Analysis of xx-top500-104-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 5..17.....3....2.....6.........248..1.............3....28........4.....6...7...5. initial

Autosolve

position: 5..17....83.4592.....63........248..1...67.......13...628345...754291386...786452 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # H1: 6,9 => CTR => H1: 3,4
* PRF # B1: 6,9 => SOL
* DIS # G6: 6,9 => CTR => G6: 5,7
* DIS # G3: 1,7 => CTR => G3: 5,9
* DIS # H3: 1,7 => CTR => H3: 4,9
* DIS # I3: 1,7 => CTR => I3: 4,5,8,9
* DIS # C2: 1,7 => CTR => C2: 6
* DIS # I7: 1,7 => CTR => I7: 9
* PRF # I5: 5,9 => SOL
* DIS # G6: 5,9 => CTR => G6: 6,7
* DIS # C5: 5,9 => CTR => C5: 2,3
* DIS # G3: 1,7 => CTR => G3: 5,9
* CNT  12 HDP CHAINS /  46 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 # H1: 6,9 => CTR => H1: 3,4
* PRF H1: 3,4 # B1: 6,9 => SOL
* STA H1: 3,4 + B1: 6,9
* CNT   2 HDP CHAINS /   2 HYP OPENED

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

Details

Positions

5..17.....3....2.....6.........248..1.............3....28........4.....6...7...5. initial
5..17....83.4592.....63........248..1...67.......13...628345...754291386...786452 autosolve
592178643836459217471632598967524831143867925285913764628345179754291386319786452 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (11)
A3: 2,4
F1: 2,8
F3: 2,8
G1: 6,9
I2: 1,7
A4: 3,9
A6: 2,4
D4: 5,9
G5: 5,9
A9: 3,9
B9: 1,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
H4,I4: 1.. / H4 = 1  => 13 pairs (_) / I4 = 1  => 15 pairs (_)
B9,C9: 1.. / B9 = 1  => 11 pairs (_) / C9 = 1  => 16 pairs (_)
B3,B9: 1.. / B3 = 1  => 16 pairs (_) / B9 = 1  => 11 pairs (_)
G3,G7: 1.. / G3 = 1  =>  0 pairs (X) / G7 = 1  => 13 pairs (_)
F1,F3: 2.. / F1 = 2  => 12 pairs (_) / F3 = 2  =>  0 pairs (*)
H5,H6: 2.. / H5 = 2  => 11 pairs (_) / H6 = 2  =>  0 pairs (X)
C1,F1: 2.. / C1 = 2  =>  0 pairs (*) / F1 = 2  =>  0 pairs (X)
C5,H5: 2.. / C5 = 2  =>  0 pairs (X) / H5 = 2  => 11 pairs (_)
A3,A6: 2.. / A3 = 2  => 12 pairs (_) / A6 = 2  =>  0 pairs (*)
H1,I1: 3.. / H1 = 3  => 11 pairs (_) / I1 = 3  =>  0 pairs (*)
A9,C9: 3.. / A9 = 3  => 13 pairs (_) / C9 = 3  =>  8 pairs (_)
A4,A9: 3.. / A4 = 3  =>  8 pairs (_) / A9 = 3  => 13 pairs (_)
A3,A6: 4.. / A3 = 4  =>  0 pairs (*) / A6 = 4  =>  0 pairs (X)
G3,I3: 5.. / G3 = 5  => 21 pairs (_) / I3 = 5  =>  0 pairs (X)
C2,H2: 6.. / C2 = 6  => 20 pairs (_) / H2 = 6  =>  0 pairs (X)
G1,G6: 6.. / G1 = 6  => 20 pairs (_) / G6 = 6  =>  0 pairs (X)
F1,F3: 8.. / F1 = 8  =>  0 pairs (*) / F3 = 8  =>  0 pairs (X)
I1,I3: 8.. / I1 = 8  => 12 pairs (_) / I3 = 8  =>  0 pairs (*)
B5,B6: 8.. / B5 = 8  => 14 pairs (_) / B6 = 8  => 13 pairs (_)
D5,D6: 8.. / D5 = 8  => 13 pairs (_) / D6 = 8  => 14 pairs (_)
F1,I1: 8.. / F1 = 8  =>  0 pairs (*) / I1 = 8  =>  0 pairs (X)
F3,I3: 8.. / F3 = 8  => 12 pairs (_) / I3 = 8  =>  0 pairs (*)
B5,D5: 8.. / B5 = 8  => 14 pairs (_) / D5 = 8  => 13 pairs (_)
B6,D6: 8.. / B6 = 8  => 13 pairs (_) / D6 = 8  => 14 pairs (_)
A4,A9: 9.. / A4 = 9  => 13 pairs (_) / A9 = 9  =>  8 pairs (_)
* DURATION: 0:00:42.917319  START: 06:19:34.531436  END: 06:20:17.448755 2017-05-04
* CP COUNT: (25)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A3,A4,A6,A9,B9,D4,F1,F3,G1,G5,I2)
* 5..17....83.4592.....63........248..1...67.......13...628345...754291386...786452
* PAIR G1: 6,9 BLK 3
H1: 6,9,3,4                              # reduction candidate for 6,9
