Analysis of xx-top500-116-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: ....236...1.....5..........3.2.7.......5...4.6...........1....8.5.4.....7.....3.. initial

Autosolve

position: 5...236...136...5..267...3.3.2.7.......5...436.53......3.1....8.5.43....76.2..3.. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # B1: 8,9 => CTR => B1: 7
* DIS # C1: 8,9 => CTR => C1: 4,7
* DIS # A5: 8,9 => CTR => A5: 1
* DIS # A8: 8,9 => CTR => A8: 1,2
* DIS # B1: 8,9 => CTR => B1: 7
* DIS # C1: 8,9 => CTR => C1: 4,7
* DIS # G6: 2,7 => CTR => G6: 1,8,9
* DIS # G8: 2,7 => CTR => G8: 1,9
* DIS # I8: 2,7 => CTR => I8: 1,6,9
* DIS # I1: 4,9 => CTR => I1: 1
* DIS # A3: 4,9 => CTR => A3: 8
* DIS # F4: 8,9 => CTR => F4: 1,4
* DIS # F5: 8,9 => CTR => F5: 2,6
* DIS # E6: 8,9 => CTR => E6: 1,4
* DIS # F6: 8,9 => CTR => F6: 1,2,4
* PRF # G4: 8,9 => SOL
* DIS # H4: 8,9 => CTR => H4: 1,6
* DIS # C9: 4,9 => CTR => C9: 1,8
* DIS # C1: 7,8 => CTR => C1: 4,9
* DIS # H8: 1,9 => CTR => H8: 2,6,7
* DIS # I8: 1,9 => CTR => I8: 2,6,7
* PRF # C9: 1,9 => SOL
* DIS # C9: 4,8 => CTR => C9: 1,9
* DIS # H1: 1,9 => CTR => H1: 8
* DIS # H4: 1,9 => CTR => H4: 6,8
* CNT  25 HDP CHAINS /  62 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 # B1: 8,9 => CTR => B1: 7
* DIS B1: 7 # C1: 8,9 => CTR => C1: 4
* PRF B1: 7 + C1: 4 # F9: 8,9 => SOL
* STA B1: 7 + C1: 4 + F9: 8,9
* CNT   3 HDP CHAINS /   3 HYP OPENED

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

Details

Positions

....236...1.....5..........3.2.7.......5...4.6...........1....8.5.4.....7.....3.. initial
5...236...136...5..267...3.3.2.7.......5...436.53......3.1....8.5.43....76.2..3.. autosolve
574923681913684752826715439342871965187596243695342817439167528258439176761258394 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (12)
A2: 8,9
D1: 8,9
E3: 1,5
F3: 1,5
G2: 2,7
I2: 2,7
I3: 4,9
D4: 8,9
C7: 4,9
G7: 4,5
H9: 1,9
I9: 4,5

