Analysis of xx-top500-304-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: ....3.21.84................3.....5.1..64..........73.....85.....7.....4...1...... initial

Autosolve

position: 5.7.3421884.1.57......784..3.4.8.571756413982..85.73644..85.127.753.1849.8174.6.. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # A3: 6,9 => SOL
* DIS # A3: 1 => CTR => A3: 6,9
* DIS # B3: 6,9 => CTR => B3: 1,3
* DIS # B7: 6,9 => CTR => B7: 3
* PRF # B7: 3 => SOL
* DIS # D3: 6,9 => CTR => D3: 2
* DIS # D4: 2 => CTR => D4: 6,9
* DIS # H3: 3,9 => CTR => H3: 5
* PRF # H3: 5 => SOL
* DIS # C2: 3,9 => CTR => C2: 2
* PRF # I3: 3,6 => SOL
* DIS # I3: 5 => CTR => I3: 3,6
* PRF # B6: 2,9 => SOL
* DIS # B6: 1 => CTR => B6: 2,9
* DIS # D4: 2,9 => CTR => D4: 6
* PRF # D4: 6 => SOL
* DIS # B6: 1,9 => CTR => B6: 2
* PRF # B6: 2 => SOL
* PRF # A3: 1,9 => SOL
* DIS # A3: 6 => CTR => A3: 1,9
* PRF # D4: 2,6 => SOL
* DIS # D4: 9 => CTR => D4: 2,6
* DIS # D4: 2,9 => CTR => D4: 6
* PRF # D4: 6 => SOL
* PRF # B6: 2,9 => SOL
* DIS # B6: 1 => CTR => B6: 2,9
* DIS # E2: 2,9 => CTR => E2: 6
* PRF # E2: 6 => SOL
* PRF # B7: 3,9 => SOL
* DIS # B7: 6 => CTR => B7: 3,9
* DIS # C2: 3,9 => CTR => C2: 2
* DIS # B7: 6,9 => CTR => B7: 3
* PRF # B7: 3 => SOL
* PRF # E2: 2,6 => SOL
* DIS # E2: 9 => CTR => E2: 2,6
* PRF # H3: 3,5 => SOL
* DIS # H3: 9 => CTR => H3: 3,5
* DIS # I3: 3,5 => CTR => I3: 6
* PRF # I3: 6 => SOL
* CNT  39 HDP CHAINS /  46 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 # A3: 6,9 => SOL
* STA A3: 6,9
* CNT   1 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

....3.21.84................3.....5.1..64..........73.....85.....7.....4...1...... initial
5.7.3421884.1.57......784..3.4.8.571756413982..85.73644..85.127.753.1849.8174.6.. autosolve
567934218842165793913278456394682571756413982128597364439856127675321849281749635 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (16)
B1: 6,9
D1: 6,9
H2: 3,9
I2: 3,6
B4: 2,9
A6: 1,9
F4: 2,6
E6: 2,9
C7: 3,9
A8: 2,6
A9: 2,9
F7: 6,9
E8: 2,6
F9: 2,9
H9: 3,5
I9: 3,5

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
A3,B3: 1.. / A3 = 1  =>  0 pairs (X) / B3 = 1  =>  0 pairs (_)
A6,B6: 1.. / A6 = 1  =>  0 pairs (*) / B6 = 1  =>  0 pairs (X)
A3,A6: 1.. / A3 = 1  =>  0 pairs (X) / A6 = 1  =>  0 pairs (_)
B3,B6: 1.. / B3 = 1  =>  0 pairs (*) / B6 = 1  =>  0 pairs (X)
C2,C3: 2.. / C2 = 2  => 21 pairs (_) / C3 = 2  =>  0 pairs (X)
E2,D3: 2.. / E2 = 2  =>  0 pairs (X) / D3 = 2  => 21 pairs (_)
B4,B6: 2.. / B4 = 2  =>  0 pairs (X) / B6 = 2  =>  0 pairs (_)
A8,A9: 2.. / A8 = 2  =>  0 pairs (X) / A9 = 2  =>  0 pairs (_)
E8,F9: 2.. / E8 = 2  =>  0 pairs (*) / F9 = 2  =>  0 pairs (X)
