Analysis of xx-top500-247-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 7......1....5.8....3.......6..27.....4....3.....1.....1.2.....9....348........... initial

Autosolve

position: 7.43.2.1821.5.874383.4172..6.82731.4.41...37232714..8.1.2...439....348214.3.21..7 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # B1: 6,9 => CTR => B1: 5
* PRF # B1: 5 => SOL
* PRF # C3: 6,9 => SOL
* DIS # C3: 5 => CTR => C3: 6,9
* DIS # C8: 6,9 => CTR => C8: 5
* PRF # C8: 5 => SOL
* DIS # B1: 6,9 => CTR => B1: 5
* PRF # B1: 5 => SOL
* PRF # G1: 6,9 => SOL
* DIS # G1: 5 => CTR => G1: 6,9
* PRF # G1: 5,6 => SOL
* DIS # G1: 9 => CTR => G1: 5,6
* DIS # H3: 5,6 => CTR => H3: 9
* PRF # H3: 9 => SOL
* PRF # C3: 5,6 => SOL
* DIS # C3: 9 => CTR => C3: 5,6
* DIS # B8: 5,9 => CTR => B8: 6,7
* DIS # F5: 6 => CTR => F5: 5,9
* DIS # F5: 6 => CTR => F5: 5,9
* PRF # G6: 5,9 => SOL
* DIS # G6: 6 => CTR => G6: 5,9
* PRF # G6: 5,9 => SOL
* DIS # G6: 6 => CTR => G6: 5,9
* PRF # H3: 5,9 => SOL
* DIS # H3: 6 => CTR => H3: 5,9
* DIS # G6: 5,6 => CTR => G6: 9
* PRF # G6: 9 => SOL
* DIS # B8: 5,9 => CTR => B8: 6,7
* DIS # F5: 5,6 => CTR => F5: 9
* PRF # F5: 9 => SOL
* PRF # G1: 5,6 => SOL
* DIS # G1: 9 => CTR => G1: 5,6
* DIS # G6: 5,6 => CTR => G6: 9
* PRF # G6: 9 => SOL
* DIS # H3: 5,6 => CTR => H3: 9
* PRF # H3: 9 => SOL
* CNT  36 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 # B1: 6,9 => CTR => B1: 5
* PRF B1: 5 => SOL
* STA B1: 5
* CNT   2 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

7......1....5.8....3.......6..27.....4....3.....1.....1.2.....9....348........... initial
7.43.2.1821.5.874383.4172..6.82731.4.41...37232714..8.1.2...439....348214.3.21..7 autosolve
754392618219568743836417295698273154541689372327145986172856439965734821483921567 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (18)
C2: 6,9
E1: 6,9
E2: 6,9
I3: 5,6
B4: 5,9
A5: 5,9
D5: 6,8
E5: 5,8
F6: 5,9
H4: 5,9
I6: 5,6
A8: 5,9
B9: 8,9
E7: 5,8
F7: 5,6
D9: 8,9
G9: 5,6
H9: 5,6

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
B1,C3: 5.. / B1 = 5  =>  0 pairs (*) / C3 = 5  =>  0 pairs (X)
B4,A5: 5.. / B4 = 5  =>  0 pairs (X) / A5 = 5  =>  0 pairs (_)
E7,F7: 5.. / E7 = 5  => 18 pairs (_) / F7 = 5  =>  0 pairs (X)
G9,H9: 5.. / G9 = 5  =>  0 pairs (*) / H9 = 5  =>  0 pairs (X)
B1,G1: 5.. / B1 = 5  =>  0 pairs (*) / G1 = 5  =>  0 pairs (X)
B4,H4: 5.. / B4 = 5  =>  0 pairs (X) / H4 = 5  =>  0 pairs (_)
A5,A8: 5.. / A5 = 5  =>  0 pairs (*) / A8 = 5  =>  0 pairs (X)
C3,C8: 5.. / C3 = 5  =>  0 pairs (X) / C8 = 5  =>  0 pairs (_)
E5,E7: 5.. / E5 = 5  =>  0 pairs (X) / E7 = 5  => 18 pairs (_)
I3,I6: 5.. / I3 = 5  =>  0 pairs (*) / I6 = 5  =>  0 pairs (X)
E1,E2: 6.. / E1 = 6  => 20 pairs (_) / E2 = 6  =>  0 pairs (*)
D5,F5: 6.. / D5 = 6  => 18 pairs (_) / F5 = 6  =>  0 pairs (X)
G6,I6: 6.. / G6 = 6  =>  0 pairs (X) / I6 = 6  =>  0 pairs (_)
G9,H9: 6.. / G9 = 6  =>  0 pairs (X) / H9 = 6  =>  0 pairs (_)
