Analysis of xx-top500-164-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: .74..........1.6......9....89....1.....4.2...5...........7...43...3...2.1........ initial

Autosolve

position: 6748..2193.92146.721.69743.8925..1.47314.2.9.5461.93.296.721.434.73..92112394.7.. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # H9: 5,8 => SOL
* DIS # H9: 6 => CTR => H9: 5,8
* PRF # I5: 5,8 => SOL
* DIS # I5: 6 => CTR => I5: 5,8
* DIS # I9: 5,8 => CTR => I9: 6
* PRF # I9: 6 => SOL
* DIS # E4: 3,6 => CTR => E4: 7
* PRF # E4: 7 => SOL
* PRF # I5: 6,8 => SOL
* DIS # I5: 5 => CTR => I5: 6,8
* PRF # E4: 6,7 => SOL
* DIS # E4: 3 => CTR => E4: 6,7
* PRF # I5: 5,8 => SOL
* DIS # I5: 6 => CTR => I5: 5,8
* DIS # F8: 5,8 => CTR => F8: 6
* PRF # F8: 6 => SOL
* PRF # F8: 5,6 => SOL
* DIS # F8: 8 => CTR => F8: 5,6
* DIS # F8: 5,8 => CTR => F8: 6
* PRF # F8: 6 => SOL
* PRF # H9: 5,8 => SOL
* DIS # H9: 6 => CTR => H9: 5,8
* DIS # I9: 5,8 => CTR => I9: 6
* PRF # I9: 6 => SOL
* PRF # H9: 5,8 => SOL
* DIS # H9: 6 => CTR => H9: 5,8
* DIS # I9: 5,8 => CTR => I9: 6
* PRF # I9: 6 => SOL
* CNT  28 HDP CHAINS /  28 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 # H9: 5,8 => SOL
* STA H9: 5,8
* CNT   1 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

.74..........1.6......9....89....1.....4.2...5...........7...43...3...2.1........ initial
6748..2193.92146.721.69743.8925..1.47314.2.9.5461.93.296.721.434.73..92112394.7.. autosolve
674835219359214687218697435892573164731462598546189372965721843487356921123948756 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (17)
B2: 5,8
C3: 5,8
E1: 3,5
F1: 3,5
H2: 5,8
I3: 5,8
F4: 3,6
E5: 6,8
E6: 7,8
H4: 6,7
G5: 5,8
H6: 7,8
C7: 5,8
B8: 5,8
E8: 5,6
F9: 5,8
G7: 5,8

