Analysis of xx-top500-111-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: .3..2.......5...7........1..4..3.6........2..1..........6...4.35..7.1......8..... initial

Autosolve

position: .3..2..6....5..37....3...1..4..3.69.3.....24.1.....73.716...483583741926...863157 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # C1: 5,7 => CTR => C1: 1,4,8
* PRF # C1: 1,4,8 => SOL
* PRF # C3: 5,7 => SOL
* DIS # C3: 2,4,8 => CTR => C3: 5,7
* DIS # B5: 6 => CTR => B5: 5,7
* DIS # C1: 5,8 => CTR => C1: 1,4,7
* DIS # A1: 4,9 => CTR => A1: 8
* PRF # A1: 8 => SOL
* PRF # D1: 4,9 => SOL
* DIS # D1: 1 => CTR => D1: 4,9
* DIS # F1: 4,9 => CTR => F1: 7,8
* PRF # C3: 5,8 => SOL
* DIS # C4: 2,8 => CTR => C4: 5,7
* DIS # F4: 2,8 => CTR => F4: 5,7
* DIS # A2: 2,8 => CTR => A2: 4,6,9
* DIS # A3: 2,8 => CTR => A3: 4,6,9
* PRF # B5: 5,6 => SOL
* DIS # B5: 7 => CTR => B5: 5,6
* PRF # I4: 5,8 => SOL
* DIS # I4: 1 => CTR => I4: 5,8
* DIS # I5: 5,8 => CTR => I5: 1
* PRF # I5: 1 => SOL
* DIS # C6: 5,8 => CTR => C6: 2,9
* DIS # F6: 5,8 => CTR => F6: 2,4,9
* DIS # A9: 4 => CTR => A9: 2,9
* PRF # C2: 2,4 => SOL
* DIS # C3: 2,4 => CTR => C3: 5,7,8
* PRF # C3: 5,7,8 => SOL
* DIS # F7: 5 => CTR => F7: 2,9
* PRF # D6: 2,9 => SOL
* DIS # F7: 5,9 => CTR => F7: 2
* DIS # E5: 5,9 => CTR => E5: 1,7,8
* DIS # E6: 5,9 => CTR => E6: 8
* CNT  33 HDP CHAINS /  60 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: 5,7 => CTR => C1: 1,4,8
* PRF C1: 1,4,8 => SOL
* STA C1: 1,4,8
* CNT   2 HDP CHAINS /   5 HYP OPENED

