Analysis of xx-top500-219-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: .5.9........4...7........3.....7...5.1....8..4...........1.56..7...6.2....3...... initial

Autosolve

position: 35.9.7......4.3.7..7.....3.....7.3.5.173..8..43....7.....1356.77..86.2.3.637..... autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # H1: 1,4 => CTR => H1: 2,6,8
* DIS # G3: 1,4 => CTR => G3: 5,9
* DIS # G9: 9 => CTR => G9: 1,4
* PRF # F5: 2,6 => SOL
* DIS # F5: 4,9 => CTR => F5: 2,6
* DIS # D6: 2,6 => CTR => D6: 5
* PRF # D6: 5 => SOL
* DIS # F6: 2,6 => CTR => F6: 1,8,9
* PRF # D3: 2,6 => SOL
* DIS # D3: 5 => CTR => D3: 2,6
* DIS # H1: 1,4 => CTR => H1: 2,6,8
* DIS # H9: 1,4 => CTR => H9: 5,8,9
* DIS # B7: 2,8 => CTR => B7: 4,9
* PRF # H9: 1,5 => SOL
* DIS # H9: 4,8,9 => CTR => H9: 1,5
* DIS # F9: 4,9 => CTR => F9: 2
* DIS # F5: 4,9 => CTR => F5: 2,6
* PRF # F5: 2,6 => SOL
* DIS # H9: 4,9 => CTR => H9: 1,5,8
* DIS # I9: 4,9 => CTR => I9: 1,8
* DIS # B7: 2,8 => CTR => B7: 4,9
* DIS # H5: 4,9 => CTR => H5: 2,6
* PRF # H9: 1,5 => SOL
* DIS # H9: 4,8,9 => CTR => H9: 1,5
* CNT  24 HDP CHAINS /  44 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 # H1: 1,4 => CTR => H1: 2,6,8
* DIS H1: 2,6,8 # G3: 1,4 => CTR => G3: 5,9
* DIS H1: 2,6,8 + G3: 5,9 # G9: 9 => CTR => G9: 1,4
* PRF H1: 2,6,8 + G3: 5,9 + G9: 1,4 # F5: 2,6 => SOL
* STA H1: 2,6,8 + G3: 5,9 + G9: 1,4 + F5: 2,6
* CNT   4 HDP CHAINS /  13 HYP OPENED

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

Details

Positions

.5.9........4...7........3.....7...5.1....8..4...........1.56..7...6.2....3...... initial
35.9.7......4.3.7..7.....3.....7.3.5.173..8..43....7.....1356.77..86.2.3.637..... autosolve
356927184821453976974618532689271345517346829432589761248135697795864213163792458 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (10)
G1: 1,4
D4: 2,6
F4: 1,4
H4: 1,4
B8: 4,9
C8: 1,5
A9: 1,5
F8: 4,9
H7: 4,9
H8: 1,5

