Analysis of xx-top500-210-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: .2.6..5....9....3.......8..4.1....9.7..5........2.....5.....6...3..9........1.... initial

Autosolve

position: .2.6..519..915..3..159..8..451.6.3927.25391..9.32417..59.3..6.113..9....2...1.9.3 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # F1: 3,8 => CTR => F1: 4,7
* PRF # F1: 4,7 => SOL
* PRF # F1: 4,7 => SOL
* DIS # F1: 3,8 => CTR => F1: 4,7
* DIS # C8: 4,7 => CTR => C8: 6,8
* DIS # C9: 4,7 => CTR => C9: 6,8
* PRF # F2: 4,7 => SOL
* DIS # I2: 4,7 => CTR => I2: 6
* PRF # I2: 6 => SOL
* DIS # F1: 7,8 => CTR => F1: 3,4
* PRF # F2: 7,8 => SOL
* DIS # F2: 2,4 => CTR => F2: 7,8
* PRF # E7: 7,8 => SOL
* DIS # E7: 2 => CTR => E7: 7,8
* PRF # F2: 2,7 => SOL
* DIS # F2: 4,8 => CTR => F2: 2,7
* DIS # F3: 2,7 => CTR => F3: 3,4
* DIS # H3: 4,6 => CTR => H3: 2,7
* PRF # E7: 2,7 => SOL
* DIS # E7: 8 => CTR => E7: 2,7
* PRF # H3: 6,7 => SOL
* DIS # F2: 2,4 => CTR => F2: 7,8
* PRF # F2: 7,8 => SOL
* PRF # I5: 6,8 => SOL
* PRF # D8: 7,8 => SOL
* DIS # D8: 4 => CTR => D8: 7,8
* DIS # D9: 7,8 => CTR => D9: 4
* PRF # D9: 4 => SOL
* DIS # F1: 7,8 => CTR => F1: 3,4
* PRF # F2: 7,8 => SOL
* DIS # F2: 2,4 => CTR => F2: 7,8
* DIS # F7: 7,8 => CTR => F7: 2
* PRF # F7: 2 => SOL
* DIS # C8: 4,7 => CTR => C8: 6,8
* DIS # C9: 4,7 => CTR => C9: 6,8
* DIS # H9: 4,7 => CTR => H9: 5,8
* PRF # H8: 2,4 => SOL
* DIS # H8: 5,7,8 => CTR => H8: 2,4
* CNT  38 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 # F1: 3,8 => CTR => F1: 4,7
* PRF F1: 4,7 => SOL
* STA F1: 4,7
* CNT   2 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

.2.6..5....9....3.......8..4.1....9.7..5........2.....5.....6...3..9........1.... initial
.2.6..519..915..3..159..8..451.6.3927.25391..9.32417..59.3..6.113..9....2...1.9.3 autosolve
327684519849157236615923874451768392762539148983241765594372681136895427278416953 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (16)
A1: 3,8
C1: 4,7
A2: 6,8
B2: 4,7
A3: 3,6
E1: 7,8
E3: 2,7
G2: 2,4
B5: 6,8
B6: 6,8
D4: 7,8
F4: 7,8
B9: 4,7
F8: 5,6
F9: 5,6
G8: 2,4

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
G2,H3: 2.. / G2 = 2  =>  0 pairs (*) / H3 = 2  =>  0 pairs (X)
E7,F7: 2.. / E7 = 2  =>  0 pairs (X) / F7 = 2  =>  0 pairs (_)
G8,H8: 2.. / G8 = 2  =>  0 pairs (X) / H8 = 2  =>  0 pairs (_)
F2,G2: 2.. / F2 = 2  =>  0 pairs (X) / G2 = 2  =>  0 pairs (_)
E3,E7: 2.. / E3 = 2  =>  0 pairs (*) / E7 = 2  =>  0 pairs (X)
G2,G8: 2.. / G2 = 2  =>  0 pairs (*) / G8 = 2  =>  0 pairs (X)
H3,H8: 2.. / H3 = 2  =>  0 pairs (X) / H8 = 2  =>  0 pairs (_)
A1,A3: 3.. / A1 = 3  =>  0 pairs (*) / A3 = 3  =>  0 pairs (X)
F1,F3: 3.. / F1 = 3  =>  0 pairs (X) / F3 = 3  =>  0 pairs (_)
