Analysis of xx-top500-459-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: .7....81..4.5.9............6.1.........3..4..2........5......6.....1...2...48.... initial

Autosolve

position: .7....81.1485.9....2.....4.6.1......8.73..4..2.4......589...164463915782712486... autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # I1: 5,6 => CTR => I1: 3,9
* DIS # I1: 5,6 => CTR => I1: 3,9
* DIS # E1: 2,6 => CTR => E1: 3,4
* PRF # D6: 1,8 => SOL
* DIS # D6: 6,7 => CTR => D6: 1,8
* DIS # F6: 1,8 => CTR => F6: 7
* PRF # F6: 7 => SOL
* DIS # E5: 5,9 => CTR => E5: 2,6
* PRF # I5: 5,9 => SOL
* DIS # F7: 2,7 => CTR => F7: 3
* PRF # D4: 2,7 => SOL
* DIS # D4: 8 => CTR => D4: 2,7
* DIS # F7: 7 => CTR => F7: 2,3
* DIS # E1: 2,3 => CTR => E1: 4,6
* CNT  14 HDP CHAINS /  29 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 # I1: 5,6 => CTR => I1: 3,9
* PRF I1: 3,9 # D6: 1,8 => SOL
* STA I1: 3,9 + D6: 1,8
* CNT   2 HDP CHAINS /   5 HYP OPENED

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

Details

Positions

.7....81..4.5.9............6.1.........3..4..2........5......6.....1...2...48.... initial
.7....81.1485.9....2.....4.6.1......8.73..4..2.4......589...164463915782712486... autosolve
375642819148579236926138547651294378897361425234857691589723164463915782712486953 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (11)
A1: 3,9
C1: 5,6
A3: 3,9
C3: 5,6
D1: 2,6
D3: 1,8
F3: 1,8
B5: 5,9
F5: 1,2
D7: 2,7
E7: 2,3