H1: 6,9 => CTR
* 54.178..383.4592..2..63...8....248..1...67.......13...628345...754291386...786452
H1: 3,4                                  # 12 pairs
* PAIR G1: 6,9 ROW 1
B1: 6,9,4                                # reduction candidate for 6,9
B1: 6,9 => SOLVED
* 592178643836459217471632598967524831143867925285913764628345179754291386319786452
B1: 4                                    # 12 pairs
C1: 6,9,2                                # reduction candidate for 6,9
C1: 6,9                                  # 12 pairs
* PAIR G1: 6,9 COL G
G6: 6,9,5,7                              # reduction candidate for 6,9
G6: 6,9 => CTR
* 54617293883.45926.2..638.45.6..248.31.3.675244.25136..628345...7542913863..786452
G6: 5,7                                  # 20 pairs
* PAIR I2: 1,7 BLK 3
H2: 1,7,6                                # reduction candidate for 1,7
H2: 1,7                                  # 20 pairs
G3: 1,7,5,9                              # reduction candidate for 1,7
G3: 1,7 => CTR
* 54617293883.45926.2..638.45.6..248.31.3.675244.25136..628345...7542913863..786452
G3: 5,9                                  # 20 pairs
H3: 1,7,4,9                              # reduction candidate for 1,7
H3: 1,7 => CTR
* 5..17.9..83.45926....63.5......248..1...67.......13...628345...754291386...786452
H3: 4,9                                  # 12 pairs
I3: 1,7,4,5,8,9                          # reduction candidate for 1,7
I3: 1,7 => CTR
* 5..1726388364592.....6385......248..1...679......13...6283451.9754291386...786452
I3: 4,5,8,9                              # 11 pairs
* PAIR I2: 1,7 ROW 2
C2: 1,7,6                                # reduction candidate for 1,7
C2: 1,7 => CTR
* 54617293883.45926.2..638.45.6..248.31.3.675244.25136..628345...7542913863..786452
C2: 6                                    # 20 pairs
* PAIR I2: 1,7 COL I
I4: 1,7,3,5,9                            # reduction candidate for 1,7
I4: 1,7                                  # 15 pairs
I7: 1,7,9                                # reduction candidate for 1,7
I7: 1,7 => CTR
* 54.172.3883.4592..2..638.4..67.2481.1.5.6792.4.2.13...628345.9.754291386...786452
I7: 9                                    # 13 pairs
* PAIR A4: 3,9 BLK 4
C4: 3,9,5,6,7                            # reduction candidate for 3,9
C4: 3,9                                  # 22 pairs
C5: 3,9,2,5                              # reduction candidate for 3,9
C5: 3,9                                  # 14 pairs
* PAIR A4: 3,9 ROW 4
H4: 3,9,1,6,7                            # reduction candidate for 3,9
H4: 3,9                                  # 23 pairs
I4: 3,9,1,5,7                            # reduction candidate for 3,9
I4: 3,9                                  # 17 pairs
* PAIR A6: 2,4 ROW 6
H6: 2,4,6,7,9                            # reduction candidate for 2,4
H6: 2,4                                  # 12 pairs
H6: 6,7,9                                # 11 pairs
* PAIR D4: 5,9 BLK 5
D5: 5,9,8                                # reduction candidate for 5,9
D5: 5,9                                  # 14 pairs
D6: 5,9,8                                # reduction candidate for 5,9
D6: 5,9                                  # 13 pairs
* PAIR D4: 5,9 ROW 4
C4: 5,9,3,6,7                            # reduction candidate for 5,9
C4: 5,9                                  # 16 pairs
