Analysis of xx-top500-108-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: ...4..52.1.8................5.34....3.......8...2...1..4....3..6...7.........1... initial

Autosolve

position: .3.41852.1.8.5..34.....318.85134.2..3.21..458...285.13.4.8..3.161357489228..31.45 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # F5: 6,9 => SOL
* PRF # B5: 7 => SOL
* DIS # I4: 6,7 => CTR => I4: 9
* DIS # F4: 9 => CTR => F4: 6,7
* DIS # G2: 6,7 => CTR => G2: 9
* CNT   5 HDP CHAINS /  30 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 # F5: 6,9 => SOL
* STA F5: 6,9
* CNT   1 HDP CHAINS /   9 HYP OPENED

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

Details

Positions

...4..52.1.8................5.34....3.......8...2...1..4....3..6...7.........1... initial
.3.41852.1.8.5..34.....318.85134.2..3.21..458...285.13.4.8..3.161357489228..31.45 autosolve
739418526168752934524693187851347269372169458496285713945826371613574892287931645 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (9)
A1: 7,9
A3: 4,5
C3: 4,5
E5: 6,9
H4: 6,7
C9: 7,9
D9: 6,9
H7: 6,7
G9: 6,7

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
B2,B3: 2.. / B2 = 2  => 11 pairs (_) / B3 = 2  => 11 pairs (_)
F2,E3: 2.. / F2 = 2  => 11 pairs (_) / E3 = 2  => 11 pairs (_)
E7,F7: 2.. / E7 = 2  => 11 pairs (_) / F7 = 2  => 11 pairs (_)
B2,F2: 2.. / B2 = 2  => 11 pairs (_) / F2 = 2  => 11 pairs (_)
B3,E3: 2.. / B3 = 2  => 11 pairs (_) / E3 = 2  => 11 pairs (_)
E3,E7: 2.. / E3 = 2  => 11 pairs (_) / E7 = 2  => 11 pairs (_)
F2,F7: 2.. / F2 = 2  => 11 pairs (_) / F7 = 2  => 11 pairs (_)
A3,C3: 4.. / A3 = 4  => 10 pairs (_) / C3 = 4  =>  8 pairs (_)
A6,C6: 4.. / A6 = 4  =>  8 pairs (_) / C6 = 4  => 10 pairs (_)
A3,A6: 4.. / A3 = 4  => 10 pairs (_) / A6 = 4  =>  8 pairs (_)
C3,C6: 4.. / C3 = 4  =>  8 pairs (_) / C6 = 4  => 10 pairs (_)
A3,C3: 5.. / A3 = 5  =>  8 pairs (_) / C3 = 5  => 10 pairs (_)
A7,C7: 5.. / A7 = 5  => 10 pairs (_) / C7 = 5  =>  8 pairs (_)
A3,A7: 5.. / A3 = 5  =>  8 pairs (_) / A7 = 5  => 10 pairs (_)
C3,C7: 5.. / C3 = 5  => 10 pairs (_) / C7 = 5  =>  8 pairs (_)
H7,G9: 6.. / H7 = 6  => 18 pairs (_) / G9 = 6  => 18 pairs (_)
C1,I1: 6.. / C1 = 6  => 10 pairs (_) / I1 = 6  => 16 pairs (_)
D9,G9: 6.. / D9 = 6  => 18 pairs (_) / G9 = 6  => 18 pairs (_)
C1,C6: 6.. / C1 = 6  => 10 pairs (_) / C6 = 6  => 16 pairs (_)
H4,H7: 6.. / H4 = 6  => 18 pairs (_) / H7 = 6  => 18 pairs (_)
D2,D3: 7.. / D2 = 7  => 12 pairs (_) / D3 = 7  => 11 pairs (_)
F4,F5: 7.. / F4 = 7  =>  0 pairs (*) / F5 = 7  =>  0 pairs (X)
H7,G9: 7.. / H7 = 7  => 18 pairs (_) / G9 = 7  => 18 pairs (_)
B5,F5: 7.. / B5 = 7  =>  0 pairs (*) / F5 = 7  =>  0 pairs (X)
C9,G9: 7.. / C9 = 7  => 18 pairs (_) / G9 = 7  => 18 pairs (_)
H4,H7: 7.. / H4 = 7  => 18 pairs (_) / H7 = 7  => 18 pairs (_)
I4,G6: 9.. / I4 = 9  => 17 pairs (_) / G6 = 9  =>  0 pairs (X)
F4,I4: 9.. / F4 = 9  =>  0 pairs (X) / I4 = 9  => 17 pairs (_)
C9,D9: 9.. / C9 = 9  => 18 pairs (_) / D9 = 9  => 18 pairs (_)
G2,G6: 9.. / G2 = 9  => 17 pairs (_) / G6 = 9  =>  0 pairs (X)
* DURATION: 0:00:53.796770  START: 06:27:33.331282  END: 06:28:27.128052 2017-05-04
* CP COUNT: (30)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,A3,C3,C9,D9,E5,G9,H4,H7)
* .3.41852.1.8.5..34.....318.85134.2..3.21..458...285.13.4.8..3.161357489228..31.45
* PAIR A1: 7,9 BLK 1
C1: 7,9,6                                # reduction candidate for 7,9
C1: 7,9                                  # 16 pairs
B2: 7,9,2,6                              # reduction candidate for 7,9
B2: 7,9                                  # 13 pairs
B3: 7,9,2,6                              # reduction candidate for 7,9
B3: 7,9                                  # 13 pairs
* PAIR A1: 7,9 ROW 1
I1: 7,9,6                                # reduction candidate for 7,9
I1: 6                                    # 16 pairs
I1: 7,9                                  # 10 pairs
* PAIR A1: 7,9 COL A
A6: 7,9,4                                # reduction candidate for 7,9
A6: 7,9                                  # 10 pairs
A7: 7,9,5                                # reduction candidate for 7,9
A7: 7,9                                  #  8 pairs
* PAIR E5: 6,9 BLK 5
F4: 6,9,7                                # reduction candidate for 6,9
F4: 6,9                                  # 12 pairs
F5: 6,9,7                                # reduction candidate for 6,9
F5: 6,9 => SOLVED
* 739418526168752934524693187851347269372169458496285713945826371613574892287931645
