493672817.1.42.3523..1547. autosolve
178659342924173856653428197315294768867531924492786513549367281781942635236815479 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (19)
C1: 7,8
A2: 6,9
F1: 8,9
F3: 8,9
H3: 6,9
A5: 8,9
B5: 6,7
C5: 6,7
B6: 8,9
E4: 8,9
E6: 8,9
H4: 6,9
G5: 8,9
B8: 6,8
C9: 6,8
D8: 8,9
D9: 8,9
G8: 6,9
I9: 6,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
A2,A3: 6.. / A2 = 6  =>  0 pairs (X) / A3 = 6  =>  0 pairs (_)
B5,C5: 6.. / B5 = 6  =>  0 pairs (*) / C5 = 6  =>  0 pairs (X)
H4,I4: 6.. / H4 = 6  =>  0 pairs (*) / I4 = 6  =>  0 pairs (X)
B8,C9: 6.. / B8 = 6  =>  0 pairs (X) / C9 = 6  =>  0 pairs (_)
G8,I9: 6.. / G8 = 6  =>  0 pairs (*) / I9 = 6  =>  0 pairs (X)
A3,H3: 6.. / A3 = 6  =>  0 pairs (*) / H3 = 6  =>  0 pairs (X)
B8,G8: 6.. / B8 = 6  =>  0 pairs (X) / G8 = 6  =>  0 pairs (_)
C9,I9: 6.. / C9 = 6  =>  0 pairs (*) / I9 = 6  =>  0 pairs (X)
B5,B8: 6.. / B5 = 6  =>  0 pairs (*) / B8 = 6  =>  0 pairs (X)
C5,C9: 6.. / C5 = 6  =>  0 pairs (X) / C9 = 6  =>  0 pairs (_)
G2,G8: 6.. / G2 = 6  =>  0 pairs (X) / G8 = 6  =>  0 pairs (_)
H3,H4: 6.. / H3 = 6  =>  0 pairs (X) / H4 = 6  =>  0 pairs (_)
B1,C1: 7.. / B1 = 7  =>  0 pairs (*) / C1 = 7  =>  0 pairs (X)
B5,C5: 7.. / B5 = 7  =>  0 pairs (X) / C5 = 7  =>  0 pairs (_)
B1,B5: 7.. / B1 = 7  =>  0 pairs (*) / B5 = 7  =>  0 pairs (X)
C1,C5: 7.. / C1 = 7  =>  0 pairs (X) / C5 = 7  =>  0 pairs (_)
F1,F3: 8.. / F1 = 8  =>  0 pairs (X) / F3 = 8  =>  0 pairs (_)
G2,I2: 8.. / G2 = 8  =>  0 pairs (*) / I2 = 8  =>  0 pairs (X)
A5,B6: 8.. / A5 = 8  =>  0 pairs (*) / B6 = 8  =>  0 pairs (X)
E4,E6: 8.. / E4 = 8  =>  0 pairs (X) / E6 = 8  =>  0 pairs (_)
I4,G5: 8.. / I4 = 8  =>  0 pairs (*) / G5 = 8  =>  0 pairs (X)
B8,C9: 8.. / B8 = 8  =>  0 pairs (*) / C9 = 8  =>  0 pairs (X)
D8,D9: 8.. / D8 = 8  =>  0 pairs (X) / D9 = 8  =>  0 pairs (_)
A3,F3: 8.. / A3 = 8  =>  0 pairs (X) / F3 = 8  =>  0 pairs (_)
E4,I4: 8.. / E4 = 8  =>  0 pairs (X) / I4 = 8  =>  0 pairs (_)
A5,G5: 8.. / A5 = 8  =>  0 pairs (*) / G5 = 8  =>  0 pairs (X)
B6,E6: 8.. / B6 = 8  =>  0 pairs (X) / E6 = 8  =>  0 pairs (_)
B8,D8: 8.. / B8 = 8  =>  0 pairs (*) / D8 = 8  =>  0 pairs (X)
C9,D9: 8.. / C9 = 8  =>  0 pairs (X) / D9 = 8  =>  0 pairs (_)
A3,A5: 8.. / A3 = 8  =>  0 pairs (X) / A5 = 8  =>  0 pairs (_)
C1,C9: 8.. / C1 = 8  =>  0 pairs (*) / C9 = 8  =>  0 pairs (X)
G2,G5: 8.. / G2 = 8  =>  0 pairs (*) / G5 = 8  =>  0 pairs (X)
I2,I4: 8.. / I2 = 8  =>  0 pairs (X) / I4 = 8  =>  0 pairs (_)
F1,F3: 9.. / F1 = 9  =>  0 pairs (*) / F3 = 9  =>  0 pairs (X)
A5,B6: 9.. / A5 = 9  =>  0 pairs (X) / B6 = 9  =>  0 pairs (_)
