Analysis of xx-top500-493-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: .586..1...1.5....4.......2.7...2..3..6...................1..5..3...7....2........ initial

Autosolve

position: 4586.21..9125.7.64637....2578..25631.6....2...2..6....8.61.35.23.527..1.2.1.5.... autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # I1: 3,9 => SOL
* DIS # I1: 7 => CTR => I1: 3,9
* DIS # I1: 7,9 => CTR => I1: 3
* PRF # I1: 3 => SOL
* DIS # H5: 7,9 => CTR => H5: 4,5,8
* DIS # H6: 7,9 => CTR => H6: 4,5,8
* DIS # H9: 7,9 => CTR => H9: 4,8
* DIS # E3: 8,9 => CTR => E3: 1,4
* DIS # F3: 8,9 => CTR => F3: 1,4
* DIS # C5: 4,9 => CTR => C5: 3
* DIS # E5: 4,9 => CTR => E5: 1,8
* PRF # F6: 4,9 => SOL
* DIS # D3: 4,9 => CTR => D3: 8
* PRF # D3: 8 => SOL
* PRF # D9: 4,9 => SOL
* DIS # D9: 8 => CTR => D9: 4,9
* DIS # B7: 4,9 => CTR => B7: 7
* PRF # D9: 4,9 => SOL
* DIS # D9: 8 => CTR => D9: 4,9
* DIS # F9: 4,9 => CTR => F9: 6,8
* PRF # F9: 6,8 => SOL
* DIS # B7: 4,9 => CTR => B7: 7
* DIS # E3: 4,9 => CTR => E3: 1,8
* DIS # E5: 4,9 => CTR => E5: 1,8
* PRF # F9: 6,8 => SOL
* DIS # F9: 4,9 => CTR => F9: 6,8
* DIS # G9: 4,9 => CTR => G9: 3,7
* DIS # H9: 4,9 => CTR => H9: 7,8
* DIS # G6: 4,9 => CTR => G6: 7
* PRF # G6: 7 => SOL
* DIS # I9: 6,8 => CTR => I9: 3,7,9
* PRF # I9: 3,7,9 => SOL
* CNT  32 HDP CHAINS /  53 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 # I1: 3,9 => SOL
* STA I1: 3,9
* CNT   1 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

.586..1...1.5....4.......2.7...2..3..6...................1..5..3...7....2........ initial
4586.21..9125.7.64637....2578..25631.6....2...2..6....8.61.35.23.527..1.2.1.5.... autosolve
458692173912537864637814925789425631563781249124369758876143592395278416241956387 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (16)
E1: 3,9
E2: 3,8
H1: 7,9
G2: 3,8
G3: 8,9
C4: 4,9
A5: 1,5
A6: 1,5
D4: 4,9
D5: 3,7
D6: 3,7
B8: 4,9
E7: 4,9
F8: 6,8
G8: 4,9
I8: 6,8

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
E3,F3: 1.. / E3 = 1  => 16 pairs (_) / F3 = 1  =>  0 pairs (X)
A5,A6: 1.. / A5 = 1  => 16 pairs (_) / A6 = 1  => 14 pairs (_)
A6,F6: 1.. / A6 = 1  => 14 pairs (_) / F6 = 1  => 16 pairs (_)
E3,E5: 1.. / E3 = 1  => 16 pairs (_) / E5 = 1  =>  0 pairs (X)
E1,E2: 3.. / E1 = 3  =>  0 pairs (X) / E2 = 3  =>  0 pairs (_)
I1,G2: 3.. / I1 = 3  =>  0 pairs (*) / G2 = 3  =>  0 pairs (X)
C5,C6: 3.. / C5 = 3  => 16 pairs (_) / C6 = 3  =>  0 pairs (X)
D5,D6: 3.. / D5 = 3  =>  0 pairs (X) / D6 = 3  => 16 pairs (_)
G9,I9: 3.. / G9 = 3  =>  0 pairs (*) / I9 = 3  =>  0 pairs (X)
E1,I1: 3.. / E1 = 3  =>  0 pairs (X) / I1 = 3  =>  0 pairs (_)
E2,G2: 3.. / E2 = 3  =>  0 pairs (*) / G2 = 3  =>  0 pairs (X)