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
C8,A9: 1.. / C8 = 1  =>  0 pairs (X) / A9 = 1  =>  0 pairs (_)
F4,H4: 1.. / F4 = 1  =>  0 pairs (*) / H4 = 1  =>  0 pairs (X)
C8,H8: 1.. / C8 = 1  =>  0 pairs (X) / H8 = 1  =>  0 pairs (_)
E9,F9: 2.. / E9 = 2  =>  0 pairs (X) / F9 = 2  => 11 pairs (_)
C1,C3: 4.. / C1 = 4  => 13 pairs (_) / C3 = 4  => 10 pairs (_)
B7,B8: 4.. / B7 = 4  =>  0 pairs (*) / B8 = 4  =>  0 pairs (X)
F4,H4: 4.. / F4 = 4  =>  0 pairs (X) / H4 = 4  =>  0 pairs (_)
B7,H7: 4.. / B7 = 4  =>  0 pairs (*) / H7 = 4  =>  0 pairs (X)
B8,F8: 4.. / B8 = 4  =>  0 pairs (X) / F8 = 4  =>  0 pairs (_)
E5,E9: 4.. / E5 = 4  =>  0 pairs (*) / E9 = 4  =>  0 pairs (X)
G2,G3: 5.. / G2 = 5  => 10 pairs (_) / G3 = 5  =>  0 pairs (*)
A5,C6: 5.. / A5 = 5  =>  0 pairs (*) / C6 = 5  =>  0 pairs (X)
C8,A9: 5.. / C8 = 5  =>  0 pairs (*) / A9 = 5  =>  0 pairs (X)
H8,H9: 5.. / H8 = 5  =>  0 pairs (X) / H9 = 5  =>  0 pairs (_)
E2,G2: 5.. / E2 = 5  =>  0 pairs (*) / G2 = 5  =>  0 pairs (X)
A5,E5: 5.. / A5 = 5  =>  0 pairs (*) / E5 = 5  =>  0 pairs (X)
C8,H8: 5.. / C8 = 5  =>  0 pairs (*) / H8 = 5  =>  0 pairs (X)
A9,H9: 5.. / A9 = 5  =>  0 pairs (X) / H9 = 5  =>  0 pairs (_)
A5,A9: 5.. / A5 = 5  =>  0 pairs (*) / A9 = 5  =>  0 pairs (X)
C6,C8: 5.. / C6 = 5  =>  0 pairs (X) / C8 = 5  =>  0 pairs (_)
D3,D6: 5.. / D3 = 5  =>  0 pairs (X) / D6 = 5  =>  0 pairs (_)
D3,F3: 6.. / D3 = 6  =>  0 pairs (*) / F3 = 6  =>  0 pairs (X)
E6,F6: 8.. / E6 = 8  =>  0 pairs (*) / F6 = 8  =>  0 pairs (X)
H9,I9: 8.. / H9 = 8  =>  0 pairs (X) / I9 = 8  => 18 pairs (_)
F3,F6: 8.. / F3 = 8  =>  0 pairs (*) / F6 = 8  =>  0 pairs (X)
H1,H9: 8.. / H1 = 8  => 18 pairs (_) / H9 = 8  =>  0 pairs (X)
B8,F8: 9.. / B8 = 9  =>  0 pairs (*) / F8 = 9  =>  0 pairs (X)
* DURATION: 0:00:48.931631  START: 10:15:30.666649  END: 10:16:19.598280 2017-05-04
* CP COUNT: (27)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A9,B8,C8,D4,F4,F8,G1,H4,H7,H8)
* 35.9.7......4.3.7..7.....3.....7.3.5.173..8..43....7.....1356.77..86.2.3.637.....
* PAIR G1: 1,4 BLK 3
H1: 1,4,2,6,8                            # reduction candidate for 1,4
H1: 1,4 => CTR
* 35.9.7......4.357..7.5.6.3.....7.3.5.1735.8..435.987.....135647741869253563742.8.
H1: 2,6,8                                # 10 pairs
I1: 1,4,2,6,8                            # reduction candidate for 1,4
I1: 1,4                                  # 16 pairs
G3: 1,4,5,9                              # reduction candidate for 1,4
G3: 1,4 => CTR
* 35.9.7......4.357..7.....3.....74315.173568944352..7.....135647741869253563742981
G3: 5,9                                  # 11 pairs
I3: 1,4,2,8,9                            # reduction candidate for 1,4
I3: 1,4                                  # 14 pairs
* PAIR G1: 1,4 ROW 1
C1: 1,4,2,6,8                            # reduction candidate for 1,4
C1: 1,4                                  # 12 pairs
C1: 2,6,8                                # 10 pairs
* PAIR G1: 1,4 COL G
G9: 1,4,9                                # reduction candidate for 1,4
G9: 9 => CTR
* 35.9.7......4.3.7..7.....3.....74315.173568944352..7.....135647741869253563742981
G9: 1,4                                  # 13 pairs
* PAIR D4: 2,6 BLK 5
F5: 2,6,4,9                              # reduction candidate for 2,6
F5: 2,6 => SOLVED
* 356927184821453976974618532689271345517346829432589761248135697795864213163792458
F5: 4,9 => CTR
* 35.9.7......4.3.7..7.....3.....713455173498..43....719.4.13569779.8642.3.63792...
D6: 2,6,5                                # reduction candidate for 2,6
D6: 2,6 => CTR
