Analysis of xx-top500-150-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 3...6.......1..8..........5....3.96...5...4...1..........5.2..79......3....8..... initial

Autosolve

position: 35..6.719..615.8.31..3..6.58...35961.359..47..19...35.4635921879.....534571843296 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # C3: 2,7 => SOL
* DIS # C3: 4,8 => CTR => C3: 2,7
* DIS # A6: 6 => CTR => A6: 2,7
* PRF # C1: 8 => SOL
* PRF # D6: 2,4 => SOL
* DIS # D6: 6,7 => CTR => D6: 2,4
* DIS # F3: 4,8 => CTR => F3: 7,9
* PRF # C1: 4,8 => SOL
* DIS # C1: 2 => CTR => C1: 4,8
* PRF # F6: 6,7 => SOL
* DIS # B2: 2,4 => CTR => B2: 9
* PRF # B3: 2,4 => SOL
* DIS # C3: 2,4 => CTR => C3: 7,8
* PRF # C4: 2,4 => SOL
* DIS # C4: 7 => CTR => C4: 2,4
* DIS # B2: 2,4 => CTR => B2: 9
* PRF # B3: 2,4 => SOL
* DIS # A6: 2,6 => CTR => A6: 7
* PRF # A6: 7 => SOL
* DIS # D6: 2,7 => CTR => D6: 4,6
* PRF # C4: 4 => SOL
* DIS # E6: 7 => CTR => E6: 2,8
* PRF # B3: 4,9 => SOL
* DIS # C3: 2,8 => CTR => C3: 4,7
* DIS # D6: 6,7 => CTR => D6: 2,4
* PRF # D6: 2,4 => SOL
* DIS # F8: 6 => CTR => F8: 1,7
* CNT  27 HDP CHAINS /  48 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 # C3: 2,7 => SOL
* STA C3: 2,7
* CNT   1 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

3...6.......1..8..........5....3.96...5...4...1..........5.2..79......3....8..... initial
35..6.719..615.8.31..3..6.58...35961.359..47..19...35.4635921879.....534571843296 autosolve
358264719296157843147389625824735961635918472719426358463592187982671534571843296 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (14)
A2: 2,7
D1: 2,4
F1: 4,8
H2: 2,4
H3: 2,4
B4: 2,4
A5: 2,6
D4: 2,7
I5: 2,8
I6: 2,8
B8: 2,8
C8: 2,8
D8: 6,7
E8: 1,7