C5,D5: 3.. / C5 = 3  => 16 pairs (_) / D5 = 3  =>  0 pairs (X)
C6,D6: 3.. / C6 = 3  =>  0 pairs (X) / D6 = 3  => 16 pairs (_)
G2,G9: 3.. / G2 = 3  =>  0 pairs (X) / G9 = 3  =>  0 pairs (_)
I1,I9: 3.. / I1 = 3  =>  0 pairs (*) / I9 = 3  =>  0 pairs (X)
C4,D4: 4.. / C4 = 4  => 18 pairs (_) / D4 = 4  => 20 pairs (_)
B8,G8: 4.. / B8 = 4  =>  0 pairs (X) / G8 = 4  =>  0 pairs (_)
A5,A6: 5.. / A5 = 5  => 14 pairs (_) / A6 = 5  => 16 pairs (_)
H5,H6: 5.. / H5 = 5  => 16 pairs (_) / H6 = 5  => 14 pairs (_)
A5,H5: 5.. / A5 = 5  => 14 pairs (_) / H5 = 5  => 16 pairs (_)
A6,H6: 5.. / A6 = 5  => 16 pairs (_) / H6 = 5  => 14 pairs (_)
F8,F9: 6.. / F8 = 6  =>  0 pairs (X) / F9 = 6  =>  0 pairs (_)
I8,I9: 6.. / I8 = 6  =>  0 pairs (*) / I9 = 6  =>  0 pairs (X)
F8,I8: 6.. / F8 = 6  =>  0 pairs (X) / I8 = 6  =>  0 pairs (_)
F9,I9: 6.. / F9 = 6  =>  0 pairs (*) / I9 = 6  =>  0 pairs (X)
H1,I1: 7.. / H1 = 7  =>  0 pairs (*) / I1 = 7  =>  0 pairs (X)
D5,D6: 7.. / D5 = 7  => 16 pairs (_) / D6 = 7  =>  0 pairs (X)
B7,B9: 7.. / B7 = 7  => 20 pairs (_) / B9 = 7  =>  0 pairs (X)
B7,H7: 7.. / B7 = 7  => 20 pairs (_) / H7 = 7  =>  0 pairs (X)
G6,G9: 7.. / G6 = 7  =>  0 pairs (*) / G9 = 7  =>  0 pairs (X)
G2,G3: 8.. / G2 = 8  =>  0 pairs (*) / G3 = 8  =>  0 pairs (X)
E2,G2: 8.. / E2 = 8  =>  0 pairs (X) / G2 = 8  =>  0 pairs (_)
F8,I8: 8.. / F8 = 8  =>  0 pairs (*) / I8 = 8  =>  0 pairs (X)
D3,D9: 8.. / D3 = 8  =>  0 pairs (*) / D9 = 8  =>  0 pairs (X)
C4,D4: 9.. / C4 = 9  => 20 pairs (_) / D4 = 9  => 18 pairs (_)
B8,G8: 9.. / B8 = 9  =>  0 pairs (*) / G8 = 9  =>  0 pairs (X)
* DURATION: 0:01:11.891788  START: 19:30:09.027999  END: 19:31:20.919787 2017-05-04
* CP COUNT: (36)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A5,A6,B8,C4,D4,D5,D6,E1,E2,E7,F8,G2,G3,G8,H1,I8)
* 4586.21..9125.7.64637....2578..25631.6....2...2..6....8.61.35.23.527..1.2.1.5....
* PAIR E1: 3,9 ROW 1
I1: 3,9,7                                # reduction candidate for 3,9
I1: 3,9 => SOLVED
* 458692173912537864637814925789425631563781249124369758876143592395278416241956387
I1: 7 => CTR
* 458632197912587364637...82578..25631.6....2...2..6....8.61.35.23.527..1.2.185...3
* PAIR H1: 7,9 BLK 3
I1: 7,9,3                                # reduction candidate for 7,9
I1: 7,9 => CTR
* 4586321..912587364637...82578..25631.6....2...2..6....8.61.35.23.527..1.2.185...3
I1: 3 => SOLVED
* 458692173912537864637814925789425631563781249124369758876143592395278416241956387
* PAIR H1: 7,9 COL H
H5: 7,9,4,5,8                            # reduction candidate for 7,9
H5: 7,9 => CTR
* 4586.21..9125.7.646378..92578..2563156..812..12..6.45.8.61.35.23.527..1.2.1.5..8.
