Analysis of xx-top500-184-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 1.35..2......4..7.6.........4..87...3.......1...............84.2..1........3..... initial

Autosolve

position: 1.35..2.4....4..7.6.4.......41.87...3.......1..........1....8432381.4...4..3.8... autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # E1: 6,9 => CTR => E1: 7
* PRF # E1: 7 => SOL
* PRF # D2: 6,9 => SOL
* DIS # H1: 6,9 => CTR => H1: 8
* PRF # H1: 8 => SOL
* PRF # D2: 2,9 => SOL
* DIS # D3: 2,9 => CTR => D3: 7,8
* DIS # B3: 2,9 => CTR => B3: 5,7,8
* DIS # A6: 5,9 => CTR => A6: 7,8
* DIS # H4: 5,9 => CTR => H4: 2,3,6
* DIS # A2: 5,9 => CTR => A2: 8
* PRF # A2: 8 => SOL
* PRF # A7: 5,9 => SOL
* DIS # A7: 7 => CTR => A7: 5,9
* CNT  14 HDP CHAINS /  32 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 # E1: 6,9 => CTR => E1: 7
* PRF E1: 7 => SOL
* STA E1: 7
* CNT   2 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

1.35..2......4..7.6.........4..87...3.......1...............84.2..1........3..... initial
1.35..2.4....4..7.6.4.......41.87...3.......1..........1....8432381.4...4..3.8... autosolve
193576284825943176674812935541687329382459761769231458916725843238164597457398612 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (8)
F1: 6,9
F2: 1,3
E3: 1,3
F3: 2,9
G2: 1,3
A4: 5,9
E6: 1,3
F6: 1,3