A1,F1: 3.. / A1 = 3  =>  0 pairs (*) / F1 = 3  =>  0 pairs (X)
A3,F3: 3.. / A3 = 3  =>  0 pairs (X) / F3 = 3  =>  0 pairs (_)
C1,B2: 4.. / C1 = 4  =>  0 pairs (X) / B2 = 4  =>  0 pairs (_)
H5,I5: 4.. / H5 = 4  =>  0 pairs (*) / I5 = 4  =>  0 pairs (X)
D8,D9: 4.. / D8 = 4  =>  0 pairs (X) / D9 = 4  =>  0 pairs (_)
C1,F1: 4.. / C1 = 4  =>  0 pairs (X) / F1 = 4  =>  0 pairs (_)
C7,H7: 4.. / C7 = 4  =>  0 pairs (*) / H7 = 4  =>  0 pairs (X)
B2,B9: 4.. / B2 = 4  =>  0 pairs (*) / B9 = 4  =>  0 pairs (X)
G2,G8: 4.. / G2 = 4  =>  0 pairs (X) / G8 = 4  =>  0 pairs (_)
H6,I6: 5.. / H6 = 5  => 16 pairs (_) / I6 = 5  => 17 pairs (_)
F8,F9: 5.. / F8 = 5  => 15 pairs (_) / F9 = 5  => 14 pairs (_)
F9,H9: 5.. / F9 = 5  => 14 pairs (_) / H9 = 5  => 15 pairs (_)
I6,I8: 5.. / I6 = 5  => 17 pairs (_) / I8 = 5  => 16 pairs (_)
A2,A3: 6.. / A2 = 6  =>  0 pairs (X) / A3 = 6  =>  0 pairs (_)
B5,B6: 6.. / B5 = 6  => 18 pairs (_) / B6 = 6  => 19 pairs (_)
C8,C9: 6.. / C8 = 6  => 15 pairs (_) / C9 = 6  => 14 pairs (_)
F8,F9: 6.. / F8 = 6  => 14 pairs (_) / F9 = 6  => 15 pairs (_)
A2,I2: 6.. / A2 = 6  =>  0 pairs (X) / I2 = 6  =>  0 pairs (_)
C8,F8: 6.. / C8 = 6  => 15 pairs (_) / F8 = 6  => 14 pairs (_)
C9,F9: 6.. / C9 = 6  => 14 pairs (_) / F9 = 6  => 15 pairs (_)
C1,B2: 7.. / C1 = 7  =>  0 pairs (*) / B2 = 7  =>  0 pairs (X)
D4,F4: 7.. / D4 = 7  =>  0 pairs (*) / F4 = 7  =>  0 pairs (X)
B2,B9: 7.. / B2 = 7  =>  0 pairs (X) / B9 = 7  =>  0 pairs (_)
A1,A2: 8.. / A1 = 8  =>  0 pairs (X) / A2 = 8  =>  0 pairs (_)
B5,B6: 8.. / B5 = 8  => 19 pairs (_) / B6 = 8  => 18 pairs (_)
D4,F4: 8.. / D4 = 8  => 23 pairs (_) / F4 = 8  =>  0 pairs (*)
A2,F2: 8.. / A2 = 8  =>  0 pairs (*) / F2 = 8  =>  0 pairs (X)
E1,E7: 8.. / E1 = 8  =>  0 pairs (*) / E7 = 8  =>  0 pairs (X)
* DURATION: 0:01:06.145788  START: 10:00:12.969890  END: 10:01:19.115678 2017-05-04
* CP COUNT: (37)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,A2,A3,B2,B5,B6,B9,C1,D4,E1,E3,F4,F8,F9,G2,G8)
* .2.6..519..915..3..159..8..451.6.3927.25391..9.32417..59.3..6.113..9....2...1.9.3
* PAIR A1: 3,8 ROW 1
F1: 3,8,4,7                              # reduction candidate for 3,8
F1: 3,8 => CTR
* .2467.519.7915..3..1592.8..451.6.3927.25391..9.32417..59.38264113.49.2..2...1.9.3
F1: 4,7 => SOLVED
* 327684519849157236615923874451768392762539148983241765594372681136895427278416953
* PAIR C1: 4,7 ROW 1
F1: 4,7,3,8                              # reduction candidate for 4,7
F1: 4,7 => SOLVED
* 327684519849157236615923874451768392762539148983241765594372681136895427278416953
F1: 3,8 => CTR
* .2467.519.7915..3..1592.8..451.6.3927.25391..9.32417..59.38264113.49.2..2...1.9.3
* PAIR C1: 4,7 COL C