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

Details

Positions

.3..2.......5...7........1..4..3.6........2..1..........6...4.35..7.1......8..... initial
.3..2..6....5..37....3...1..4..3.69.3.....24.1.....73.716...483583741926...863157 autosolve
831427569692518374475396812247135698358679241169284735716952483583741926924863157 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (13)
B2: 2,9
B3: 5,7
G1: 5,8
I1: 4,9
G3: 5,8
A4: 2,8
B6: 5,6
D4: 1,2
I6: 5,8
B9: 2,9
C9: 2,4
D7: 2,9
E7: 5,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
C1,C2: 1.. / C1 = 1  =>  0 pairs (*) / C2 = 1  =>  0 pairs (X)
D1,E2: 1.. / D1 = 1  =>  0 pairs (X) / E2 = 1  =>  0 pairs (_)
I4,I5: 1.. / I4 = 1  =>  0 pairs (X) / I5 = 1  =>  0 pairs (_)
C1,D1: 1.. / C1 = 1  =>  0 pairs (*) / D1 = 1  =>  0 pairs (X)
C2,E2: 1.. / C2 = 1  =>  0 pairs (X) / E2 = 1  =>  0 pairs (_)
D4,I4: 1.. / D4 = 1  =>  0 pairs (*) / I4 = 1  =>  0 pairs (X)
E2,E5: 1.. / E2 = 1  =>  0 pairs (*) / E5 = 1  =>  0 pairs (X)
I2,I3: 2.. / I2 = 2  => 16 pairs (_) / I3 = 2  => 14 pairs (_)
D7,F7: 2.. / D7 = 2  =>  0 pairs (X) / F7 = 2  => 14 pairs (_)
B2,B9: 2.. / B2 = 2  => 13 pairs (_) / B9 = 2  => 13 pairs (_)
D6,F6: 4.. / D6 = 4  => 14 pairs (_) / F6 = 4  =>  0 pairs (*)
A9,C9: 4.. / A9 = 4  =>  0 pairs (X) / C9 = 4  => 13 pairs (_)
D1,D6: 4.. / D1 = 4  =>  0 pairs (*) / D6 = 4  =>  0 pairs (X)
G1,G3: 5.. / G1 = 5  => 12 pairs (_) / G3 = 5  =>  0 pairs (X)
E7,F7: 5.. / E7 = 5  => 14 pairs (_) / F7 = 5  =>  0 pairs (X)
C1,G1: 5.. / C1 = 5  =>  0 pairs (X) / G1 = 5  => 12 pairs (_)
A2,A3: 6.. / A2 = 6  => 13 pairs (_) / A3 = 6  => 13 pairs (_)
F2,F3: 6.. / F2 = 6  => 13 pairs (_) / F3 = 6  => 13 pairs (_)
B5,B6: 6.. / B5 = 6  =>  0 pairs (X) / B6 = 6  => 13 pairs (_)
D5,D6: 6.. / D5 = 6  => 13 pairs (_) / D6 = 6  =>  0 pairs (X)
A2,F2: 6.. / A2 = 6  => 13 pairs (_) / F2 = 6  => 13 pairs (_)
A3,F3: 6.. / A3 = 6  => 13 pairs (_) / F3 = 6  => 13 pairs (_)
B5,D5: 6.. / B5 = 6  =>  0 pairs (X) / D5 = 6  => 13 pairs (_)
B6,D6: 6.. / B6 = 6  => 13 pairs (_) / D6 = 6  =>  0 pairs (X)
C1,F1: 7.. / C1 = 7  =>  0 pairs (X) / F1 = 7  =>  0 pairs (_)
C4,F4: 7.. / C4 = 7  =>  0 pairs (*) / F4 = 7  =>  0 pairs (X)
B3,B5: 7.. / B3 = 7  =>  0 pairs (*) / B5 = 7  =>  0 pairs (X)
E3,E5: 7.. / E3 = 7  =>  0 pairs (X) / E5 = 7  =>  0 pairs (_)
G1,G3: 8.. / G1 = 8  =>  0 pairs (X) / G3 = 8  => 12 pairs (_)
C5,C6: 9.. / C5 = 9  => 14 pairs (_) / C6 = 9  =>  0 pairs (*)
A9,B9: 9.. / A9 = 9  => 13 pairs (_) / B9 = 9  => 13 pairs (_)
B2,B9: 9.. / B2 = 9  => 13 pairs (_) / B9 = 9  => 13 pairs (_)
* DURATION: 0:00:54.189283  START: 06:33:43.200678  END: 06:34:37.389961 2017-05-04
* CP COUNT: (32)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A4,B2,B3,B6,B9,C9,D4,D7,E7,G1,G3,I1,I6)
* .3..2..6....5..37....3...1..4..3.69.3.....24.1.....73.716...483583741926...863157
* PAIR B2: 2,9 BLK 1
A2: 2,9,4,6,8                            # reduction candidate for 2,9
A2: 2,9                                  # 17 pairs
A3: 2,9,4,6,8                            # reduction candidate for 2,9
A3: 2,9                                  # 15 pairs
* PAIR B2: 2,9 ROW 2
I2: 2,9,4                                # reduction candidate for 2,9
I2: 2,9                                  # 15 pairs
I2: 4                                    # 14 pairs
* PAIR B3: 5,7 BLK 1
C1: 5,7,1,4,8                            # reduction candidate for 5,7
C1: 5,7 => CTR
* .3712.56...15..37..5837..1.84.23.69137961.24.1624..73.716952483583741926..4863157
C1: 1,4,8 => SOLVED
* 831427569692518374475396812247135698358679241169284735716952483583741926924863157
C3: 5,7,2,4,8                            # reduction candidate for 5,7
C3: 5,7 => SOLVED
* 831427569692518374475396812247135698358679241169284735716952483583741926924863157
C3: 2,4,8 => CTR
* .3.12..6...15..37...837.51..4.23.6913...1.24.1.24..73.716952483583741926..4863157
* PAIR B3: 5,7 COL B
B5: 5,7,6                                # reduction candidate for 5,7
B5: 6 => CTR
* .3.427.69...51.37..7.38.51..47.3.69.36..7.24.15.6.4738716.5.483583741926...863157
B5: 5,7                                  # 13 pairs
* PAIR G1: 5,8 ROW 1
C1: 5,8,1,4,7                            # reduction candidate for 5,8
