Analysis of xx-top500-190-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 93..........41........5.8........1.476.............5.....2.6.3....3...7...1...... initial

Autosolve

position: 935...41..8.41.75...7.5.8...5....1.47641.538......45.7578246931...3812753215..648 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # F3: 3,9 => SOL
* DIS # F3: 2 => CTR => F3: 3,9
* DIS # I3: 6,9 => CTR => I3: 2,3
* PRF # I3: 2,3 => SOL
* PRF # I3: 2,6 => SOL
* DIS # I3: 3,9 => CTR => I3: 2,6
* PRF # E1: 7 => SOL
* DIS # I3: 3,9 => CTR => I3: 2,6
* PRF # I3: 2,6 => SOL
* PRF # I3: 2,9 => SOL
* DIS # F3: 2,9 => CTR => F3: 3
* PRF # F3: 3 => SOL
* DIS # F4: 7,9 => CTR => F4: 2,8
* DIS # E4: 2,9 => CTR => E4: 3,6,7
* DIS # F4: 2,9 => CTR => F4: 7,8
* DIS # E6: 2,9 => CTR => E6: 3,6
* PRF # I3: 2,9 => SOL
* DIS # E4: 7,9 => CTR => E4: 2,3,6
* DIS # F4: 7,9 => CTR => F4: 2,8
* CNT  19 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 # F3: 3,9 => SOL
* STA F3: 3,9
* CNT   1 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