C2,E2: 6.. / C2 = 6  => 20 pairs (_) / E2 = 6  =>  0 pairs (*)
F5,F7: 6.. / F5 = 6  =>  0 pairs (X) / F7 = 6  => 18 pairs (_)
H3,H9: 6.. / H3 = 6  =>  0 pairs (X) / H9 = 6  =>  0 pairs (_)
I3,I6: 6.. / I3 = 6  =>  0 pairs (X) / I6 = 6  =>  0 pairs (_)
B7,B8: 7.. / B7 = 7  => 17 pairs (_) / B8 = 7  => 20 pairs (_)
D7,D8: 7.. / D7 = 7  => 20 pairs (_) / D8 = 7  => 17 pairs (_)
B7,D7: 7.. / B7 = 7  => 17 pairs (_) / D7 = 7  => 20 pairs (_)
B8,D8: 7.. / B8 = 7  => 20 pairs (_) / D8 = 7  => 17 pairs (_)
D5,E5: 8.. / D5 = 8  =>  0 pairs (X) / E5 = 8  => 18 pairs (_)
B7,B9: 8.. / B7 = 8  =>  0 pairs (X) / B9 = 8  => 18 pairs (_)
B9,D9: 8.. / B9 = 8  => 18 pairs (_) / D9 = 8  =>  0 pairs (X)
E5,E7: 8.. / E5 = 8  => 18 pairs (_) / E7 = 8  =>  0 pairs (X)
E1,E2: 9.. / E1 = 9  =>  0 pairs (*) / E2 = 9  =>  0 pairs (X)
G1,H3: 9.. / G1 = 9  =>  0 pairs (X) / H3 = 9  =>  0 pairs (_)
B4,A5: 9.. / B4 = 9  =>  0 pairs (*) / A5 = 9  =>  0 pairs (X)
F5,F6: 9.. / F5 = 9  =>  0 pairs (*) / F6 = 9  =>  0 pairs (X)
H4,G6: 9.. / H4 = 9  =>  0 pairs (X) / G6 = 9  =>  0 pairs (_)
D8,D9: 9.. / D8 = 9  =>  0 pairs (X) / D9 = 9  => 18 pairs (_)
C2,E2: 9.. / C2 = 9  =>  0 pairs (*) / E2 = 9  =>  0 pairs (X)
C3,H3: 9.. / C3 = 9  =>  0 pairs (X) / H3 = 9  =>  0 pairs (_)
B4,H4: 9.. / B4 = 9  =>  0 pairs (*) / H4 = 9  =>  0 pairs (X)
A5,F5: 9.. / A5 = 9  =>  0 pairs (X) / F5 = 9  =>  0 pairs (_)
F6,G6: 9.. / F6 = 9  =>  0 pairs (X) / G6 = 9  =>  0 pairs (_)
B9,D9: 9.. / B9 = 9  =>  0 pairs (X) / D9 = 9  => 18 pairs (_)
A5,A8: 9.. / A5 = 9  =>  0 pairs (X) / A8 = 9  =>  0 pairs (_)
G1,G6: 9.. / G1 = 9  =>  0 pairs (X) / G6 = 9  =>  0 pairs (_)
H3,H4: 9.. / H3 = 9  =>  0 pairs (*) / H4 = 9  =>  0 pairs (X)
* DURATION: 0:01:15.473047  START: 11:13:34.153201  END: 11:14:49.626248 2017-05-04
* CP COUNT: (41)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A5,A8,B4,B9,C2,D5,D9,E1,E2,E5,E7,F6,F7,G9,H4,H9,I3,I6)
* 7.43.2.1821.5.874383.4172..6.82731.4.41...37232714..8.1.2...439....348214.3.21..7
* PAIR C2: 6,9 BLK 1
B1: 6,9,5                                # reduction candidate for 6,9
B1: 6,9 => CTR
* 7.43.251821.5.8743835417296698273154.41...37232714..8.1.2...439....348214.3.21..7
B1: 5 => SOLVED
* 754392618219568743836417295698273154541689372327145986172856439965734821483921567
C3: 6,9,5                                # reduction candidate for 6,9
C3: 6,9 => SOLVED
* 754392618219568743836417295698273154541689372327145986172856439965734821483921567
C3: 5 => CTR
* 7.43.2.1821.5.8743835417296698273154.41...37232714..8.1.2...439....348214.3.21..7
* PAIR C2: 6,9 COL C
C8: 6,9,5                                # reduction candidate for 6,9
C8: 6,9 => CTR
* 7.43.2.1821.5.8743835417296698273154.41...37232714..8.1.2...439....348214.3.21..7
C8: 5 => SOLVED
* 754392618219568743836417295698273154541689372327145986172856439965734821483921567
* PAIR E1: 6,9 ROW 1
