Analysis of xx-top500-283-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: .462........4..5....1......5..3.2...7......6.........13.....2...8..6...........4. initial

Autosolve

position: .46251..32374.651..51.3.62456.3124..71.54..6242.6...513.41.52.6182.64.356.5.2314. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # F3: 8,9 => SOL
* PRF # F3: 8,9 => SOL
* PRF # E6: 8,9 => SOL
* DIS # I4: 8,9 => CTR => I4: 7
* DIS # I4: 8,9 => CTR => I4: 7
* PRF # E6: 8,9 => SOL
* PRF # F3: 8,9 => SOL
* DIS # H7: 7,9 => CTR => H7: 8
* DIS # D9: 7,9 => CTR => D9: 8
* DIS # D9: 7,9 => CTR => D9: 8
* DIS # D3: 8 => CTR => D3: 7,9
* DIS # H7: 7,9 => CTR => H7: 8
* DIS # G1: 8 => CTR => G1: 7,9
* CNT  13 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:

* PRF # F3: 8,9 => SOL
* STA F3: 8,9
* CNT   1 HDP CHAINS /   4 HYP OPENED

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

Details

Positions

.462........4..5....1......5..3.2...7......6.........13.....2...8..6...........4. initial
.46251..32374.651..51.3.62456.3124..71.54..6242.6...513.41.52.6182.64.356.5.2314. autosolve
846251973237496518951738624568312497713549862429687351394175286182964735675823149 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (10)
A1: 8,9
A3: 8,9
E2: 8,9
I2: 8,9
C4: 8,9
F5: 8,9
B7: 7,9
B9: 7,9
D8: 7,9
G8: 7,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
C5,C6: 3.. / C5 = 3  => 12 pairs (_) / C6 = 3  => 12 pairs (_)
G5,G6: 3.. / G5 = 3  => 12 pairs (_) / G6 = 3  => 12 pairs (_)
C5,G5: 3.. / C5 = 3  => 12 pairs (_) / G5 = 3  => 12 pairs (_)
C6,G6: 3.. / C6 = 3  => 12 pairs (_) / G6 = 3  => 12 pairs (_)
D3,F3: 7.. / D3 = 7  =>  0 pairs (*) / F3 = 7  =>  0 pairs (X)
G1,H1: 7.. / G1 = 7  => 20 pairs (_) / H1 = 7  => 15 pairs (_)
E6,F6: 7.. / E6 = 7  => 13 pairs (_) / F6 = 7  =>  0 pairs (*)
H4,I4: 7.. / H4 = 7  =>  0 pairs (X) / I4 = 7  => 12 pairs (_)
B7,B9: 7.. / B7 = 7  => 14 pairs (_) / B9 = 7  => 14 pairs (_)
D8,G8: 7.. / D8 = 7  => 20 pairs (_) / G8 = 7  => 15 pairs (_)
E6,E7: 7.. / E6 = 7  => 13 pairs (_) / E7 = 7  =>  0 pairs (*)
F3,F6: 7.. / F3 = 7  => 13 pairs (_) / F6 = 7  =>  0 pairs (*)
G1,G8: 7.. / G1 = 7  => 20 pairs (_) / G8 = 7  => 15 pairs (_)
I4,I9: 7.. / I4 = 7  => 12 pairs (_) / I9 = 7  =>  0 pairs (X)
A1,A3: 8.. / A1 = 8  =>  0 pairs (*) / A3 = 8  =>  0 pairs (X)
E7,D9: 8.. / E7 = 8  =>  0 pairs (X) / D9 = 8  => 15 pairs (_)
H7,I9: 8.. / H7 = 8  => 15 pairs (_) / I9 = 8  =>  0 pairs (X)
E2,I2: 8.. / E2 = 8  =>  0 pairs (X) / I2 = 8  =>  0 pairs (_)
E7,H7: 8.. / E7 = 8  =>  0 pairs (X) / H7 = 8  => 15 pairs (_)
D9,I9: 8.. / D9 = 8  => 15 pairs (_) / I9 = 8  =>  0 pairs (X)
D3,D9: 8.. / D3 = 8  =>  0 pairs (X) / D9 = 8  => 15 pairs (_)
A1,A3: 9.. / A1 = 9  =>  0 pairs (X) / A3 = 9  =>  0 pairs (_)
B7,B9: 9.. / B7 = 9  => 14 pairs (_) / B9 = 9  => 14 pairs (_)
E2,I2: 9.. / E2 = 9  =>  0 pairs (*) / I2 = 9  =>  0 pairs (X)
D8,G8: 9.. / D8 = 9  => 15 pairs (_) / G8 = 9  => 20 pairs (_)
* DURATION: 0:00:43.321103  START: 12:35:45.026101  END: 12:36:28.347204 2017-05-04
* CP COUNT: (25)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,A3,B7,B9,C4,D8,E2,F5,G8,I2)
* .46251..32374.651..51.3.62456.3124..71.54..6242.6...513.41.52.6182.64.356.5.2314.
* PAIR A1: 8,9 ROW 1
G1: 8,9,7                                # reduction candidate for 8,9
G1: 8,9                                  # 15 pairs
H1: 8,9,7                                # reduction candidate for 8,9
H1: 8,9                                  # 20 pairs
* PAIR A3: 8,9 ROW 3
D3: 8,9,7                                # reduction candidate for 8,9
D3: 8,9                                  # 13 pairs
F3: 8,9,7                                # reduction candidate for 8,9
F3: 8,9 => SOLVED
* 846251973237496518951738624568312497713549862429687351394175286182964735675823149
F3: 7                                    # 13 pairs
* PAIR E2: 8,9 BLK 2
D3: 8,9,7                                # reduction candidate for 8,9
D3: 8,9                                  # 13 pairs
F3: 8,9,7                                # reduction candidate for 8,9
F3: 8,9 => SOLVED
* 846251973237496518951738624568312497713549862429687351394175286182964735675823149
F3: 7                                    # 13 pairs
* PAIR E2: 8,9 COL E
E6: 8,9,7                                # reduction candidate for 8,9
E6: 8,9 => SOLVED
* 846251973237496518951738624568312497713549862429687351394175286182964735675823149
E6: 7                                    # 13 pairs
E7: 8,9,7                                # reduction candidate for 8,9
E7: 8,9                                  # 13 pairs
* PAIR I2: 8,9 BLK 3
G1: 8,9,7                                # reduction candidate for 8,9
G1: 8,9                                  # 15 pairs
H1: 8,9,7                                # reduction candidate for 8,9
H1: 8,9                                  # 20 pairs
* PAIR I2: 8,9 COL I
I4: 8,9,7                                # reduction candidate for 8,9
I4: 8,9 => CTR
* 84625179323749651..51.3.62456.31247.71.54..6242.6...513741.5286182764935695823147
I4: 7                                    # 12 pairs