93..........41........5.8........1.476.............5.....2.6.3....3...7...1...... initial
935...41..8.41.75...7.5.8...5....1.47641.538......45.7578246931...3812753215..648 autosolve
935872416682419753147653892259738164764125389813964527578246931496381275321597648 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (18)
A2: 2,6
C2: 2,6
A3: 1,4
B3: 1,4
F2: 3,9
D3: 6,9
I1: 2,6
I2: 3,9
H3: 2,9
A4: 2,8
B6: 1,9
E5: 2,9
I5: 2,9
A8: 4,6
B8: 4,9
C8: 6,9
E9: 7,9
F9: 7,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
A3,B3: 1.. / A3 = 1  => 13 pairs (_) / B3 = 1  => 13 pairs (_)
A6,B6: 1.. / A6 = 1  => 13 pairs (_) / B6 = 1  => 13 pairs (_)
A3,A6: 1.. / A3 = 1  => 13 pairs (_) / A6 = 1  => 13 pairs (_)
B3,B6: 1.. / B3 = 1  => 13 pairs (_) / B6 = 1  => 13 pairs (_)
A2,C2: 2.. / A2 = 2  => 13 pairs (_) / C2 = 2  => 13 pairs (_)
E5,I5: 2.. / E5 = 2  =>  0 pairs (*) / I5 = 2  =>  0 pairs (X)
F2,F3: 3.. / F2 = 3  =>  0 pairs (X) / F3 = 3  =>  0 pairs (_)
I2,I3: 3.. / I2 = 3  =>  0 pairs (*) / I3 = 3  =>  0 pairs (X)
C4,C6: 3.. / C4 = 3  => 21 pairs (_) / C6 = 3  => 19 pairs (_)
E4,E6: 3.. / E4 = 3  => 19 pairs (_) / E6 = 3  => 21 pairs (_)
F2,I2: 3.. / F2 = 3  =>  0 pairs (X) / I2 = 3  =>  0 pairs (_)
F3,I3: 3.. / F3 = 3  =>  0 pairs (*) / I3 = 3  =>  0 pairs (X)
C4,E4: 3.. / C4 = 3  => 21 pairs (_) / E4 = 3  => 19 pairs (_)
C6,E6: 3.. / C6 = 3  => 19 pairs (_) / E6 = 3  => 21 pairs (_)
A3,B3: 4.. / A3 = 4  => 13 pairs (_) / B3 = 4  => 13 pairs (_)
A8,B8: 4.. / A8 = 4  => 13 pairs (_) / B8 = 4  => 13 pairs (_)
A3,A8: 4.. / A3 = 4  => 13 pairs (_) / A8 = 4  => 13 pairs (_)
B3,B8: 4.. / B3 = 4  => 13 pairs (_) / B8 = 4  => 13 pairs (_)
A2,C2: 6.. / A2 = 6  => 13 pairs (_) / C2 = 6  => 13 pairs (_)
I1,I3: 6.. / I1 = 6  =>  0 pairs (*) / I3 = 6  =>  0 pairs (X)
H4,H6: 6.. / H4 = 6  => 19 pairs (_) / H6 = 6  => 20 pairs (_)
A8,C8: 6.. / A8 = 6  => 13 pairs (_) / C8 = 6  => 13 pairs (_)
D3,I3: 6.. / D3 = 6  =>  0 pairs (*) / I3 = 6  =>  0 pairs (X)
A2,A8: 6.. / A2 = 6  => 13 pairs (_) / A8 = 6  => 13 pairs (_)
C2,C8: 6.. / C2 = 6  => 13 pairs (_) / C8 = 6  => 13 pairs (_)
E9,F9: 7.. / E9 = 7  =>  0 pairs (X) / F9 = 7  =>  0 pairs (_)
D1,D4: 7.. / D1 = 7  => 19 pairs (_) / D4 = 7  => 19 pairs (_)
D1,F1: 8.. / D1 = 8  => 15 pairs (_) / F1 = 8  => 19 pairs (_)
A4,A6: 8.. / A4 = 8  => 19 pairs (_) / A6 = 8  => 16 pairs (_)
A6,D6: 8.. / A6 = 8  => 16 pairs (_) / D6 = 8  => 19 pairs (_)
F1,F4: 8.. / F1 = 8  => 19 pairs (_) / F4 = 8  => 15 pairs (_)
B8,C8: 9.. / B8 = 9  => 13 pairs (_) / C8 = 9  => 13 pairs (_)
E9,F9: 9.. / E9 = 9  =>  0 pairs (*) / F9 = 9  =>  0 pairs (X)
F2,I2: 9.. / F2 = 9  =>  0 pairs (*) / I2 = 9  =>  0 pairs (X)
E5,I5: 9.. / E5 = 9  =>  0 pairs (X) / I5 = 9  =>  0 pairs (_)
B6,B8: 9.. / B6 = 9  => 13 pairs (_) / B8 = 9  => 13 pairs (_)
* DURATION: 0:01:16.123821  START: 09:12:12.176540  END: 09:13:28.300361 2017-05-04
* CP COUNT: (36)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A2,A3,A4,A8,B3,B6,B8,C2,C8,D3,E5,E9,F2,F9,H3,I1,I2,I5)
* 935...41..8.41.75...7.5.8...5....1.47641.538......45.7578246931...3812753215..648
* PAIR F2: 3,9 BLK 2
F3: 3,9,2                                # reduction candidate for 3,9
F3: 3,9 => SOLVED
* 935872416682419753147653892259738164764125389813964527578246931496381275321597648
F3: 2 => CTR
* 935...41..8.413759..79528...5....1.47641.538......45.7578246931...3812753215..648
* PAIR D3: 6,9 ROW 3
I3: 6,9,2,3                              # reduction candidate for 6,9
I3: 6,9 => CTR
* 935...41..8.41.753..7.53829.5....1.4764195382.....45.7578246931...381275321579648
I3: 2,3 => SOLVED
* 935872416682419753147653892259738164764125389813964527578246931496381275321597648
* PAIR D3: 6,9 COL D
D4: 6,9,7,8                              # reduction candidate for 6,9
D4: 6,9                                  # 20 pairs
D6: 6,9,8                                # reduction candidate for 6,9
D6: 6,9                                  # 16 pairs
* PAIR I1: 2,6 BLK 3
I3: 2,6,3,9                              # reduction candidate for 2,6
I3: 2,6 => SOLVED
* 935872416682419753147653892259738164764125389813964527578246931496381275321597648
I3: 3,9 => CTR
* 935...416.8.41.75...765.82..5....1.4764195382...8.45.7578246931...381275321579648
* PAIR I1: 2,6 ROW 1
E1: 2,6,7                                # reduction candidate for 2,6
E1: 7 => SOLVED
* 935872416682419753147653892259738164764125389813964527578246931496381275321597648
E1: 2,6                                  # 21 pairs
* PAIR I2: 3,9 BLK 3