C2,E2: 2.. / C2 = 2  => 21 pairs (_) / E2 = 2  =>  0 pairs (X)
C3,D3: 2.. / C3 = 2  =>  0 pairs (X) / D3 = 2  => 21 pairs (_)
B6,E6: 2.. / B6 = 2  =>  0 pairs (*) / E6 = 2  =>  0 pairs (X)
A8,E8: 2.. / A8 = 2  =>  0 pairs (X) / E8 = 2  =>  0 pairs (_)
A9,F9: 2.. / A9 = 2  =>  0 pairs (*) / F9 = 2  =>  0 pairs (X)
D3,D4: 2.. / D3 = 2  => 21 pairs (_) / D4 = 2  =>  0 pairs (X)
F4,F9: 2.. / F4 = 2  =>  0 pairs (*) / F9 = 2  =>  0 pairs (X)
B7,C7: 3.. / B7 = 3  =>  0 pairs (*) / C7 = 3  =>  0 pairs (X)
H9,I9: 3.. / H9 = 3  =>  0 pairs (*) / I9 = 3  =>  0 pairs (X)
B3,B7: 3.. / B3 = 3  =>  0 pairs (X) / B7 = 3  =>  0 pairs (_)
H3,I3: 5.. / H3 = 5  =>  0 pairs (*) / I3 = 5  =>  0 pairs (X)
H9,I9: 5.. / H9 = 5  =>  0 pairs (X) / I9 = 5  =>  0 pairs (_)
H3,H9: 5.. / H3 = 5  =>  0 pairs (*) / H9 = 5  =>  0 pairs (X)
I3,I9: 5.. / I3 = 5  =>  0 pairs (X) / I9 = 5  =>  0 pairs (_)
I2,I3: 6.. / I2 = 6  =>  0 pairs (X) / I3 = 6  =>  0 pairs (_)
D4,F4: 6.. / D4 = 6  =>  0 pairs (*) / F4 = 6  =>  0 pairs (X)
B7,A8: 6.. / B7 = 6  =>  0 pairs (X) / A8 = 6  =>  0 pairs (_)
F7,E8: 6.. / F7 = 6  =>  0 pairs (*) / E8 = 6  =>  0 pairs (X)
B1,D1: 6.. / B1 = 6  =>  0 pairs (*) / D1 = 6  =>  0 pairs (X)
E2,I2: 6.. / E2 = 6  =>  0 pairs (*) / I2 = 6  =>  0 pairs (X)
B7,F7: 6.. / B7 = 6  =>  0 pairs (X) / F7 = 6  =>  0 pairs (_)
A8,E8: 6.. / A8 = 6  =>  0 pairs (*) / E8 = 6  =>  0 pairs (X)
A3,A8: 6.. / A3 = 6  =>  0 pairs (X) / A8 = 6  =>  0 pairs (_)
E2,E8: 6.. / E2 = 6  =>  0 pairs (*) / E8 = 6  =>  0 pairs (X)
F4,F7: 6.. / F4 = 6  =>  0 pairs (X) / F7 = 6  =>  0 pairs (_)
H2,H3: 9.. / H2 = 9  =>  0 pairs (*) / H3 = 9  =>  0 pairs (X)
D4,E6: 9.. / D4 = 9  =>  0 pairs (X) / E6 = 9  =>  0 pairs (_)
F7,F9: 9.. / F7 = 9  =>  0 pairs (X) / F9 = 9  =>  0 pairs (_)
B1,D1: 9.. / B1 = 9  =>  0 pairs (X) / D1 = 9  =>  0 pairs (_)
B4,D4: 9.. / B4 = 9  =>  0 pairs (*) / D4 = 9  =>  0 pairs (X)
A9,F9: 9.. / A9 = 9  =>  0 pairs (X) / F9 = 9  =>  0 pairs (_)
E2,E6: 9.. / E2 = 9  =>  0 pairs (X) / E6 = 9  =>  0 pairs (_)
* DURATION: 0:01:08.545689  START: 13:21:42.007728  END: 13:22:50.553417 2017-05-04
* CP COUNT: (41)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A6,A8,A9,B1,B4,C7,D1,E6,E8,F4,F7,F9,H2,H9,I2,I9)
* 5.7.3421884.1.57......784..3.4.8.571756413982..85.73644..85.127.753.1849.8174.6..
* PAIR B1: 6,9 BLK 1
A3: 6,9,1                                # reduction candidate for 6,9
A3: 6,9 => SOLVED
* 567934218842165793913278456394682571756413982128597364439856127675321849281749635
A3: 1 => CTR
* 5.7.3421884.1.57..1...784..3.4.8.5717564139829185273644..85.127.753.1849.8174.6..