F5: 7                                    # 12 pairs
* PAIR E5: 6,9 ROW 5
B5: 6,9,7                                # reduction candidate for 6,9
B5: 7 => SOLVED
* 739418526168752934524693187851347269372169458496285713945826371613574892287931645
B5: 6,9                                  # 12 pairs
* PAIR E5: 6,9 COL E
E3: 6,9,2                                # reduction candidate for 6,9
E3: 6,9                                  # 11 pairs
E7: 6,9,2                                # reduction candidate for 6,9
E7: 6,9                                  # 11 pairs
* PAIR H4: 6,7 BLK 6
I4: 6,7,9                                # reduction candidate for 6,7
I4: 6,7 => CTR
* .3.41852.1.895..34...7231898513492..392167458...285913.4.892361613574892289631745
I4: 9                                    # 17 pairs
G6: 6,7,9                                # reduction candidate for 6,7
G6: 6,7                                  # 17 pairs
* PAIR H4: 6,7 ROW 4
F4: 6,7,9                                # reduction candidate for 6,7
F4: 9 => CTR
* .3.41852.1.895..34...7231898513492..392167458...285913.4.892361613574892289631745
F4: 6,7                                  # 17 pairs
* PAIR C9: 7,9 BLK 7
A7: 7,9,5                                # reduction candidate for 7,9
A7: 7,9                                  #  8 pairs
C7: 7,9,5                                # reduction candidate for 7,9
C7: 7,9                                  # 10 pairs
* PAIR C9: 7,9 COL C
C1: 7,9,6                                # reduction candidate for 7,9
C1: 7,9                                  # 16 pairs
C6: 7,9,4,6                              # reduction candidate for 7,9
C6: 7,9                                  # 10 pairs
* PAIR D9: 6,9 BLK 8
E7: 6,9,2                                # reduction candidate for 6,9
E7: 6,9                                  # 11 pairs
F7: 6,9,2                                # reduction candidate for 6,9
F7: 6,9                                  # 11 pairs
* PAIR D9: 6,9 COL D
D2: 6,9,7                                # reduction candidate for 6,9
D2: 6,9                                  # 11 pairs
D3: 6,9,7                                # reduction candidate for 6,9
D3: 6,9                                  # 12 pairs
* PAIR G9: 6,7 COL G
G2: 6,7,9                                # reduction candidate for 6,7
G2: 6,7 => CTR
* .3.41852.1.895..34...7231898513492..392167458...285913.4.892361613574892289631745
G2: 9                                    # 17 pairs
G6: 6,7,9                                # reduction candidate for 6,7
G6: 6,7                                  # 17 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-108-base-pr-000.dot
* REASONING
* PRF # F5: 6,9 => SOL
* PRF # B5: 7 => SOL
* DIS # I4: 6,7 => CTR => I4: 9
* DIS # F4: 9 => CTR => F4: 6,7
* DIS # G2: 6,7 => CTR => G2: 9
* CNT   5 HDP CHAINS /  30 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,A3,C3,C9,D9,E5,G9,H4,H7)
* .3.41852.1.8.5..34.....318.85134.2..3.21..458...285.13.4.8..3.161357489228..31.45
* PAIR A1: 7,9 BLK 1
C1: 7,9,6                                # reduction candidate for 7,9
C1: 7,9                                  # 16 pairs
B2: 7,9,2,6                              # reduction candidate for 7,9
B2: 7,9                                  # 13 pairs
B3: 7,9,2,6                              # reduction candidate for 7,9
B3: 7,9                                  # 13 pairs
* PAIR A1: 7,9 ROW 1
I1: 7,9,6                                # reduction candidate for 7,9
I1: 6                                    # 16 pairs
I1: 7,9                                  # 10 pairs
* PAIR A1: 7,9 COL A
A6: 7,9,4                                # reduction candidate for 7,9
A6: 7,9                                  # 10 pairs
A7: 7,9,5                                # reduction candidate for 7,9
A7: 7,9                                  #  8 pairs
* PAIR E5: 6,9 BLK 5
F4: 6,9,7                                # reduction candidate for 6,9
F4: 6,9                                  # 12 pairs
F5: 6,9,7                                # reduction candidate for 6,9
F5: 6,9 => SOLVED
* 739418526168752934524693187851347269372169458496285713945826371613574892287931645
* DURATION: 0:00:10.077442  START: 06:28:57.958293  END: 06:29:08.035735 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-108-base-pr-001.dot
* REASONING
* PRF # F5: 6,9 => SOL
* STA F5: 6,9
* CNT   1 HDP CHAINS /   9 HYP OPENED