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
E3,F3: 1.. / E3 = 1  => 11 pairs (_) / F3 = 1  => 15 pairs (_)
H1,I1: 1.. / H1 = 1  =>  0 pairs (X) / I1 = 1  => 16 pairs (_)
A5,C5: 1.. / A5 = 1  => 12 pairs (_) / C5 = 1  =>  0 pairs (X)
C9,H9: 1.. / C9 = 1  =>  0 pairs (*) / H9 = 1  =>  0 pairs (X)
A5,A8: 1.. / A5 = 1  => 12 pairs (_) / A8 = 1  =>  0 pairs (X)
E3,E6: 1.. / E3 = 1  => 11 pairs (_) / E6 = 1  => 15 pairs (_)
G2,I2: 2.. / G2 = 2  =>  0 pairs (X) / I2 = 2  => 10 pairs (_)
F5,F6: 2.. / F5 = 2  =>  0 pairs (X) / F6 = 2  => 14 pairs (_)
A7,A8: 2.. / A7 = 2  =>  0 pairs (X) / A8 = 2  => 16 pairs (_)
F5,G5: 2.. / F5 = 2  =>  0 pairs (X) / G5 = 2  => 14 pairs (_)
A7,H7: 2.. / A7 = 2  =>  0 pairs (X) / H7 = 2  => 16 pairs (_)
C1,A3: 4.. / C1 = 4  => 16 pairs (_) / A3 = 4  =>  0 pairs (X)
E2,F2: 4.. / E2 = 4  => 13 pairs (_) / F2 = 4  => 12 pairs (_)
B4,B6: 4.. / B4 = 4  => 12 pairs (_) / B6 = 4  => 16 pairs (_)
G7,I9: 4.. / G7 = 4  =>  0 pairs (X) / I9 = 4  => 16 pairs (_)
C1,I1: 4.. / C1 = 4  => 16 pairs (_) / I1 = 4  =>  0 pairs (X)
B4,F4: 4.. / B4 = 4  => 12 pairs (_) / F4 = 4  => 16 pairs (_)
C9,I9: 4.. / C9 = 4  =>  0 pairs (X) / I9 = 4  => 16 pairs (_)
A3,A7: 4.. / A3 = 4  =>  0 pairs (X) / A7 = 4  => 16 pairs (_)
E2,E6: 4.. / E2 = 4  => 13 pairs (_) / E6 = 4  => 12 pairs (_)
G3,G7: 4.. / G3 = 4  => 16 pairs (_) / G7 = 4  =>  0 pairs (X)
E3,F3: 5.. / E3 = 5  => 15 pairs (_) / F3 = 5  => 11 pairs (_)
G4,I4: 5.. / G4 = 5  =>  0 pairs (X) / I4 = 5  => 16 pairs (_)
G7,I9: 5.. / G7 = 5  => 16 pairs (_) / I9 = 5  =>  0 pairs (X)
G4,G7: 5.. / G4 = 5  =>  0 pairs (X) / G7 = 5  => 16 pairs (_)
I4,I9: 5.. / I4 = 5  => 16 pairs (_) / I9 = 5  =>  0 pairs (X)
E5,F5: 6.. / E5 = 6  =>  0 pairs (X) / F5 = 6  => 16 pairs (_)
H4,I4: 6.. / H4 = 6  => 13 pairs (_) / I4 = 6  =>  0 pairs (X)
E5,E7: 6.. / E5 = 6  =>  0 pairs (X) / E7 = 6  => 16 pairs (_)
I4,I8: 6.. / I4 = 6  =>  0 pairs (X) / I8 = 6  => 13 pairs (_)
B1,C1: 7.. / B1 = 7  => 13 pairs (_) / C1 = 7  =>  0 pairs (X)
G2,I2: 7.. / G2 = 7  => 10 pairs (_) / I2 = 7  =>  0 pairs (X)
F7,F8: 7.. / F7 = 7  => 12 pairs (_) / F8 = 7  =>  0 pairs (X)
F7,H7: 7.. / F7 = 7  => 12 pairs (_) / H7 = 7  =>  0 pairs (X)
C1,C5: 7.. / C1 = 7  =>  0 pairs (X) / C5 = 7  => 13 pairs (_)
H1,G3: 8.. / H1 = 8  => 16 pairs (_) / G3 = 8  =>  0 pairs (X)
A3,G3: 8.. / A3 = 8  => 16 pairs (_) / G3 = 8  =>  0 pairs (X)
D1,D4: 8.. / D1 = 8  =>  0 pairs (X) / D4 = 8  => 19 pairs (_)
D1,D4: 9.. / D1 = 9  => 19 pairs (_) / D4 = 9  =>  0 pairs (X)
* DURATION: 0:01:08.398208  START: 06:43:52.839729  END: 06:45:01.237937 2017-05-04
* CP COUNT: (39)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A2,C7,D1,D4,E3,F3,G2,G7,H9,I2,I3,I9)
* 5...236...136...5..267...3.3.2.7.......5...436.53......3.1....8.5.43....76.2..3..
* PAIR A2: 8,9 BLK 1
B1: 8,9,7                                # reduction candidate for 8,9
B1: 8,9 => CTR