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
D3,F3: 1.. / D3 = 1  => 10 pairs (_) / F3 = 1  =>  0 pairs (X)
I5,I6: 1.. / I5 = 1  =>  0 pairs (X) / I6 = 1  =>  0 pairs (_)
F5,I5: 1.. / F5 = 1  =>  0 pairs (*) / I5 = 1  =>  0 pairs (X)
D3,D6: 1.. / D3 = 1  => 10 pairs (_) / D6 = 1  =>  0 pairs (X)
G2,H2: 2.. / G2 = 2  => 12 pairs (_) / H2 = 2  => 19 pairs (_)
G2,G4: 2.. / G2 = 2  => 12 pairs (_) / G4 = 2  => 19 pairs (_)
A1,A3: 3.. / A1 = 3  => 12 pairs (_) / A3 = 3  => 10 pairs (_)
B4,B6: 3.. / B4 = 3  => 12 pairs (_) / B6 = 3  => 12 pairs (_)
E7,F7: 3.. / E7 = 3  =>  0 pairs (X) / F7 = 3  => 11 pairs (_)
F1,F7: 3.. / F1 = 3  =>  0 pairs (X) / F7 = 3  => 11 pairs (_)
E1,F1: 4.. / E1 = 4  => 12 pairs (_) / F1 = 4  =>  0 pairs (X)
E4,F4: 4.. / E4 = 4  =>  0 pairs (X) / F4 = 4  => 12 pairs (_)
E1,E4: 4.. / E1 = 4  => 12 pairs (_) / E4 = 4  =>  0 pairs (X)
F1,F4: 4.. / F1 = 4  =>  0 pairs (X) / F4 = 4  => 12 pairs (_)
C1,C3: 5.. / C1 = 5  => 10 pairs (_) / C3 = 5  =>  0 pairs (X)
C1,I1: 5.. / C1 = 5  => 10 pairs (_) / I1 = 5  =>  0 pairs (X)
C1,C3: 6.. / C1 = 6  =>  0 pairs (X) / C3 = 6  => 10 pairs (_)
E5,I5: 6.. / E5 = 6  =>  0 pairs (*) / I5 = 6  =>  0 pairs (X)
D1,D6: 6.. / D1 = 6  =>  0 pairs (*) / D6 = 6  =>  0 pairs (X)
E2,E3: 7.. / E2 = 7  => 16 pairs (_) / E3 = 7  => 12 pairs (_)
D7,F7: 7.. / D7 = 7  => 12 pairs (_) / F7 = 7  =>  0 pairs (X)
E3,I3: 7.. / E3 = 7  => 12 pairs (_) / I3 = 7  => 16 pairs (_)
D3,F3: 8.. / D3 = 8  =>  0 pairs (X) / F3 = 8  => 10 pairs (_)
I4,I6: 8.. / I4 = 8  =>  0 pairs (*) / I6 = 8  =>  0 pairs (X)
A1,A3: 9.. / A1 = 9  => 10 pairs (_) / A3 = 9  => 12 pairs (_)
A1,I1: 9.. / A1 = 9  => 10 pairs (_) / I1 = 9  => 12 pairs (_)
* DURATION: 0:00:38.319084  START: 18:25:48.837237  END: 18:26:27.156321 2017-05-04
* CP COUNT: (26)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,A3,B5,C1,C3,D1,D3,D7,E7,F3,F5)
* .7....81.1485.9....2.....4.6.1......8.73..4..2.4......589...164463915782712486...
* PAIR A1: 3,9 ROW 1
I1: 3,9,5,6                              # reduction candidate for 3,9
I1: 5,6 => CTR
* 9762..8151485.9...3251.8.4.6.18.....8.73.14.62.46.7..15897..164463915782712486...
I1: 3,9                                  # 13 pairs
* PAIR C1: 5,6 ROW 1
I1: 5,6,3,9                              # reduction candidate for 5,6
I1: 5,6 => CTR
* 9762..8151485.9...3251.8.4.6.18.....8.73.14.62.46.7..15897..164463915782712486...
I1: 3,9                                  # 13 pairs
* PAIR A3: 3,9 ROW 3
G3: 3,9,5,6                              # reduction candidate for 3,9
G3: 3,9                                  # 14 pairs
I3: 3,9,5,6,7                            # reduction candidate for 3,9
I3: 3,9                                  # 15 pairs
* PAIR C3: 5,6 ROW 3
G3: 5,6,3,9                              # reduction candidate for 5,6
G3: 5,6                                  # 14 pairs
I3: 5,6,3,7,9                            # reduction candidate for 5,6
I3: 5,6                                  # 15 pairs
* PAIR D1: 2,6 BLK 2
E1: 2,6,3,4                              # reduction candidate for 2,6
E1: 2,6 => CTR
* .7.26481.1485.9....26....4.6.184....8.73..4.62.46.....589723164463915782712486...
E1: 3,4                                  # 12 pairs
* PAIR D3: 1,8 COL D
D6: 1,8,6,7                              # reduction candidate for 1,8
D6: 1,8 => SOLVED
* 375642819148579236926138547651294378897361425234857691589723164463915782712486953
D6: 6,7 => CTR
* .7.6..81.1485.9..6.261.8.4.6.18.....8.73624.12.47.16.8589237164463915782712486...
* PAIR F3: 1,8 COL F
F6: 1,8,7                                # reduction candidate for 1,8
F6: 1,8 => CTR
* .7.62481.1485.9....26....4.6.1.47...8.73624.12.4......589...164463915782712486...
F6: 7 => SOLVED
* 375642819148579236926138547651294378897361425234857691589723164463915782712486953
* PAIR B5: 5,9 BLK 4
B4: 5,9,3                                # reduction candidate for 5,9
B4: 5,9                                  # 12 pairs
B6: 5,9,3                                # reduction candidate for 5,9
B6: 5,9                                  # 12 pairs
* PAIR B5: 5,9 ROW 5
E5: 5,9,2,6                              # reduction candidate for 5,9
E5: 5,9 => CTR
* .7....81.1485.9....2.1.8.4.6.1.....88.73.14262.4867..15897..164463915782712486...
E5: 2,6                                  # 15 pairs
H5: 5,9,2                                # reduction candidate for 5,9
H5: 5,9                                  # 18 pairs
I5: 5,9,1,6                              # reduction candidate for 5,9
I5: 5,9 => SOLVED
* 375642819148579236926138547651294378897361425234857691589723164463915782712486953
I5: 1,6                                  # 12 pairs
* PAIR D7: 2,7 BLK 8
F7: 2,7,3                                # reduction candidate for 2,7
F7: 2,7 => CTR
* 97.24381.1485.9...32.1.8.4.6.18.4...8.73.14.62.46.....589732164463915782712486...
F7: 3                                    # 11 pairs
* PAIR D7: 2,7 COL D
D4: 2,7,8                                # reduction candidate for 2,7
D4: 2,7 => SOLVED
* 375642819148579236926138547651294378897361425234857691589723164463915782712486953
D4: 8 => CTR
* .7.6..81.1485.9..6.261.8.4.6.18.....8.73624.12.47.16.8589237164463915782712486...
* PAIR E7: 2,3 BLK 8
F7: 2,3,7                                # reduction candidate for 2,3
F7: 7 => CTR
* .7...381.1485.9...32.....4.6.1..4...8.73.24.12.4......589.37164463915782712486...
F7: 2,3                                  # 12 pairs
* PAIR E7: 2,3 COL E
E1: 2,3,4,6                              # reduction candidate for 2,3
E1: 2,3 => CTR
* .7.23481.1485.9...32.....4.6.184....8.73..4..2.46....8589723164463915782712486...
E1: 4,6                                  # 12 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-459-base-pr-000.dot
* REASONING
* DIS # I1: 5,6 => CTR => I1: 3,9
* DIS # I1: 5,6 => CTR => I1: 3,9
* DIS # E1: 2,6 => CTR => E1: 3,4
* PRF # D6: 1,8 => SOL
* DIS # D6: 6,7 => CTR => D6: 1,8
* DIS # F6: 1,8 => CTR => F6: 7
* PRF # F6: 7 => SOL
* DIS # E5: 5,9 => CTR => E5: 2,6
* PRF # I5: 5,9 => SOL
* DIS # F7: 2,7 => CTR => F7: 3
* PRF # D4: 2,7 => SOL
* DIS # D4: 8 => CTR => D4: 2,7
* DIS # F7: 7 => CTR => F7: 2,3
* DIS # E1: 2,3 => CTR => E1: 4,6
* CNT  14 HDP CHAINS /  29 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,A3,B5,C1,C3,D1,D3,D7,E7,F3,F5)
* .7....81.1485.9....2.....4.6.1......8.73..4..2.4......589...164463915782712486...
* PAIR A1: 3,9 ROW 1
I1: 3,9,5,6                              # reduction candidate for 3,9
I1: 5,6 => CTR
* 9762..8151485.9...3251.8.4.6.18.....8.73.14.62.46.7..15897..164463915782712486...
* PAIR RESTART
* PAIR A3: 3,9 ROW 3
G3: 3,9,5                                # reduction candidate for 3,9
G3: 3,9                                  # 18 pairs
I3: 3,9,5,7                              # reduction candidate for 3,9
I3: 3,9                                  # 19 pairs
* PAIR D3: 1,8 COL D
D6: 1,8,6                                # reduction candidate for 1,8
D6: 1,8 => SOLVED
* 375642819148579236926138547651294378897361425234857691589723164463915782712486953
* DURATION: 0:00:06.519180  START: 18:26:53.885697  END: 18:27:00.404877 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-459-base-pr-001.dot
* REASONING
* DIS # I1: 5,6 => CTR => I1: 3,9
* PRF I1: 3,9 # D6: 1,8 => SOL
* STA I1: 3,9 + D6: 1,8
* CNT   2 HDP CHAINS /   5 HYP OPENED

