Analysis of xx-top500-043-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: .3.5.............4.......6.6.4...1.....3..7..2............64.2.....1.3...8......5 initial

Autosolve

position: .3.5.............4.......6.6.4...1.....3..7..2.3......3...64.2.....153...8......5 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # C1: 2,6 => CTR => C1: 1,7,8,9
* PRF # C1: 1,7,8,9 => SOL
* DIS # C2: 2,6 => CTR => C2: 1,5,7,8,9
* DIS # F2: 2,6 => CTR => F2: 1,3,7,8,9
* DIS # B8: 2,6 => CTR => B8: 4
* PRF # B8: 4 => SOL
* DIS # E3: 2,4 => CTR => E3: 3,7,8,9
* PRF # B8: 2,4 => SOL
* DIS # B8: 6 => CTR => B8: 2,4
* PRF # F1: 1,6 => SOL
* DIS # F1: 2,7,8,9 => CTR => F1: 1,6
* DIS # F2: 1,6 => CTR => F2: 2,3,7,8,9
* DIS # C2: 1,6 => CTR => C2: 2,5,7,8,9
* PRF # D6: 1,6 => SOL
* DIS # D6: 4 => CTR => D6: 1,6
* DIS # A3: 1,4 => CTR => A3: 5,7,8,9
* DIS # D6: 1,4 => CTR => D6: 6
* PRF # D6: 6 => SOL
* DIS # D6: 1 => CTR => D6: 4,6
* DIS # I8: 8,9 => CTR => I8: 6,7
* CNT  20 HDP CHAINS /  35 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 # C1: 2,6 => CTR => C1: 1,7,8,9
* PRF C1: 1,7,8,9 => SOL
* STA C1: 1,7,8,9
* CNT   2 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

.3.5.............4.......6.6.4...1.....3..7..2............64.2.....1.3...8......5 initial
.3.5.............4.......6.6.4...1.....3..7..2.3......3...64.2.....153...8......5 autosolve
438576219569123874721489563694758132815342796273691458357864921946215387182937645 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (7)
B2: 2,6
B3: 2,4
D2: 1,6
D3: 1,4
G6: 4,6
G7: 8,9
G9: 4,6