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
E1,F1: 3.. / E1 = 3  =>  0 pairs (*) / F1 = 3  =>  0 pairs (X)
E4,F4: 3.. / E4 = 3  =>  0 pairs (X) / F4 = 3  =>  0 pairs (_)
E1,E4: 3.. / E1 = 3  =>  0 pairs (*) / E4 = 3  =>  0 pairs (X)
F1,F4: 3.. / F1 = 3  =>  0 pairs (X) / F4 = 3  =>  0 pairs (_)
B2,C3: 5.. / B2 = 5  =>  0 pairs (*) / C3 = 5  =>  0 pairs (X)
E1,F1: 5.. / E1 = 5  =>  0 pairs (X) / F1 = 5  =>  0 pairs (_)
H2,I3: 5.. / H2 = 5  =>  0 pairs (X) / I3 = 5  =>  0 pairs (_)
G5,I5: 5.. / G5 = 5  =>  0 pairs (*) / I5 = 5  =>  0 pairs (X)
C7,B8: 5.. / C7 = 5  =>  0 pairs (*) / B8 = 5  =>  0 pairs (X)
B2,H2: 5.. / B2 = 5  =>  0 pairs (*) / H2 = 5  =>  0 pairs (X)
C3,I3: 5.. / C3 = 5  =>  0 pairs (X) / I3 = 5  =>  0 pairs (_)
C7,G7: 5.. / C7 = 5  =>  0 pairs (*) / G7 = 5  =>  0 pairs (X)
B2,B8: 5.. / B2 = 5  =>  0 pairs (*) / B8 = 5  =>  0 pairs (X)
C3,C7: 5.. / C3 = 5  =>  0 pairs (X) / C7 = 5  =>  0 pairs (_)
E1,E8: 5.. / E1 = 5  =>  0 pairs (X) / E8 = 5  =>  0 pairs (_)
G5,G7: 5.. / G5 = 5  =>  0 pairs (*) / G7 = 5  =>  0 pairs (X)
H2,H9: 5.. / H2 = 5  =>  0 pairs (X) / H9 = 5  =>  0 pairs (_)
H4,I5: 6.. / H4 = 6  =>  0 pairs (*) / I5 = 6  =>  0 pairs (X)
E8,F8: 6.. / E8 = 6  =>  0 pairs (X) / F8 = 6  =>  0 pairs (_)
H9,I9: 6.. / H9 = 6  =>  0 pairs (X) / I9 = 6  =>  0 pairs (_)
E5,I5: 6.. / E5 = 6  =>  0 pairs (*) / I5 = 6  =>  0 pairs (X)
F4,F8: 6.. / F4 = 6  =>  0 pairs (X) / F8 = 6  =>  0 pairs (_)
H4,H9: 6.. / H4 = 6  =>  0 pairs (*) / H9 = 6  =>  0 pairs (X)
I5,I9: 6.. / I5 = 6  =>  0 pairs (X) / I9 = 6  =>  0 pairs (_)
E4,E6: 7.. / E4 = 7  =>  0 pairs (*) / E6 = 7  =>  0 pairs (X)
H4,H6: 7.. / H4 = 7  =>  0 pairs (X) / H6 = 7  =>  0 pairs (_)
E4,H4: 7.. / E4 = 7  =>  0 pairs (*) / H4 = 7  =>  0 pairs (X)
E6,H6: 7.. / E6 = 7  =>  0 pairs (X) / H6 = 7  =>  0 pairs (_)
B2,C3: 8.. / B2 = 8  =>  0 pairs (X) / C3 = 8  =>  0 pairs (_)
H2,I3: 8.. / H2 = 8  =>  0 pairs (*) / I3 = 8  =>  0 pairs (X)
E5,E6: 8.. / E5 = 8  =>  0 pairs (X) / E6 = 8  =>  0 pairs (_)
C7,B8: 8.. / C7 = 8  =>  0 pairs (X) / B8 = 8  =>  0 pairs (_)
F8,F9: 8.. / F8 = 8  =>  0 pairs (X) / F9 = 8  =>  0 pairs (_)
B2,H2: 8.. / B2 = 8  =>  0 pairs (X) / H2 = 8  =>  0 pairs (_)
C3,I3: 8.. / C3 = 8  =>  0 pairs (*) / I3 = 8  =>  0 pairs (X)
E6,H6: 8.. / E6 = 8  =>  0 pairs (*) / H6 = 8  =>  0 pairs (X)
C7,G7: 8.. / C7 = 8  =>  0 pairs (X) / G7 = 8  =>  0 pairs (_)
B8,F8: 8.. / B8 = 8  =>  0 pairs (*) / F8 = 8  =>  0 pairs (X)
B2,B8: 8.. / B2 = 8  =>  0 pairs (X) / B8 = 8  =>  0 pairs (_)
C3,C7: 8.. / C3 = 8  =>  0 pairs (*) / C7 = 8  =>  0 pairs (X)
G5,G7: 8.. / G5 = 8  =>  0 pairs (X) / G7 = 8  =>  0 pairs (_)
* DURATION: 0:01:15.515170  START: 08:21:09.240422  END: 08:22:24.755592 2017-05-04
* CP COUNT: (41)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B2,B8,C3,C7,E1,E5,E6,E8,F1,F4,F9,G5,G7,H2,H4,H6,I3)
* 6748..2193.92146.721.69743.8925..1.47314.2.9.5461.93.296.721.434.73..92112394.7..
* PAIR H2: 5,8 COL H
H9: 5,8,6                                # reduction candidate for 5,8
H9: 5,8 => SOLVED
* 674835219359214687218697435892573164731462598546189372965721843487356921123948756
H9: 6 => CTR
* 6748..2193.92146572156974388925..1.47314.2.9.5461.9382968721.434.73..92112394.7..
* PAIR I3: 5,8 COL I
I5: 5,8,6                                # reduction candidate for 5,8
I5: 5,8 => SOLVED
* 674835219359214687218697435892573164731462598546189372965721843487356921123948756
I5: 6 => CTR
* 6748..2193.92146.721.69743.8925..1.47314.25965461.93829657218434873..92112394.7..
I9: 5,8,6                                # reduction candidate for 5,8
I9: 5,8 => CTR
* 6748..2193.92146572156974388925..1747314825965461.93.296.721.434.73..92112394.76.
I9: 6 => SOLVED
* 674835219359214687218697435892573164731462598546189372965721843487356921123948756
* PAIR F4: 3,6 BLK 5
E4: 3,6,7                                # reduction candidate for 3,6
E4: 3,6 => CTR
* 6748..2193.92146.721.69743.8925..1747314.2.9654617938296.7218434873..921123948765
E4: 7 => SOLVED
* 674835219359214687218697435892573164731462598546189372965721843487356921123948756
* PAIR E5: 6,8 ROW 5
I5: 6,8,5                                # reduction candidate for 6,8
I5: 6,8 => SOLVED
* 674835219359214687218697435892573164731462598546189372965721843487356921123948756