* 5.7.236.4.136...5.4267..8393.2.7.......5...436.53......3.1..4.8.5.43....7642..31.
B1: 7                                    # 13 pairs
C1: 8,9,4,7                              # reduction candidate for 8,9
C1: 8,9 => CTR
* 57..236.4.136...5.4267..8393.2.7......75...436.53......3.1..4.8.5.43....7642..31.
C1: 4,7                                  # 13 pairs
A3: 8,9,4                                # reduction candidate for 8,9
A3: 8,9                                  # 16 pairs
* PAIR A2: 8,9 ROW 2
E2: 8,9,4                                # reduction candidate for 8,9
E2: 8,9                                  # 12 pairs
F2: 8,9,4                                # reduction candidate for 8,9
F2: 8,9                                  # 13 pairs
* PAIR A2: 8,9 COL A
A5: 8,9,1                                # reduction candidate for 8,9
A5: 8,9 => CTR
* 5.7.236...136...5..267...3.3.2.7......15...436.53......3.1....815.43....76.2..31.
A5: 1                                    # 12 pairs
A8: 8,9,1,2                              # reduction candidate for 8,9
A8: 8,9 => CTR
* 5...236...136...5.4267..8393.2.7....1..5...436.53.....23.1..4.8.5.43....7642..31.
A8: 1,2                                  # 13 pairs
* PAIR D1: 8,9 BLK 2
E2: 8,9,4                                # reduction candidate for 8,9
E2: 8,9                                  # 12 pairs
F2: 8,9,4                                # reduction candidate for 8,9
F2: 8,9                                  # 13 pairs
* PAIR D1: 8,9 ROW 1
B1: 8,9,7                                # reduction candidate for 8,9
B1: 8,9 => CTR
* 5.7.236.4.136...5.4267..8393.2.7.......5...436.53......3.1..4.8.5.43....7642..31.
B1: 7                                    # 13 pairs
C1: 8,9,4,7                              # reduction candidate for 8,9
C1: 8,9 => CTR
* 57..236.4.136...5.4267..8393.2.7......75...436.53......3.1..4.8.5.43....7642..31.
C1: 4,7                                  # 13 pairs
H1: 8,9,1                                # reduction candidate for 8,9
H1: 8,9                                  # 16 pairs
* PAIR G2: 2,7 COL G
G5: 2,7,8,9                              # reduction candidate for 2,7
G5: 2,7                                  # 14 pairs
G6: 2,7,1,8,9                            # reduction candidate for 2,7
G6: 2,7 => CTR
* 5...236...136...5.4267..8393.2.7.......5629436.53.....23.1..4.8.5.43.1..76.2..3..
G6: 1,8,9                                # 12 pairs
G8: 2,7,1,9                              # reduction candidate for 2,7
G8: 2,7 => CTR
* 5...236...136...5.4267..8393.2.7..86...5629436.53..1..23.1..4.8.5.43...176.2..3..
G8: 1,9                                  # 13 pairs
* PAIR I2: 2,7 COL I
I6: 2,7,1,9                              # reduction candidate for 2,7
I6: 2,7                                  # 13 pairs
I8: 2,7,1,6,9                            # reduction candidate for 2,7
I8: 2,7 => CTR
* 5...236...136...5..267...3.3.2.7.5.6...5...436.53......3.1..4.8.5.43....7642..315