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
E5,F5: 1.. / E5 = 1  => 23 pairs (_) / F5 = 1  => 18 pairs (_)
E8,F8: 1.. / E8 = 1  => 18 pairs (_) / F8 = 1  => 23 pairs (_)
E5,E8: 1.. / E5 = 1  => 23 pairs (_) / E8 = 1  => 18 pairs (_)
F5,F8: 1.. / F5 = 1  => 18 pairs (_) / F8 = 1  => 23 pairs (_)
D1,E3: 2.. / D1 = 2  =>  0 pairs (*) / E3 = 2  =>  0 pairs (X)
H2,H3: 2.. / H2 = 2  =>  0 pairs (X) / H3 = 2  =>  0 pairs (_)
I5,I6: 2.. / I5 = 2  => 17 pairs (_) / I6 = 2  => 16 pairs (_)
B8,C8: 2.. / B8 = 2  => 15 pairs (_) / C8 = 2  =>  0 pairs (*)
C1,D1: 2.. / C1 = 2  =>  0 pairs (X) / D1 = 2  =>  0 pairs (_)
H2,H3: 4.. / H2 = 4  =>  0 pairs (*) / H3 = 4  =>  0 pairs (X)
B4,C4: 4.. / B4 = 4  => 15 pairs (_) / C4 = 4  =>  0 pairs (*)
D6,F6: 4.. / D6 = 4  =>  0 pairs (*) / F6 = 4  =>  0 pairs (X)
D1,D6: 4.. / D1 = 4  =>  0 pairs (X) / D6 = 4  =>  0 pairs (_)
A5,A6: 6.. / A5 = 6  => 17 pairs (_) / A6 = 6  =>  0 pairs (X)
D8,F8: 6.. / D8 = 6  => 18 pairs (_) / F8 = 6  =>  0 pairs (X)
A5,F5: 6.. / A5 = 6  => 17 pairs (_) / F5 = 6  =>  0 pairs (X)
D6,D8: 6.. / D6 = 6  =>  0 pairs (X) / D8 = 6  => 18 pairs (_)
A2,C3: 7.. / A2 = 7  =>  0 pairs (X) / C3 = 7  =>  0 pairs (_)
C4,A6: 7.. / C4 = 7  =>  0 pairs (X) / A6 = 7  =>  0 pairs (_)
A2,F2: 7.. / A2 = 7  =>  0 pairs (X) / F2 = 7  =>  0 pairs (_)
C4,D4: 7.. / C4 = 7  =>  0 pairs (X) / D4 = 7  =>  0 pairs (_)
A2,A6: 7.. / A2 = 7  =>  0 pairs (X) / A6 = 7  =>  0 pairs (_)
C3,C4: 7.. / C3 = 7  =>  0 pairs (*) / C4 = 7  =>  0 pairs (X)
I5,I6: 8.. / I5 = 8  => 16 pairs (_) / I6 = 8  => 17 pairs (_)
B8,C8: 8.. / B8 = 8  =>  0 pairs (*) / C8 = 8  =>  0 pairs (X)
C1,F1: 8.. / C1 = 8  =>  0 pairs (*) / F1 = 8  =>  0 pairs (X)
B3,B8: 8.. / B3 = 8  => 15 pairs (_) / B8 = 8  =>  0 pairs (*)
B2,B3: 9.. / B2 = 9  => 15 pairs (_) / B3 = 9  =>  0 pairs (X)
F2,F3: 9.. / F2 = 9  =>  0 pairs (X) / F3 = 9  => 15 pairs (_)
B2,F2: 9.. / B2 = 9  => 15 pairs (_) / F2 = 9  =>  0 pairs (X)
B3,F3: 9.. / B3 = 9  =>  0 pairs (X) / F3 = 9  => 15 pairs (_)
* DURATION: 0:01:02.352701  START: 07:52:37.114049  END: 07:53:39.466750 2017-05-04
* CP COUNT: (31)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A2,A5,B4,B8,C8,D1,D4,D8,E8,F1,H2,H3,I5,I6)
* 35..6.719..615.8.31..3..6.58...35961.359..47..19...35.4635921879.....534571843296
* PAIR A2: 2,7 BLK 1
C3: 2,7,4,8                              # reduction candidate for 2,7
C3: 2,7 => SOLVED
* 358264719296157843147389625824735961635918472719426358463592187982671534571843296
C3: 4,8 => CTR
* 3524687197.615982319.3..6.58.7235961.359..47..19...35.4635921879.....534571843296
* PAIR A2: 2,7 COL A
A6: 2,7,6                                # reduction candidate for 2,7
A6: 6 => CTR
* 3524687197.615982319.3..6.58.72359612359.6478619...3524635921879..6.1534571843296
A6: 2,7                                  # 17 pairs
* PAIR D1: 2,4 ROW 1
C1: 2,4,8                                # reduction candidate for 2,4
C1: 8 => SOLVED
* 358264719296157843147389625824735961635918472719426358463592187982671534571843296
C1: 2,4                                  # 16 pairs
* PAIR D1: 2,4 COL D
D6: 2,4,6,7                              # reduction candidate for 2,4
D6: 2,4 => SOLVED
* 358264719296157843147389625824735961635918472719426358463592187982671534571843296
D6: 6,7 => CTR
* 35.468719..615.8.31..32.6458.4.35961.359..47..19...35.4635921879.....534571843296
* PAIR F1: 4,8 BLK 2
F3: 4,8,7,9                              # reduction candidate for 4,8
F3: 4,8 => CTR
* 35..6.719..61598.319.37.6.58.7235961.359..47..19.8.352463592187982.1.534571843296
F3: 7,9                                  # 15 pairs
* PAIR F1: 4,8 ROW 1
C1: 4,8,2                                # reduction candidate for 4,8
C1: 4,8 => SOLVED
* 358264719296157843147389625824735961635918472719426358463592187982671534571843296
C1: 2 => CTR
* 3524687197.61598231983..6.58...35961.359..47..19...35.4635921879.....534571843296
* PAIR F1: 4,8 COL F
F6: 4,8,6,7                              # reduction candidate for 4,8
F6: 6,7 => SOLVED
* 358264719296157843147389625824735961635918472719426358463592187982671534571843296
F6: 4,8                                  # 23 pairs
* PAIR H2: 2,4 ROW 2
B2: 2,4,9                                # reduction candidate for 2,4
B2: 2,4 => CTR
* 35.26.71972615984319.3..625847.35961.359..47..19...35.463592187982...534571843296
B2: 9                                    # 15 pairs
* PAIR H3: 2,4 ROW 3
B3: 2,4,8,9                              # reduction candidate for 2,4
B3: 2,4 => SOLVED
* 358264719296157843147389625824735961635918472719426358463592187982671534571843296
B3: 8,9                                  # 15 pairs
C3: 2,4,7,8                              # reduction candidate for 2,4
C3: 2,4 => CTR
* 3524687197.61598231..3..6.58.7235961.359..47..19...35.4635921879.....534571843296
C3: 7,8                                  # 15 pairs
* PAIR B4: 2,4 BLK 4
