Analysis of xx-top500-248-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 7...1.....9.....8..........6.....1.2.4.8.9......3.....1.2...6..5......9....4..... initial

Autosolve

position: 723.184.94962...81815.9432.689.4.132341829...2573619481.298.6.45641.289.9.84.621. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # H5: 5,6 => SOL
* DIS # H5: 7 => CTR => H5: 5,6
* DIS # F2: 5,7 => CTR => F2: 3
* PRF # I5: 6,7 => SOL
* DIS # I5: 5 => CTR => I5: 6,7
* DIS # F2: 5,7 => CTR => F2: 3
* DIS # H5: 5,7 => CTR => H5: 6
* PRF # H5: 6 => SOL
* PRF # I5: 5,7 => SOL
* DIS # I5: 6 => CTR => I5: 5,7
* DIS # F7: 3,7 => CTR => F7: 5
* PRF # F7: 5 => SOL
* PRF # E9: 3,7 => SOL
* DIS # E9: 5 => CTR => E9: 3,7
* DIS # I9: 3,7 => CTR => I9: 5
* PRF # I9: 5 => SOL
* DIS # F7: 3,7 => CTR => F7: 5
* PRF # F7: 5 => SOL
* PRF # E9: 3,7 => SOL
* DIS # E9: 5 => CTR => E9: 3,7
* DIS # E2: 3,7 => CTR => E2: 5
* PRF # E2: 5 => SOL
* DIS # I9: 3 => CTR => I9: 5,7
* DIS # F7: 3 => CTR => F7: 5,7
* DIS # H5: 5,7 => CTR => H5: 6
* PRF # H5: 6 => SOL
* DIS # I9: 3,7 => CTR => I9: 5
* PRF # I9: 5 => SOL
* CNT  28 HDP CHAINS /  34 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 # H5: 5,6 => SOL
* STA H5: 5,6
* CNT   1 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

7...1.....9.....8..........6.....1.2.4.8.9......3.....1.2...6..5......9....4..... initial
723.184.94962...81815.9432.689.4.132341829...2573619481.298.6.45641.289.9.84.621. autosolve
723618459496253781815794326689547132341829567257361948132985674564172893978436215 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (13)
D1: 5,6
D3: 6,7
H1: 5,6
G2: 5,7
I3: 6,7
D4: 5,7
F4: 5,7
G5: 5,7
B7: 3,7
B9: 3,7
E8: 3,7
H7: 5,7
I8: 3,7

