Analysis of xx-top500-032-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: .5....2..6...1.......8......7.9............31......46....5..7.23...6....1........ initial

Autosolve

position: 7513..2..6.8.123..23.85.1..476931.2.58267493191328546786.5.371232.16....1...2.6.3 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # H2: 4,9 => SOL
* DIS # I2: 4,9 => CTR => I2: 5
* DIS # H3: 4,9 => CTR => H3: 7
* PRF # H3: 7 => SOL
* PRF # I3: 4,9 => SOL
* DIS # H1: 4,9 => CTR => H1: 8
* PRF # F3: 6,9 => SOL
* DIS # F3: 7 => CTR => F3: 6,9
* PRF # I1: 6,9 => SOL
* DIS # H2: 4,7 => CTR => H2: 5,9
* PRF # H2: 5,9 => SOL
* DIS # I8: 5,8 => CTR => I8: 4,9
* DIS # H8: 5,8 => CTR => H8: 4,9
* DIS # I8: 5,8 => CTR => I8: 4,9
* CNT  14 HDP CHAINS /  24 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 # H2: 4,9 => SOL
* STA H2: 4,9
* CNT   1 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

.5....2..6...1.......8......7.9............31......46....5..7.23...6....1........ initial
7513..2..6.8.123..23.85.1..476931.2.58267493191328546786.5.371232.16....1...2.6.3 autosolve
751349286648712395239856174476931528582674931913285467864593712325167849197428653 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (14)
B2: 4,9
C3: 4,9
E1: 4,9
F1: 6,9
D2: 4,7
G4: 5,8
I4: 5,8
C7: 4,9
C8: 5,7
B9: 4,9
C9: 5,7
E7: 4,9
D9: 4,7
G8: 5,8