H5: 4,5,8                                # 16 pairs
H6: 7,9,4,5,8                            # reduction candidate for 7,9
H6: 7,9 => CTR
* 4586321..912587364637.1.82578..2563116....25.52..614.8876193542345278916291456783
H6: 4,5,8                                # 16 pairs
H7: 7,9,4                                # reduction candidate for 7,9
H7: 7,9                                  # 18 pairs
H9: 7,9,4,8                              # reduction candidate for 7,9
H9: 7,9 => CTR
* 4586.21..9125.7.64637....2578..25631.6....2...2..6....8.61.35.23.527..1.2.1.5....
H9: 4,8                                  # 17 pairs
* PAIR G3: 8,9 ROW 3
D3: 8,9,4                                # reduction candidate for 8,9
D3: 8,9                                  # 19 pairs
E3: 8,9,1,4                              # reduction candidate for 8,9
E3: 8,9 => CTR
* 4586.21.391253786463748192578492563156..1.28.12..6845.8.61435.23.527..1.2.1859..6
E3: 1,4                                  # 17 pairs
F3: 8,9,1,4                              # reduction candidate for 8,9
F3: 8,9 => CTR
* 4586.21.3912537864637418925784925631.6..8.2...2..6..8.8.61435.2395276418241859376
F3: 1,4                                  # 17 pairs
* PAIR C4: 4,9 BLK 4
C5: 4,9,3                                # reduction candidate for 4,9
C5: 4,9 => CTR
* 4586321..912587364637...82578..25631.6.3..2...2376....8761.35.23.527..162.185.7.3
C5: 3                                    # 16 pairs
C6: 4,9,3                                # reduction candidate for 4,9
C6: 4,9                                  # 16 pairs
* PAIR D4: 4,9 BLK 5
E5: 4,9,1,8                              # reduction candidate for 4,9
E5: 4,9 => CTR
* 4586.21..912587364637.1.82578..25631.6....2...2..6....8.61.35.23.527..1.2.185...3
E5: 1,8                                  # 17 pairs
F5: 4,9,1,8                              # reduction candidate for 4,9
F5: 4,9                                  # 19 pairs
F6: 4,9,1,8                              # reduction candidate for 4,9
F6: 4,9 => SOLVED
* 458692173912537864637814925789425631563781249124369758876143592395278416241956387
F6: 1,8                                  # 17 pairs
* PAIR D4: 4,9 COL D
D3: 4,9,8                                # reduction candidate for 4,9
D3: 4,9 => CTR
* 4586.21.3912537864637...92578.925631.6....2...2..6....8.61.35.23952764182.1859376
D3: 8 => SOLVED
* 458692173912537864637814925789425631563781249124369758876143592395278416241956387
D9: 4,9,8                                # reduction candidate for 4,9
D9: 4,9 => SOLVED
* 458692173912537864637814925789425631563781249124369758876143592395278416241956387
D9: 8 => CTR
* 4586.21.3912537864637...92578.925631.6....2...2..6....8.61.35.23952764182.1859376
* PAIR B8: 4,9 BLK 7
B7: 4,9,7                                # reduction candidate for 4,9
B7: 4,9 => CTR
* 4586.21979125.7364637...82578..25631.6.7..2...2.36.7..8.61.35723.527..1.27185..43
B7: 7                                    # 20 pairs
B9: 4,9,7                                # reduction candidate for 4,9
B9: 4,9                                  # 20 pairs
* PAIR E7: 4,9 BLK 8
D9: 4,9,8                                # reduction candidate for 4,9
D9: 4,9 => SOLVED
* 458692173912537864637814925789425631563781249124369758876143592395278416241956387
D9: 8 => CTR
* 4586.21.3912537864637...92578.925631.6....2...2..6....8.61.35.23952764182.1859376
F9: 4,9,6,8                              # reduction candidate for 4,9
F9: 4,9 => CTR
* 4586.21.3912537864637...92578.925631.6....2...2..6....8.61.35.23952764182.1859376
F9: 6,8 => SOLVED
