Analysis of xx-top500-209-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: ....7...5.6..4.....1.......5..6.3...7.......2...1..4..2..8...........63........1. initial

Autosolve

position: ....7...5.6..4.....1.......5..6.3...7.......2...1.74..2..81....1.....63.......21. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # D2: 3,9 => CTR => D2: 2,5
* DIS # D3: 3,9 => CTR => D3: 2,5
* DIS # G1: 3,9 => CTR => G1: 1,8
* DIS # D9: 4,5,7 => CTR => D9: 3,9
* DIS # I3: 4,7,9 => CTR => I3: 3,6
* DIS # D8: 5,9 => CTR => D8: 2,4,7
* DIS # F8: 5,9 => CTR => F8: 2,4
* DIS # D9: 5,9 => CTR => D9: 3,4,7
* CNT   8 HDP CHAINS /  24 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 # D2: 3,9 => CTR => D2: 2,5
* DIS D2: 2,5 # D3: 3,9 => CTR => D3: 2,5
* DIS D2: 2,5 + D3: 2,5 # G1: 3,9 => CTR => G1: 1,8
* DIS D2: 2,5 + D3: 2,5 + G1: 1,8 # D9: 4,7 => CTR => D9: 3,9
* DIS D2: 2,5 + D3: 2,5 + G1: 1,8 + D9: 3,9 # I3: 4,7,9 => CTR => I3: 3,6
* PRF D2: 2,5 + D3: 2,5 + G1: 1,8 + D9: 3,9 + I3: 3,6 # F9: 5,9 => SOL
* STA D2: 2,5 + D3: 2,5 + G1: 1,8 + D9: 3,9 + I3: 3,6 + F9: 5,9
* CNT   6 HDP CHAINS /  14 HYP OPENED

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

Details

Positions

....7...5.6..4.....1.......5..6.3...7.......2...1..4..2..8...........63........1. initial
....7...5.6..4.....1.......5..6.3...7.......2...1.74..2..81....1.....63.......21. autosolve
342976185867541923915238746594623871781459362623187459236814597158792634479365218 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (6)
C2: 5,7
C3: 5,7
D1: 3,9
E3: 3,6
E8: 5,9
E9: 3,6