C4: 2,4,7                                # reduction candidate for 2,4
C4: 2,4 => SOLVED
* 358264719296157843147389625824735961635918472719426358463592187982671534571843296
C4: 7 => CTR
* 3524687197.615.8.31..3..6.5847235961.359..47..19...35.4635921879.....534571843296
* PAIR B4: 2,4 COL B
B2: 2,4,9                                # reduction candidate for 2,4
B2: 2,4 => CTR
* 35.26.71972615984319.3..625847.35961.359..47..19...35.463592187982...534571843296
B2: 9                                    # 15 pairs
B3: 2,4,8,9                              # reduction candidate for 2,4
B3: 2,4 => SOLVED
* 358264719296157843147389625824735961635918472719426358463592187982671534571843296
B3: 8,9                                  # 15 pairs
* PAIR A5: 2,6 BLK 4
A6: 2,6,7                                # reduction candidate for 2,6
A6: 2,6 => CTR
* 3524687197.615982319.3..6.58.7235961.359..47..19...35.4635921879.....534571843296
A6: 7 => SOLVED
* 358264719296157843147389625824735961635918472719426358463592187982671534571843296
* PAIR D4: 2,7 BLK 5
D6: 2,7,4,6                              # reduction candidate for 2,7
D6: 2,7 => CTR
* 35.468719..615.8.31..32.6458.4735961.359..47.7192..35.4635921879.....534571843296
D6: 4,6                                  # 15 pairs
E6: 2,7,8                                # reduction candidate for 2,7
E6: 2,7                                  # 17 pairs
* PAIR D4: 2,7 ROW 4
C4: 2,7,4                                # reduction candidate for 2,7
C4: 4 => SOLVED
* 358264719296157843147389625824735961635918472719426358463592187982671534571843296
C4: 2,7                                  # 15 pairs
* PAIR I5: 2,8 ROW 5
E5: 2,8,1                                # reduction candidate for 2,8
E5: 1                                    # 23 pairs
E5: 2,8                                  # 18 pairs
* PAIR I6: 2,8 ROW 6
E6: 2,8,7                                # reduction candidate for 2,8
E6: 7 => CTR
* 3524687197.615982319.3.76.58.72359616359814722196743584635921879..716534571843296
E6: 2,8                                  # 16 pairs
* PAIR B8: 2,8 COL B
B3: 2,8,4,9                              # reduction candidate for 2,8
B3: 4,9 => SOLVED
* 358264719296157843147389625824735961635918472719426358463592187982671534571843296
B3: 2,8                                  # 16 pairs
* PAIR C8: 2,8 COL C
C1: 2,8,4                                # reduction candidate for 2,8
C1: 2,8                                  # 18 pairs
C3: 2,8,4,7                              # reduction candidate for 2,8
C3: 2,8 => CTR
* 35..6.7197.615.8.31..3..6.58.7235961.359..47..19...35.4635921879.....534571843296
C3: 4,7                                  # 15 pairs
* PAIR D8: 6,7 BLK 8
F8: 6,7,1                                # reduction candidate for 6,7
F8: 1                                    # 23 pairs
F8: 6,7                                  # 18 pairs
* PAIR D8: 6,7 COL D
D6: 6,7,2,4                              # reduction candidate for 6,7
D6: 6,7 => CTR
* 35.468719..615.8.31..32.6458.4.35961.359..47..19...35.4635921879.....534571843296
D6: 2,4 => SOLVED
* 358264719296157843147389625824735961635918472719426358463592187982671534571843296
* PAIR E8: 1,7 BLK 8
F8: 1,7,6                                # reduction candidate for 1,7
F8: 6 => CTR
* 35.468719..615.8.31..32.6458...359616359.147..196.435.4635921879..716534571843296
F8: 1,7                                  # 18 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-150-base-pr-000.dot
* REASONING
* PRF # C3: 2,7 => SOL
* DIS # C3: 4,8 => CTR => C3: 2,7
* DIS # A6: 6 => CTR => A6: 2,7
* PRF # C1: 8 => SOL
* PRF # D6: 2,4 => SOL
* DIS # D6: 6,7 => CTR => D6: 2,4
* DIS # F3: 4,8 => CTR => F3: 7,9
* PRF # C1: 4,8 => SOL
* DIS # C1: 2 => CTR => C1: 4,8
* PRF # F6: 6,7 => SOL
* DIS # B2: 2,4 => CTR => B2: 9
* PRF # B3: 2,4 => SOL
* DIS # C3: 2,4 => CTR => C3: 7,8
* PRF # C4: 2,4 => SOL
* DIS # C4: 7 => CTR => C4: 2,4
* DIS # B2: 2,4 => CTR => B2: 9
* PRF # B3: 2,4 => SOL
* DIS # A6: 2,6 => CTR => A6: 7
* PRF # A6: 7 => SOL
* DIS # D6: 2,7 => CTR => D6: 4,6
* PRF # C4: 4 => SOL
* DIS # E6: 7 => CTR => E6: 2,8
* PRF # B3: 4,9 => SOL
* DIS # C3: 2,8 => CTR => C3: 4,7
* DIS # D6: 6,7 => CTR => D6: 2,4
* PRF # D6: 2,4 => SOL
* DIS # F8: 6 => CTR => F8: 1,7
* CNT  27 HDP CHAINS /  48 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A2,A5,B4,B8,C8,D1,D4,D8,E8,F1,H2,H3,I5,I6)
* 35..6.719..615.8.31..3..6.58...35961.359..47..19...35.4635921879.....534571843296
* PAIR A2: 2,7 BLK 1
C3: 2,7,4,8                              # reduction candidate for 2,7
C3: 2,7 => SOLVED
* 358264719296157843147389625824735961635918472719426358463592187982671534571843296
* DURATION: 0:00:02.319601  START: 07:54:36.226936  END: 07:54:38.546537 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-150-base-pr-001.dot
* REASONING
* PRF # C3: 2,7 => SOL
* STA C3: 2,7
* CNT   1 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 150