B1: 6,9,5                                # reduction candidate for 6,9
B1: 6,9 => CTR
* 7.43.251821.5.8743835417296698273154.41...37232714..8.1.2...439....348214.3.21..7
B1: 5 => SOLVED
* 754392618219568743836417295698273154541689372327145986172856439965734821483921567
G1: 6,9,5                                # reduction candidate for 6,9
G1: 6,9 => SOLVED
* 754392618219568743836417295698273154541689372327145986172856439965734821483921567
G1: 5 => CTR
* 7.43.251821.5.8743835417296698273154.41...37232714..8.1.2...439....348214.3.21..7
* PAIR I3: 5,6 BLK 3
G1: 5,6,9                                # reduction candidate for 5,6
G1: 5,6 => SOLVED
* 754392618219568743836417295698273154541689372327145986172856439965734821483921567
G1: 9 => CTR
* 7543629182165987438394172..6982731.4.41...37232714..8.1.2...439....348214.3.21..7
H3: 5,6,9                                # reduction candidate for 5,6
H3: 5,6 => CTR
* 7.43.291821.5987438394172..6.8273194941...372327149.8.1.2...4395.6.348214.3.21..7
H3: 9 => SOLVED
* 754392618219568743836417295698273154541689372327145986172856439965734821483921567
* PAIR I3: 5,6 ROW 3
C3: 5,6,9                                # reduction candidate for 5,6
C3: 5,6 => SOLVED
* 754392618219568743836417295698273154541689372327145986172856439965734821483921567
C3: 9 => CTR
* 7543.2.182165987438394172..6982731.4.41...37232714..8.1.2...439....348214.3.21..7
* PAIR B4: 5,9 COL B
B1: 5,9,6                                # reduction candidate for 5,9
B1: 5,9                                  # 21 pairs
B8: 5,9,6,7                              # reduction candidate for 5,9
B8: 5,9 => CTR
* 764392518219568743835417296698273154.41...37232714..8.172...439..6734821483921..7
B8: 6,7                                  # 19 pairs
* PAIR A5: 5,9 ROW 5
F5: 5,9,6                                # reduction candidate for 5,9
F5: 6 => CTR
* 7.43.291821.59874383.4172..6.82731.4941.56372327149.8.1.2.854395...34821483921..7
F5: 5,9                                  # 18 pairs
* PAIR D5: 6,8 COL D
D7: 6,8,7                                # reduction candidate for 6,8
D7: 7                                    # 20 pairs
D7: 6,8                                  # 17 pairs
* PAIR F6: 5,9 BLK 5
F5: 5,9,6                                # reduction candidate for 5,9
F5: 6 => CTR
* 7.43.291821.59874383.4172..6.82731.4941.56372327149.8.1.2.854395...34821483921..7
F5: 5,9                                  # 18 pairs
* PAIR F6: 5,9 ROW 6
G6: 5,9,6                                # reduction candidate for 5,9
G6: 5,9 => SOLVED
* 754392618219568743836417295698273154541689372327145986172856439965734821483921567
G6: 6 => CTR
* 7.43.291821.5987438394172..6.8273194941...3723271496851.2...4395.6.348214.3.21..7
* PAIR H4: 5,9 BLK 6
G6: 5,9,6                                # reduction candidate for 5,9
G6: 5,9 => SOLVED
* 754392618219568743836417295698273154541689372327145986172856439965734821483921567