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
F1,F2: 1.. / F1 = 1  =>  0 pairs (X) / F2 = 1  =>  0 pairs (_)
C4,C5: 1.. / C4 = 1  =>  0 pairs (X) / C5 = 1  =>  0 pairs (_)
F1,G1: 1.. / F1 = 1  =>  0 pairs (X) / G1 = 1  =>  0 pairs (_)
C5,G5: 1.. / C5 = 1  =>  0 pairs (*) / G5 = 1  =>  0 pairs (X)
I2,I4: 1.. / I2 = 1  =>  0 pairs (X) / I4 = 1  =>  0 pairs (_)
B1,C1: 2.. / B1 = 2  =>  6 pairs (_) / C1 = 2  =>  6 pairs (_)
H2,H3: 2.. / H2 = 2  =>  6 pairs (_) / H3 = 2  =>  8 pairs (_)
E4,E6: 2.. / E4 = 2  =>  6 pairs (_) / E6 = 2  =>  0 pairs (X)
D8,F8: 2.. / D8 = 2  =>  0 pairs (X) / F8 = 2  =>  6 pairs (_)
G5,I6: 3.. / G5 = 3  =>  0 pairs (*) / I6 = 3  =>  0 pairs (X)
B7,C7: 3.. / B7 = 3  =>  0 pairs (*) / C7 = 3  =>  0 pairs (X)
D9,E9: 3.. / D9 = 3  =>  0 pairs (*) / E9 = 3  =>  0 pairs (X)
E3,E9: 3.. / E3 = 3  =>  0 pairs (*) / E9 = 3  =>  0 pairs (X)
B4,C4: 4.. / B4 = 4  =>  6 pairs (_) / C4 = 4  =>  0 pairs (*)
D5,F5: 4.. / D5 = 4  =>  7 pairs (_) / F5 = 4  =>  0 pairs (X)
C2,C3: 5.. / C2 = 5  =>  4 pairs (_) / C3 = 5  =>  4 pairs (_)
B8,B9: 5.. / B8 = 5  => 13 pairs (_) / B9 = 5  =>  6 pairs (_)
G7,H7: 5.. / G7 = 5  =>  6 pairs (_) / H7 = 5  =>  0 pairs (X)
E6,H6: 5.. / E6 = 5  =>  0 pairs (X) / H6 = 5  =>  6 pairs (_)
G5,G7: 5.. / G5 = 5  =>  0 pairs (X) / G7 = 5  =>  6 pairs (_)
F1,H1: 6.. / F1 = 6  =>  0 pairs (*) / H1 = 6  =>  0 pairs (X)
C5,H5: 6.. / C5 = 6  =>  0 pairs (X) / H5 = 6  =>  0 pairs (_)
C7,F7: 6.. / C7 = 6  =>  0 pairs (*) / F7 = 6  =>  0 pairs (X)
A6,A9: 6.. / A6 = 6  =>  0 pairs (*) / A9 = 6  =>  0 pairs (X)
E3,E9: 6.. / E3 = 6  =>  0 pairs (X) / E9 = 6  =>  0 pairs (_)
I3,I6: 6.. / I3 = 6  =>  0 pairs (*) / I6 = 6  =>  0 pairs (X)
C2,C3: 7.. / C2 = 7  =>  4 pairs (_) / C3 = 7  =>  4 pairs (_)
D8,D9: 7.. / D8 = 7  =>  6 pairs (_) / D9 = 7  =>  0 pairs (X)
I8,I9: 8.. / I8 = 8  =>  7 pairs (_) / I9 = 8  =>  6 pairs (_)
* DURATION: 0:00:47.677059  START: 09:58:36.289368  END: 09:59:23.966427 2017-05-04
* CP COUNT: (29)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (C2,C3,D1,E3,E8,E9)
* ....7...5.6..4.....1.......5..6.3...7.......2...1.74..2..81....1.....63.......21.
* PAIR D1: 3,9 BLK 2
D2: 3,9,2,5                              # reduction candidate for 3,9
D2: 3,9 => CTR
* ....7..65.6..4.....1..6....5..6.3...7.6...1.2...1.74..2..81....1.....63.......21.
D2: 2,5                                  #  7 pairs
D3: 3,9,2,5                              # reduction candidate for 3,9
D3: 3,9 => CTR
* ....7..65.6..4.....1..6....5..6.3...7.6...1.2...1.74..2..81....1.....63.......21.
D3: 2,5                                  #  7 pairs
* PAIR D1: 3,9 ROW 1
A1: 3,9,4,8                              # reduction candidate for 3,9
A1: 3,9                                  #  9 pairs
B1: 3,9,2,4,8                            # reduction candidate for 3,9
B1: 3,9                                  # 10 pairs
C1: 3,9,2,4,8                            # reduction candidate for 3,9
C1: 3,9                                  # 10 pairs
G1: 3,9,1,8                              # reduction candidate for 3,9
G1: 3,9 => CTR
* ....71.65.6..4.....1.......5..6.3...7.6...1.2...1.74..2..81....1.....63.......21.
G1: 1,8                                  #  7 pairs
* PAIR D1: 3,9 COL D
D9: 3,9,4,5,7                            # reduction candidate for 3,9
D9: 4,5,7 => CTR
* ....7..65.6..4.....1..6....5..6.3...7.6.....2...1.74.62..81....1.....63.6...3.21.
D9: 3,9                                  # 10 pairs
* PAIR E3: 3,6 ROW 3
I3: 3,6,4,7,9                            # reduction candidate for 3,6
I3: 4,7,9 => CTR
* ....7...5.6..4...3.1..6....5..6.3..17.......2...1.74.62..81....1.....63.6...3.21.
I3: 3,6                                  #  7 pairs
* PAIR E8: 5,9 BLK 8
D8: 5,9,2,4,7                            # reduction candidate for 5,9
D8: 5,9 => CTR
* ....7..65.6..4.....1..6....5..6.3...7.64....2...1.74.62..81....1....263.6..73.21.
D8: 2,4,7                                #  6 pairs
F8: 5,9,2,4                              # reduction candidate for 5,9