E4,E6: 9.. / E4 = 9  =>  0 pairs (*) / E6 = 9  =>  0 pairs (X)
D8,D9: 9.. / D8 = 9  =>  0 pairs (*) / D9 = 9  =>  0 pairs (X)
G8,I9: 9.. / G8 = 9  =>  0 pairs (X) / I9 = 9  =>  0 pairs (_)
B1,F1: 9.. / B1 = 9  =>  0 pairs (X) / F1 = 9  =>  0 pairs (_)
A5,G5: 9.. / A5 = 9  =>  0 pairs (X) / G5 = 9  =>  0 pairs (_)
B6,E6: 9.. / B6 = 9  =>  0 pairs (*) / E6 = 9  =>  0 pairs (X)
D8,G8: 9.. / D8 = 9  =>  0 pairs (*) / G8 = 9  =>  0 pairs (X)
D9,I9: 9.. / D9 = 9  =>  0 pairs (X) / I9 = 9  =>  0 pairs (_)
B1,B6: 9.. / B1 = 9  =>  0 pairs (X) / B6 = 9  =>  0 pairs (_)
H3,H4: 9.. / H3 = 9  =>  0 pairs (*) / H4 = 9  =>  0 pairs (X)
* DURATION: 0:01:50.730894  START: 15:07:00.405071  END: 15:08:51.135965 2017-05-04
* CP COUNT: (45)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A2,A5,B5,B6,B8,C1,C5,C9,D8,D9,E4,E6,F1,F3,G5,G8,H3,H4,I9)
* 1..65.342.24173.5..5342.1.73152.47.....531.244.27.65135493672817.1.42.3523..1547.
* PAIR C1: 7,8 BLK 1
B1: 7,8,9                                # reduction candidate for 7,8
B1: 7,8 => SOLVED
* 178659342924173856653428197315294768867531924492786513549367281781942635236815479
B1: 9 => CTR
* 197658342624173.5.8534291673152.4796976531.244.27.65135493672817.1.42.3523..1547.
* PAIR A2: 6,9 BLK 1
A3: 6,9,8                                # reduction candidate for 6,9
A3: 6,9 => SOLVED
* 178659342924173856653428197315294768867531924492786513549367281781942635236815479
A3: 8 => CTR
* 1..65.342624173.5.8534291673152.47969..531824482796513549367281761.42.3523..1547.
* PAIR A2: 6,9 ROW 2
G2: 6,9,8                                # reduction candidate for 6,9
G2: 6,9 => CTR
* 197658342624173.58.5342.1.73152847.....531824482796513549367281761842935238915476
G2: 8 => SOLVED
* 178659342924173856653428197315294768867531924492786513549367281781942635236815479
I2: 6,9,8                                # reduction candidate for 6,9
I2: 6,9 => SOLVED
* 178659342924173856653428197315294768867531924492786513549367281781942635236815479
I2: 8 => CTR
* 197658342624173.58.5342.1.73152847.....531824482796513549367281761842935238915476
* PAIR F1: 8,9 ROW 1
B1: 8,9,7                                # reduction candidate for 8,9
B1: 8,9 => CTR
* 1.765.342.24173658653428197315284769.76531.244.27.6513549367281761842935238915476
B1: 7 => SOLVED
* 178659342924173856653428197315294768867531924492786513549367281781942635236815479
* PAIR F3: 8,9 ROW 3
A3: 8,9,6                                # reduction candidate for 8,9
A3: 8,9 => CTR
* 1..65.342624173.5..5342.1673152.47969..531824482796513549367281761.42.3523..1547.