G6: 6 => CTR
* 7.43.291821.5987438394172..6.8273194941...3723271496851.2...4395.6.348214.3.21..7
* PAIR H4: 5,9 COL H
H3: 5,9,6                                # reduction candidate for 5,9
H3: 5,9 => SOLVED
* 754392618219568743836417295698273154541689372327145986172856439965734821483921567
H3: 6 => CTR
* 7.43.291821.5987438394172656.8273194941...3723271495861.2...4395.6.348214.3.21..7
* PAIR I6: 5,6 BLK 6
G6: 5,6,9                                # reduction candidate for 5,6
G6: 5,6 => CTR
* 7.43.291821.5987438394172..6.8273194941...372327149.8.1.2...4395.6.348214.3.21..7
G6: 9 => SOLVED
* 754392618219568743836417295698273154541689372327145986172856439965734821483921567
* PAIR A8: 5,9 BLK 7
B8: 5,9,6,7                              # reduction candidate for 5,9
B8: 5,9 => CTR
* 764392518219568743835417296698273154.41...37232714..8.172...439..6734821483921..7
B8: 6,7                                  # 19 pairs
C8: 5,9,6                                # reduction candidate for 5,9
C8: 5,9                                  # 21 pairs
* PAIR F7: 5,6 COL F
F5: 5,6,9                                # reduction candidate for 5,6
F5: 5,6 => CTR
* 7.43.291821.59874383.4172..6.82731.4941...372327149.8.1.2...4395...348214.3.21..7
F5: 9 => SOLVED
* 754392618219568743836417295698273154541689372327145986172856439965734821483921567
* PAIR G9: 5,6 COL G
G1: 5,6,9                                # reduction candidate for 5,6
G1: 5,6 => SOLVED
* 754392618219568743836417295698273154541689372327145986172856439965734821483921567
G1: 9 => CTR
* 7543629182165987438394172..6982731.4.41...37232714..8.1.2...439....348214.3.21..7
G6: 5,6,9                                # reduction candidate for 5,6
G6: 5,6 => CTR
* 7.43.291821.5987438394172..6.8273194941...372327149.8.1.2...4395.6.348214.3.21..7
G6: 9 => SOLVED
* 754392618219568743836417295698273154541689372327145986172856439965734821483921567
* PAIR H9: 5,6 COL H
H3: 5,6,9                                # reduction candidate for 5,6
H3: 5,6 => CTR
* 7.43.291821.5987438394172..6.8273194941...372327149.8.1.2...4395.6.348214.3.21..7
H3: 9 => SOLVED
* 754392618219568743836417295698273154541689372327145986172856439965734821483921567
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-247-base-pr-000.dot
* REASONING
* DIS # B1: 6,9 => CTR => B1: 5
* PRF # B1: 5 => SOL
* PRF # C3: 6,9 => SOL
* DIS # C3: 5 => CTR => C3: 6,9
* DIS # C8: 6,9 => CTR => C8: 5
* PRF # C8: 5 => SOL
* DIS # B1: 6,9 => CTR => B1: 5
* PRF # B1: 5 => SOL
* PRF # G1: 6,9 => SOL
* DIS # G1: 5 => CTR => G1: 6,9
* PRF # G1: 5,6 => SOL
* DIS # G1: 9 => CTR => G1: 5,6
* DIS # H3: 5,6 => CTR => H3: 9
* PRF # H3: 9 => SOL
* PRF # C3: 5,6 => SOL
* DIS # C3: 9 => CTR => C3: 5,6
* DIS # B8: 5,9 => CTR => B8: 6,7
* DIS # F5: 6 => CTR => F5: 5,9
* DIS # F5: 6 => CTR => F5: 5,9
* PRF # G6: 5,9 => SOL
* DIS # G6: 6 => CTR => G6: 5,9