F8: 5,9 => CTR
* ....7..65.6..4.....1..6....5..6.3...7.64....2...1.74.62..81....1..2..63.6..73.21.
F8: 2,4                                  #  7 pairs
D9: 5,9,3,4,7                            # reduction candidate for 5,9
D9: 5,9 => CTR
* ....7..65.6..4.....1..6....5..6.3...7.64....2...1.74.62..81....1..7.263.6...3.21.
D9: 3,4,7                                #  6 pairs
F9: 5,9,4,6                              # reduction candidate for 5,9
F9: 5,9                                  #  9 pairs
* PAIR E8: 5,9 ROW 8
B8: 5,9,4,7,8                            # reduction candidate for 5,9
B8: 5,9                                  #  9 pairs
B8: 4,7,8                                #  6 pairs
* PAIR E8: 5,9 COL E
E5: 5,9,8                                # reduction candidate for 5,9
E5: 5,9                                  # 11 pairs
E6: 5,9,2,8                              # reduction candidate for 5,9
E6: 5,9                                  #  8 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-209-base-pr-000.dot
* REASONING
* DIS # D2: 3,9 => CTR => D2: 2,5
* DIS # D3: 3,9 => CTR => D3: 2,5
* DIS # G1: 3,9 => CTR => G1: 1,8
* DIS # D9: 4,5,7 => CTR => D9: 3,9
* DIS # I3: 4,7,9 => CTR => I3: 3,6
* DIS # D8: 5,9 => CTR => D8: 2,4,7
* DIS # F8: 5,9 => CTR => F8: 2,4
* DIS # D9: 5,9 => CTR => D9: 3,4,7
* CNT   8 HDP CHAINS /  24 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (C2,C3,D1,E3,E8,E9)
* ....7...5.6..4.....1.......5..6.3...7.......2...1.74..2..81....1.....63.......21.
* PAIR D1: 3,9 BLK 2
D2: 3,9,2,5                              # reduction candidate for 3,9
D2: 3,9 => CTR
* ....7..65.6..4.....1..6....5..6.3...7.6...1.2...1.74..2..81....1.....63.......21.
D3: 3,9,2,5                              # reduction candidate for 3,9
D3: 3,9 => CTR
* ....7..65.6..4.....1..6....5..6.3...7.6...1.2...1.74..2..81....1.....63.......21.
* RESTART
* PAIR D1: 3,9 ROW 1
A1: 3,9,4,8                              # reduction candidate for 3,9
A1: 3,9                                  # 12 pairs
B1: 3,9,2,4,8                            # reduction candidate for 3,9
B1: 3,9                                  # 13 pairs
C1: 3,9,2,4,8                            # reduction candidate for 3,9
C1: 3,9                                  # 13 pairs
G1: 3,9,1,8                              # reduction candidate for 3,9
G1: 3,9 => CTR
* ....71.65.6..4.....1.......5..6.3...7.6...1.2...1.74..2..81....1....263.......21.
* PAIR D1: 3,9 COL D
D9: 3,9,4,7                              # reduction candidate for 3,9
D9: 4,7 => CTR
* ...37..65.6..4.....1..6....5..6.3...7.6.....2...1.74.62..81....1....263.6...3.21.
* PAIR RESTART
* PAIR D1: 3,9 ROW 1
A1: 3,9,4,8                              # reduction candidate for 3,9
A1: 3,9                                  # 13 pairs
B1: 3,9,2,4,8                            # reduction candidate for 3,9
B1: 3,9                                  # 16 pairs
C1: 3,9,2,4,8                            # reduction candidate for 3,9
C1: 3,9                                  # 16 pairs
* PAIR E3: 3,6 ROW 3
I3: 3,6,4,7,9                            # reduction candidate for 3,6
I3: 4,7,9 => CTR
* ...37...5.6..4...331..6....5..6.3..17..4....2...1.74.62..81....1..7.263.6...3.21.
* PAIR RESTART
* PAIR E8: 5,9 BLK 8
F9: 5,9,4,6                              # reduction candidate for 5,9
F9: 5,9 => SOLVED
* 342976185867541923915238746594623871781459362623187459236814597158792634479365218
* DURATION: 0:00:14.877870  START: 09:59:42.425878  END: 09:59:57.303748 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-209-base-pr-001.dot
* REASONING
* DIS # D2: 3,9 => CTR => D2: 2,5
* DIS D2: 2,5 # D3: 3,9 => CTR => D3: 2,5
* DIS D2: 2,5 + D3: 2,5 # G1: 3,9 => CTR => G1: 1,8
* DIS D2: 2,5 + D3: 2,5 + G1: 1,8 # D9: 4,7 => CTR => D9: 3,9
* DIS D2: 2,5 + D3: 2,5 + G1: 1,8 + D9: 3,9 # I3: 4,7,9 => CTR => I3: 3,6
* PRF D2: 2,5 + D3: 2,5 + G1: 1,8 + D9: 3,9 + I3: 3,6 # F9: 5,9 => SOL
* STA D2: 2,5 + D3: 2,5 + G1: 1,8 + D9: 3,9 + I3: 3,6 + F9: 5,9
* CNT   6 HDP CHAINS /  14 HYP OPENED