I4: 5,9,1,3,7                            # reduction candidate for 5,9
I4: 5,9                                  # 18 pairs
* PAIR G5: 5,9 BLK 6
I4: 5,9,1,3,7                            # reduction candidate for 5,9
I4: 5,9                                  # 18 pairs
I5: 5,9,3,4                              # reduction candidate for 5,9
I5: 5,9 => SOLVED
* 592178643836459217471632598967524831143867925285913764628345179754291386319786452
I5: 3,4                                  # 12 pairs
G6: 5,9,6,7                              # reduction candidate for 5,9
G6: 5,9 => CTR
* 5..17.6..8364592.....63........248..1...67.......13...628345...754291386...786452
G6: 6,7                                  # 12 pairs
I6: 5,9,4,7                              # reduction candidate for 5,9
I6: 5,9                                  # 14 pairs
* PAIR G5: 5,9 ROW 5
C5: 5,9,2,3                              # reduction candidate for 5,9
C5: 5,9 => CTR
* 5.21786348364592..4..632598.6..248..14586792328..13745628345179754291386...786452
C5: 2,3                                  # 12 pairs
D5: 5,9,8                                # reduction candidate for 5,9
D5: 5,9                                  # 14 pairs
* PAIR G5: 5,9 COL G
G3: 5,9,1,7                              # reduction candidate for 5,9
G3: 1,7 => CTR
* 54617293883.45926.2..638.45.6..248.31.3.675244.25136..628345...7542913863..786452
G3: 5,9                                  # 20 pairs
* PAIR A9: 3,9 BLK 7
C9: 3,9,1                                # reduction candidate for 3,9
C9: 1                                    # 16 pairs
C9: 3,9                                  # 11 pairs
* PAIR B9: 1,9 BLK 7
C9: 1,9,3                                # reduction candidate for 1,9
C9: 1,9                                  # 13 pairs
C9: 3                                    #  8 pairs
* PAIR B9: 1,9 COL B
B3: 1,9,4,7                              # reduction candidate for 1,9
B3: 1,9                                  # 15 pairs
B3: 4,7                                  # 12 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-104-base-pr-000.dot
* REASONING
* DIS # H1: 6,9 => CTR => H1: 3,4
* PRF # B1: 6,9 => SOL
* DIS # G6: 6,9 => CTR => G6: 5,7
* DIS # G3: 1,7 => CTR => G3: 5,9
* DIS # H3: 1,7 => CTR => H3: 4,9
* DIS # I3: 1,7 => CTR => I3: 4,5,8,9
* DIS # C2: 1,7 => CTR => C2: 6
* DIS # I7: 1,7 => CTR => I7: 9
* PRF # I5: 5,9 => SOL
* DIS # G6: 5,9 => CTR => G6: 6,7
* DIS # C5: 5,9 => CTR => C5: 2,3
* DIS # G3: 1,7 => CTR => G3: 5,9
* CNT  12 HDP CHAINS /  46 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A3,A4,A6,A9,B9,D4,F1,F3,G1,G5,I2)
* 5..17....83.4592.....63........248..1...67.......13...628345...754291386...786452
* PAIR G1: 6,9 BLK 3
H1: 6,9,3,4                              # reduction candidate for 6,9
H1: 6,9 => CTR
* 54.178..383.4592..2..63...8....248..1...67.......13...628345...754291386...786452
* PAIR G1: 6,9 ROW 1
B1: 6,9,4                                # reduction candidate for 6,9
B1: 6,9 => SOLVED
* 592178643836459217471632598967524831143867925285913764628345179754291386319786452
* DURATION: 0:00:04.122722  START: 06:20:59.562580  END: 06:21:03.685302 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-104-base-pr-001.dot
* REASONING
* DIS # H1: 6,9 => CTR => H1: 3,4
* PRF H1: 3,4 # B1: 6,9 => SOL
* STA H1: 3,4 + B1: 6,9
* CNT   2 HDP CHAINS /   2 HYP OPENED