I9: 8,9,7                                # reduction candidate for 8,9
I9: 8,9                                  # 12 pairs
* PAIR C4: 8,9 BLK 4
C5: 8,9,3                                # reduction candidate for 8,9
C5: 8,9                                  # 12 pairs
C6: 8,9,3                                # reduction candidate for 8,9
C6: 8,9                                  # 12 pairs
* PAIR C4: 8,9 ROW 4
H4: 8,9,7                                # reduction candidate for 8,9
H4: 8,9                                  # 12 pairs
I4: 8,9,7                                # reduction candidate for 8,9
I4: 8,9 => CTR
* 84625179323749651..51.3.62456.31247.71.54..6242.6...513741.5286182764935695823147
I4: 7                                    # 12 pairs
* PAIR F5: 8,9 BLK 5
E6: 8,9,7                                # reduction candidate for 8,9
E6: 8,9 => SOLVED
* 846251973237496518951738624568312497713549862429687351394175286182964735675823149
E6: 7                                    # 13 pairs
F6: 8,9,7                                # reduction candidate for 8,9
F6: 8,9                                  # 13 pairs
* PAIR F5: 8,9 ROW 5
C5: 8,9,3                                # reduction candidate for 8,9
C5: 8,9                                  # 12 pairs
G5: 8,9,3                                # reduction candidate for 8,9
G5: 8,9                                  # 12 pairs
* PAIR F5: 8,9 COL F
F3: 8,9,7                                # reduction candidate for 8,9
F3: 8,9 => SOLVED
* 846251973237496518951738624568312497713549862429687351394175286182964735675823149
F3: 7                                    # 13 pairs
* PAIR B7: 7,9 ROW 7
E7: 7,9,8                                # reduction candidate for 7,9
E7: 7,9                                  # 15 pairs
H7: 7,9,8                                # reduction candidate for 7,9
H7: 7,9 => CTR
* .46251..32374.651..51.3.62456.3124..71.54..6242.6...513.41852.6182.64.356.5.23148
H7: 8                                    # 15 pairs
* PAIR B9: 7,9 ROW 9
D9: 7,9,8                                # reduction candidate for 7,9
D9: 7,9 => CTR
* .46251..32374.651..5183762456.3124..71.54..6242.67..513.41852.6182.64.356.5.23148
D9: 8                                    # 15 pairs
I9: 7,9,8                                # reduction candidate for 7,9
I9: 7,9                                  # 15 pairs
* PAIR D8: 7,9 BLK 8
E7: 7,9,8                                # reduction candidate for 7,9
E7: 7,9                                  # 15 pairs
D9: 7,9,8                                # reduction candidate for 7,9
D9: 7,9 => CTR
* .46251..32374.651..5183762456.3124..71.54..6242.67..513.41852.6182.64.356.5.23148
D9: 8                                    # 15 pairs
* PAIR D8: 7,9 COL D
D3: 7,9,8                                # reduction candidate for 7,9
D3: 8 => CTR
* .46251..32374.651..5183762456.3124..71.54..6242.67..513.41852.6182.64.356.5.23148
D3: 7,9                                  # 15 pairs
* PAIR G8: 7,9 BLK 9
H7: 7,9,8                                # reduction candidate for 7,9
H7: 7,9 => CTR
* .46251..32374.651..51.3.62456.3124..71.54..6242.6...513.41852.6182.64.356.5.23148
H7: 8                                    # 15 pairs
I9: 7,9,8                                # reduction candidate for 7,9
I9: 7,9                                  # 15 pairs
* PAIR G8: 7,9 COL G
G1: 7,9,8                                # reduction candidate for 7,9
G1: 8 => CTR
* .46251873237486519851.3.62456.3124.771.54..6242.6...513.41.5286182.64.356.5.2314.
G1: 7,9                                  # 16 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-283-base-pr-000.dot
* REASONING
* PRF # F3: 8,9 => SOL
* PRF # F3: 8,9 => SOL
* PRF # E6: 8,9 => SOL
* DIS # I4: 8,9 => CTR => I4: 7
* DIS # I4: 8,9 => CTR => I4: 7
* PRF # E6: 8,9 => SOL
* PRF # F3: 8,9 => SOL
* DIS # H7: 7,9 => CTR => H7: 8
* DIS # D9: 7,9 => CTR => D9: 8
* DIS # D9: 7,9 => CTR => D9: 8
* DIS # D3: 8 => CTR => D3: 7,9
* DIS # H7: 7,9 => CTR => H7: 8
* DIS # G1: 8 => CTR => G1: 7,9
* CNT  13 HDP CHAINS /  44 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,A3,B7,B9,C4,D8,E2,F5,G8,I2)
* .46251..32374.651..51.3.62456.3124..71.54..6242.6...513.41.52.6182.64.356.5.2314.
* PAIR A1: 8,9 ROW 1
G1: 8,9,7                                # reduction candidate for 8,9
G1: 8,9                                  # 15 pairs
H1: 8,9,7                                # reduction candidate for 8,9
H1: 8,9                                  # 20 pairs
* PAIR A3: 8,9 ROW 3
D3: 8,9,7                                # reduction candidate for 8,9
D3: 8,9                                  # 13 pairs
F3: 8,9,7                                # reduction candidate for 8,9
F3: 8,9 => SOLVED
* 846251973237496518951738624568312497713549862429687351394175286182964735675823149
* DURATION: 0:00:04.769462  START: 12:37:09.507713  END: 12:37:14.277175 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-283-base-pr-001.dot
* REASONING
* PRF # F3: 8,9 => SOL
* STA F3: 8,9
* CNT   1 HDP CHAINS /   4 HYP OPENED