Header Info

Top 500 Minimum 17 459

solution: 375642819148579236926138547651294378897361425234857691589723164463915782712486953
info: 95523    FNBTHXYK S8.f     44938

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

Solution

position: 375642819148579236926138547651294378897361425234857691589723164463915782712486953 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 # I1: 3,9 => UNS
* DIS # I1: 5,6 => CTR => I1: 3,9
* DIS # I1: 5,6 => CTR => I1: 3,9
* INC # I1: 3,9 => UNS
* INC # G3: 3,9 => UNS
* INC # I3: 3,9 => UNS
* INC # G3: 5,6 => UNS
* INC # I3: 5,6 => UNS
* DIS # E1: 2,6 => CTR => E1: 3,4
* INC # E1: 3,4 => UNS
* PRF # D6: 1,8 => SOL
* DIS # D6: 6,7 => CTR => D6: 1,8
* DIS # F6: 1,8 => CTR => F6: 7
* PRF # F6: 7 => SOL
* INC # B4: 5,9 => UNS
* INC # B6: 5,9 => UNS
* DIS # E5: 5,9 => CTR => E5: 2,6
* INC # E5: 2,6 => UNS
* INC # H5: 5,9 => UNS
* PRF # I5: 5,9 => SOL
* INC # I5: 1,6 => UNS
* DIS # F7: 2,7 => CTR => F7: 3
* INC # F7: 3 => UNS
* PRF # D4: 2,7 => SOL
* DIS # D4: 8 => CTR => D4: 2,7
* INC # F7: 2,3 => UNS
* DIS # F7: 7 => CTR => F7: 2,3
* DIS # E1: 2,3 => CTR => E1: 4,6
* INC # E1: 4,6 => UNS
* CNT  29 HDP CHAINS /  29 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # I1: 3,9 => UNS
* DIS # I1: 5,6 => CTR => I1: 3,9
* INC I1: 3,9 # G3: 3,9 => UNS
* INC I1: 3,9 # I3: 3,9 => UNS
* PRF I1: 3,9 # D6: 1,8 => SOL
* STA I1: 3,9 + D6: 1,8
* CNT   5 HDP CHAINS /   5 HYP OPENED