Header Info

Top 500 Minimum 17 108

solution: 739418526168752934524693187851347269372169458496285713945826371613574892287931645
info: 1629     FNBHWXY  S8.f     9130

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

Solution

position: 739418526168752934524693187851347269372169458496285713945826371613574892287931645 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:

* INC # C1: 7,9 => UNS
* INC # B2: 7,9 => UNS
* INC # B3: 7,9 => UNS
* INC # I1: 7,9 => UNS
* INC # I1: 6 => UNS
* INC # A6: 7,9 => UNS
* INC # A7: 7,9 => UNS
* INC # F4: 6,9 => UNS
* PRF # F5: 6,9 => SOL
* INC # F5: 7 => UNS
* INC # B5: 6,9 => UNS
* PRF # B5: 7 => SOL
* INC # E3: 6,9 => UNS
* INC # E7: 6,9 => UNS
* DIS # I4: 6,7 => CTR => I4: 9
* INC # I4: 9 => UNS
* INC # G6: 6,7 => UNS
* INC # F4: 6,7 => UNS
* DIS # F4: 9 => CTR => F4: 6,7
* INC # A7: 7,9 => UNS
* INC # C7: 7,9 => UNS
* INC # C1: 7,9 => UNS
* INC # C6: 7,9 => UNS
* INC # E7: 6,9 => UNS
* INC # F7: 6,9 => UNS
* INC # D2: 6,9 => UNS
* INC # D3: 6,9 => UNS
* DIS # G2: 6,7 => CTR => G2: 9
* INC # G2: 9 => UNS
* INC # G6: 6,7 => UNS
* CNT  30 HDP CHAINS /  30 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # C1: 7,9 => UNS
* INC # B2: 7,9 => UNS
* INC # B3: 7,9 => UNS
* INC # I1: 7,9 => UNS
* INC # I1: 6 => UNS
* INC # A6: 7,9 => UNS
* INC # A7: 7,9 => UNS
* INC # F4: 6,9 => UNS
* PRF # F5: 6,9 => SOL
* STA F5: 6,9
* CNT   9 HDP CHAINS /   9 HYP OPENED