I8: 1,6,9                                # 13 pairs
* PAIR I3: 4,9 BLK 3
I1: 4,9,1                                # reduction candidate for 4,9
I1: 4,9 => CTR
* 5...2361..136...5..267..83.3.2.7.......5...436.53......3.1..4.8.5.43....76.2..3..
I1: 1                                    # 16 pairs
G3: 4,9,8                                # reduction candidate for 4,9
G3: 4,9                                  # 16 pairs
* PAIR I3: 4,9 ROW 3
A3: 4,9,8                                # reduction candidate for 4,9
A3: 4,9 => CTR
* 5...236...136...5..267..83.3.2.7.......5...436.53......3.1..4.8.5.43....7642..315
A3: 8                                    # 16 pairs
* PAIR D4: 8,9 BLK 5
F4: 8,9,1,4                              # reduction candidate for 8,9
F4: 8,9 => CTR
* 5...236...136...5.4267..839342.7.......562.436.53...8.23.1..4.8.5.43..2.7642..3..
F4: 1,4                                  # 13 pairs
E5: 8,9,6                                # reduction candidate for 8,9
E5: 8,9                                  # 16 pairs
F5: 8,9,2,6                              # reduction candidate for 8,9
F5: 8,9 => CTR
* 5...236...136..7524267..8393.2.7.......56.2436.53.2...23.1..4.8.5.43..2.7642..31.
F5: 2,6                                  # 13 pairs
E6: 8,9,1,4                              # reduction candidate for 8,9
E6: 8,9 => CTR
* 5...236...1364..5.4267158393.2.7.......562.436.53.....23.1..4.8.5.43....7642..31.
E6: 1,4                                  # 13 pairs
F6: 8,9,1,2,4                            # reduction candidate for 8,9
F6: 8,9 => CTR
* 5...236...136...5.4267..8393.2.7.......562.436.53.....23.1..4.8.5.43....7642..31.
F6: 1,2,4                                # 12 pairs
* PAIR D4: 8,9 ROW 4
B4: 8,9,4                                # reduction candidate for 8,9
B4: 8,9                                  # 16 pairs
G4: 8,9,1,5                              # reduction candidate for 8,9
G4: 8,9 => SOLVED
* 574923681913684752826715439342871965187596243695342817439167528258439176761258394
G4: 1,5                                  # 13 pairs
H4: 8,9,1,6                              # reduction candidate for 8,9
H4: 8,9 => CTR
* 5...236...136...5..267...3.3.2.7.5.6...5...436.53......3.1..4.8.5.43....7642..315
H4: 1,6                                  # 13 pairs
* PAIR C7: 4,9 BLK 7
A7: 4,9,2                                # reduction candidate for 4,9
A7: 4,9                                  # 16 pairs
C9: 4,9,1,8                              # reduction candidate for 4,9
C9: 4,9 => CTR
* 5.4.236.1.136...5..267...3.3.2.7......75...436.53.....43.1....8.5.43....76.2..31.
C9: 1,8                                  # 16 pairs
* PAIR C7: 4,9 COL C
C1: 4,9,7,8                              # reduction candidate for 4,9
C1: 7,8 => CTR
* 5...236.4.136...5.4267..8393.2.7.......5...436.53......3.1..4.8.5.43....7642..31.
C1: 4,9                                  # 16 pairs
* PAIR H9: 1,9 BLK 9