C1: 5,8 => CTR
* .3.127.6...15..37....3...1..4723.69.3.....24.1.....73.716...483583741926...863157
C1: 1,4,7                                # 12 pairs
* PAIR I1: 4,9 BLK 3
I2: 4,9,2                                # reduction candidate for 4,9
I2: 4,9                                  # 14 pairs
I3: 4,9,2                                # reduction candidate for 4,9
I3: 4,9                                  # 16 pairs
* PAIR I1: 4,9 ROW 1
A1: 4,9,8                                # reduction candidate for 4,9
A1: 4,9 => CTR
* .3712856...159.37..5837..1.84.23.69137961.24.1624..73.716952483583741926..4863157
A1: 8 => SOLVED
* 831427569692518374475396812247135698358679241169284735716952483583741926924863157
D1: 4,9,1                                # reduction candidate for 4,9
D1: 4,9 => SOLVED
* 831427569692518374475396812247135698358679241169284735716952483583741926924863157
D1: 1 => CTR
* .3712.56...15..37..5837..1.84.23.69137961.24.1624..73.716952483583741926..4863157
F1: 4,9,7,8                              # reduction candidate for 4,9
F1: 4,9 => CTR
* .3712.56...15..37..5.3..81..4.23769137.61.24.1624..73.716952483583741926..4863157
F1: 7,8                                  # 14 pairs
* PAIR G3: 5,8 ROW 3
C3: 5,8,2,4,7                            # reduction candidate for 5,8
C3: 5,8 => SOLVED
* 831427569692518374475396812247135698358679241169284735716952483583741926924863157
C3: 2,4,7                                # 13 pairs
* PAIR A4: 2,8 BLK 4
C4: 2,8,5,7                              # reduction candidate for 2,8
C4: 2,8 => CTR
* .3712.56...15..37..5.37.81..4.23769537.6..2411624..738716952483583741926..4863157
C4: 5,7                                  # 15 pairs
C6: 2,8,5,9                              # reduction candidate for 2,8
C6: 2,8                                  # 16 pairs
* PAIR A4: 2,8 ROW 4
F4: 2,8,5,7                              # reduction candidate for 2,8
F4: 2,8 => CTR
* .31.2756....51.37..7538..1..4713.6953...7.2411.....738716...483583741926...863157
F4: 5,7                                  # 14 pairs
* PAIR A4: 2,8 COL A
A2: 2,8,4,6,9                            # reduction candidate for 2,8
A2: 2,8 => CTR
* .3.12..6...15.63746..3.4.12.4.23.6913...1.24.1.24..73.71695.483583741926...863157
A2: 4,6,9                                # 13 pairs
A3: 2,8,4,6,9                            # reduction candidate for 2,8
A3: 2,8 => CTR
* 43.12..6969158437....3.6.1..4.23.6913...1.24.1.24..73.716952483583741926.24863157
A3: 4,6,9                                # 13 pairs
* PAIR B6: 5,6 BLK 4
B5: 5,6,7                                # reduction candidate for 5,6
B5: 5,6 => SOLVED
* 831427569692518374475396812247135698358679241169284735716952483583741926924863157
B5: 7 => CTR
* .3712.56...15..37..5.37.81..4.23769137.61.24.1624..73.716952483583741926..4863157
* PAIR I6: 5,8 BLK 6
I4: 5,8,1                                # reduction candidate for 5,8
I4: 5,8 => SOLVED
* 831427569692518374475396812247135698358679241169284735716952483583741926924863157
I4: 1 => CTR
* .3.12..6...158.37....39..1.84.23.6913.9...24.1.2...73.716952483583741926..4863157
I5: 5,8,1                                # reduction candidate for 5,8
I5: 5,8 => CTR
* .3.12..6...158.37....39..1.84.23.6913.9...24.1.2...73.716952483583741926..4863157
I5: 1 => SOLVED
* 831427569692518374475396812247135698358679241169284735716952483583741926924863157
* PAIR I6: 5,8 ROW 6
C6: 5,8,2,9                              # reduction candidate for 5,8
C6: 5,8 => CTR
* .31.2756....51.37....3..81..4713.69.359678241168...735716.5.483583741926...863157
C6: 2,9                                  # 14 pairs
E6: 5,8,9                                # reduction candidate for 5,8
E6: 5,8                                  # 15 pairs
F6: 5,8,2,4,9                            # reduction candidate for 5,8
F6: 5,8 => CTR
* .3..2..6....5..37....3...1.84..3.69.3.96..24.16249.73.716.5.483583741926..4863157
F6: 2,4,9                                # 13 pairs
* PAIR B9: 2,9 BLK 7
A9: 2,9,4                                # reduction candidate for 2,9
A9: 4 => CTR
* 831.2756..245183799..3..81224713.69.3...7.2411...8.735716.5.483583741926492863157
A9: 2,9                                  # 13 pairs
* PAIR C9: 2,4 BLK 7