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
B2,C3: 4.. / B2 = 4  =>  0 pairs (*) / C3 = 4  =>  0 pairs (X)
E1,D2: 4.. / E1 = 4  =>  0 pairs (*) / D2 = 4  =>  0 pairs (X)
C7,B9: 4.. / C7 = 4  =>  0 pairs (*) / B9 = 4  =>  0 pairs (X)
E7,D9: 4.. / E7 = 4  =>  0 pairs (X) / D9 = 4  =>  0 pairs (_)
H8,I8: 4.. / H8 = 4  => 16 pairs (_) / I8 = 4  => 18 pairs (_)
C7,E7: 4.. / C7 = 4  =>  0 pairs (*) / E7 = 4  =>  0 pairs (X)
B9,D9: 4.. / B9 = 4  =>  0 pairs (X) / D9 = 4  =>  0 pairs (_)
B2,B9: 4.. / B2 = 4  =>  0 pairs (*) / B9 = 4  =>  0 pairs (X)
C3,C7: 4.. / C3 = 4  =>  0 pairs (X) / C7 = 4  =>  0 pairs (_)
D2,D9: 4.. / D2 = 4  =>  0 pairs (X) / D9 = 4  =>  0 pairs (_)
E1,E7: 4.. / E1 = 4  =>  0 pairs (*) / E7 = 4  =>  0 pairs (X)
H2,I2: 5.. / H2 = 5  =>  0 pairs (X) / I2 = 5  => 14 pairs (_)
G4,I4: 5.. / G4 = 5  => 13 pairs (_) / I4 = 5  =>  0 pairs (X)
C8,C9: 5.. / C8 = 5  =>  0 pairs (*) / C9 = 5  =>  0 pairs (X)
C9,H9: 5.. / C9 = 5  => 14 pairs (_) / H9 = 5  =>  0 pairs (*)
G4,G8: 5.. / G4 = 5  => 13 pairs (_) / G8 = 5  =>  0 pairs (X)
F1,F3: 6.. / F1 = 6  => 14 pairs (_) / F3 = 6  =>  0 pairs (*)
I1,I3: 6.. / I1 = 6  =>  0 pairs (*) / I3 = 6  =>  0 pairs (X)
F1,I1: 6.. / F1 = 6  => 14 pairs (_) / I1 = 6  =>  0 pairs (*)
F3,I3: 6.. / F3 = 6  =>  0 pairs (*) / I3 = 6  =>  0 pairs (X)
D2,F3: 7.. / D2 = 7  =>  0 pairs (*) / F3 = 7  =>  0 pairs (X)
H2,H3: 7.. / H2 = 7  =>  0 pairs (X) / H3 = 7  =>  0 pairs (_)
C8,C9: 7.. / C8 = 7  => 14 pairs (_) / C9 = 7  =>  0 pairs (*)
D2,H2: 7.. / D2 = 7  =>  0 pairs (*) / H2 = 7  =>  0 pairs (X)
F3,H3: 7.. / F3 = 7  =>  0 pairs (X) / H3 = 7  =>  0 pairs (_)
C8,F8: 7.. / C8 = 7  => 14 pairs (_) / F8 = 7  =>  0 pairs (*)
D2,D9: 7.. / D2 = 7  =>  0 pairs (*) / D9 = 7  =>  0 pairs (X)
H1,I1: 8.. / H1 = 8  => 16 pairs (_) / I1 = 8  =>  0 pairs (X)
G4,I4: 8.. / G4 = 8  =>  0 pairs (X) / I4 = 8  => 13 pairs (_)
F8,F9: 8.. / F8 = 8  =>  0 pairs (X) / F9 = 8  => 16 pairs (_)
F9,H9: 8.. / F9 = 8  => 16 pairs (_) / H9 = 8  =>  0 pairs (X)
G4,G8: 8.. / G4 = 8  =>  0 pairs (X) / G8 = 8  => 13 pairs (_)
B2,C3: 9.. / B2 = 9  =>  0 pairs (X) / C3 = 9  =>  0 pairs (_)
C7,B9: 9.. / C7 = 9  =>  0 pairs (X) / B9 = 9  =>  0 pairs (_)
C7,E7: 9.. / C7 = 9  =>  0 pairs (X) / E7 = 9  =>  0 pairs (_)
B2,B9: 9.. / B2 = 9  =>  0 pairs (X) / B9 = 9  =>  0 pairs (_)
C3,C7: 9.. / C3 = 9  =>  0 pairs (*) / C7 = 9  =>  0 pairs (X)
E1,E7: 9.. / E1 = 9  =>  0 pairs (X) / E7 = 9  =>  0 pairs (_)
* DURATION: 0:01:31.818884  START: 03:44:46.820882  END: 03:46:18.639766 2017-05-04
* CP COUNT: (38)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B2,B9,C3,C7,C8,C9,D2,D9,E1,E7,F1,G4,G8,I4)
* 7513..2..6.8.123..23.85.1..476931.2.58267493191328546786.5.371232.16....1...2.6.3
* PAIR B2: 4,9 ROW 2
H2: 4,9,5,7                              # reduction candidate for 4,9
H2: 4,9 => SOLVED
* 751349286648712395239856174476931528582674931913285467864593712325167849197428653
H2: 5,7                                  # 15 pairs
I2: 4,9,5                                # reduction candidate for 4,9
I2: 4,9 => CTR
* 75134.2986.871235.23.85.17.476931.2.58267493191328546786.5.371232716....1.5427683
I2: 5                                    # 14 pairs
* PAIR C3: 4,9 ROW 3
H3: 4,9,7                                # reduction candidate for 4,9
H3: 4,9 => CTR
* 7513.62896.8.1237523.8571.647693152858267493191328546786.5.371232716.8541.5728693
H3: 7 => SOLVED
* 751349286648712395239856174476931528582674931913285467864593712325167849197428653
I3: 4,9,6                                # reduction candidate for 4,9
I3: 4,9 => SOLVED
* 751349286648712395239856174476931528582674931913285467864593712325167849197428653
I3: 6                                    # 14 pairs
* PAIR E1: 4,9 ROW 1
H1: 4,9,8                                # reduction candidate for 4,9
H1: 4,9 => CTR
* 7513.62.86.871235.2348591764769318255826749319132854678695.371232716.5..1.5.27683
H1: 8                                    # 16 pairs
I1: 4,9,6,8                              # reduction candidate for 4,9
I1: 4,9                                  # 17 pairs
* PAIR F1: 6,9 BLK 2
F3: 6,9,7                                # reduction candidate for 6,9
F3: 6,9 => SOLVED
* 751349286648712395239856174476931528582674931913285467864593712325167849197428653
F3: 7 => CTR
* 7513962..6.841237523485719647693152858267493191328546786954371232716.8..1.572.6.3
* PAIR F1: 6,9 ROW 1
I1: 6,9,4,8                              # reduction candidate for 6,9
I1: 6,9 => SOLVED
* 751349286648712395239856174476931528582674931913285467864593712325167849197428653
I1: 4,8                                  # 15 pairs
* PAIR D2: 4,7 ROW 2
H2: 4,7,5,9                              # reduction candidate for 4,7
H2: 4,7 => CTR
* 7513..28.698.123.523485.1..47693152858267493191328546786954371232.1698.414.728693
H2: 5,9 => SOLVED
* 751349286648712395239856174476931528582674931913285467864593712325167849197428653
* PAIR I4: 5,8 COL I
I8: 5,8,4,9                              # reduction candidate for 5,8
I8: 5,8 => CTR
* 7513..28.698.1235423485.17.476931.2.58267493191328546786954371232.16..4.1...2.693
I8: 4,9                                  # 15 pairs
* PAIR G8: 5,8 BLK 9
H8: 5,8,4,9                              # reduction candidate for 5,8
H8: 5,8 => CTR
* 7513..2..698.123.523485.17.47693152858267493191328546786954371232.1698541...2.693
H8: 4,9                                  # 15 pairs
I8: 5,8,4,9                              # reduction candidate for 5,8
I8: 5,8 => CTR
* 7513..28.698.1235423485.17.476931.2.58267493191328546786954371232.16..4.1...2.693
I8: 4,9                                  # 15 pairs
H9: 5,8,9                                # reduction candidate for 5,8
H9: 5,8                                  # 18 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-032-base-pr-000.dot
* REASONING
* PRF # H2: 4,9 => SOL
* DIS # I2: 4,9 => CTR => I2: 5
* DIS # H3: 4,9 => CTR => H3: 7
* PRF # H3: 7 => SOL
* PRF # I3: 4,9 => SOL
* DIS # H1: 4,9 => CTR => H1: 8
* PRF # F3: 6,9 => SOL
* DIS # F3: 7 => CTR => F3: 6,9
* PRF # I1: 6,9 => SOL
* DIS # H2: 4,7 => CTR => H2: 5,9
* PRF # H2: 5,9 => SOL
* DIS # I8: 5,8 => CTR => I8: 4,9
* DIS # H8: 5,8 => CTR => H8: 4,9
* DIS # I8: 5,8 => CTR => I8: 4,9
* CNT  14 HDP CHAINS /  24 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B2,B9,C3,C7,C8,C9,D2,D9,E1,E7,F1,G4,G8,I4)
* 7513..2..6.8.123..23.85.1..476931.2.58267493191328546786.5.371232.16....1...2.6.3
* PAIR B2: 4,9 ROW 2
H2: 4,9,5,7                              # reduction candidate for 4,9
H2: 4,9 => SOLVED
* 751349286648712395239856174476931528582674931913285467864593712325167849197428653
* DURATION: 0:00:02.459007  START: 03:46:53.957441  END: 03:46:56.416448 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-032-base-pr-001.dot
* REASONING
* PRF # H2: 4,9 => SOL
* STA H2: 4,9
* CNT   1 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 032