* 35.9.7......4.357..7.5.693.....71345.1734.8..43..587.9.4.135697795864213163792458
D6: 5 => SOLVED
* 356927184821453976974618532689271345517346829432589761248135697795864213163792458
F6: 2,6,1,8,9                            # reduction candidate for 2,6
F6: 2,6 => CTR
* 35.9.7......4.3.7..7.6.8.3....271345.173498..43.5867.9.4.135697795864213163792458
F6: 1,8,9                                # 10 pairs
* PAIR D4: 2,6 ROW 4
A4: 2,6,8,9                              # reduction candidate for 2,6
A4: 2,6                                  # 13 pairs
C4: 2,6,8,9                              # reduction candidate for 2,6
C4: 2,6                                  # 13 pairs
* PAIR D4: 2,6 COL D
D3: 2,6,5                                # reduction candidate for 2,6
D3: 2,6 => SOLVED
* 356927184821453976974618532689271345517346829432589761248135697795864213163792458
D3: 5 => CTR
* 35.9.7......4.357..7.5.693.....71345.1734.8..43..587.9.4.135697795864213163792458
* PAIR H4: 1,4 COL H
H1: 1,4,2,6,8                            # reduction candidate for 1,4
H1: 1,4 => CTR
* 35.9.7......4.357..7.5.6.3.....7.3.5.1735.8..435.987.....135647741869253563742.8.
H1: 2,6,8                                # 10 pairs
H9: 1,4,5,8,9                            # reduction candidate for 1,4
H9: 1,4 => CTR
* 35.9.7.8....4.3.7..7.....3.....7.3.5.1735.8..435...7.....1356.77.186.253563742918
H9: 5,8,9                                # 10 pairs
* PAIR B8: 4,9 BLK 7
B7: 4,9,2,8                              # reduction candidate for 4,9
B7: 2,8 => CTR
* 35.9.7......4.3.7..7.....3.....74315.173568944352..7.....135647741869253563742...
B7: 4,9                                  # 15 pairs
* PAIR A9: 1,5 ROW 9
H9: 1,5,4,8,9                            # reduction candidate for 1,5
H9: 1,5 => SOLVED
* 356927184821453976974618532689271345517346829432589761248135697795864213163792458
H9: 4,8,9 => CTR
* 35.9.7......4.357..7.5.6.3.....7.3.5.1735.8..435.987.....135647741869253563742...
* PAIR F8: 4,9 BLK 8
E9: 4,9,2                                # reduction candidate for 4,9
E9: 4,9                                  # 11 pairs
F9: 4,9,2                                # reduction candidate for 4,9
F9: 4,9 => CTR
* 35.9.718....4.3.7..7.....3.....7134551734.8..43.5987...4.135697795864213163729458
F9: 2                                    # 11 pairs
* PAIR F8: 4,9 COL F
F5: 4,9,2,6                              # reduction candidate for 4,9
F5: 4,9 => CTR
* 35.9.7......4.3.7..7.....3.....713455173498..43....719.4.13569779.8642.3.63792...
F5: 2,6 => SOLVED
* 356927184821453976974618532689271345517346829432589761248135697795864213163792458
* PAIR H7: 4,9 BLK 9
G9: 4,9,1                                # reduction candidate for 4,9
G9: 4,9                                  # 12 pairs
H9: 4,9,1,5,8                            # reduction candidate for 4,9
H9: 4,9 => CTR
* 35.9.748....4.357..745.693.....7.3.5.1735.8.4435.9.7.....1356.77.186.253563742198
H9: 1,5,8                                # 10 pairs
I9: 4,9,1,8                              # reduction candidate for 4,9
I9: 4,9 => CTR
* 35.9.74.....4.357..745.693.....7.3.5.1735.8.4435.9.7.....1356.77.186.253563742189
I9: 1,8                                  # 11 pairs
* PAIR H7: 4,9 ROW 7
B7: 4,9,2,8                              # reduction candidate for 4,9
B7: 2,8 => CTR
* 35.9.7......4.3.7..7.....3.....74315.173568944352..7.....135647741869253563742...
B7: 4,9                                  # 15 pairs
* PAIR H7: 4,9 COL H
H5: 4,9,2,6                              # reduction candidate for 4,9
H5: 4,9 => CTR