A9: 2,4,9                                # reduction candidate for 2,4
A9: 9                                    # 13 pairs
A9: 2,4                                  # 13 pairs
* PAIR C9: 2,4 COL C
C2: 2,4,1,8                              # reduction candidate for 2,4
C2: 2,4 => SOLVED
* 831427569692518374475396812247135698358679241169284735716952483583741926924863157
C2: 1,8                                  # 14 pairs
C3: 2,4,5,7,8                            # reduction candidate for 2,4
C3: 2,4 => CTR
* .3.12..6...15..37....3...1.24..3.69.3.....24.1.....73.716...483583741926...863157
C3: 5,7,8 => SOLVED
* 831427569692518374475396812247135698358679241169284735716952483583741926924863157
* PAIR D7: 2,9 BLK 8
F7: 2,9,5                                # reduction candidate for 2,9
F7: 5 => CTR
* .31.2756....51.37....38..1..4.13.69.3.....2411.....73.716295483583741926...863157
F7: 2,9                                  # 14 pairs
* PAIR D7: 2,9 COL D
D6: 2,9,4,6                              # reduction candidate for 2,9
D6: 2,9 => SOLVED
* 831427569692518374475396812247135698358679241169284735716952483583741926924863157
D6: 4,6                                  # 14 pairs
* PAIR E7: 5,9 BLK 8
F7: 5,9,2                                # reduction candidate for 5,9
F7: 5,9 => CTR
* 831.2756....51837..7539681.24713569.3...7.2411...8.735716259483583741926...863157
F7: 2                                    # 14 pairs
* PAIR E7: 5,9 COL E
E5: 5,9,1,7,8                            # reduction candidate for 5,9
E5: 5,9 => CTR
* .3..2..6....51.37....37..1..4..3.69.37.6..24116..8.735716...483583741926...863157
E5: 1,7,8                                # 13 pairs
E6: 5,9,8                                # reduction candidate for 5,9
E6: 5,9 => CTR
* .31.2756...85..37....3...1.24.13.69.3.....2411.....73.716...483583741926...863157
E6: 8                                    # 20 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-111-base-pr-000.dot
* REASONING
* DIS # C1: 5,7 => CTR => C1: 1,4,8
* PRF # C1: 1,4,8 => SOL
* PRF # C3: 5,7 => SOL
* DIS # C3: 2,4,8 => CTR => C3: 5,7
* DIS # B5: 6 => CTR => B5: 5,7
* DIS # C1: 5,8 => CTR => C1: 1,4,7
* DIS # A1: 4,9 => CTR => A1: 8
* PRF # A1: 8 => SOL
* PRF # D1: 4,9 => SOL
* DIS # D1: 1 => CTR => D1: 4,9
* DIS # F1: 4,9 => CTR => F1: 7,8
* PRF # C3: 5,8 => SOL
* DIS # C4: 2,8 => CTR => C4: 5,7
* DIS # F4: 2,8 => CTR => F4: 5,7
* DIS # A2: 2,8 => CTR => A2: 4,6,9
* DIS # A3: 2,8 => CTR => A3: 4,6,9
* PRF # B5: 5,6 => SOL
* DIS # B5: 7 => CTR => B5: 5,6
* PRF # I4: 5,8 => SOL
* DIS # I4: 1 => CTR => I4: 5,8
* DIS # I5: 5,8 => CTR => I5: 1
* PRF # I5: 1 => SOL
* DIS # C6: 5,8 => CTR => C6: 2,9
* DIS # F6: 5,8 => CTR => F6: 2,4,9
* DIS # A9: 4 => CTR => A9: 2,9
* PRF # C2: 2,4 => SOL
* DIS # C3: 2,4 => CTR => C3: 5,7,8
* PRF # C3: 5,7,8 => SOL
* DIS # F7: 5 => CTR => F7: 2,9
* PRF # D6: 2,9 => SOL
* DIS # F7: 5,9 => CTR => F7: 2
* DIS # E5: 5,9 => CTR => E5: 1,7,8
* DIS # E6: 5,9 => CTR => E6: 8
* CNT  33 HDP CHAINS /  60 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A4,B2,B3,B6,B9,C9,D4,D7,E7,G1,G3,I1,I6)
* .3..2..6....5..37....3...1..4..3.69.3.....24.1.....73.716...483583741926...863157
* PAIR B2: 2,9 BLK 1
A2: 2,9,4,6,8                            # reduction candidate for 2,9
A2: 2,9                                  # 17 pairs
A3: 2,9,4,6,8                            # reduction candidate for 2,9
A3: 2,9                                  # 15 pairs
* PAIR B2: 2,9 ROW 2
I2: 2,9,4                                # reduction candidate for 2,9
I2: 2,9                                  # 15 pairs
I2: 4                                    # 14 pairs
* PAIR B3: 5,7 BLK 1
C1: 5,7,1,4,8                            # reduction candidate for 5,7
C1: 5,7 => CTR
* .3712.56...15..37..5837..1.84.23.69137961.24.1624..73.716952483583741926..4863157
C1: 1,4,8 => SOLVED
* 831427569692518374475396812247135698358679241169284735716952483583741926924863157
* DURATION: 0:00:05.483766  START: 06:35:37.455686  END: 06:35:42.939452 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-111-base-pr-001.dot
* REASONING
* DIS # C1: 5,7 => CTR => C1: 1,4,8
* PRF C1: 1,4,8 => SOL
* STA C1: 1,4,8
* CNT   2 HDP CHAINS /   5 HYP OPENED