I3: 3,9,2,6                              # reduction candidate for 3,9
I3: 3,9 => CTR
* 935...416.8.41.75...765.82..5....1.4764195382...8.45.7578246931...381275321579648
I3: 2,6 => SOLVED
* 935872416682419753147653892259738164764125389813964527578246931496381275321597648
* PAIR H3: 2,9 BLK 3
I3: 2,9,3,6                              # reduction candidate for 2,9
I3: 2,9 => SOLVED
* 935872416682419753147653892259738164764125389813964527578246931496381275321597648
I3: 3,6                                  # 19 pairs
* PAIR H3: 2,9 ROW 3
F3: 2,9,3                                # reduction candidate for 2,9
F3: 2,9 => CTR
* 935...41..8.413759..7.5.823.5....1.4764195382.....45.7578246931...381275321579648
F3: 3 => SOLVED
* 935872416682419753147653892259738164764125389813964527578246931496381275321597648
* PAIR H3: 2,9 COL H
H4: 2,9,6                                # reduction candidate for 2,9
H4: 2,9                                  # 20 pairs
H6: 2,9,6                                # reduction candidate for 2,9
H6: 2,9                                  # 19 pairs
* PAIR A4: 2,8 BLK 4
A6: 2,8,1                                # reduction candidate for 2,8
A6: 2,8                                  # 13 pairs
A6: 1                                    # 13 pairs
* PAIR A4: 2,8 ROW 4
F4: 2,8,7,9                              # reduction candidate for 2,8
F4: 7,9 => CTR
* 935..841..8.41.75...7.52893.5....1.47641.538......45.7578246931...3812753215..648
F4: 2,8                                  # 21 pairs
* PAIR E5: 2,9 BLK 5
E4: 2,9,3,6,7                            # reduction candidate for 2,9
E4: 2,9 => CTR
* 935.6.412.8.41.75...795.8...53...1.47641.538.....345.7578246931...3812753215..648
E4: 3,6,7                                # 18 pairs
F4: 2,9,7,8                              # reduction candidate for 2,9
F4: 2,9 => CTR
* 935..8412.8.41975...7.5.8...5....1.4764125389.....45.7578246931...381275321597648
F4: 7,8                                  # 20 pairs
E6: 2,9,3,6                              # reduction candidate for 2,9
E6: 2,9 => CTR
* 935.6.412.8.41.75...795.8...5..3.1.47641.538...3..45.7578246931...3812753215..648
E6: 3,6                                  # 19 pairs
* PAIR I5: 2,9 BLK 6
H4: 2,9,6                                # reduction candidate for 2,9
H4: 2,9                                  # 20 pairs
H6: 2,9,6                                # reduction candidate for 2,9
H6: 2,9                                  # 19 pairs
* PAIR I5: 2,9 COL I
I3: 2,9,3,6                              # reduction candidate for 2,9
I3: 2,9 => SOLVED
* 935872416682419753147653892259738164764125389813964527578246931496381275321597648
I3: 3,6                                  # 19 pairs
* PAIR E9: 7,9 COL E
E4: 7,9,2,3,6                            # reduction candidate for 7,9
E4: 7,9 => CTR
* 935.6.412.8.41.75...795.8...53...1.47641.538.....345.7578246931...3812753215..648
E4: 2,3,6                                # 18 pairs
* PAIR F9: 7,9 COL F
F4: 7,9,2,8                              # reduction candidate for 7,9
F4: 7,9 => CTR
* 935..841..8.41.75...7.52893.5....1.47641.538......45.7578246931...3812753215..648
F4: 2,8                                  # 21 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-190-base-pr-000.dot
* REASONING
* PRF # F3: 3,9 => SOL
* DIS # F3: 2 => CTR => F3: 3,9
* DIS # I3: 6,9 => CTR => I3: 2,3
* PRF # I3: 2,3 => SOL
* PRF # I3: 2,6 => SOL
* DIS # I3: 3,9 => CTR => I3: 2,6
* PRF # E1: 7 => SOL
* DIS # I3: 3,9 => CTR => I3: 2,6
* PRF # I3: 2,6 => SOL
* PRF # I3: 2,9 => SOL
* DIS # F3: 2,9 => CTR => F3: 3
* PRF # F3: 3 => SOL
* DIS # F4: 7,9 => CTR => F4: 2,8
* DIS # E4: 2,9 => CTR => E4: 3,6,7
* DIS # F4: 2,9 => CTR => F4: 7,8
* DIS # E6: 2,9 => CTR => E6: 3,6
* PRF # I3: 2,9 => SOL
* DIS # E4: 7,9 => CTR => E4: 2,3,6
* DIS # F4: 7,9 => CTR => F4: 2,8
* CNT  19 HDP CHAINS /  36 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A2,A3,A4,A8,B3,B6,B8,C2,C8,D3,E5,E9,F2,F9,H3,I1,I2,I5)
* 935...41..8.41.75...7.5.8...5....1.47641.538......45.7578246931...3812753215..648
* PAIR F2: 3,9 BLK 2
F3: 3,9,2                                # reduction candidate for 3,9
F3: 3,9 => SOLVED
* 935872416682419753147653892259738164764125389813964527578246931496381275321597648
* DURATION: 0:00:02.723830  START: 09:14:12.397866  END: 09:14:15.121696 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-190-base-pr-001.dot
* REASONING
* PRF # F3: 3,9 => SOL
* STA F3: 3,9
* CNT   1 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 190