I5: 5 => CTR
* 6748..2193.92146.721.69743.8925..1647314628955461893729687215434573..92112394.7..
* PAIR H4: 6,7 ROW 4
E4: 6,7,3                                # reduction candidate for 6,7
E4: 6,7 => SOLVED
* 674835219359214687218697435892573164731462598546189372965721843487356921123948756
E4: 3 => CTR
* 6748..2193.92146.721.69743.8925361747314825965461793829657218434873..92112394.7..
* PAIR G5: 5,8 BLK 6
I5: 5,8,6                                # reduction candidate for 5,8
I5: 5,8 => SOLVED
* 674835219359214687218697435892573164731462598546189372965721843487356921123948756
I5: 6 => CTR
* 6748..2193.92146.721.69743.8925..1.47314.25965461.93829657218434873..92112394.7..
* PAIR B8: 5,8 ROW 8
F8: 5,8,6                                # reduction candidate for 5,8
F8: 5,8 => CTR
* 6748..2193.92146.721.69743.8925.61747314825965461793829657218434873..92112394.7..
F8: 6 => SOLVED
* 674835219359214687218697435892573164731462598546189372965721843487356921123948756
* PAIR E8: 5,6 BLK 8
F8: 5,6,8                                # reduction candidate for 5,6
F8: 5,6 => SOLVED
* 674835219359214687218697435892573164731462598546189372965721843487356921123948756
F8: 8 => CTR
* 6748..2193.92146.721.69743.8925.61747314825965461793829657218434873..92112394.7..
* PAIR F9: 5,8 BLK 8
F8: 5,8,6                                # reduction candidate for 5,8
F8: 5,8 => CTR
* 6748..2193.92146.721.69743.8925.61747314825965461793829657218434873..92112394.7..
F8: 6 => SOLVED
* 674835219359214687218697435892573164731462598546189372965721843487356921123948756
* PAIR F9: 5,8 ROW 9
H9: 5,8,6                                # reduction candidate for 5,8
H9: 5,8 => SOLVED
* 674835219359214687218697435892573164731462598546189372965721843487356921123948756
H9: 6 => CTR
* 6748..2193.92146572156974388925..1.47314.2.9.5461.9382968721.434.73..92112394.7..
I9: 5,8,6                                # reduction candidate for 5,8
I9: 5,8 => CTR
* 6748..2193.92146572156974388925..1747314825965461.93.296.721.434.73..92112394.76.
I9: 6 => SOLVED
* 674835219359214687218697435892573164731462598546189372965721843487356921123948756
* PAIR G7: 5,8 BLK 9
H9: 5,8,6                                # reduction candidate for 5,8
H9: 5,8 => SOLVED
* 674835219359214687218697435892573164731462598546189372965721843487356921123948756
H9: 6 => CTR
* 6748..2193.92146572156974388925..1.47314.2.9.5461.9382968721.434.73..92112394.7..
I9: 5,8,6                                # reduction candidate for 5,8
I9: 5,8 => CTR
* 6748..2193.92146572156974388925..1747314825965461.93.296.721.434.73..92112394.76.
I9: 6 => SOLVED
* 674835219359214687218697435892573164731462598546189372965721843487356921123948756
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-164-base-pr-000.dot
* REASONING
* PRF # H9: 5,8 => SOL
* DIS # H9: 6 => CTR => H9: 5,8
* PRF # I5: 5,8 => SOL
* DIS # I5: 6 => CTR => I5: 5,8
* DIS # I9: 5,8 => CTR => I9: 6
* PRF # I9: 6 => SOL
* DIS # E4: 3,6 => CTR => E4: 7
* PRF # E4: 7 => SOL
* PRF # I5: 6,8 => SOL
* DIS # I5: 5 => CTR => I5: 6,8
* PRF # E4: 6,7 => SOL
* DIS # E4: 3 => CTR => E4: 6,7
* PRF # I5: 5,8 => SOL
* DIS # I5: 6 => CTR => I5: 5,8
* DIS # F8: 5,8 => CTR => F8: 6
* PRF # F8: 6 => SOL
* PRF # F8: 5,6 => SOL
* DIS # F8: 8 => CTR => F8: 5,6
* DIS # F8: 5,8 => CTR => F8: 6
* PRF # F8: 6 => SOL
* PRF # H9: 5,8 => SOL
* DIS # H9: 6 => CTR => H9: 5,8
* DIS # I9: 5,8 => CTR => I9: 6
* PRF # I9: 6 => SOL
* PRF # H9: 5,8 => SOL
* DIS # H9: 6 => CTR => H9: 5,8
* DIS # I9: 5,8 => CTR => I9: 6
* PRF # I9: 6 => SOL
* CNT  28 HDP CHAINS /  28 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B2,B8,C3,C7,E1,E5,E6,E8,F1,F4,F9,G5,G7,H2,H4,H6,I3)
* 6748..2193.92146.721.69743.8925..1.47314.2.9.5461.93.296.721.434.73..92112394.7..
* PAIR H2: 5,8 COL H
H9: 5,8,6                                # reduction candidate for 5,8
H9: 5,8 => SOLVED
* 674835219359214687218697435892573164731462598546189372965721843487356921123948756
* DURATION: 0:00:02.088696  START: 08:22:59.206772  END: 08:23:01.295468 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-164-base-pr-001.dot
* REASONING
* PRF # H9: 5,8 => SOL
* STA H9: 5,8
* CNT   1 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 164