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
E2,F2: 3.. / E2 = 3  =>  0 pairs (X) / F2 = 3  => 15 pairs (_)
B7,B9: 3.. / B7 = 3  => 15 pairs (_) / B9 = 3  =>  0 pairs (X)
I8,I9: 3.. / I8 = 3  => 15 pairs (_) / I9 = 3  =>  0 pairs (X)
B7,F7: 3.. / B7 = 3  => 15 pairs (_) / F7 = 3  =>  0 pairs (X)
E8,I8: 3.. / E8 = 3  =>  0 pairs (X) / I8 = 3  => 15 pairs (_)
F2,F7: 3.. / F2 = 3  => 15 pairs (_) / F7 = 3  =>  0 pairs (X)
H1,G2: 5.. / H1 = 5  =>  0 pairs (*) / G2 = 5  =>  0 pairs (X)
D4,F4: 5.. / D4 = 5  =>  0 pairs (*) / F4 = 5  =>  0 pairs (X)
F7,E9: 5.. / F7 = 5  =>  0 pairs (*) / E9 = 5  =>  0 pairs (X)
H7,I9: 5.. / H7 = 5  =>  0 pairs (X) / I9 = 5  =>  0 pairs (_)
D1,H1: 5.. / D1 = 5  =>  0 pairs (X) / H1 = 5  =>  0 pairs (_)
F7,H7: 5.. / F7 = 5  =>  0 pairs (*) / H7 = 5  =>  0 pairs (X)
E9,I9: 5.. / E9 = 5  =>  0 pairs (X) / I9 = 5  =>  0 pairs (_)
D1,D4: 5.. / D1 = 5  =>  0 pairs (X) / D4 = 5  =>  0 pairs (_)
E2,E9: 5.. / E2 = 5  =>  0 pairs (*) / E9 = 5  =>  0 pairs (X)
G2,G5: 5.. / G2 = 5  =>  0 pairs (X) / G5 = 5  =>  0 pairs (_)
I5,I9: 5.. / I5 = 5  =>  0 pairs (X) / I9 = 5  =>  0 pairs (_)
D1,D3: 6.. / D1 = 6  =>  0 pairs (*) / D3 = 6  =>  0 pairs (X)
H1,I3: 6.. / H1 = 6  =>  0 pairs (X) / I3 = 6  =>  0 pairs (_)
H5,I5: 6.. / H5 = 6  =>  0 pairs (*) / I5 = 6  =>  0 pairs (X)
D1,H1: 6.. / D1 = 6  =>  0 pairs (*) / H1 = 6  =>  0 pairs (X)
D3,I3: 6.. / D3 = 6  =>  0 pairs (X) / I3 = 6  =>  0 pairs (_)
H1,H5: 6.. / H1 = 6  =>  0 pairs (X) / H5 = 6  =>  0 pairs (_)
I3,I5: 6.. / I3 = 6  =>  0 pairs (*) / I5 = 6  =>  0 pairs (X)
G2,I3: 7.. / G2 = 7  =>  0 pairs (*) / I3 = 7  =>  0 pairs (X)
D4,F4: 7.. / D4 = 7  =>  0 pairs (X) / F4 = 7  =>  0 pairs (_)
B7,B9: 7.. / B7 = 7  =>  0 pairs (X) / B9 = 7  => 15 pairs (_)
D3,I3: 7.. / D3 = 7  =>  0 pairs (*) / I3 = 7  =>  0 pairs (X)
E8,I8: 7.. / E8 = 7  => 15 pairs (_) / I8 = 7  =>  0 pairs (X)
D3,D4: 7.. / D3 = 7  =>  0 pairs (*) / D4 = 7  =>  0 pairs (X)
G2,G5: 7.. / G2 = 7  =>  0 pairs (*) / G5 = 7  =>  0 pairs (X)
H5,H7: 7.. / H5 = 7  =>  0 pairs (X) / H7 = 7  =>  0 pairs (_)
* DURATION: 0:00:53.728771  START: 11:15:56.780368  END: 11:16:50.509139 2017-05-04
* CP COUNT: (32)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B7,B9,D1,D3,D4,E8,F4,G2,G5,H1,H7,I3,I8)
* 723.184.94962...81815.9432.689.4.132341829...2573619481.298.6.45641.289.9.84.621.
* PAIR H1: 5,6 COL H
H5: 5,6,7                                # reduction candidate for 5,6
H5: 5,6 => SOLVED
* 723618459496253781815794326689547132341829567257361948132985674564172893978436215
H5: 7 => CTR
* 723.184694962..581815694327689.4.132341829...2573619481.298.6.45641.289.9.84.621.
* PAIR G2: 5,7 ROW 2
E2: 5,7,3                                # reduction candidate for 5,7
E2: 5,7                                  # 15 pairs
F2: 5,7,3                                # reduction candidate for 5,7
F2: 5,7 => CTR
* 723.184.949623..81815.9432.689.4.132341829...2573619481.2983654564172893938456217
F2: 3                                    # 15 pairs
* PAIR I3: 6,7 COL I
I5: 6,7,5                                # reduction candidate for 6,7
I5: 6,7 => SOLVED
* 723618459496253781815794326689547132341829567257361948132985674564172893978436215
I5: 5 => CTR
* 723.184.94962...81815.94326689.4.132341829.652573619481.298.6.45641.289.9.84.621.
* PAIR F4: 5,7 COL F
F2: 5,7,3                                # reduction candidate for 5,7
F2: 5,7 => CTR
* 723.184.949623..81815.9432.689.4.132341829...2573619481.2983654564172893938456217
F2: 3                                    # 15 pairs
F7: 5,7,3                                # reduction candidate for 5,7
F7: 5,7                                  # 15 pairs
* PAIR G5: 5,7 BLK 6
H5: 5,7,6                                # reduction candidate for 5,7
H5: 5,7 => CTR
* 723.184694962..58181569432768974513234182975.2573619481.298.6.45641.289.9.84.621.
H5: 6 => SOLVED
* 723618459496253781815794326689547132341829567257361948132985674564172893978436215
I5: 5,7,6                                # reduction candidate for 5,7
I5: 5,7 => SOLVED
* 723618459496253781815794326689547132341829567257361948132985674564172893978436215
I5: 6 => CTR
* 723.1846949625..81815.9432.689.4.132341829..62573619481.298.6.45641.289.9.84.6215
* PAIR B7: 3,7 ROW 7