solution: 935872416682419753147653892259738164764125389813964527578246931496381275321597648
info: 1840     FNBTWY   S8.f     39174

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

Solution

position: 935872416682419753147653892259738164764125389813964527578246931496381275321597648 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 # F3: 3,9 => SOL
* DIS # F3: 2 => CTR => F3: 3,9
* DIS # I3: 6,9 => CTR => I3: 2,3
* PRF # I3: 2,3 => SOL
* INC # D4: 6,9 => UNS
* INC # D6: 6,9 => UNS
* PRF # I3: 2,6 => SOL
* DIS # I3: 3,9 => CTR => I3: 2,6
* INC # E1: 2,6 => UNS
* PRF # E1: 7 => SOL
* DIS # I3: 3,9 => CTR => I3: 2,6
* PRF # I3: 2,6 => SOL
* PRF # I3: 2,9 => SOL
* INC # I3: 3,6 => UNS
* DIS # F3: 2,9 => CTR => F3: 3
* PRF # F3: 3 => SOL
* INC # H4: 2,9 => UNS
* INC # H6: 2,9 => UNS
* INC # A6: 2,8 => UNS
* INC # A6: 1 => UNS
* INC # F4: 2,8 => UNS
* DIS # F4: 7,9 => CTR => F4: 2,8
* DIS # E4: 2,9 => CTR => E4: 3,6,7
* INC # E4: 3,6,7 => UNS
* DIS # F4: 2,9 => CTR => F4: 7,8
* INC # F4: 7,8 => UNS
* DIS # E6: 2,9 => CTR => E6: 3,6
* INC # E6: 3,6 => UNS
* INC # H4: 2,9 => UNS
* INC # H6: 2,9 => UNS
* PRF # I3: 2,9 => SOL
* INC # I3: 3,6 => UNS
* DIS # E4: 7,9 => CTR => E4: 2,3,6
* INC # E4: 2,3,6 => UNS
* DIS # F4: 7,9 => CTR => F4: 2,8
* INC # F4: 2,8 => UNS
* CNT  36 HDP CHAINS /  36 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* PRF # F3: 3,9 => SOL
* STA F3: 3,9
* CNT   1 HDP CHAINS /   1 HYP OPENED