G8: 1,9,2,7                              # reduction candidate for 1,9
G8: 1,9                                  # 13 pairs
H8: 1,9,2,6,7                            # reduction candidate for 1,9
H8: 1,9 => CTR
* 5...23681.136...5.8267...3.3.287..6....5.2.436.53.....4391..52825.43.7.676.2..3.4
H8: 2,6,7                                # 12 pairs
I8: 1,9,2,6,7                            # reduction candidate for 1,9
I8: 1,9 => CTR
* 5...236...136...5..267...3.3.2.7.5.6...5...436.53......3.1..4.8.5.43....7642..315
I8: 2,6,7                                # 12 pairs
* PAIR H9: 1,9 ROW 9
C9: 1,9,4,8                              # reduction candidate for 1,9
C9: 1,9 => SOLVED
* 574923681913684752826715439342871965187596243695342817439167528258439176761258394
C9: 4,8 => CTR
* 574923681913684.5.8267..43934287..651.7596243695342...439167528251438..67682..314
* PAIR H9: 1,9 COL H
H1: 1,9,8                                # reduction candidate for 1,9
H1: 1,9 => CTR
* 5...236...136...5..267..83.3.2.7.......5...436.53......3.1..4.8.5.43....7642..315
H1: 8                                    # 16 pairs
H4: 1,9,6,8                              # reduction candidate for 1,9
H4: 1,9 => CTR
* 5...236...136...5..267...3.3.2.7.5.6...5...436.53......3.1..4.8.5.43....7642..315
H4: 6,8                                  # 13 pairs
H6: 1,9,2,7,8                            # reduction candidate for 1,9
H6: 1,9                                  # 16 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-116-base-pr-000.dot
* REASONING
* DIS # B1: 8,9 => CTR => B1: 7
* DIS # C1: 8,9 => CTR => C1: 4,7
* DIS # A5: 8,9 => CTR => A5: 1
* DIS # A8: 8,9 => CTR => A8: 1,2
* DIS # B1: 8,9 => CTR => B1: 7
* DIS # C1: 8,9 => CTR => C1: 4,7
* DIS # G6: 2,7 => CTR => G6: 1,8,9
* DIS # G8: 2,7 => CTR => G8: 1,9
* DIS # I8: 2,7 => CTR => I8: 1,6,9
* DIS # I1: 4,9 => CTR => I1: 1
* DIS # A3: 4,9 => CTR => A3: 8
* DIS # F4: 8,9 => CTR => F4: 1,4
* DIS # F5: 8,9 => CTR => F5: 2,6
* DIS # E6: 8,9 => CTR => E6: 1,4
* DIS # F6: 8,9 => CTR => F6: 1,2,4
* PRF # G4: 8,9 => SOL
* DIS # H4: 8,9 => CTR => H4: 1,6
* DIS # C9: 4,9 => CTR => C9: 1,8
* DIS # C1: 7,8 => CTR => C1: 4,9
* DIS # H8: 1,9 => CTR => H8: 2,6,7
* DIS # I8: 1,9 => CTR => I8: 2,6,7
* PRF # C9: 1,9 => SOL
* DIS # C9: 4,8 => CTR => C9: 1,9
* DIS # H1: 1,9 => CTR => H1: 8
* DIS # H4: 1,9 => CTR => H4: 6,8
* CNT  25 HDP CHAINS /  62 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A2,C7,D1,D4,E3,F3,G2,G7,H9,I2,I3,I9)
* 5...236...136...5..267...3.3.2.7.......5...436.53......3.1....8.5.43....76.2..3..
* PAIR A2: 8,9 BLK 1
B1: 8,9,7                                # reduction candidate for 8,9
B1: 8,9 => CTR
* 5.7.236.4.136...5.4267..8393.2.7.......5...436.53......3.1..4.8.5.43....7642..31.
C1: 8,9,4                                # reduction candidate for 8,9
C1: 8,9 => CTR
* 57..236.4.136...5.4267..8393.2.7....1.75...436.53......3.1..4.8.5.43....7642..31.