* 35.9.7......4.3.7..7.....3.....74315.173568..4352..7.....1356.7741869253563742.8.
H5: 2,6                                  # 11 pairs
* PAIR H8: 1,5 BLK 9
H9: 1,5,4,8,9                            # reduction candidate for 1,5
H9: 1,5 => SOLVED
* 356927184821453976974618532689271345517346829432589761248135697795864213163792458
H9: 4,8,9 => CTR
* 35.9.7......4.357..7.5.6.3.....7.3.5.1735.8..435.987.....135647741869253563742...
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-219-base-pr-000.dot
* REASONING
* DIS # H1: 1,4 => CTR => H1: 2,6,8
* DIS # G3: 1,4 => CTR => G3: 5,9
* DIS # G9: 9 => CTR => G9: 1,4
* PRF # F5: 2,6 => SOL
* DIS # F5: 4,9 => CTR => F5: 2,6
* DIS # D6: 2,6 => CTR => D6: 5
* PRF # D6: 5 => SOL
* DIS # F6: 2,6 => CTR => F6: 1,8,9
* PRF # D3: 2,6 => SOL
* DIS # D3: 5 => CTR => D3: 2,6
* DIS # H1: 1,4 => CTR => H1: 2,6,8
* DIS # H9: 1,4 => CTR => H9: 5,8,9
* DIS # B7: 2,8 => CTR => B7: 4,9
* PRF # H9: 1,5 => SOL
* DIS # H9: 4,8,9 => CTR => H9: 1,5
* DIS # F9: 4,9 => CTR => F9: 2
* DIS # F5: 4,9 => CTR => F5: 2,6
* PRF # F5: 2,6 => SOL
* DIS # H9: 4,9 => CTR => H9: 1,5,8
* DIS # I9: 4,9 => CTR => I9: 1,8
* DIS # B7: 2,8 => CTR => B7: 4,9
* DIS # H5: 4,9 => CTR => H5: 2,6
* PRF # H9: 1,5 => SOL
* DIS # H9: 4,8,9 => CTR => H9: 1,5
* CNT  24 HDP CHAINS /  44 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A9,B8,C8,D4,F4,F8,G1,H4,H7,H8)
* 35.9.7......4.3.7..7.....3.....7.3.5.173..8..43....7.....1356.77..86.2.3.637.....
* PAIR G1: 1,4 BLK 3
H1: 1,4,2,6,8                            # reduction candidate for 1,4
H1: 1,4 => CTR
* 35.9.7......4.357..7.5.6.3.....7.3.5.1735.8..435.987.....135647741869253563742.8.
I1: 1,4,2,6,8                            # reduction candidate for 1,4
I1: 1,4                                  # 16 pairs
G3: 1,4,5,9                              # reduction candidate for 1,4
G3: 1,4 => CTR
* 35.9.7......4.357..7.....3.....74315.173568944352..7.....135647741869253563742981
I3: 1,4,2,8,9                            # reduction candidate for 1,4
I3: 1,4                                  # 14 pairs
* PAIR G1: 1,4 ROW 1
C1: 1,4,2,6,8                            # reduction candidate for 1,4
C1: 1,4                                  # 13 pairs
C1: 2,6,8                                # 11 pairs
* PAIR G1: 1,4 COL G
G9: 1,4,9                                # reduction candidate for 1,4
G9: 9 => CTR
* 35.9.74.....4.317..74...53.....7.3.5.173..8..43.5..7.....1356.77.586.2131637..958
* PAIR RESTART
* PAIR G1: 1,4 BLK 3
I1: 1,4,2,6,8                            # reduction candidate for 1,4
I1: 1,4                                  # 16 pairs
I3: 1,4,2,8                              # reduction candidate for 1,4
I3: 1,4                                  # 14 pairs
* PAIR G1: 1,4 ROW 1
C1: 1,4,2,6,8                            # reduction candidate for 1,4
C1: 1,4                                  # 15 pairs
C1: 2,6,8                                # 13 pairs
* PAIR D4: 2,6 BLK 5
F5: 2,6,4,9                              # reduction candidate for 2,6
F5: 2,6 => SOLVED
* 356927184821453976974618532689271345517346829432589761248135697795864213163792458
* DURATION: 0:00:13.520930  START: 10:17:02.320587  END: 10:17:15.841517 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-219-base-pr-001.dot
* REASONING
* DIS # H1: 1,4 => CTR => H1: 2,6,8
* DIS H1: 2,6,8 # G3: 1,4 => CTR => G3: 5,9
* DIS H1: 2,6,8 + G3: 5,9 # G9: 9 => CTR => G9: 1,4
* PRF H1: 2,6,8 + G3: 5,9 + G9: 1,4 # F5: 2,6 => SOL
* STA H1: 2,6,8 + G3: 5,9 + G9: 1,4 + F5: 2,6
* CNT   4 HDP CHAINS /  13 HYP OPENED