Header Info

Top 500 Minimum 17 209

solution: 342976185867541923915238746594623871781459362623187459236814597158792634479365218
info: 1941     FNBHWY   S8.f     5570

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

Solution

position: 342976185867541923915238746594623871781459362623187459236814597158792634479365218 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:

* DIS # D2: 3,9 => CTR => D2: 2,5
* INC # D2: 2,5 => UNS
* DIS # D3: 3,9 => CTR => D3: 2,5
* INC # D3: 2,5 => UNS
* INC # A1: 3,9 => UNS
* INC # B1: 3,9 => UNS
* INC # C1: 3,9 => UNS
* DIS # G1: 3,9 => CTR => G1: 1,8
* INC # G1: 1,8 => UNS
* INC # D9: 3,9 => UNS
* DIS # D9: 4,5,7 => CTR => D9: 3,9
* INC # I3: 3,6 => UNS
* DIS # I3: 4,7,9 => CTR => I3: 3,6
* DIS # D8: 5,9 => CTR => D8: 2,4,7
* INC # D8: 2,4,7 => UNS
* DIS # F8: 5,9 => CTR => F8: 2,4
* INC # F8: 2,4 => UNS
* DIS # D9: 5,9 => CTR => D9: 3,4,7
* INC # D9: 3,4,7 => UNS
* INC # F9: 5,9 => UNS
* INC # B8: 5,9 => UNS
* INC # B8: 4,7,8 => UNS
* INC # E5: 5,9 => UNS
* INC # E6: 5,9 => UNS
* CNT  24 HDP CHAINS /  24 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # D2: 3,9 => CTR => D2: 2,5
* DIS D2: 2,5 # D3: 3,9 => CTR => D3: 2,5
* INC D2: 2,5 + D3: 2,5 # A1: 3,9 => UNS
* INC D2: 2,5 + D3: 2,5 # B1: 3,9 => UNS
* INC D2: 2,5 + D3: 2,5 # C1: 3,9 => UNS
* DIS D2: 2,5 + D3: 2,5 # G1: 3,9 => CTR => G1: 1,8
* INC D2: 2,5 + D3: 2,5 + G1: 1,8 # D9: 3,9 => UNS
* DIS D2: 2,5 + D3: 2,5 + G1: 1,8 # D9: 4,7 => CTR => D9: 3,9
* INC D2: 2,5 + D3: 2,5 + G1: 1,8 + D9: 3,9 # A1: 3,9 => UNS
* INC D2: 2,5 + D3: 2,5 + G1: 1,8 + D9: 3,9 # B1: 3,9 => UNS
* INC D2: 2,5 + D3: 2,5 + G1: 1,8 + D9: 3,9 # C1: 3,9 => UNS
* INC D2: 2,5 + D3: 2,5 + G1: 1,8 + D9: 3,9 # I3: 3,6 => UNS
* DIS D2: 2,5 + D3: 2,5 + G1: 1,8 + D9: 3,9 # I3: 4,7,9 => CTR => I3: 3,6
* PRF D2: 2,5 + D3: 2,5 + G1: 1,8 + D9: 3,9 + I3: 3,6 # F9: 5,9 => SOL
* STA D2: 2,5 + D3: 2,5 + G1: 1,8 + D9: 3,9 + I3: 3,6 + F9: 5,9
* CNT  14 HDP CHAINS /  14 HYP OPENED