C7: 4,7,8                                # reduction candidate for 4,7
C7: 4,7                                  # 19 pairs
C8: 4,7,6,8                              # reduction candidate for 4,7
C8: 4,7 => CTR
* .2.68.5198.915243661597.8..451.6.3927.25391..9.32417..5983..64113..962..2.6.159.3
C8: 6,8                                  # 17 pairs
C9: 4,7,6,8                              # reduction candidate for 4,7
C9: 4,7 => CTR
* .2.68.5198.915243661597.8..451.6.3927.25391..9.32417.55983..6411364952..2..816953
C9: 6,8                                  # 17 pairs
* PAIR B2: 4,7 ROW 2
F2: 4,7,2,8                              # reduction candidate for 4,7
F2: 4,7 => SOLVED
* 327684519849157236615923874451768392762539148983241765594372681136895427278416953
F2: 2,8                                  # 20 pairs
I2: 4,7,6                                # reduction candidate for 4,7
I2: 4,7 => CTR
* 82.6735196.915823.3159..8..4518673927.25391..9.32417..59.3826.113..9.42.2..41.9.3
I2: 6 => SOLVED
* 327684519849157236615923874451768392762539148983241765594372681136895427278416953
* PAIR E1: 7,8 BLK 2
F1: 7,8,3,4                              # reduction candidate for 7,8
F1: 7,8 => CTR
* 3246..51987915..366159.38..451.6.3927.25391..9.32417..59.3..64113.49.2..24..1.9.3
F1: 3,4                                  # 17 pairs
F2: 7,8,2,4                              # reduction candidate for 7,8
F2: 7,8 => SOLVED
* 327684519849157236615923874451768392762539148983241765594372681136895427278416953
F2: 2,4 => CTR
* 3246..5198791542366159238..451.6.3927.25391..9.32417..59.3.264113..9....24..1.9.3
* PAIR E1: 7,8 COL E
E7: 7,8,2                                # reduction candidate for 7,8
E7: 7,8 => SOLVED
* 327684519849157236615923874451768392762539148983241765594372681136895427278416953
E7: 2 => CTR
* .2.68.5198.915..36615973824451.6.3927.25391..9.32417..59.3..6.113..9....2...1.9.3
* PAIR E3: 2,7 BLK 2
F2: 2,7,4,8                              # reduction candidate for 2,7
F2: 2,7 => SOLVED
* 327684519849157236615923874451768392762539148983241765594372681136895427278416953
F2: 4,8 => CTR
* .2.6..519.49158237.159..8..4518673927.25391..9.32417..59438267113.79.42.27.41.9.3
F3: 2,7,3,4                              # reduction candidate for 2,7
F3: 2,7 => CTR
* .2.6.3519..915423.3159..8..451.6.3927.25391..9.32417..59.3..6.113..9.42.24..1.9.3
F3: 3,4                                  # 17 pairs
* PAIR E3: 2,7 ROW 3
H3: 2,7,4,6                              # reduction candidate for 2,7
H3: 4,6 => CTR
* .276845198491572366159238474517683927.25391.49.32417..59437.6.113..9.42.27.41.9.3
H3: 2,7                                  # 21 pairs
* PAIR E3: 2,7 COL E