* 458692173912537864637814925789425631563781249124369758876143592395278416241956387
* PAIR E7: 4,9 ROW 7
B7: 4,9,7                                # reduction candidate for 4,9
B7: 4,9 => CTR
* 4586.21979125.7364637...82578..25631.6.7..2...2.36.7..8.61.35723.527..1.27185..43
B7: 7                                    # 20 pairs
H7: 4,9,7                                # reduction candidate for 4,9
H7: 4,9                                  # 20 pairs
* PAIR E7: 4,9 COL E
E3: 4,9,1,8                              # reduction candidate for 4,9
E3: 4,9 => CTR
* 4586.21..912587364637..182578..2563156..1.2..12..6..5.8.61.35.23.527..1.2.185...3
E3: 1,8                                  # 17 pairs
E5: 4,9,1,8                              # reduction candidate for 4,9
E5: 4,9 => CTR
* 4586.21..912587364637.1.82578..25631.6....2...2..6....8.61.35.23.527..1.2.185...3
E5: 1,8                                  # 17 pairs
* PAIR F8: 6,8 BLK 8
F9: 6,8,4,9                              # reduction candidate for 6,8
F9: 6,8 => SOLVED
* 458692173912537864637814925789425631563781249124369758876143592395278416241956387
F9: 4,9 => CTR
* 4586.21.3912537864637...92578.925631.6....2...2..6....8.61.35.23952764182.1859376
* PAIR G8: 4,9 BLK 9
H7: 4,9,7                                # reduction candidate for 4,9
H7: 4,9                                  # 20 pairs
G9: 4,9,3,7                              # reduction candidate for 4,9
G9: 4,9 => CTR
* 4586.21..9125.7364637...82578..25631.6....2...2..6.7..8.61.35.23.527..1.2.185...3
G9: 3,7                                  # 17 pairs
H9: 4,9,7,8                              # reduction candidate for 4,9
H9: 4,9 => CTR
* 4586.21..9125.7.64637....2578..25631.6....2...2..6....8.61.35.23.527..1.2.1.5....
H9: 7,8                                  # 17 pairs
* PAIR G8: 4,9 COL G
G6: 4,9,7                                # reduction candidate for 4,9
G6: 4,9 => CTR
* 4586321..912587364637...82578..25631.6....2...2..6....8761.35.23.527..162.185.7.3
G6: 7 => SOLVED
* 458692173912537864637814925789425631563781249124369758876143592395278416241956387
* PAIR I8: 6,8 BLK 9
I9: 6,8,3,7,9                            # reduction candidate for 6,8
I9: 6,8 => CTR
* 458692173912537864637...92578..25631.6....2...2..6.7..87614359239527.41.241.5.386
I9: 3,7,9 => SOLVED
* 458692173912537864637814925789425631563781249124369758876143592395278416241956387
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-493-base-pr-000.dot
* REASONING
* PRF # I1: 3,9 => SOL
* DIS # I1: 7 => CTR => I1: 3,9
* DIS # I1: 7,9 => CTR => I1: 3
* PRF # I1: 3 => SOL
* DIS # H5: 7,9 => CTR => H5: 4,5,8
* DIS # H6: 7,9 => CTR => H6: 4,5,8
* DIS # H9: 7,9 => CTR => H9: 4,8
* DIS # E3: 8,9 => CTR => E3: 1,4
* DIS # F3: 8,9 => CTR => F3: 1,4
* DIS # C5: 4,9 => CTR => C5: 3
* DIS # E5: 4,9 => CTR => E5: 1,8
* PRF # F6: 4,9 => SOL
* DIS # D3: 4,9 => CTR => D3: 8
* PRF # D3: 8 => SOL
* PRF # D9: 4,9 => SOL
* DIS # D9: 8 => CTR => D9: 4,9
* DIS # B7: 4,9 => CTR => B7: 7
* PRF # D9: 4,9 => SOL
* DIS # D9: 8 => CTR => D9: 4,9
* DIS # F9: 4,9 => CTR => F9: 6,8
* PRF # F9: 6,8 => SOL
* DIS # B7: 4,9 => CTR => B7: 7
* DIS # E3: 4,9 => CTR => E3: 1,8
* DIS # E5: 4,9 => CTR => E5: 1,8
* PRF # F9: 6,8 => SOL
* DIS # F9: 4,9 => CTR => F9: 6,8
* DIS # G9: 4,9 => CTR => G9: 3,7
* DIS # H9: 4,9 => CTR => H9: 7,8
* DIS # G6: 4,9 => CTR => G6: 7
* PRF # G6: 7 => SOL
* DIS # I9: 6,8 => CTR => I9: 3,7,9
* PRF # I9: 3,7,9 => SOL
* CNT  32 HDP CHAINS /  53 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A5,A6,B8,C4,D4,D5,D6,E1,E2,E7,F8,G2,G3,G8,H1,I8)
* 4586.21..9125.7.64637....2578..25631.6....2...2..6....8.61.35.23.527..1.2.1.5....
