Analysis of xx-top500-151-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 4.73...........1..6........21....5.....48.......7..........2.47.5..6...........3. initial

Autosolve

position: 4.7316.5.....47163631.5.7.4214693578.7.48.3..3..72.4..1..532.47753.64....4217.635 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # D3: 8,9 => SOL
* PRF # H3: 2 => SOL
* DIS # G1: 2,9 => CTR => G1: 8
* PRF # G1: 8 => SOL
* PRF # H3: 2,9 => SOL
* DIS # H3: 8 => CTR => H3: 2,9
* PRF # B1: 2,9 => SOL
* DIS # B1: 8 => CTR => B1: 2,9
* DIS # I8: 2,9 => CTR => I8: 1
* PRF # C6: 5,9 => SOL
* DIS # A2: 5,9 => CTR => A2: 8
* PRF # A2: 8 => SOL
* DIS # H8: 1,9 => CTR => H8: 2,8
* DIS # A2: 5 => CTR => A2: 8,9
* DIS # G8: 8,9 => CTR => G8: 2
* PRF # D3: 8,9 => SOL
* DIS # G8: 8,9 => CTR => G8: 2
* DIS # G1: 2 => CTR => G1: 8,9
* CNT  18 HDP CHAINS /  41 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 # D3: 8,9 => SOL
* STA D3: 8,9
* CNT   1 HDP CHAINS /   2 HYP OPENED