A3: 6 => SOLVED
* 178659342924173856653428197315294768867531924492786513549367281781942635236815479
* PAIR H3: 6,9 BLK 3
G2: 6,9,8                                # reduction candidate for 6,9
G2: 6,9 => CTR
* 197658342624173.58.5342.1.73152847.....531824482796513549367281761842935238915476
G2: 8 => SOLVED
* 178659342924173856653428197315294768867531924492786513549367281781942635236815479
I2: 6,9,8                                # reduction candidate for 6,9
I2: 6,9 => SOLVED
* 178659342924173856653428197315294768867531924492786513549367281781942635236815479
I2: 8 => CTR
* 197658342624173.58.5342.1.73152847.....531824482796513549367281761842935238915476
* PAIR H3: 6,9 ROW 3
A3: 6,9,8                                # reduction candidate for 6,9
A3: 6,9 => SOLVED
* 178659342924173856653428197315294768867531924492786513549367281781942635236815479
A3: 8 => CTR
* 1..65.342624173.5.8534291673152.47969..531824482796513549367281761.42.3523..1547.
* PAIR A5: 8,9 COL A
A3: 8,9,6                                # reduction candidate for 8,9
A3: 8,9 => CTR
* 1..65.342624173.5..5342.1673152.47969..531824482796513549367281761.42.3523..1547.
A3: 6 => SOLVED
* 178659342924173856653428197315294768867531924492786513549367281781942635236815479
* PAIR B6: 8,9 COL B
B1: 8,9,7                                # reduction candidate for 8,9
B1: 8,9 => CTR
* 1.765.342.24173658653428197315284769.76531.244.27.6513549367281761842935238915476
B1: 7 => SOLVED
* 178659342924173856653428197315294768867531924492786513549367281781942635236815479
* PAIR E4: 8,9 ROW 4
I4: 8,9,6                                # reduction candidate for 8,9
I4: 8,9 => SOLVED
* 178659342924173856653428197315294768867531924492786513549367281781942635236815479
I4: 6 => CTR
* 1..65.342.24173.58.5342.1.73152847969..531824482796513549367281761.42.3523..1547.
* PAIR H4: 6,9 BLK 6
I4: 6,9,8                                # reduction candidate for 6,9
I4: 6,9 => CTR
* 197658342624173.58.5342.1.73152847.....531824482796513549367281761842935238915476
I4: 8 => SOLVED
* 178659342924173856653428197315294768867531924492786513549367281781942635236815479
* PAIR G5: 8,9 BLK 6
I4: 8,9,6                                # reduction candidate for 8,9
I4: 8,9 => SOLVED
* 178659342924173856653428197315294768867531924492786513549367281781942635236815479
I4: 6 => CTR
* 1..65.342.24173.58.5342.1.73152847969..531824482796513549367281761.42.3523..1547.
* PAIR G5: 8,9 COL G
G2: 8,9,6                                # reduction candidate for 8,9
G2: 8,9 => SOLVED
* 178659342924173856653428197315294768867531924492786513549367281781942635236815479
G2: 6 => CTR
* 1..65.342.24173658653428197315284769...531.244.27.65135493672817.1.42.3523..1547.
* PAIR G8: 6,9 COL G
G2: 6,9,8                                # reduction candidate for 6,9
G2: 6,9 => CTR
* 197658342624173.58.5342.1.73152847.....531824482796513549367281761842935238915476
G2: 8 => SOLVED
* 178659342924173856653428197315294768867531924492786513549367281781942635236815479
* PAIR I9: 6,9 COL I
I2: 6,9,8                                # reduction candidate for 6,9
I2: 6,9 => SOLVED
* 178659342924173856653428197315294768867531924492786513549367281781942635236815479
I2: 8 => CTR
* 197658342624173.58.5342.1.73152847.....531824482796513549367281761842935238915476
I4: 6,9,8                                # reduction candidate for 6,9
I4: 6,9 => CTR