solution: 751349286648712395239856174476931528582674931913285467864593712325167849197428653
info: 1333     FNBTWXY  S8.f     19751

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

Solution

position: 751349286648712395239856174476931528582674931913285467864593712325167849197428653 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 # H2: 4,9 => SOL
* INC # H2: 5,7 => UNS
* DIS # I2: 4,9 => CTR => I2: 5
* INC # I2: 5 => UNS
* DIS # H3: 4,9 => CTR => H3: 7
* PRF # H3: 7 => SOL
* PRF # I3: 4,9 => SOL
* INC # I3: 6 => UNS
* DIS # H1: 4,9 => CTR => H1: 8
* INC # H1: 8 => UNS
* INC # I1: 4,9 => UNS
* PRF # F3: 6,9 => SOL
* DIS # F3: 7 => CTR => F3: 6,9
* PRF # I1: 6,9 => SOL
* INC # I1: 4,8 => UNS
* DIS # H2: 4,7 => CTR => H2: 5,9
* PRF # H2: 5,9 => SOL
* DIS # I8: 5,8 => CTR => I8: 4,9
* INC # I8: 4,9 => UNS
* DIS # H8: 5,8 => CTR => H8: 4,9
* INC # H8: 4,9 => UNS
* DIS # I8: 5,8 => CTR => I8: 4,9
* INC # I8: 4,9 => UNS
* INC # H9: 5,8 => UNS
* CNT  24 HDP CHAINS /  24 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* PRF # H2: 4,9 => SOL
* STA H2: 4,9
* CNT   1 HDP CHAINS /   1 HYP OPENED