Header Info

Top 500 Minimum 17 283

solution: 846251973237496518951738624568312497713549862429687351394175286182964735675823149
info: 2321     FNBWXY   S8.f     19504

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

Solution

position: 846251973237496518951738624568312497713549862429687351394175286182964735675823149 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:

* INC # G1: 8,9 => UNS
* INC # H1: 8,9 => UNS
* INC # D3: 8,9 => UNS
* PRF # F3: 8,9 => SOL
* INC # F3: 7 => UNS
* INC # D3: 8,9 => UNS
* PRF # F3: 8,9 => SOL
* INC # F3: 7 => UNS
* PRF # E6: 8,9 => SOL
* INC # E6: 7 => UNS
* INC # E7: 8,9 => UNS
* INC # G1: 8,9 => UNS
* INC # H1: 8,9 => UNS
* DIS # I4: 8,9 => CTR => I4: 7
* INC # I4: 7 => UNS
* INC # I9: 8,9 => UNS
* INC # C5: 8,9 => UNS
* INC # C6: 8,9 => UNS
* INC # H4: 8,9 => UNS
* DIS # I4: 8,9 => CTR => I4: 7
* INC # I4: 7 => UNS
* PRF # E6: 8,9 => SOL
* INC # E6: 7 => UNS
* INC # F6: 8,9 => UNS
* INC # C5: 8,9 => UNS
* INC # G5: 8,9 => UNS
* PRF # F3: 8,9 => SOL
* INC # F3: 7 => UNS
* INC # E7: 7,9 => UNS
* DIS # H7: 7,9 => CTR => H7: 8
* INC # H7: 8 => UNS
* DIS # D9: 7,9 => CTR => D9: 8
* INC # D9: 8 => UNS
* INC # I9: 7,9 => UNS
* INC # E7: 7,9 => UNS
* DIS # D9: 7,9 => CTR => D9: 8
* INC # D9: 8 => UNS
* INC # D3: 7,9 => UNS
* DIS # D3: 8 => CTR => D3: 7,9
* DIS # H7: 7,9 => CTR => H7: 8
* INC # H7: 8 => UNS
* INC # I9: 7,9 => UNS
* INC # G1: 7,9 => UNS
* DIS # G1: 8 => CTR => G1: 7,9
* CNT  44 HDP CHAINS /  44 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # G1: 8,9 => UNS
* INC # H1: 8,9 => UNS
* INC # D3: 8,9 => UNS
* PRF # F3: 8,9 => SOL
* STA F3: 8,9
* CNT   4 HDP CHAINS /   4 HYP OPENED