E7: 2,7,8                                # reduction candidate for 2,7
E7: 2,7 => SOLVED
* 327684519849157236615923874451768392762539148983241765594372681136895427278416953
E7: 8 => CTR
* .2.67.519.7915.23..1592.8..4518673927.25391..9.32417..59.3826.113..9.42.24.71.9.3
* PAIR G2: 2,4 BLK 3
H3: 2,4,6,7                              # reduction candidate for 2,4
H3: 6,7 => SOLVED
* 327684519849157236615923874451768392762539148983241765594372681136895427278416953
H3: 2,4                                  # 21 pairs
* PAIR G2: 2,4 ROW 2
F2: 2,4,7,8                              # reduction candidate for 2,4
F2: 2,4 => CTR
* 3246..5198791542366159238..451.6.3927.25391..9.32417..59.3.264113..9....24..1.9.3
F2: 7,8 => SOLVED
* 327684519849157236615923874451768392762539148983241765594372681136895427278416953
* PAIR B5: 6,8 ROW 5
H5: 6,8,4                                # reduction candidate for 6,8
H5: 6,8                                  # 22 pairs
I5: 6,8,4                                # reduction candidate for 6,8
I5: 6,8 => SOLVED
* 327684519849157236615923874451768392762539148983241765594372681136895427278416953
I5: 4                                    # 22 pairs
* PAIR B6: 6,8 ROW 6
H6: 6,8,5                                # reduction candidate for 6,8
H6: 6,8                                  # 17 pairs
I6: 6,8,5                                # reduction candidate for 6,8
I6: 6,8                                  # 16 pairs
* PAIR D4: 7,8 COL D
D8: 7,8,4                                # reduction candidate for 7,8
D8: 7,8 => SOLVED
* 327684519849157236615923874451768392762539148983241765594372681136895427278416953
D8: 4 => CTR
* .2.6..519..915243..15974826451.6.3927.25391.49.32417..59.32.6.113.49.2..24..1.9.3
D9: 7,8,4                                # reduction candidate for 7,8
D9: 7,8 => CTR
* .2.6..519..915243..15974826451.6.3927.25391.49.32417..59.32.6.113.49.2..24..1.9.3
D9: 4 => SOLVED
* 327684519849157236615923874451768392762539148983241765594372681136895427278416953
* PAIR F4: 7,8 COL F
F1: 7,8,3,4                              # reduction candidate for 7,8
F1: 7,8 => CTR
* 3246..51987915..366159.38..451.6.3927.25391..9.32417..59.3..64113.49.2..24..1.9.3
F1: 3,4                                  # 17 pairs
F2: 7,8,2,4                              # reduction candidate for 7,8
F2: 7,8 => SOLVED
* 327684519849157236615923874451768392762539148983241765594372681136895427278416953
F2: 2,4 => CTR
* 3246..5198791542366159238..451.6.3927.25391..9.32417..59.3.264113..9....24..1.9.3
F7: 7,8,2                                # reduction candidate for 7,8
F7: 7,8 => CTR
* .2.68.5198.915..36615973824451.6.3927.25391..9.32417..59.32.6.113..9....2...1.9.3
F7: 2 => SOLVED