B3: 6,9,1,3                              # reduction candidate for 6,9
B3: 6,9 => CTR
* 5.7.3421884.1.57..1...784..3.4.8.57175641398291852736443.85.127.753.1849.8174.6..
B3: 1,3                                  # 17 pairs
* PAIR B1: 6,9 COL B
B7: 6,9,3                                # reduction candidate for 6,9
B7: 6,9 => CTR
* 5.7.3421884.1.57...3..784..3.4.8.571756413982.185273644.385.12727536184998174.6..
B7: 3 => SOLVED
* 567934218842165793913278456394682571756413982128597364439856127675321849281749635
* PAIR D1: 6,9 BLK 2
E2: 6,9,2                                # reduction candidate for 6,9
E2: 6,9                                  # 21 pairs
D3: 6,9,2                                # reduction candidate for 6,9
D3: 6,9 => CTR
* 5.7.3421884.1257.6..2.784..3.4286571756413982.285973644638591272753618499817426..
D3: 2                                    # 21 pairs
* PAIR D1: 6,9 COL D
D4: 6,9,2                                # reduction candidate for 6,9
D4: 2 => CTR
* 5.7.3421884.1.57......784..39428657175641398212859736446.85.127.753.1849.8174.6..
D4: 6,9                                  # 21 pairs
* PAIR H2: 3,9 BLK 3
H3: 3,9,5                                # reduction candidate for 3,9
H3: 3,9 => CTR
* 5.7.3421884.1.57.661..784.53.4.865717564139821.85.73644..85.127.75361849.81742653
H3: 5 => SOLVED
* 567934218842165793913278456394682571756413982128597364439856127675321849281749635
* PAIR H2: 3,9 ROW 2
C2: 3,9,2                                # reduction candidate for 3,9
C2: 3,9 => CTR
* 5.7.3421884.1257.6..2.784..3.4286571756413982.285973644638591272753618499817426..
C2: 2                                    # 21 pairs
* PAIR I2: 3,6 BLK 3
I3: 3,6,5                                # reduction candidate for 3,6
I3: 3,6 => SOLVED
* 567934218842165793913278456394682571756413982128597364439856127675321849281749635
I3: 5 => CTR
* 5.7.3421884.1.57.661..784.53.4.865717564139821.85.73644..85.127.75361849.81742653
* PAIR B4: 2,9 BLK 4
B6: 2,9,1                                # reduction candidate for 2,9
B6: 2,9 => SOLVED
* 567934218842165793913278456394682571756413982128597364439856127675321849281749635
B6: 1 => CTR
* 5.7.3421884.1.57......784..32498657175641398291852736446.85.127.753.1849.8174.6..
* PAIR B4: 2,9 ROW 4
D4: 2,9,6                                # reduction candidate for 2,9
D4: 2,9 => CTR
* 5976342188421.57......784..3.4.86571756413982..85.73644638591272753618499817426..
D4: 6 => SOLVED
* 567934218842165793913278456394682571756413982128597364439856127675321849281749635
* PAIR A6: 1,9 BLK 4
B6: 1,9,2                                # reduction candidate for 1,9
B6: 1,9 => CTR
* 5976342188421.57......784..324986571756413982..85273644638591272753618499817426..
B6: 2 => SOLVED
* 567934218842165793913278456394682571756413982128597364439856127675321849281749635
* PAIR A6: 1,9 COL A
A3: 1,9,6                                # reduction candidate for 1,9
A3: 1,9 => SOLVED
* 567934218842165793913278456394682571756413982128597364439856127675321849281749635
A3: 6 => CTR
* 5.7.3421884.1.57..61..784..3.4.8.5717564139821.85.73644..85.127.753.1849.8174.6..
* PAIR F4: 2,6 BLK 5
D4: 2,6,9                                # reduction candidate for 2,6
D4: 2,6 => SOLVED
* 567934218842165793913278456394682571756413982128597364439856127675321849281749635
D4: 9 => CTR
* 5.7.3421884.1.57.....2784..3.4986571756413982..85273644638591272753618499817426..
* PAIR E6: 2,9 BLK 5
D4: 2,9,6                                # reduction candidate for 2,9
D4: 2,9 => CTR
* 5976342188421.57......784..3.4.86571756413982..85.73644638591272753618499817426..