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
F2,E3: 1.. / F2 = 1  =>  3 pairs (_) / E3 = 1  =>  3 pairs (_)
E6,F6: 1.. / E6 = 1  =>  3 pairs (_) / F6 = 1  =>  3 pairs (_)
G9,H9: 1.. / G9 = 1  =>  4 pairs (_) / H9 = 1  =>  8 pairs (_)
F2,G2: 1.. / F2 = 1  =>  3 pairs (_) / G2 = 1  =>  3 pairs (_)
E3,E6: 1.. / E3 = 1  =>  3 pairs (_) / E6 = 1  =>  3 pairs (_)
F2,F6: 1.. / F2 = 1  =>  3 pairs (_) / F6 = 1  =>  3 pairs (_)
H3,H9: 1.. / H3 = 1  =>  4 pairs (_) / H9 = 1  =>  8 pairs (_)
H9,I9: 2.. / H9 = 2  =>  4 pairs (_) / I9 = 2  =>  8 pairs (_)
E5,E7: 2.. / E5 = 2  => 17 pairs (_) / E7 = 2  =>  8 pairs (_)
F2,E3: 3.. / F2 = 3  =>  3 pairs (_) / E3 = 3  =>  3 pairs (_)
E6,F6: 3.. / E6 = 3  =>  3 pairs (_) / F6 = 3  =>  3 pairs (_)
G4,H4: 3.. / G4 = 3  =>  4 pairs (_) / H4 = 3  =>  8 pairs (_)
F2,G2: 3.. / F2 = 3  =>  3 pairs (_) / G2 = 3  =>  3 pairs (_)
E3,E6: 3.. / E3 = 3  =>  3 pairs (_) / E6 = 3  =>  3 pairs (_)
F2,F6: 3.. / F2 = 3  =>  3 pairs (_) / F6 = 3  =>  3 pairs (_)
H3,H4: 3.. / H3 = 3  =>  4 pairs (_) / H4 = 3  =>  8 pairs (_)
D5,D6: 4.. / D5 = 4  =>  8 pairs (_) / D6 = 4  =>  0 pairs (X)
G5,G6: 4.. / G5 = 4  =>  0 pairs (X) / G6 = 4  =>  8 pairs (_)
D5,G5: 4.. / D5 = 4  =>  8 pairs (_) / G5 = 4  =>  0 pairs (X)
D6,G6: 4.. / D6 = 4  =>  0 pairs (X) / G6 = 4  =>  8 pairs (_)
E5,F5: 5.. / E5 = 5  =>  9 pairs (_) / F5 = 5  =>  8 pairs (_)
F5,F7: 5.. / F5 = 5  =>  8 pairs (_) / F7 = 5  =>  9 pairs (_)
H1,I2: 6.. / H1 = 6  =>  0 pairs (X) / I2 = 6  =>  9 pairs (_)
D2,I2: 6.. / D2 = 6  =>  0 pairs (X) / I2 = 6  =>  9 pairs (_)
B1,B3: 7.. / B1 = 7  =>  0 pairs (X) / B3 = 7  =>  0 pairs (_)
E1,D3: 7.. / E1 = 7  =>  0 pairs (*) / D3 = 7  =>  0 pairs (X)
B1,E1: 7.. / B1 = 7  =>  0 pairs (X) / E1 = 7  =>  0 pairs (_)
B3,D3: 7.. / B3 = 7  =>  0 pairs (*) / D3 = 7  =>  0 pairs (X)
C5,G5: 7.. / C5 = 7  =>  0 pairs (X) / G5 = 7  =>  8 pairs (_)
A6,A7: 7.. / A6 = 7  =>  0 pairs (*) / A7 = 7  =>  0 pairs (X)
D3,D7: 7.. / D3 = 7  =>  0 pairs (X) / D7 = 7  =>  0 pairs (_)
D2,D3: 8.. / D2 = 8  =>  0 pairs (X) / D3 = 8  =>  0 pairs (_)
B1,H1: 8.. / B1 = 8  =>  0 pairs (X) / H1 = 8  =>  0 pairs (_)
B5,H5: 8.. / B5 = 8  =>  0 pairs (*) / H5 = 8  =>  0 pairs (X)
A2,A6: 8.. / A2 = 8  =>  0 pairs (*) / A6 = 8  =>  0 pairs (X)
* DURATION: 0:00:55.049054  START: 08:58:58.360237  END: 08:59:53.409291 2017-05-04
* CP COUNT: (35)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A4,E3,E6,F1,F2,F3,F6,G2)
* 1.35..2.4....4..7.6.4.......41.87...3.......1..........1....8432381.4...4..3.8...
* PAIR F1: 6,9 BLK 2
E1: 6,9,7                                # reduction candidate for 6,9
E1: 6,9 => CTR
* 1735..284....4..766.47......41.87...38......1........8.1....8432381.4...4..3.8...
E1: 7 => SOLVED
* 193576284825943176674812935541687329382459761769231458916725843238164597457398612
D2: 6,9,2,8                              # reduction candidate for 6,9
D2: 6,9 => SOLVED
* 193576284825943176674812935541687329382459761769231458916725843238164597457398612
D2: 2,8                                  # 11 pairs
* PAIR F1: 6,9 ROW 1
H1: 6,9,8                                # reduction candidate for 6,9
H1: 6,9 => CTR
* 18357.2.4....4..7.674.......41.87...3......818........71....8432381.4...4..3.8...
H1: 8 => SOLVED
* 193576284825943176674812935541687329382459761769231458916725843238164597457398612
* PAIR F1: 6,9 COL F
F5: 6,9,2,5                              # reduction candidate for 6,9
F5: 6,9                                  #  9 pairs
F7: 6,9,2,5                              # reduction candidate for 6,9
F7: 6,9                                  #  8 pairs
* PAIR E3: 1,3 ROW 3
G3: 1,3,5,9                              # reduction candidate for 1,3
G3: 1,3                                  #  8 pairs
H3: 1,3,5,8,9                            # reduction candidate for 1,3
H3: 1,3                                  # 10 pairs
* PAIR F3: 2,9 BLK 2
D2: 2,9,6,8                              # reduction candidate for 2,9
D2: 2,9 => SOLVED
* 193576284825943176674812935541687329382459761769231458916725843238164597457398612
D2: 6,8                                  #  9 pairs
D3: 2,9,7,8                              # reduction candidate for 2,9
D3: 2,9 => CTR
* 1.357.2.4...84..76674.......41.87...3.......18........71....8432381.4...4..3.8...
D3: 7,8                                  #  9 pairs
* PAIR F3: 2,9 ROW 3
B3: 2,9,5,7,8                            # reduction candidate for 2,9
B3: 2,9 => CTR
* 1735..284....4..766.4.......41.87...3.......1..........1....8432381.4...4..3.8...
B3: 5,7,8                                #  8 pairs
* PAIR F3: 2,9 COL F
F5: 2,9,5,6                              # reduction candidate for 2,9
F5: 2,9                                  # 13 pairs
F7: 2,9,5,6                              # reduction candidate for 2,9
F7: 2,9                                  # 10 pairs
* PAIR G2: 1,3 BLK 3
G3: 1,3,5,9                              # reduction candidate for 1,3
G3: 1,3                                  #  8 pairs
H3: 1,3,5,8,9                            # reduction candidate for 1,3
H3: 1,3                                  # 10 pairs
* PAIR A4: 5,9 BLK 4
A6: 5,9,7,8                              # reduction candidate for 5,9
A6: 5,9 => CTR
* 1.35..2.48...4..7.6.48......41.87...3.......1........871....8432381.4...4..3.8...
A6: 7,8                                  #  9 pairs
B6: 5,9,2,6,8                            # reduction candidate for 5,9
B6: 5,9                                  # 10 pairs
C6: 5,9,2,6,7                            # reduction candidate for 5,9
C6: 5,9                                  # 10 pairs
* PAIR A4: 5,9 ROW 4
G4: 5,9,3,6                              # reduction candidate for 5,9
G4: 5,9                                  # 11 pairs
H4: 5,9,2,3,6                            # reduction candidate for 5,9
H4: 5,9 => CTR
* 183579264...643178674812.3..412873.63.....781....31....1.72.8432381.4...4.73.8.12
H4: 2,3,6                                #  8 pairs
I4: 5,9,2,6                              # reduction candidate for 5,9
I4: 5,9                                  # 11 pairs
* PAIR A4: 5,9 COL A
A2: 5,9,8                                # reduction candidate for 5,9
A2: 5,9 => CTR
* 1.35..2.4....4..7.6.47......41.87...3......818........71....8432381.4...4..3.8...
A2: 8 => SOLVED
* 193576284825943176674812935541687329382459761769231458916725843238164597457398612
A7: 5,9,7                                # reduction candidate for 5,9
A7: 5,9 => SOLVED
* 193576284825943176674812935541687329382459761769231458916725843238164597457398612
A7: 7 => CTR
* 1735..284...84..766847.2....41.87...3.......18........71....8432381.4...4..3.8...
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-184-base-pr-000.dot
* REASONING
* DIS # E1: 6,9 => CTR => E1: 7
* PRF # E1: 7 => SOL
* PRF # D2: 6,9 => SOL
* DIS # H1: 6,9 => CTR => H1: 8
* PRF # H1: 8 => SOL
* PRF # D2: 2,9 => SOL
* DIS # D3: 2,9 => CTR => D3: 7,8
* DIS # B3: 2,9 => CTR => B3: 5,7,8
* DIS # A6: 5,9 => CTR => A6: 7,8
* DIS # H4: 5,9 => CTR => H4: 2,3,6
* DIS # A2: 5,9 => CTR => A2: 8
* PRF # A2: 8 => SOL
* PRF # A7: 5,9 => SOL
* DIS # A7: 7 => CTR => A7: 5,9
* CNT  14 HDP CHAINS /  32 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A4,E3,E6,F1,F2,F3,F6,G2)
* 1.35..2.4....4..7.6.4.......41.87...3.......1..........1....8432381.4...4..3.8...
* PAIR F1: 6,9 BLK 2
E1: 6,9,7                                # reduction candidate for 6,9
E1: 6,9 => CTR
* 1735..284....4..766.47......41.87...38......1........8.1....8432381.4...4..3.8...
E1: 7 => SOLVED
* 193576284825943176674812935541687329382459761769231458916725843238164597457398612
* DURATION: 0:00:01.778809  START: 09:00:23.451850  END: 09:00:25.230659 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-184-base-pr-001.dot
* REASONING
* DIS # E1: 6,9 => CTR => E1: 7
* PRF E1: 7 => SOL
* STA E1: 7
* CNT   2 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 184