* 327684519849157236615923874451768392762539148983241765594372681136895427278416953
* PAIR B9: 4,7 BLK 7
C7: 4,7,8                                # reduction candidate for 4,7
C7: 4,7                                  # 19 pairs
C8: 4,7,6,8                              # reduction candidate for 4,7
C8: 4,7 => CTR
* .2.68.5198.915243661597.8..451.6.3927.25391..9.32417..5983..64113..962..2.6.159.3
C8: 6,8                                  # 17 pairs
C9: 4,7,6,8                              # reduction candidate for 4,7
C9: 4,7 => CTR
* .2.68.5198.915243661597.8..451.6.3927.25391..9.32417.55983..6411364952..2..816953
C9: 6,8                                  # 17 pairs
* PAIR B9: 4,7 ROW 9
D9: 4,7,8                                # reduction candidate for 4,7
D9: 4,7                                  # 19 pairs
H9: 4,7,5,8                              # reduction candidate for 4,7
H9: 4,7 => CTR
* 32.68.5198.91524366159738..4517683927.25391..9.32417..59.3..6.113.4962..2.68159.3
H9: 5,8                                  # 17 pairs
* PAIR G8: 2,4 BLK 9
H8: 2,4,5,7,8                            # reduction candidate for 2,4
H8: 2,4 => SOLVED
* 327684519849157236615923874451768392762539148983241765594372681136895427278416953
H8: 5,7,8 => CTR
* .2.68.5198.915243661597.82.451.6.3927.25391..9.32417..59.32.6.113..9.2..2...1.9.3
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-210-base-pr-000.dot
* REASONING
* DIS # F1: 3,8 => CTR => F1: 4,7
* PRF # F1: 4,7 => SOL
* PRF # F1: 4,7 => SOL
* DIS # F1: 3,8 => CTR => F1: 4,7
* DIS # C8: 4,7 => CTR => C8: 6,8
* DIS # C9: 4,7 => CTR => C9: 6,8
* PRF # F2: 4,7 => SOL
* DIS # I2: 4,7 => CTR => I2: 6
* PRF # I2: 6 => SOL
* DIS # F1: 7,8 => CTR => F1: 3,4
* PRF # F2: 7,8 => SOL
* DIS # F2: 2,4 => CTR => F2: 7,8
* PRF # E7: 7,8 => SOL
* DIS # E7: 2 => CTR => E7: 7,8
* PRF # F2: 2,7 => SOL
* DIS # F2: 4,8 => CTR => F2: 2,7
* DIS # F3: 2,7 => CTR => F3: 3,4
* DIS # H3: 4,6 => CTR => H3: 2,7
* PRF # E7: 2,7 => SOL
* DIS # E7: 8 => CTR => E7: 2,7
* PRF # H3: 6,7 => SOL
* DIS # F2: 2,4 => CTR => F2: 7,8
* PRF # F2: 7,8 => SOL
* PRF # I5: 6,8 => SOL
* PRF # D8: 7,8 => SOL
* DIS # D8: 4 => CTR => D8: 7,8
* DIS # D9: 7,8 => CTR => D9: 4
* PRF # D9: 4 => SOL
* DIS # F1: 7,8 => CTR => F1: 3,4
* PRF # F2: 7,8 => SOL
* DIS # F2: 2,4 => CTR => F2: 7,8
* DIS # F7: 7,8 => CTR => F7: 2
* PRF # F7: 2 => SOL
* DIS # C8: 4,7 => CTR => C8: 6,8
* DIS # C9: 4,7 => CTR => C9: 6,8
* DIS # H9: 4,7 => CTR => H9: 5,8
* PRF # H8: 2,4 => SOL
* DIS # H8: 5,7,8 => CTR => H8: 2,4
* CNT  38 HDP CHAINS /  56 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,A2,A3,B2,B5,B6,B9,C1,D4,E1,E3,F4,F8,F9,G2,G8)