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
I7,H9: 1.. / I7 = 1  =>  8 pairs (_) / H9 = 1  =>  9 pairs (_)
I4,I5: 2.. / I4 = 2  =>  9 pairs (_) / I5 = 2  =>  0 pairs (X)
H2,I3: 3.. / H2 = 3  =>  0 pairs (X) / I3 = 3  =>  7 pairs (_)
H4,I4: 3.. / H4 = 3  =>  7 pairs (_) / I4 = 3  =>  0 pairs (X)
E9,F9: 3.. / E9 = 3  =>  7 pairs (_) / F9 = 3  =>  7 pairs (_)
H2,H4: 3.. / H2 = 3  =>  0 pairs (X) / H4 = 3  =>  7 pairs (_)
I3,I4: 3.. / I3 = 3  =>  7 pairs (_) / I4 = 3  =>  0 pairs (X)
A1,E1: 4.. / A1 = 4  =>  0 pairs (*) / E1 = 4  =>  0 pairs (X)
E5,H5: 4.. / E5 = 4  =>  0 pairs (*) / H5 = 4  =>  0 pairs (X)
B3,B8: 4.. / B3 = 4  =>  0 pairs (X) / B8 = 4  =>  0 pairs (_)
D3,D6: 4.. / D3 = 4  =>  0 pairs (*) / D6 = 4  =>  0 pairs (X)
G6,G9: 4.. / G6 = 4  =>  0 pairs (*) / G9 = 4  =>  0 pairs (X)
G2,G3: 5.. / G2 = 5  =>  7 pairs (_) / G3 = 5  =>  7 pairs (_)
B7,C7: 5.. / B7 = 5  => 12 pairs (_) / C7 = 5  =>  8 pairs (_)
I8,G9: 6.. / I8 = 6  =>  0 pairs (X) / G9 = 6  =>  0 pairs (_)
C1,F1: 6.. / C1 = 6  =>  0 pairs (X) / F1 = 6  =>  0 pairs (_)
F5,I5: 6.. / F5 = 6  =>  0 pairs (X) / I5 = 6  =>  0 pairs (_)
C9,G9: 6.. / C9 = 6  =>  0 pairs (X) / G9 = 6  =>  0 pairs (_)
B2,B8: 6.. / B2 = 6  =>  0 pairs (*) / B8 = 6  =>  0 pairs (X)
D2,D6: 6.. / D2 = 6  =>  0 pairs (X) / D6 = 6  =>  0 pairs (_)
G6,G9: 6.. / G6 = 6  =>  0 pairs (X) / G9 = 6  =>  0 pairs (_)
B4,B6: 7.. / B4 = 7  =>  8 pairs (_) / B6 = 7  =>  8 pairs (_)
A5,C5: 8.. / A5 = 8  =>  7 pairs (_) / C5 = 8  =>  7 pairs (_)
D7,D8: 8.. / D7 = 8  =>  9 pairs (_) / D8 = 8  =>  8 pairs (_)
* DURATION: 0:00:38.607219  START: 04:08:40.904343  END: 04:09:19.511562 2017-05-04
* CP COUNT: (24)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B2,B3,D2,D3,G6,G7,G9)
* .3.5.............4.......6.6.4...1.....3..7..2.3......3...64.2.....153...8......5
* PAIR B2: 2,6 BLK 1
C1: 2,6,1,7,8,9                          # reduction candidate for 2,6
C1: 2,6 => CTR
* .32546...........4.4.1...6.6.4...1.....3..7..2.34..6..3...64.2.....153.6.86...4.5
C1: 1,7,8,9 => SOLVED
* 438576219569123874721489563694758132815342796273691458357864921946215387182937645
C2: 2,6,1,5,7,8,9                        # reduction candidate for 2,6
C2: 2,6 => CTR
* .3.5.6......1....4.4.....6.6.4...1.....3..7..2.3......3...64.2.....153...8......5
C2: 1,5,7,8,9                            #  7 pairs
* PAIR B2: 2,6 ROW 2
F2: 2,6,1,3,7,8,9                        # reduction candidate for 2,6
F2: 2,6 => CTR
* 43.5...1..6.1.2..4.2.4...6.6.4...1.....34.7..2.36..4..3...64.2..4..153...8....645
F2: 1,3,7,8,9                            #  7 pairs
* PAIR B2: 2,6 COL B
B8: 2,6,4                                # reduction candidate for 2,6
B8: 2,6 => CTR
* .3.546...........4.4.1...6.6.4...1.....3..7..2.34..6..3...64.2.....153.6.86...4.5
B8: 4 => SOLVED
* 438576219569123874721489563694758132815342796273691458357864921946215387182937645
* PAIR B3: 2,4 ROW 3
E3: 2,4,3,7,8,9                          # reduction candidate for 2,4
E3: 2,4 => CTR
* .3.5.6...........4...1...6.6.4...1.....3..7..2.34..6..3...64.2.....153.6.86...4.5
E3: 3,7,8,9                              #  7 pairs
* PAIR B3: 2,4 COL B
B8: 2,4,6                                # reduction candidate for 2,4
B8: 2,4 => SOLVED
* 438576219569123874721489563694758132815342796273691458357864921946215387182937645
B8: 6 => CTR
* .3.5.............4.4.1...6.6.4...1.....3..7..2.34..6..3...64.2..6..153...8....4.5
* PAIR D2: 1,6 BLK 2
F1: 1,6,2,7,8,9                          # reduction candidate for 1,6
F1: 1,6 => SOLVED
* 438576219569123874721489563694758132815342796273691458357864921946215387182937645
F1: 2,7,8,9 => CTR
* .365......2......4.4.1...6.6.4...1.....3..7..2.34..6..3...64.2.....153...8......5
F2: 1,6,2,3,7,8,9                        # reduction candidate for 1,6
F2: 1,6 => CTR
* .365......2......4.4.....6.6.4...1.....3..7..2.3......3...64.2.....153...8......5
F2: 2,3,7,8,9                            #  7 pairs