D4: 6 => SOLVED
* 567934218842165793913278456394682571756413982128597364439856127675321849281749635
* PAIR E6: 2,9 ROW 6
B6: 2,9,1                                # reduction candidate for 2,9
B6: 2,9 => SOLVED
* 567934218842165793913278456394682571756413982128597364439856127675321849281749635
B6: 1 => CTR
* 5.7.3421884.1.57......784..32498657175641398291852736446.85.127.753.1849.8174.6..
* PAIR E6: 2,9 COL E
E2: 2,9,6                                # reduction candidate for 2,9
E2: 2,9 => CTR
* 5.7.3421884.1.57.661..784..3.4.865717564139821.85.73644..85.127.75361849.817426..
E2: 6 => SOLVED
* 567934218842165793913278456394682571756413982128597364439856127675321849281749635
* PAIR C7: 3,9 BLK 7
B7: 3,9,6                                # reduction candidate for 3,9
B7: 3,9 => SOLVED
* 567934218842165793913278456394682571756413982128597364439856127675321849281749635
B7: 6 => CTR
* 5.7.3421884.1.57...3..784..3.4.8.571756413982.185273644638591272753.1849.8174.6..
* PAIR C7: 3,9 COL C
C2: 3,9,2                                # reduction candidate for 3,9
C2: 3,9 => CTR
* 5.7.3421884.1257.6..2.784..3.4286571756413982.285973644638591272753618499817426..
C2: 2                                    # 21 pairs
C3: 3,9,2                                # reduction candidate for 3,9
C3: 3,9                                  # 21 pairs
* PAIR F7: 6,9 ROW 7
B7: 6,9,3                                # reduction candidate for 6,9
B7: 6,9 => CTR
* 5.7.3421884.1.57...3..784..3.4.8.571756413982.185273644.385.12727536184998174.6..
B7: 3 => SOLVED
* 567934218842165793913278456394682571756413982128597364439856127675321849281749635
* PAIR E8: 2,6 COL E
E2: 2,6,9                                # reduction candidate for 2,6
E2: 2,6 => SOLVED
* 567934218842165793913278456394682571756413982128597364439856127675321849281749635
E2: 9 => CTR
* 5.7.34218842195736...2784953.4986571756413982..852736446.85.127.753.1849.8174.6..
* PAIR H9: 3,5 COL H
H3: 3,5,9                                # reduction candidate for 3,5
H3: 3,5 => SOLVED
* 567934218842165793913278456394682571756413982128597364439856127675321849281749635
H3: 9 => CTR
* 5.7.3421884.1.5736613278495324.8.571756413982..85.73644..85.127.75361849.81742653
* PAIR I9: 3,5 COL I
I3: 3,5,6                                # reduction candidate for 3,5
I3: 3,5 => CTR
* 5.7.3421884.1.57.661..784..3.4.865717564139821.85.73644..85.127.75361849.817426..
I3: 6 => SOLVED
* 567934218842165793913278456394682571756413982128597364439856127675321849281749635
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-304-base-pr-000.dot
* REASONING
* PRF # A3: 6,9 => SOL
* DIS # A3: 1 => CTR => A3: 6,9
* DIS # B3: 6,9 => CTR => B3: 1,3
* DIS # B7: 6,9 => CTR => B7: 3
* PRF # B7: 3 => SOL
* DIS # D3: 6,9 => CTR => D3: 2
* DIS # D4: 2 => CTR => D4: 6,9
* DIS # H3: 3,9 => CTR => H3: 5
* PRF # H3: 5 => SOL
* DIS # C2: 3,9 => CTR => C2: 2
* PRF # I3: 3,6 => SOL
* DIS # I3: 5 => CTR => I3: 3,6
* PRF # B6: 2,9 => SOL
* DIS # B6: 1 => CTR => B6: 2,9
* DIS # D4: 2,9 => CTR => D4: 6
* PRF # D4: 6 => SOL
* DIS # B6: 1,9 => CTR => B6: 2
* PRF # B6: 2 => SOL
* PRF # A3: 1,9 => SOL
* DIS # A3: 6 => CTR => A3: 1,9
* PRF # D4: 2,6 => SOL
* DIS # D4: 9 => CTR => D4: 2,6
* DIS # D4: 2,9 => CTR => D4: 6
* PRF # D4: 6 => SOL
* PRF # B6: 2,9 => SOL
* DIS # B6: 1 => CTR => B6: 2,9
* DIS # E2: 2,9 => CTR => E2: 6
* PRF # E2: 6 => SOL
* PRF # B7: 3,9 => SOL
* DIS # B7: 6 => CTR => B7: 3,9
* DIS # C2: 3,9 => CTR => C2: 2
* DIS # B7: 6,9 => CTR => B7: 3
* PRF # B7: 3 => SOL
* PRF # E2: 2,6 => SOL
* DIS # E2: 9 => CTR => E2: 2,6
* PRF # H3: 3,5 => SOL
* DIS # H3: 9 => CTR => H3: 3,5
* DIS # I3: 3,5 => CTR => I3: 6
* PRF # I3: 6 => SOL
* CNT  39 HDP CHAINS /  46 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A6,A8,A9,B1,B4,C7,D1,E6,E8,F4,F7,F9,H2,H9,I2,I9)
* 5.7.3421884.1.57......784..3.4.8.571756413982..85.73644..85.127.753.1849.8174.6..