solution: 674835219359214687218697435892573164731462598546189372965721843487356921123948756
info: 1822     FNBWX    S8.f     23080

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

Solution

position: 674835219359214687218697435892573164731462598546189372965721843487356921123948756 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 # H9: 5,8 => SOL
* DIS # H9: 6 => CTR => H9: 5,8
* PRF # I5: 5,8 => SOL
* DIS # I5: 6 => CTR => I5: 5,8
* DIS # I9: 5,8 => CTR => I9: 6
* PRF # I9: 6 => SOL
* DIS # E4: 3,6 => CTR => E4: 7
* PRF # E4: 7 => SOL
* PRF # I5: 6,8 => SOL
* DIS # I5: 5 => CTR => I5: 6,8
* PRF # E4: 6,7 => SOL
* DIS # E4: 3 => CTR => E4: 6,7
* PRF # I5: 5,8 => SOL
* DIS # I5: 6 => CTR => I5: 5,8
* DIS # F8: 5,8 => CTR => F8: 6
* PRF # F8: 6 => SOL
* PRF # F8: 5,6 => SOL
* DIS # F8: 8 => CTR => F8: 5,6
* DIS # F8: 5,8 => CTR => F8: 6
* PRF # F8: 6 => SOL
* PRF # H9: 5,8 => SOL
* DIS # H9: 6 => CTR => H9: 5,8
* DIS # I9: 5,8 => CTR => I9: 6
* PRF # I9: 6 => SOL
* PRF # H9: 5,8 => SOL
* DIS # H9: 6 => CTR => H9: 5,8
* DIS # I9: 5,8 => CTR => I9: 6
* PRF # I9: 6 => SOL
* CNT  28 HDP CHAINS /  28 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* PRF # H9: 5,8 => SOL
* STA H9: 5,8
* CNT   1 HDP CHAINS /   1 HYP OPENED