* .2.6..519..915..3..159..8..451.6.3927.25391..9.32417..59.3..6.113..9....2...1.9.3
* PAIR A1: 3,8 ROW 1
F1: 3,8,4,7                              # reduction candidate for 3,8
F1: 3,8 => CTR
* .2467.519.7915..3..1592.8..451.6.3927.25391..9.32417..59.38264113.49.2..2...1.9.3
F1: 4,7 => SOLVED
* 327684519849157236615923874451768392762539148983241765594372681136895427278416953
* DURATION: 0:00:03.183256  START: 10:02:17.698404  END: 10:02:20.881660 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-210-base-pr-001.dot
* REASONING
* DIS # F1: 3,8 => CTR => F1: 4,7
* PRF F1: 4,7 => SOL
* STA F1: 4,7
* CNT   2 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 210

solution: 327684519849157236615923874451768392762539148983241765594372681136895427278416953
info: 1942     FNBHWY   S8.f     16867

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

Solution

position: 327684519849157236615923874451768392762539148983241765594372681136895427278416953 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 # F1: 3,8 => CTR => F1: 4,7
* PRF # F1: 4,7 => SOL
* PRF # F1: 4,7 => SOL
* DIS # F1: 3,8 => CTR => F1: 4,7
* INC # C7: 4,7 => UNS
* DIS # C8: 4,7 => CTR => C8: 6,8
* INC # C8: 6,8 => UNS
* DIS # C9: 4,7 => CTR => C9: 6,8
* INC # C9: 6,8 => UNS
* PRF # F2: 4,7 => SOL
* INC # F2: 2,8 => UNS
* DIS # I2: 4,7 => CTR => I2: 6
* PRF # I2: 6 => SOL
* DIS # F1: 7,8 => CTR => F1: 3,4
* INC # F1: 3,4 => UNS
* PRF # F2: 7,8 => SOL
* DIS # F2: 2,4 => CTR => F2: 7,8
* PRF # E7: 7,8 => SOL
* DIS # E7: 2 => CTR => E7: 7,8
* PRF # F2: 2,7 => SOL
* DIS # F2: 4,8 => CTR => F2: 2,7
* DIS # F3: 2,7 => CTR => F3: 3,4
* INC # F3: 3,4 => UNS
* INC # H3: 2,7 => UNS
* DIS # H3: 4,6 => CTR => H3: 2,7
* PRF # E7: 2,7 => SOL
* DIS # E7: 8 => CTR => E7: 2,7
* INC # H3: 2,4 => UNS
* PRF # H3: 6,7 => SOL
* DIS # F2: 2,4 => CTR => F2: 7,8
* PRF # F2: 7,8 => SOL
* INC # H5: 6,8 => UNS
* PRF # I5: 6,8 => SOL
* INC # I5: 4 => UNS
* INC # H6: 6,8 => UNS
* INC # I6: 6,8 => UNS
* PRF # D8: 7,8 => SOL
* DIS # D8: 4 => CTR => D8: 7,8
* DIS # D9: 7,8 => CTR => D9: 4
* PRF # D9: 4 => SOL
* DIS # F1: 7,8 => CTR => F1: 3,4
* INC # F1: 3,4 => UNS
* PRF # F2: 7,8 => SOL
* DIS # F2: 2,4 => CTR => F2: 7,8
* DIS # F7: 7,8 => CTR => F7: 2
* PRF # F7: 2 => SOL
* INC # C7: 4,7 => UNS
* DIS # C8: 4,7 => CTR => C8: 6,8
* INC # C8: 6,8 => UNS
* DIS # C9: 4,7 => CTR => C9: 6,8
* INC # C9: 6,8 => UNS
* INC # D9: 4,7 => UNS
* DIS # H9: 4,7 => CTR => H9: 5,8
* INC # H9: 5,8 => UNS
* PRF # H8: 2,4 => SOL
* DIS # H8: 5,7,8 => CTR => H8: 2,4
* CNT  56 HDP CHAINS /  56 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # F1: 3,8 => CTR => F1: 4,7
* PRF F1: 4,7 => SOL
* STA F1: 4,7
* CNT   2 HDP CHAINS /   1 HYP OPENED