Header Info

Top 500 Minimum 17 111

solution: 831427569692518374475396812247135698358679241169284735716952483583741926924863157
info: 1646     FNBTHWY  S8.f     17717

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

Solution

position: 831427569692518374475396812247135698358679241169284735716952483583741926924863157 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 # A2: 2,9 => UNS
* INC # A3: 2,9 => UNS
* INC # I2: 2,9 => UNS
* INC # I2: 4 => UNS
* DIS # C1: 5,7 => CTR => C1: 1,4,8
* PRF # C1: 1,4,8 => SOL
* PRF # C3: 5,7 => SOL
* DIS # C3: 2,4,8 => CTR => C3: 5,7
* INC # B5: 5,7 => UNS
* DIS # B5: 6 => CTR => B5: 5,7
* DIS # C1: 5,8 => CTR => C1: 1,4,7
* INC # C1: 1,4,7 => UNS
* INC # I2: 4,9 => UNS
* INC # I3: 4,9 => UNS
* DIS # A1: 4,9 => CTR => A1: 8
* PRF # A1: 8 => SOL
* PRF # D1: 4,9 => SOL
* DIS # D1: 1 => CTR => D1: 4,9
* DIS # F1: 4,9 => CTR => F1: 7,8
* INC # F1: 7,8 => UNS
* PRF # C3: 5,8 => SOL
* INC # C3: 2,4,7 => UNS
* DIS # C4: 2,8 => CTR => C4: 5,7
* INC # C4: 5,7 => UNS
* INC # C6: 2,8 => UNS
* DIS # F4: 2,8 => CTR => F4: 5,7
* INC # F4: 5,7 => UNS
* DIS # A2: 2,8 => CTR => A2: 4,6,9
* INC # A2: 4,6,9 => UNS
* DIS # A3: 2,8 => CTR => A3: 4,6,9
* INC # A3: 4,6,9 => UNS
* PRF # B5: 5,6 => SOL
* DIS # B5: 7 => CTR => B5: 5,6
* PRF # I4: 5,8 => SOL
* DIS # I4: 1 => CTR => I4: 5,8
* DIS # I5: 5,8 => CTR => I5: 1
* PRF # I5: 1 => SOL
* DIS # C6: 5,8 => CTR => C6: 2,9
* INC # C6: 2,9 => UNS
* INC # E6: 5,8 => UNS
* DIS # F6: 5,8 => CTR => F6: 2,4,9
* INC # F6: 2,4,9 => UNS
* INC # A9: 2,9 => UNS
* DIS # A9: 4 => CTR => A9: 2,9
* INC # A9: 2,4 => UNS
* INC # A9: 9 => UNS
* PRF # C2: 2,4 => SOL
* INC # C2: 1,8 => UNS
* DIS # C3: 2,4 => CTR => C3: 5,7,8
* PRF # C3: 5,7,8 => SOL
* INC # F7: 2,9 => UNS
* DIS # F7: 5 => CTR => F7: 2,9
* PRF # D6: 2,9 => SOL
* INC # D6: 4,6 => UNS
* DIS # F7: 5,9 => CTR => F7: 2
* INC # F7: 2 => UNS
* DIS # E5: 5,9 => CTR => E5: 1,7,8
* INC # E5: 1,7,8 => UNS
* DIS # E6: 5,9 => CTR => E6: 8
* INC # E6: 8 => UNS
* CNT  60 HDP CHAINS /  60 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # A2: 2,9 => UNS
* INC # A3: 2,9 => UNS
* INC # I2: 2,9 => UNS
* INC # I2: 4 => UNS
* DIS # C1: 5,7 => CTR => C1: 1,4,8
* PRF C1: 1,4,8 => SOL
* STA C1: 1,4,8
* CNT   6 HDP CHAINS /   5 HYP OPENED