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

Details

Positions

4.73...........1..6........21....5.....48.......7..........2.47.5..6...........3. initial
4.7316.5.....47163631.5.7.4214693578.7.48.3..3..72.4..1..532.47753.64....4217.635 autosolve
427316859895247163631859724214693578576481392389725416168532947753964281942178635 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (10)
F3: 8,9
I1: 2,9
A5: 5,9
F5: 1,5
F6: 1,5
H6: 1,9
A9: 8,9
D8: 8,9
F9: 8,9
G7: 8,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
F5,F6: 1.. / F5 = 1  =>  9 pairs (_) / F6 = 1  =>  0 pairs (X)
H8,I8: 1.. / H8 = 1  =>  0 pairs (X) / I8 = 1  => 11 pairs (_)
B1,B2: 2.. / B1 = 2  =>  0 pairs (*) / B2 = 2  =>  0 pairs (X)
D2,D3: 2.. / D2 = 2  =>  0 pairs (*) / D3 = 2  =>  0 pairs (X)
H5,I5: 2.. / H5 = 2  => 13 pairs (_) / I5 = 2  => 17 pairs (_)
B2,D2: 2.. / B2 = 2  => 13 pairs (_) / D2 = 2  =>  0 pairs (*)
D3,H3: 2.. / D3 = 2  => 13 pairs (_) / H3 = 2  =>  0 pairs (*)
G1,G8: 2.. / G1 = 2  =>  0 pairs (X) / G8 = 2  => 12 pairs (_)
A2,C2: 5.. / A2 = 5  =>  0 pairs (X) / C2 = 5  => 10 pairs (_)
F5,F6: 5.. / F5 = 5  =>  0 pairs (X) / F6 = 5  =>  9 pairs (_)
C6,F6: 5.. / C6 = 5  =>  0 pairs (X) / F6 = 5  =>  9 pairs (_)
A2,A5: 5.. / A2 = 5  =>  0 pairs (X) / A5 = 5  => 10 pairs (_)
I5,I6: 6.. / I5 = 6  => 15 pairs (_) / I6 = 6  => 12 pairs (_)
B7,C7: 6.. / B7 = 6  => 12 pairs (_) / C7 = 6  => 15 pairs (_)
C5,I5: 6.. / C5 = 6  => 12 pairs (_) / I5 = 6  => 15 pairs (_)
B6,B7: 6.. / B6 = 6  => 15 pairs (_) / B7 = 6  => 12 pairs (_)
G1,H3: 8.. / G1 = 8  =>  0 pairs (*) / H3 = 8  =>  0 pairs (X)
B6,C6: 8.. / B6 = 8  =>  0 pairs (*) / C6 = 8  =>  0 pairs (X)
D8,F9: 8.. / D8 = 8  =>  0 pairs (X) / F9 = 8  =>  0 pairs (_)
B1,G1: 8.. / B1 = 8  =>  0 pairs (X) / G1 = 8  =>  0 pairs (_)
A9,F9: 8.. / A9 = 8  =>  0 pairs (X) / F9 = 8  =>  0 pairs (_)
A2,A9: 8.. / A2 = 8  =>  0 pairs (*) / A9 = 8  =>  0 pairs (X)
F3,F9: 8.. / F3 = 8  =>  0 pairs (X) / F9 = 8  =>  0 pairs (_)
H3,H8: 8.. / H3 = 8  =>  0 pairs (X) / H8 = 8  =>  0 pairs (_)
D8,F9: 9.. / D8 = 9  =>  0 pairs (*) / F9 = 9  =>  0 pairs (X)
A9,F9: 9.. / A9 = 9  =>  0 pairs (*) / F9 = 9  =>  0 pairs (X)
F3,F9: 9.. / F3 = 9  =>  0 pairs (*) / F9 = 9  =>  0 pairs (X)
* DURATION: 0:00:47.129618  START: 07:55:01.661312  END: 07:55:48.790930 2017-05-04
* CP COUNT: (27)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A5,A9,D8,F3,F5,F6,F9,G7,H6,I1)
* 4.7316.5.....47163631.5.7.4214693578.7.48.3..3..72.4..1..532.47753.64....4217.635
* PAIR F3: 8,9 BLK 2
D2: 8,9,2                                # reduction candidate for 8,9
D2: 8,9                                  # 13 pairs
D3: 8,9,2                                # reduction candidate for 8,9
D3: 8,9 => SOLVED
* 427316859895247163631859724214693578576481392389725416168532947753964281942178635
D3: 2                                    # 13 pairs
* PAIR F3: 8,9 ROW 3
H3: 8,9,2                                # reduction candidate for 8,9
H3: 2 => SOLVED
* 427316859895247163631859724214693578576481392389725416168532947753964281942178635
H3: 8,9                                  # 13 pairs
* PAIR I1: 2,9 BLK 3
G1: 2,9,8                                # reduction candidate for 2,9
G1: 2,9 => CTR
* 487316.5..2.847163631259784214693578.7.48.3..3.87254..1..53284775396421..4217.635
G1: 8 => SOLVED
* 427316859895247163631859724214693578576481392389725416168532947753964281942178635
H3: 2,9,8                                # reduction candidate for 2,9
H3: 2,9 => SOLVED
* 427316859895247163631859724214693578576481392389725416168532947753964281942178635
H3: 8 => CTR
* 4873162595...47163631259784214693578.7.48.3..3..72.4..1..532.477539648..942178635
* PAIR I1: 2,9 ROW 1
B1: 2,9,8                                # reduction candidate for 2,9
B1: 2,9 => SOLVED
* 427316859895247163631859724214693578576481392389725416168532947753964281942178635
B1: 8 => CTR
* 487316.5..2.847163631259784214693578.7.48.3..3.87254..1..53284775396421..4217.635
* PAIR I1: 2,9 COL I
I5: 2,9,1,6                              # reduction candidate for 2,9
I5: 2,9                                  # 13 pairs
I8: 2,9,1                                # reduction candidate for 2,9
I8: 2,9 => CTR
* 487316.5..2.847163631259784214693578.7.48.32.36872.49.1..532.47753.64.1..42178635
I8: 1                                    # 11 pairs
* PAIR A5: 5,9 BLK 4
C5: 5,9,6                                # reduction candidate for 5,9
C5: 5,9                                  # 15 pairs
C6: 5,9,6,8                              # reduction candidate for 5,9