* PAIR B1: 6,9 BLK 1
A3: 6,9,1                                # reduction candidate for 6,9
A3: 6,9 => SOLVED
* 567934218842165793913278456394682571756413982128597364439856127675321849281749635
* DURATION: 0:00:02.006549  START: 13:23:39.634693  END: 13:23:41.641242 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-304-base-pr-001.dot
* REASONING
* PRF # A3: 6,9 => SOL
* STA A3: 6,9
* CNT   1 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 304

solution: 567934218842165793913278456394682571756413982128597364439856127675321849281749635
info: 2591     FNBWY    S8.f     43060

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

Solution

position: 567934218842165793913278456394682571756413982128597364439856127675321849281749635 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 # A3: 6,9 => SOL
* DIS # A3: 1 => CTR => A3: 6,9
* DIS # B3: 6,9 => CTR => B3: 1,3
* INC # B3: 1,3 => UNS
* DIS # B7: 6,9 => CTR => B7: 3
* PRF # B7: 3 => SOL
* INC # E2: 6,9 => UNS
* DIS # D3: 6,9 => CTR => D3: 2
* INC # D3: 2 => UNS
* INC # D4: 6,9 => UNS
* DIS # D4: 2 => CTR => D4: 6,9
* DIS # H3: 3,9 => CTR => H3: 5
* PRF # H3: 5 => SOL
* DIS # C2: 3,9 => CTR => C2: 2
* INC # C2: 2 => UNS
* PRF # I3: 3,6 => SOL
* DIS # I3: 5 => CTR => I3: 3,6
* PRF # B6: 2,9 => SOL
* DIS # B6: 1 => CTR => B6: 2,9
* DIS # D4: 2,9 => CTR => D4: 6
* PRF # D4: 6 => SOL
* DIS # B6: 1,9 => CTR => B6: 2
* PRF # B6: 2 => SOL
* PRF # A3: 1,9 => SOL
* DIS # A3: 6 => CTR => A3: 1,9
* PRF # D4: 2,6 => SOL
* DIS # D4: 9 => CTR => D4: 2,6
* DIS # D4: 2,9 => CTR => D4: 6
* PRF # D4: 6 => SOL
* PRF # B6: 2,9 => SOL
* DIS # B6: 1 => CTR => B6: 2,9
* DIS # E2: 2,9 => CTR => E2: 6
* PRF # E2: 6 => SOL
* PRF # B7: 3,9 => SOL
* DIS # B7: 6 => CTR => B7: 3,9
* DIS # C2: 3,9 => CTR => C2: 2
* INC # C2: 2 => UNS
* INC # C3: 3,9 => UNS
* DIS # B7: 6,9 => CTR => B7: 3
* PRF # B7: 3 => SOL
* PRF # E2: 2,6 => SOL
* DIS # E2: 9 => CTR => E2: 2,6
* PRF # H3: 3,5 => SOL
* DIS # H3: 9 => CTR => H3: 3,5
* DIS # I3: 3,5 => CTR => I3: 6
* PRF # I3: 6 => SOL
* CNT  46 HDP CHAINS /  46 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* PRF # A3: 6,9 => SOL
* STA A3: 6,9
* CNT   1 HDP CHAINS /   1 HYP OPENED