F7: 3,7,5                                # reduction candidate for 3,7
F7: 3,7 => CTR
* 7235184694962..581815694327689.4.132341829...2573619481.298.6545641.289.9.845621.
F7: 5 => SOLVED
* 723618459496253781815794326689547132341829567257361948132985674564172893978436215
* PAIR B9: 3,7 ROW 9
E9: 3,7,5                                # reduction candidate for 3,7
E9: 3,7 => SOLVED
* 723618459496253781815794326689547132341829567257361948132985674564172893978436215
E9: 5 => CTR
* 723.184.94962...81815.9432.689.4.132341829..52573619481.298.6545641.289.9.845621.
I9: 3,7,5                                # reduction candidate for 3,7
I9: 3,7 => CTR
* 723.184.94962...81815.9432.689.4.132341829..52573619481.298.6545641.289.9.845621.
I9: 5 => SOLVED
* 723618459496253781815794326689547132341829567257361948132985674564172893978436215
* PAIR E8: 3,7 BLK 8
F7: 3,7,5                                # reduction candidate for 3,7
F7: 3,7 => CTR
* 7235184694962..581815694327689.4.132341829...2573619481.298.6545641.289.9.845621.
F7: 5 => SOLVED
* 723618459496253781815794326689547132341829567257361948132985674564172893978436215
E9: 3,7,5                                # reduction candidate for 3,7
E9: 3,7 => SOLVED
* 723618459496253781815794326689547132341829567257361948132985674564172893978436215
E9: 5 => CTR
* 723.184.94962...81815.9432.689.4.132341829..52573619481.298.6545641.289.9.845621.
* PAIR E8: 3,7 COL E
E2: 3,7,5                                # reduction candidate for 3,7
E2: 3,7 => CTR
* 723.184.94962...81815.9432.689.4.132341829..52573619481.298.6545641.289.9.845621.
E2: 5 => SOLVED
* 723618459496253781815794326689547132341829567257361948132985674564172893978436215
* PAIR H7: 5,7 BLK 9
I9: 5,7,3                                # reduction candidate for 5,7
I9: 3 => CTR
* 723.184.94962...81815.9432.689.4.132341829..52573619481.298.6545641.28979.8456213
I9: 5,7                                  # 15 pairs
* PAIR H7: 5,7 ROW 7
F7: 5,7,3                                # reduction candidate for 5,7
F7: 3 => CTR
* 723.184.94962...81815.9432.689.4.132341829...2573619481.2983654564172893938456217
F7: 5,7                                  # 15 pairs
* PAIR H7: 5,7 COL H
H5: 5,7,6                                # reduction candidate for 5,7
H5: 5,7 => CTR
* 723.184694962..58181569432768974513234182975.2573619481.298.6.45641.289.9.84.621.
H5: 6 => SOLVED
* 723618459496253781815794326689547132341829567257361948132985674564172893978436215
* PAIR I8: 3,7 BLK 9
I9: 3,7,5                                # reduction candidate for 3,7
I9: 3,7 => CTR
* 723.184.94962...81815.9432.689.4.132341829..52573619481.298.6545641.289.9.845621.
I9: 5 => SOLVED
* 723618459496253781815794326689547132341829567257361948132985674564172893978436215
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-248-base-pr-000.dot
* REASONING
* PRF # H5: 5,6 => SOL
* DIS # H5: 7 => CTR => H5: 5,6
* DIS # F2: 5,7 => CTR => F2: 3
* PRF # I5: 6,7 => SOL
* DIS # I5: 5 => CTR => I5: 6,7
* DIS # F2: 5,7 => CTR => F2: 3
* DIS # H5: 5,7 => CTR => H5: 6
* PRF # H5: 6 => SOL
* PRF # I5: 5,7 => SOL
* DIS # I5: 6 => CTR => I5: 5,7
* DIS # F7: 3,7 => CTR => F7: 5
* PRF # F7: 5 => SOL
* PRF # E9: 3,7 => SOL
* DIS # E9: 5 => CTR => E9: 3,7
* DIS # I9: 3,7 => CTR => I9: 5
* PRF # I9: 5 => SOL
* DIS # F7: 3,7 => CTR => F7: 5
* PRF # F7: 5 => SOL
* PRF # E9: 3,7 => SOL
* DIS # E9: 5 => CTR => E9: 3,7
* DIS # E2: 3,7 => CTR => E2: 5
* PRF # E2: 5 => SOL
* DIS # I9: 3 => CTR => I9: 5,7
* DIS # F7: 3 => CTR => F7: 5,7
* DIS # H5: 5,7 => CTR => H5: 6
* PRF # H5: 6 => SOL
* DIS # I9: 3,7 => CTR => I9: 5
* PRF # I9: 5 => SOL
* CNT  28 HDP CHAINS /  34 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B7,B9,D1,D3,D4,E8,F4,G2,G5,H1,H7,I3,I8)
* 723.184.94962...81815.9432.689.4.132341829...2573619481.298.6.45641.289.9.84.621.
* PAIR H1: 5,6 COL H
H5: 5,6,7                                # reduction candidate for 5,6
H5: 5,6 => SOLVED
* 723618459496253781815794326689547132341829567257361948132985674564172893978436215
* DURATION: 0:00:01.987876  START: 11:17:27.374482  END: 11:17:29.362358 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-248-base-pr-001.dot
* REASONING
* PRF # H5: 5,6 => SOL
* STA H5: 5,6
* CNT   1 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 248