C6: 5,9 => SOLVED
* 427316859895247163631859724214693578576481392389725416168532947753964281942178635
C6: 6,8                                  # 10 pairs
* PAIR A5: 5,9 COL A
A2: 5,9,8                                # reduction candidate for 5,9
A2: 5,9 => CTR
* 4.7316.5.....47163631.587.4214693578.7.48.3..3..72.4..1..532847753864...842179635
A2: 8 => SOLVED
* 427316859895247163631859724214693578576481392389725416168532947753964281942178635
* PAIR H6: 1,9 BLK 6
H5: 1,9,2                                # reduction candidate for 1,9
H5: 1,9                                  # 17 pairs
I5: 1,9,2,6                              # reduction candidate for 1,9
I5: 1,9                                  # 16 pairs
I6: 1,9,6                                # reduction candidate for 1,9
I6: 1,9                                  # 15 pairs
* PAIR H6: 1,9 COL H
H8: 1,9,2,8                              # reduction candidate for 1,9
H8: 1,9 => CTR
* 487316.5..2.847163631259784214693578.7.48.32.3.87254..1..53284775396421..42178635
H8: 2,8                                  # 13 pairs
* PAIR A9: 8,9 BLK 7
B7: 8,9,6                                # reduction candidate for 8,9
B7: 8,9                                  # 15 pairs
C7: 8,9,6                                # reduction candidate for 8,9
C7: 8,9                                  # 12 pairs
* PAIR A9: 8,9 COL A
A2: 8,9,5                                # reduction candidate for 8,9
A2: 5 => CTR
* 4.7316.5.5...47163631.587.421469357897.48.3..3..72.4..1..532847753864...842179635
A2: 8,9                                  # 10 pairs
* PAIR D8: 8,9 ROW 8
G8: 8,9,2                                # reduction candidate for 8,9
G8: 8,9 => CTR
* 48731625952..47163631259784214693578.7.48.3..3..72.4..1..532.477539648..942178635
G8: 2                                    # 12 pairs
H8: 8,9,1,2                              # reduction candidate for 8,9
H8: 8,9                                  # 13 pairs
* PAIR D8: 8,9 COL D
D2: 8,9,2                                # reduction candidate for 8,9
D2: 8,9                                  # 13 pairs
D3: 8,9,2                                # reduction candidate for 8,9
D3: 8,9 => SOLVED
* 427316859895247163631859724214693578576481392389725416168532947753964281942178635
D3: 2                                    # 13 pairs
* PAIR G7: 8,9 BLK 9
G8: 8,9,2                                # reduction candidate for 8,9
G8: 8,9 => CTR
* 48731625952..47163631259784214693578.7.48.3..3..72.4..1..532.477539648..942178635
G8: 2                                    # 12 pairs
H8: 8,9,1,2                              # reduction candidate for 8,9
H8: 8,9                                  # 13 pairs
* PAIR G7: 8,9 ROW 7
B7: 8,9,6                                # reduction candidate for 8,9
B7: 8,9                                  # 15 pairs
C7: 8,9,6                                # reduction candidate for 8,9
C7: 8,9                                  # 12 pairs
* PAIR G7: 8,9 COL G
G1: 8,9,2                                # reduction candidate for 8,9
G1: 2 => CTR
* 487316259.2.847163631259784214693578.7.48.3..3.87254..1..532847753964....4217.635
G1: 8,9                                  # 12 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-151-base-pr-000.dot
* REASONING
* PRF # D3: 8,9 => SOL
* PRF # H3: 2 => SOL
* DIS # G1: 2,9 => CTR => G1: 8
* PRF # G1: 8 => SOL
* PRF # H3: 2,9 => SOL
* DIS # H3: 8 => CTR => H3: 2,9
* PRF # B1: 2,9 => SOL
* DIS # B1: 8 => CTR => B1: 2,9
* DIS # I8: 2,9 => CTR => I8: 1
* PRF # C6: 5,9 => SOL
* DIS # A2: 5,9 => CTR => A2: 8
* PRF # A2: 8 => SOL
* DIS # H8: 1,9 => CTR => H8: 2,8
* DIS # A2: 5 => CTR => A2: 8,9
* DIS # G8: 8,9 => CTR => G8: 2
* PRF # D3: 8,9 => SOL
* DIS # G8: 8,9 => CTR => G8: 2
* DIS # G1: 2 => CTR => G1: 8,9
* CNT  18 HDP CHAINS /  41 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A5,A9,D8,F3,F5,F6,F9,G7,H6,I1)
* 4.7316.5.....47163631.5.7.4214693578.7.48.3..3..72.4..1..532.47753.64....4217.635
* PAIR F3: 8,9 BLK 2
D2: 8,9,2                                # reduction candidate for 8,9
D2: 8,9                                  # 13 pairs
D3: 8,9,2                                # reduction candidate for 8,9
D3: 8,9 => SOLVED
* 427316859895247163631859724214693578576481392389725416168532947753964281942178635
* DURATION: 0:00:02.985276  START: 07:56:32.988977  END: 07:56:35.974253 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-151-base-pr-001.dot
* REASONING
* PRF # D3: 8,9 => SOL
* STA D3: 8,9
* CNT   1 HDP CHAINS /   2 HYP OPENED