* PAIR E1: 3,9 ROW 1
I1: 3,9,7                                # reduction candidate for 3,9
I1: 3,9 => SOLVED
* 458692173912537864637814925789425631563781249124369758876143592395278416241956387
* DURATION: 0:00:02.584656  START: 19:32:23.892083  END: 19:32:26.476739 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-493-base-pr-001.dot
* REASONING
* PRF # I1: 3,9 => SOL
* STA I1: 3,9
* CNT   1 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 493

solution: 458692173912537864637814925789425631563781249124369758876143592395278416241956387
info: 96272    FNBTHXK  S8.f     20734

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

Solution

position: 458692173912537864637814925789425631563781249124369758876143592395278416241956387 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 # I1: 3,9 => SOL
* DIS # I1: 7 => CTR => I1: 3,9
* DIS # I1: 7,9 => CTR => I1: 3
* PRF # I1: 3 => SOL
* DIS # H5: 7,9 => CTR => H5: 4,5,8
* INC # H5: 4,5,8 => UNS
* DIS # H6: 7,9 => CTR => H6: 4,5,8
* INC # H6: 4,5,8 => UNS
* INC # H7: 7,9 => UNS
* DIS # H9: 7,9 => CTR => H9: 4,8
* INC # H9: 4,8 => UNS
* INC # D3: 8,9 => UNS
* DIS # E3: 8,9 => CTR => E3: 1,4
* INC # E3: 1,4 => UNS
* DIS # F3: 8,9 => CTR => F3: 1,4
* INC # F3: 1,4 => UNS
* DIS # C5: 4,9 => CTR => C5: 3
* INC # C5: 3 => UNS
* INC # C6: 4,9 => UNS
* DIS # E5: 4,9 => CTR => E5: 1,8
* INC # E5: 1,8 => UNS
* INC # F5: 4,9 => UNS
* PRF # F6: 4,9 => SOL
* INC # F6: 1,8 => UNS
* DIS # D3: 4,9 => CTR => D3: 8
* PRF # D3: 8 => SOL
* PRF # D9: 4,9 => SOL
* DIS # D9: 8 => CTR => D9: 4,9
* DIS # B7: 4,9 => CTR => B7: 7
* INC # B7: 7 => UNS
* INC # B9: 4,9 => UNS
* PRF # D9: 4,9 => SOL
* DIS # D9: 8 => CTR => D9: 4,9
* DIS # F9: 4,9 => CTR => F9: 6,8
* PRF # F9: 6,8 => SOL
* DIS # B7: 4,9 => CTR => B7: 7
* INC # B7: 7 => UNS
* INC # H7: 4,9 => UNS
* DIS # E3: 4,9 => CTR => E3: 1,8
* INC # E3: 1,8 => UNS
* DIS # E5: 4,9 => CTR => E5: 1,8
* INC # E5: 1,8 => UNS
* PRF # F9: 6,8 => SOL
* DIS # F9: 4,9 => CTR => F9: 6,8
* INC # H7: 4,9 => UNS
* DIS # G9: 4,9 => CTR => G9: 3,7
* INC # G9: 3,7 => UNS
* DIS # H9: 4,9 => CTR => H9: 7,8
* INC # H9: 7,8 => UNS
* DIS # G6: 4,9 => CTR => G6: 7
* PRF # G6: 7 => SOL
* DIS # I9: 6,8 => CTR => I9: 3,7,9
* PRF # I9: 3,7,9 => SOL
* CNT  53 HDP CHAINS /  53 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* PRF # I1: 3,9 => SOL
* STA I1: 3,9
* CNT   1 HDP CHAINS /   1 HYP OPENED