* PRF # G6: 5,9 => SOL
* DIS # G6: 6 => CTR => G6: 5,9
* PRF # H3: 5,9 => SOL
* DIS # H3: 6 => CTR => H3: 5,9
* DIS # G6: 5,6 => CTR => G6: 9
* PRF # G6: 9 => SOL
* DIS # B8: 5,9 => CTR => B8: 6,7
* DIS # F5: 5,6 => CTR => F5: 9
* PRF # F5: 9 => SOL
* PRF # G1: 5,6 => SOL
* DIS # G1: 9 => CTR => G1: 5,6
* DIS # G6: 5,6 => CTR => G6: 9
* PRF # G6: 9 => SOL
* DIS # H3: 5,6 => CTR => H3: 9
* PRF # H3: 9 => SOL
* CNT  36 HDP CHAINS /  44 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A5,A8,B4,B9,C2,D5,D9,E1,E2,E5,E7,F6,F7,G9,H4,H9,I3,I6)
* 7.43.2.1821.5.874383.4172..6.82731.4.41...37232714..8.1.2...439....348214.3.21..7
* PAIR C2: 6,9 BLK 1
B1: 6,9,5                                # reduction candidate for 6,9
B1: 6,9 => CTR
* 7.43.251821.5.8743835417296698273154.41...37232714..8.1.2...439....348214.3.21..7
B1: 5 => SOLVED
* 754392618219568743836417295698273154541689372327145986172856439965734821483921567
* DURATION: 0:00:01.654732  START: 11:15:40.346689  END: 11:15:42.001421 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-247-base-pr-001.dot
* REASONING
* DIS # B1: 6,9 => CTR => B1: 5
* PRF B1: 5 => SOL
* STA B1: 5
* CNT   2 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 247

solution: 754392618219568743836417295698273154541689372327145986172856439965734821483921567
info: 2072     FNBWXY   S8.f     36232

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

Solution

position: 754392618219568743836417295698273154541689372327145986172856439965734821483921567 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 # B1: 6,9 => CTR => B1: 5
* PRF # B1: 5 => SOL
* PRF # C3: 6,9 => SOL
* DIS # C3: 5 => CTR => C3: 6,9
* DIS # C8: 6,9 => CTR => C8: 5
* PRF # C8: 5 => SOL
* DIS # B1: 6,9 => CTR => B1: 5
* PRF # B1: 5 => SOL
* PRF # G1: 6,9 => SOL
* DIS # G1: 5 => CTR => G1: 6,9
* PRF # G1: 5,6 => SOL
* DIS # G1: 9 => CTR => G1: 5,6
* DIS # H3: 5,6 => CTR => H3: 9
* PRF # H3: 9 => SOL
* PRF # C3: 5,6 => SOL
* DIS # C3: 9 => CTR => C3: 5,6
* INC # B1: 5,9 => UNS
* DIS # B8: 5,9 => CTR => B8: 6,7
* INC # B8: 6,7 => UNS
* INC # F5: 5,9 => UNS
* DIS # F5: 6 => CTR => F5: 5,9
* INC # D7: 6,8 => UNS
* INC # D7: 7 => UNS
* INC # F5: 5,9 => UNS
* DIS # F5: 6 => CTR => F5: 5,9
* PRF # G6: 5,9 => SOL
* DIS # G6: 6 => CTR => G6: 5,9
* PRF # G6: 5,9 => SOL
* DIS # G6: 6 => CTR => G6: 5,9
* PRF # H3: 5,9 => SOL
* DIS # H3: 6 => CTR => H3: 5,9
* DIS # G6: 5,6 => CTR => G6: 9
* PRF # G6: 9 => SOL
* DIS # B8: 5,9 => CTR => B8: 6,7
* INC # B8: 6,7 => UNS
* INC # C8: 5,9 => UNS
* DIS # F5: 5,6 => CTR => F5: 9
* PRF # F5: 9 => SOL
* PRF # G1: 5,6 => SOL
* DIS # G1: 9 => CTR => G1: 5,6
* DIS # G6: 5,6 => CTR => G6: 9
* PRF # G6: 9 => SOL
* DIS # H3: 5,6 => CTR => H3: 9
* PRF # H3: 9 => SOL
* CNT  44 HDP CHAINS /  44 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # B1: 6,9 => CTR => B1: 5
* PRF B1: 5 => SOL
* STA B1: 5
* CNT   2 HDP CHAINS /   1 HYP OPENED