solution: 193576284825943176674812935541687329382459761769231458916725843238164597457398612
info: 1829     FNBTHWY  S8.f     26017

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

Solution

position: 193576284825943176674812935541687329382459761769231458916725843238164597457398612 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 # E1: 6,9 => CTR => E1: 7
* PRF # E1: 7 => SOL
* PRF # D2: 6,9 => SOL
* INC # D2: 2,8 => UNS
* DIS # H1: 6,9 => CTR => H1: 8
* PRF # H1: 8 => SOL
* INC # F5: 6,9 => UNS
* INC # F7: 6,9 => UNS
* INC # G3: 1,3 => UNS
* INC # H3: 1,3 => UNS
* PRF # D2: 2,9 => SOL
* INC # D2: 6,8 => UNS
* DIS # D3: 2,9 => CTR => D3: 7,8
* INC # D3: 7,8 => UNS
* DIS # B3: 2,9 => CTR => B3: 5,7,8
* INC # B3: 5,7,8 => UNS
* INC # F5: 2,9 => UNS
* INC # F7: 2,9 => UNS
* INC # G3: 1,3 => UNS
* INC # H3: 1,3 => UNS
* DIS # A6: 5,9 => CTR => A6: 7,8
* INC # A6: 7,8 => UNS
* INC # B6: 5,9 => UNS
* INC # C6: 5,9 => UNS
* INC # G4: 5,9 => UNS
* DIS # H4: 5,9 => CTR => H4: 2,3,6
* INC # H4: 2,3,6 => UNS
* INC # I4: 5,9 => UNS
* DIS # A2: 5,9 => CTR => A2: 8
* PRF # A2: 8 => SOL
* PRF # A7: 5,9 => SOL
* DIS # A7: 7 => CTR => A7: 5,9
* CNT  32 HDP CHAINS /  32 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # E1: 6,9 => CTR => E1: 7
* PRF E1: 7 => SOL
* STA E1: 7
* CNT   2 HDP CHAINS /   1 HYP OPENED