Header Info

Top 500 Minimum 17 219

solution: 356927184821453976974618532689271345517346829432589761248135697795864213163792458
info: 1957     FNBTHWY  S8.f     40482

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

Solution

position: 356927184821453976974618532689271345517346829432589761248135697795864213163792458 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 # H1: 1,4 => CTR => H1: 2,6,8
* INC # H1: 2,6,8 => UNS
* INC # I1: 1,4 => UNS
* DIS # G3: 1,4 => CTR => G3: 5,9
* INC # G3: 5,9 => UNS
* INC # I3: 1,4 => UNS
* INC # C1: 1,4 => UNS
* INC # C1: 2,6,8 => UNS
* INC # G9: 1,4 => UNS
* DIS # G9: 9 => CTR => G9: 1,4
* PRF # F5: 2,6 => SOL
* DIS # F5: 4,9 => CTR => F5: 2,6
* DIS # D6: 2,6 => CTR => D6: 5
* PRF # D6: 5 => SOL
* DIS # F6: 2,6 => CTR => F6: 1,8,9
* INC # F6: 1,8,9 => UNS
* INC # A4: 2,6 => UNS
* INC # C4: 2,6 => UNS
* PRF # D3: 2,6 => SOL
* DIS # D3: 5 => CTR => D3: 2,6
* DIS # H1: 1,4 => CTR => H1: 2,6,8
* INC # H1: 2,6,8 => UNS
* DIS # H9: 1,4 => CTR => H9: 5,8,9
* INC # H9: 5,8,9 => UNS
* INC # B7: 4,9 => UNS
* DIS # B7: 2,8 => CTR => B7: 4,9
* PRF # H9: 1,5 => SOL
* DIS # H9: 4,8,9 => CTR => H9: 1,5
* INC # E9: 4,9 => UNS
* DIS # F9: 4,9 => CTR => F9: 2
* INC # F9: 2 => UNS
* DIS # F5: 4,9 => CTR => F5: 2,6
* PRF # F5: 2,6 => SOL
* INC # G9: 4,9 => UNS
* DIS # H9: 4,9 => CTR => H9: 1,5,8
* INC # H9: 1,5,8 => UNS
* DIS # I9: 4,9 => CTR => I9: 1,8
* INC # I9: 1,8 => UNS
* INC # B7: 4,9 => UNS
* DIS # B7: 2,8 => CTR => B7: 4,9
* DIS # H5: 4,9 => CTR => H5: 2,6
* INC # H5: 2,6 => UNS
* PRF # H9: 1,5 => SOL
* DIS # H9: 4,8,9 => CTR => H9: 1,5
* CNT  44 HDP CHAINS /  44 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # H1: 1,4 => CTR => H1: 2,6,8
* INC H1: 2,6,8 # I1: 1,4 => UNS
* DIS H1: 2,6,8 # G3: 1,4 => CTR => G3: 5,9
* INC H1: 2,6,8 + G3: 5,9 # I3: 1,4 => UNS
* INC H1: 2,6,8 + G3: 5,9 # C1: 1,4 => UNS
* INC H1: 2,6,8 + G3: 5,9 # C1: 2,6,8 => UNS
* INC H1: 2,6,8 + G3: 5,9 # G9: 1,4 => UNS
* DIS H1: 2,6,8 + G3: 5,9 # G9: 9 => CTR => G9: 1,4
* INC H1: 2,6,8 + G3: 5,9 + G9: 1,4 # I1: 1,4 => UNS
* INC H1: 2,6,8 + G3: 5,9 + G9: 1,4 # I3: 1,4 => UNS
* INC H1: 2,6,8 + G3: 5,9 + G9: 1,4 # C1: 1,4 => UNS
* INC H1: 2,6,8 + G3: 5,9 + G9: 1,4 # C1: 2,6,8 => UNS
* PRF H1: 2,6,8 + G3: 5,9 + G9: 1,4 # F5: 2,6 => SOL
* STA H1: 2,6,8 + G3: 5,9 + G9: 1,4 + F5: 2,6
* CNT  13 HDP CHAINS /  13 HYP OPENED