* LEVEL 0 PASS 1 ROUND 2 (AUTO SOLVE) (B4,B6,C8,C9,E2,E3,E6,E9,F2,F3,F4,F8,G4,G8,H6,H9)
* 5749236819136..7528267..4393.287..651875962436.53.28.743916752825.43..7676.2..3.4
* PAIR F8: 8,9 BLK 8
F9: 8,9,5                                # reduction candidate for 8,9
F9: 8,9 => SOLVED
* 574923681913684752826715439342871965187596243695342817439167528258439176761258394
* DURATION: 0:00:05.528666  START: 06:46:00.795536  END: 06:46:06.324202 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-116-base-pr-001.dot
* REASONING
* DIS # B1: 8,9 => CTR => B1: 7
* DIS B1: 7 # C1: 8,9 => CTR => C1: 4
* PRF B1: 7 + C1: 4 # F9: 8,9 => SOL
* STA B1: 7 + C1: 4 + F9: 8,9
* CNT   3 HDP CHAINS /   3 HYP OPENED

Header Info

Top 500 Minimum 17 116

solution: 574923681913684752826715439342871965187596243695342817439167528258439176761258394
info: 1754     FNBHWXY  S8.f     3556

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

Solution

position: 574923681913684752826715439342871965187596243695342817439167528258439176761258394 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 # B1: 8,9 => CTR => B1: 7
* INC # B1: 7 => UNS
* DIS # C1: 8,9 => CTR => C1: 4,7
* INC # C1: 4,7 => UNS
* INC # A3: 8,9 => UNS
* INC # E2: 8,9 => UNS
* INC # F2: 8,9 => UNS
* DIS # A5: 8,9 => CTR => A5: 1
* INC # A5: 1 => UNS
* DIS # A8: 8,9 => CTR => A8: 1,2
* INC # A8: 1,2 => UNS
* INC # E2: 8,9 => UNS
* INC # F2: 8,9 => UNS
* DIS # B1: 8,9 => CTR => B1: 7
* INC # B1: 7 => UNS
* DIS # C1: 8,9 => CTR => C1: 4,7
* INC # C1: 4,7 => UNS
* INC # H1: 8,9 => UNS
* INC # G5: 2,7 => UNS
* DIS # G6: 2,7 => CTR => G6: 1,8,9
* INC # G6: 1,8,9 => UNS
* DIS # G8: 2,7 => CTR => G8: 1,9
* INC # G8: 1,9 => UNS
* INC # I6: 2,7 => UNS
* DIS # I8: 2,7 => CTR => I8: 1,6,9
* INC # I8: 1,6,9 => UNS
* DIS # I1: 4,9 => CTR => I1: 1
* INC # I1: 1 => UNS
* INC # G3: 4,9 => UNS
* DIS # A3: 4,9 => CTR => A3: 8
* INC # A3: 8 => UNS
* DIS # F4: 8,9 => CTR => F4: 1,4
* INC # F4: 1,4 => UNS
* INC # E5: 8,9 => UNS
* DIS # F5: 8,9 => CTR => F5: 2,6
* INC # F5: 2,6 => UNS
* DIS # E6: 8,9 => CTR => E6: 1,4
* INC # E6: 1,4 => UNS
* DIS # F6: 8,9 => CTR => F6: 1,2,4
* INC # F6: 1,2,4 => UNS
* INC # B4: 8,9 => UNS
* PRF # G4: 8,9 => SOL
* INC # G4: 1,5 => UNS
* DIS # H4: 8,9 => CTR => H4: 1,6
* INC # H4: 1,6 => UNS
* INC # A7: 4,9 => UNS
* DIS # C9: 4,9 => CTR => C9: 1,8
* INC # C9: 1,8 => UNS
* INC # C1: 4,9 => UNS
* DIS # C1: 7,8 => CTR => C1: 4,9
* INC # G8: 1,9 => UNS
* DIS # H8: 1,9 => CTR => H8: 2,6,7
* INC # H8: 2,6,7 => UNS
* DIS # I8: 1,9 => CTR => I8: 2,6,7
* INC # I8: 2,6,7 => UNS
* PRF # C9: 1,9 => SOL
* DIS # C9: 4,8 => CTR => C9: 1,9
* DIS # H1: 1,9 => CTR => H1: 8
* INC # H1: 8 => UNS
* DIS # H4: 1,9 => CTR => H4: 6,8
* INC # H4: 6,8 => UNS
* INC # H6: 1,9 => UNS
* CNT  62 HDP CHAINS /  62 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # B1: 8,9 => CTR => B1: 7
* DIS B1: 7 # C1: 8,9 => CTR => C1: 4
* PRF B1: 7 + C1: 4 # F9: 8,9 => SOL
* STA B1: 7 + C1: 4 + F9: 8,9
* CNT   3 HDP CHAINS /   3 HYP OPENED