solution: 358264719296157843147389625824735961635918472719426358463592187982671534571843296
info: 1816     FNBWY    S8.f     29206

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

Solution

position: 358264719296157843147389625824735961635918472719426358463592187982671534571843296 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:

* PRF # C3: 2,7 => SOL
* DIS # C3: 4,8 => CTR => C3: 2,7
* INC # A6: 2,7 => UNS
* DIS # A6: 6 => CTR => A6: 2,7
* INC # C1: 2,4 => UNS
* PRF # C1: 8 => SOL
* PRF # D6: 2,4 => SOL
* DIS # D6: 6,7 => CTR => D6: 2,4
* DIS # F3: 4,8 => CTR => F3: 7,9
* INC # F3: 7,9 => UNS
* PRF # C1: 4,8 => SOL
* DIS # C1: 2 => CTR => C1: 4,8
* INC # F6: 4,8 => UNS
* PRF # F6: 6,7 => SOL
* DIS # B2: 2,4 => CTR => B2: 9
* INC # B2: 9 => UNS
* PRF # B3: 2,4 => SOL
* INC # B3: 8,9 => UNS
* DIS # C3: 2,4 => CTR => C3: 7,8
* INC # C3: 7,8 => UNS
* PRF # C4: 2,4 => SOL
* DIS # C4: 7 => CTR => C4: 2,4
* DIS # B2: 2,4 => CTR => B2: 9
* INC # B2: 9 => UNS
* PRF # B3: 2,4 => SOL
* INC # B3: 8,9 => UNS
* DIS # A6: 2,6 => CTR => A6: 7
* PRF # A6: 7 => SOL
* DIS # D6: 2,7 => CTR => D6: 4,6
* INC # D6: 4,6 => UNS
* INC # E6: 2,7 => UNS
* INC # C4: 2,7 => UNS
* PRF # C4: 4 => SOL
* INC # E5: 2,8 => UNS
* INC # E5: 1 => UNS
* INC # E6: 2,8 => UNS
* DIS # E6: 7 => CTR => E6: 2,8
* INC # B3: 2,8 => UNS
* PRF # B3: 4,9 => SOL
* INC # C1: 2,8 => UNS
* DIS # C3: 2,8 => CTR => C3: 4,7
* INC # C3: 4,7 => UNS
* INC # F8: 6,7 => UNS
* INC # F8: 1 => UNS
* DIS # D6: 6,7 => CTR => D6: 2,4
* PRF # D6: 2,4 => SOL
* INC # F8: 1,7 => UNS
* DIS # F8: 6 => CTR => F8: 1,7
* CNT  48 HDP CHAINS /  48 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* PRF # C3: 2,7 => SOL
* STA C3: 2,7
* CNT   1 HDP CHAINS /   1 HYP OPENED