solution: 723618459496253781815794326689547132341829567257361948132985674564172893978436215
info: 2072     FNBWXY   S8.f     36589

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

Solution

position: 723618459496253781815794326689547132341829567257361948132985674564172893978436215 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 # H5: 5,6 => SOL
* DIS # H5: 7 => CTR => H5: 5,6
* INC # E2: 5,7 => UNS
* DIS # F2: 5,7 => CTR => F2: 3
* INC # F2: 3 => UNS
* PRF # I5: 6,7 => SOL
* DIS # I5: 5 => CTR => I5: 6,7
* DIS # F2: 5,7 => CTR => F2: 3
* INC # F2: 3 => UNS
* INC # F7: 5,7 => UNS
* DIS # H5: 5,7 => CTR => H5: 6
* PRF # H5: 6 => SOL
* PRF # I5: 5,7 => SOL
* DIS # I5: 6 => CTR => I5: 5,7
* DIS # F7: 3,7 => CTR => F7: 5
* PRF # F7: 5 => SOL
* PRF # E9: 3,7 => SOL
* DIS # E9: 5 => CTR => E9: 3,7
* DIS # I9: 3,7 => CTR => I9: 5
* PRF # I9: 5 => SOL
* DIS # F7: 3,7 => CTR => F7: 5
* PRF # F7: 5 => SOL
* PRF # E9: 3,7 => SOL
* DIS # E9: 5 => CTR => E9: 3,7
* DIS # E2: 3,7 => CTR => E2: 5
* PRF # E2: 5 => SOL
* INC # I9: 5,7 => UNS
* DIS # I9: 3 => CTR => I9: 5,7
* INC # F7: 5,7 => UNS
* DIS # F7: 3 => CTR => F7: 5,7
* DIS # H5: 5,7 => CTR => H5: 6
* PRF # H5: 6 => SOL
* DIS # I9: 3,7 => CTR => I9: 5
* PRF # I9: 5 => SOL
* CNT  34 HDP CHAINS /  34 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* PRF # H5: 5,6 => SOL
* STA H5: 5,6
* CNT   1 HDP CHAINS /   1 HYP OPENED