Header Info

Top 500 Minimum 17 104

solution: 592178643836459217471632598967524831143867925285913764628345179754291386319786452
info: 1620     FNBHXY   S8.f     32733

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

Solution

position: 592178643836459217471632598967524831143867925285913764628345179754291386319786452 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 # H1: 6,9 => CTR => H1: 3,4
* INC # H1: 3,4 => UNS
* PRF # B1: 6,9 => SOL
* INC # B1: 4 => UNS
* INC # C1: 6,9 => UNS
* DIS # G6: 6,9 => CTR => G6: 5,7
* INC # G6: 5,7 => UNS
* INC # H2: 1,7 => UNS
* DIS # G3: 1,7 => CTR => G3: 5,9
* INC # G3: 5,9 => UNS
* DIS # H3: 1,7 => CTR => H3: 4,9
* INC # H3: 4,9 => UNS
* DIS # I3: 1,7 => CTR => I3: 4,5,8,9
* INC # I3: 4,5,8,9 => UNS
* DIS # C2: 1,7 => CTR => C2: 6
* INC # C2: 6 => UNS
* INC # I4: 1,7 => UNS
* DIS # I7: 1,7 => CTR => I7: 9
* INC # I7: 9 => UNS
* INC # C4: 3,9 => UNS
* INC # C5: 3,9 => UNS
* INC # H4: 3,9 => UNS
* INC # I4: 3,9 => UNS
* INC # H6: 2,4 => UNS
* INC # H6: 6,7,9 => UNS
* INC # D5: 5,9 => UNS
* INC # D6: 5,9 => UNS
* INC # C4: 5,9 => UNS
* INC # I4: 5,9 => UNS
* INC # I4: 5,9 => UNS
* PRF # I5: 5,9 => SOL
* INC # I5: 3,4 => UNS
* DIS # G6: 5,9 => CTR => G6: 6,7
* INC # G6: 6,7 => UNS
* INC # I6: 5,9 => UNS
* DIS # C5: 5,9 => CTR => C5: 2,3
* INC # C5: 2,3 => UNS
* INC # D5: 5,9 => UNS
* INC # G3: 5,9 => UNS
* DIS # G3: 1,7 => CTR => G3: 5,9
* INC # C9: 3,9 => UNS
* INC # C9: 1 => UNS
* INC # C9: 1,9 => UNS
* INC # C9: 3 => UNS
* INC # B3: 1,9 => UNS
* INC # B3: 4,7 => UNS
* CNT  46 HDP CHAINS /  46 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # H1: 6,9 => CTR => H1: 3,4
* PRF H1: 3,4 # B1: 6,9 => SOL
* STA H1: 3,4 + B1: 6,9
* CNT   2 HDP CHAINS /   2 HYP OPENED