* PAIR D2: 1,6 ROW 2
C2: 1,6,2,5,7,8,9                        # reduction candidate for 1,6
C2: 1,6 => CTR
* .3.5......2......4.4.1...6.6.4...1.....3..7..2.34..6..3...64.2..6..153...8....4.5
C2: 2,5,7,8,9                            #  7 pairs
* PAIR D2: 1,6 COL D
D6: 1,6,4                                # reduction candidate for 1,6
D6: 1,6 => SOLVED
* 438576219569123874721489563694758132815342796273691458357864921946215387182937645
D6: 4 => CTR
* .3.5........6....4...1...6.6.4...1.....3..7..2.34..6..3...64.2..6..153...8....4.5
* PAIR D3: 1,4 ROW 3
A3: 1,4,5,7,8,9                          # reduction candidate for 1,4
A3: 1,4 => CTR
* 43.5.6.1..6.1....412.4...6.6.4...1.....34.7.62.36..4..3...64.21.462153...8....645
A3: 5,7,8,9                              #  7 pairs
* PAIR D3: 1,4 COL D
D6: 1,4,6                                # reduction candidate for 1,4
D6: 1,4 => CTR
* .365......2.6....4.4.1...6.6.4...1.....3..7..2.34.....3...64.2..6..153...8....6.5
D6: 6 => SOLVED
* 438576219569123874721489563694758132815342796273691458357864921946215387182937645
* PAIR G6: 4,6 ROW 6
D6: 4,6,1                                # reduction candidate for 4,6
D6: 1 => CTR
* .3.5........6....4...4...6.6.4...1.....3..7..2.31.....3...64.2.....153...8......5
D6: 4,6                                  #  9 pairs
* PAIR G7: 8,9 BLK 9
I7: 8,9,1,7                              # reduction candidate for 8,9
I7: 8,9                                  # 17 pairs
H8: 8,9,4,7                              # reduction candidate for 8,9
H8: 8,9                                  # 10 pairs
I8: 8,9,6,7                              # reduction candidate for 8,9
I8: 8,9 => CTR
* 43.5.6.17.6.1...94.214...636.4...132.193427562.36.14.9357864921946215378182...645
I8: 6,7                                  #  8 pairs
* PAIR G7: 8,9 ROW 7
D7: 8,9,7                                # reduction candidate for 8,9
D7: 8,9                                  # 10 pairs
D7: 7                                    #  9 pairs
* PAIR G7: 8,9 COL G
G1: 8,9,2                                # reduction candidate for 8,9
G1: 8,9                                  # 10 pairs
G2: 8,9,2,5                              # reduction candidate for 8,9
G2: 8,9                                  #  8 pairs
G3: 8,9,2,5                              # reduction candidate for 8,9
G3: 8,9                                  #  8 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-043-base-pr-000.dot
* REASONING
* DIS # C1: 2,6 => CTR => C1: 1,7,8,9
* PRF # C1: 1,7,8,9 => SOL
* DIS # C2: 2,6 => CTR => C2: 1,5,7,8,9
* DIS # F2: 2,6 => CTR => F2: 1,3,7,8,9
* DIS # B8: 2,6 => CTR => B8: 4
* PRF # B8: 4 => SOL
* DIS # E3: 2,4 => CTR => E3: 3,7,8,9
* PRF # B8: 2,4 => SOL
* DIS # B8: 6 => CTR => B8: 2,4
* PRF # F1: 1,6 => SOL
* DIS # F1: 2,7,8,9 => CTR => F1: 1,6
* DIS # F2: 1,6 => CTR => F2: 2,3,7,8,9
* DIS # C2: 1,6 => CTR => C2: 2,5,7,8,9
* PRF # D6: 1,6 => SOL
* DIS # D6: 4 => CTR => D6: 1,6
* DIS # A3: 1,4 => CTR => A3: 5,7,8,9
* DIS # D6: 1,4 => CTR => D6: 6
* PRF # D6: 6 => SOL
* DIS # D6: 1 => CTR => D6: 4,6
* DIS # I8: 8,9 => CTR => I8: 6,7
* CNT  20 HDP CHAINS /  35 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B2,B3,D2,D3,G6,G7,G9)
* .3.5.............4.......6.6.4...1.....3..7..2.3......3...64.2.....153...8......5
* PAIR B2: 2,6 BLK 1
C1: 2,6,1,7,8,9                          # reduction candidate for 2,6
C1: 2,6 => CTR
* .32546...........4.4.1...6.6.4...1.....3..7..2.34..6..3...64.2.....153.6.86...4.5
C1: 1,7,8,9 => SOLVED
* 438576219569123874721489563694758132815342796273691458357864921946215387182937645
* DURATION: 0:00:01.892583  START: 04:09:50.440293  END: 04:09:52.332876 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-043-base-pr-001.dot
* REASONING
* DIS # C1: 2,6 => CTR => C1: 1,7,8,9
* PRF C1: 1,7,8,9 => SOL
* STA C1: 1,7,8,9
* CNT   2 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 043