* 197658342624173.58.5342.1.73152847.....531824482796513549367281761842935238915476
I4: 8 => SOLVED
* 178659342924173856653428197315294768867531924492786513549367281781942635236815479
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-361-base-pr-000.dot
* REASONING
* PRF # B1: 7,8 => SOL
* DIS # B1: 9 => CTR => B1: 7,8
* PRF # A3: 6,9 => SOL
* DIS # A3: 8 => CTR => A3: 6,9
* DIS # G2: 6,9 => CTR => G2: 8
* PRF # G2: 8 => SOL
* PRF # I2: 6,9 => SOL
* DIS # I2: 8 => CTR => I2: 6,9
* DIS # B1: 8,9 => CTR => B1: 7
* PRF # B1: 7 => SOL
* DIS # A3: 8,9 => CTR => A3: 6
* PRF # A3: 6 => SOL
* DIS # G2: 6,9 => CTR => G2: 8
* PRF # G2: 8 => SOL
* PRF # I2: 6,9 => SOL
* DIS # I2: 8 => CTR => I2: 6,9
* PRF # A3: 6,9 => SOL
* DIS # A3: 8 => CTR => A3: 6,9
* DIS # A3: 8,9 => CTR => A3: 6
* PRF # A3: 6 => SOL
* DIS # B1: 8,9 => CTR => B1: 7
* PRF # B1: 7 => SOL
* PRF # I4: 8,9 => SOL
* DIS # I4: 6 => CTR => I4: 8,9
* DIS # I4: 6,9 => CTR => I4: 8
* PRF # I4: 8 => SOL
* PRF # I4: 8,9 => SOL
* DIS # I4: 6 => CTR => I4: 8,9
* PRF # G2: 8,9 => SOL
* DIS # G2: 6 => CTR => G2: 8,9
* DIS # G2: 6,9 => CTR => G2: 8
* PRF # G2: 8 => SOL
* PRF # I2: 6,9 => SOL
* DIS # I2: 8 => CTR => I2: 6,9
* DIS # I4: 6,9 => CTR => I4: 8
* PRF # I4: 8 => SOL
* CNT  36 HDP CHAINS /  36 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A2,A5,B5,B6,B8,C1,C5,C9,D8,D9,E4,E6,F1,F3,G5,G8,H3,H4,I9)
* 1..65.342.24173.5..5342.1.73152.47.....531.244.27.65135493672817.1.42.3523..1547.
* PAIR C1: 7,8 BLK 1
B1: 7,8,9                                # reduction candidate for 7,8
B1: 7,8 => SOLVED
* 178659342924173856653428197315294768867531924492786513549367281781942635236815479
* DURATION: 0:00:02.431159  START: 15:09:51.486973  END: 15:09:53.918132 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-361-base-pr-001.dot
* REASONING
* PRF # B1: 7,8 => SOL
* STA B1: 7,8
* CNT   1 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 361

solution: 178659342924173856653428197315294768867531924492786513549367281781942635236815479
info: 4911     FNBTWY   S8.f     43409

http://www.sfsudoku.com/su17ExtremeDiff500.txt from http://www.minimumsudoku.com/

Solution

position: 178659342924173856653428197315294768867531924492786513549367281781942635236815479 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 # B1: 7,8 => SOL
* DIS # B1: 9 => CTR => B1: 7,8
* PRF # A3: 6,9 => SOL
* DIS # A3: 8 => CTR => A3: 6,9
* DIS # G2: 6,9 => CTR => G2: 8
* PRF # G2: 8 => SOL
* PRF # I2: 6,9 => SOL
* DIS # I2: 8 => CTR => I2: 6,9
* DIS # B1: 8,9 => CTR => B1: 7
* PRF # B1: 7 => SOL
* DIS # A3: 8,9 => CTR => A3: 6
* PRF # A3: 6 => SOL
* DIS # G2: 6,9 => CTR => G2: 8
* PRF # G2: 8 => SOL
* PRF # I2: 6,9 => SOL
* DIS # I2: 8 => CTR => I2: 6,9
* PRF # A3: 6,9 => SOL
* DIS # A3: 8 => CTR => A3: 6,9
* DIS # A3: 8,9 => CTR => A3: 6
* PRF # A3: 6 => SOL
* DIS # B1: 8,9 => CTR => B1: 7
* PRF # B1: 7 => SOL
* PRF # I4: 8,9 => SOL
* DIS # I4: 6 => CTR => I4: 8,9
* DIS # I4: 6,9 => CTR => I4: 8
* PRF # I4: 8 => SOL
* PRF # I4: 8,9 => SOL
* DIS # I4: 6 => CTR => I4: 8,9
* PRF # G2: 8,9 => SOL
* DIS # G2: 6 => CTR => G2: 8,9
* DIS # G2: 6,9 => CTR => G2: 8
* PRF # G2: 8 => SOL
* PRF # I2: 6,9 => SOL
* DIS # I2: 8 => CTR => I2: 6,9
* DIS # I4: 6,9 => CTR => I4: 8
* PRF # I4: 8 => SOL
* CNT  36 HDP CHAINS /  36 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* PRF # B1: 7,8 => SOL
* STA B1: 7,8
* CNT   1 HDP CHAINS /   1 HYP OPENED