Header Info

Top 500 Minimum 17 151

solution: 427316859895247163631859724214693578576481392389725416168532947753964281942178635
info: 1816     FNBWX    S8.f     39334

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

Solution

position: 427316859895247163631859724214693578576481392389725416168532947753964281942178635 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 # D2: 8,9 => UNS
* PRF # D3: 8,9 => SOL
* INC # D3: 2 => UNS
* INC # H3: 8,9 => UNS
* PRF # H3: 2 => SOL
* DIS # G1: 2,9 => CTR => G1: 8
* PRF # G1: 8 => SOL
* PRF # H3: 2,9 => SOL
* DIS # H3: 8 => CTR => H3: 2,9
* PRF # B1: 2,9 => SOL
* DIS # B1: 8 => CTR => B1: 2,9
* INC # I5: 2,9 => UNS
* DIS # I8: 2,9 => CTR => I8: 1
* INC # I8: 1 => UNS
* INC # C5: 5,9 => UNS
* PRF # C6: 5,9 => SOL
* INC # C6: 6,8 => UNS
* DIS # A2: 5,9 => CTR => A2: 8
* PRF # A2: 8 => SOL
* INC # H5: 1,9 => UNS
* INC # I5: 1,9 => UNS
* INC # I6: 1,9 => UNS
* DIS # H8: 1,9 => CTR => H8: 2,8
* INC # H8: 2,8 => UNS
* INC # B7: 8,9 => UNS
* INC # C7: 8,9 => UNS
* INC # A2: 8,9 => UNS
* DIS # A2: 5 => CTR => A2: 8,9
* DIS # G8: 8,9 => CTR => G8: 2
* INC # G8: 2 => UNS
* INC # H8: 8,9 => UNS
* INC # D2: 8,9 => UNS
* PRF # D3: 8,9 => SOL
* INC # D3: 2 => UNS
* DIS # G8: 8,9 => CTR => G8: 2
* INC # G8: 2 => UNS
* INC # H8: 8,9 => UNS
* INC # B7: 8,9 => UNS
* INC # C7: 8,9 => UNS
* INC # G1: 8,9 => UNS
* DIS # G1: 2 => CTR => G1: 8,9
* CNT  41 HDP CHAINS /  41 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # D2: 8,9 => UNS
* PRF # D3: 8,9 => SOL
* STA D3: 8,9
* CNT   2 HDP CHAINS /   2 HYP OPENED