solution: 438576219569123874721489563694758132815342796273691458357864921946215387182937645
info: 1375     FNBHX    S8.f     17956

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

Solution

position: 438576219569123874721489563694758132815342796273691458357864921946215387182937645 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 # C1: 2,6 => CTR => C1: 1,7,8,9
* PRF # C1: 1,7,8,9 => SOL
* DIS # C2: 2,6 => CTR => C2: 1,5,7,8,9
* INC # C2: 1,5,7,8,9 => UNS
* DIS # F2: 2,6 => CTR => F2: 1,3,7,8,9
* INC # F2: 1,3,7,8,9 => UNS
* DIS # B8: 2,6 => CTR => B8: 4
* PRF # B8: 4 => SOL
* DIS # E3: 2,4 => CTR => E3: 3,7,8,9
* INC # E3: 3,7,8,9 => UNS
* PRF # B8: 2,4 => SOL
* DIS # B8: 6 => CTR => B8: 2,4
* PRF # F1: 1,6 => SOL
* DIS # F1: 2,7,8,9 => CTR => F1: 1,6
* DIS # F2: 1,6 => CTR => F2: 2,3,7,8,9
* INC # F2: 2,3,7,8,9 => UNS
* DIS # C2: 1,6 => CTR => C2: 2,5,7,8,9
* INC # C2: 2,5,7,8,9 => UNS
* PRF # D6: 1,6 => SOL
* DIS # D6: 4 => CTR => D6: 1,6
* DIS # A3: 1,4 => CTR => A3: 5,7,8,9
* INC # A3: 5,7,8,9 => UNS
* DIS # D6: 1,4 => CTR => D6: 6
* PRF # D6: 6 => SOL
* INC # D6: 4,6 => UNS
* DIS # D6: 1 => CTR => D6: 4,6
* INC # I7: 8,9 => UNS
* INC # H8: 8,9 => UNS
* DIS # I8: 8,9 => CTR => I8: 6,7
* INC # I8: 6,7 => UNS
* INC # D7: 8,9 => UNS
* INC # D7: 7 => UNS
* INC # G1: 8,9 => UNS
* INC # G2: 8,9 => UNS
* INC # G3: 8,9 => UNS
* CNT  35 HDP CHAINS /  35 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # C1: 2,6 => CTR => C1: 1,7,8,9
* PRF C1: 1,7,8,9 => SOL
* STA C1: 1,7,8,9
* CNT   2 HDP CHAINS /   1 HYP OPENED