Analysis of xx-top500-416-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: ..71..........85..6...............41...2...7.3........58....3.....72....1...4.... initial

Autosolve

position: ..71..4......785..6.....7..7......41...2...733....7...584...3279..725184172843... autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # I1: 2,8 => SOL
* DIS # I1: 6,9 => CTR => I1: 2,8
* DIS # D4: 6,9 => CTR => D4: 3,5
* DIS # E4: 6,9 => CTR => E4: 3,5,8
* DIS # E5: 6,9 => CTR => E5: 1,5,8
* DIS # F5: 6,9 => CTR => F5: 1,4
* PRF # D6: 6,9 => SOL
* DIS # D6: 4 => CTR => D6: 6,9
* DIS # E6: 6,9 => CTR => E6: 1,8
* DIS # B4: 6,9 => CTR => B4: 2,5
* DIS # G4: 6,9 => CTR => G4: 2,8
* PRF # F1: 6,9 => SOL
* DIS # F1: 2 => CTR => F1: 6,9
* DIS # F7: 6,9 => CTR => F7: 1
* DIS # F7: 6,9 => CTR => F7: 1
* DIS # D2: 6,9 => CTR => D2: 3,4
* DIS # D4: 6,9 => CTR => D4: 3,5
* PRF # D6: 6,9 => SOL
* DIS # D6: 4 => CTR => D6: 6,9
* DIS # G4: 6,9 => CTR => G4: 2,8
* DIS # G6: 6,9 => CTR => G6: 2,8
* CNT  21 HDP CHAINS /  39 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 # I1: 2,8 => SOL
* STA I1: 2,8
* CNT   1 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

..71..........85..6...............41...2...7.3........58....3.....72....1...4.... initial
..71..4......785..6.....7..7......41...2...733....7...584...3279..725184172843... autosolve
257196438419378562638452719726539841895214673341687295584961327963725184172843956 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (8)
A1: 2,8
A2: 2,4
A5: 4,8
F4: 6,9
B8: 3,6
C8: 3,6
D7: 6,9
G9: 6,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
H2,H3: 1.. / H2 = 1  => 10 pairs (_) / H3 = 1  =>  8 pairs (_)
E7,F7: 1.. / E7 = 1  =>  0 pairs (X) / F7 = 1  => 11 pairs (_)
F5,F7: 1.. / F5 = 1  =>  0 pairs (X) / F7 = 1  => 11 pairs (_)
A1,A2: 2.. / A1 = 2  =>  0 pairs (*) / A2 = 2  =>  0 pairs (X)
F1,F3: 2.. / F1 = 2  =>  0 pairs (X) / F3 = 2  =>  0 pairs (_)
B4,B6: 2.. / B4 = 2  =>  8 pairs (_) / B6 = 2  =>  0 pairs (X)
G4,G6: 2.. / G4 = 2  =>  0 pairs (X) / G6 = 2  =>  8 pairs (_)
A2,I2: 2.. / A2 = 2  =>  0 pairs (X) / I2 = 2  =>  0 pairs (_)
F3,I3: 2.. / F3 = 2  =>  0 pairs (*) / I3 = 2  =>  0 pairs (X)
B4,G4: 2.. / B4 = 2  =>  8 pairs (_) / G4 = 2  =>  0 pairs (X)
B6,G6: 2.. / B6 = 2  =>  0 pairs (X) / G6 = 2  =>  8 pairs (_)
D4,E4: 3.. / D4 = 3  =>  9 pairs (_) / E4 = 3  =>  9 pairs (_)
B8,C8: 3.. / B8 = 3  =>  7 pairs (_) / C8 = 3  =>  7 pairs (_)
F5,D6: 4.. / F5 = 4  =>  0 pairs (*) / D6 = 4  =>  0 pairs (X)
B6,D6: 4.. / B6 = 4  =>  0 pairs (*) / D6 = 4  =>  0 pairs (X)
A2,A5: 4.. / A2 = 4  =>  0 pairs (*) / A5 = 4  =>  0 pairs (X)
F3,F5: 4.. / F3 = 4  =>  0 pairs (X) / F5 = 4  =>  0 pairs (_)
H6,I6: 5.. / H6 = 5  => 10 pairs (_) / I6 = 5  => 10 pairs (_)
H9,I9: 5.. / H9 = 5  => 10 pairs (_) / I9 = 5  => 10 pairs (_)
B1,E1: 5.. / B1 = 5  =>  8 pairs (_) / E1 = 5  => 15 pairs (_)
D3,D4: 5.. / D3 = 5  =>  9 pairs (_) / D4 = 5  =>  9 pairs (_)
H6,H9: 5.. / H6 = 5  => 10 pairs (_) / H9 = 5  => 10 pairs (_)
I6,I9: 5.. / I6 = 5  => 10 pairs (_) / I9 = 5  => 10 pairs (_)
B8,C8: 6.. / B8 = 6  =>  7 pairs (_) / C8 = 6  =>  7 pairs (_)
A1,C3: 8.. / A1 = 8  =>  0 pairs (X) / C3 = 8  =>  0 pairs (_)
I1,I3: 8.. / I1 = 8  =>  0 pairs (*) / I3 = 8  =>  0 pairs (X)
A1,I1: 8.. / A1 = 8  =>  0 pairs (X) / I1 = 8  =>  0 pairs (_)
C3,I3: 8.. / C3 = 8  =>  0 pairs (*) / I3 = 8  =>  0 pairs (X)
A1,A5: 8.. / A1 = 8  =>  0 pairs (X) / A5 = 8  =>  0 pairs (_)
* DURATION: 0:00:42.815916  START: 17:02:51.773982  END: 17:03:34.589898 2017-05-04
* CP COUNT: (29)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,A2,A5,B8,C8,D7,F4,G9)
* ..71..4......785..6.....7..7......41...2...733....7...584...3279..725184172843...
* PAIR A1: 2,8 ROW 1
I1: 2,8,6,9                              # reduction candidate for 2,8
I1: 2,8 => SOLVED
* 257196438419378562638452719726539841895214673341687295584961327963725184172843956
I1: 6,9 => CTR
* 8.71.24..2...785..6.....7..7......41...2...733....7...584...3279..725184172843...
* PAIR F4: 6,9 BLK 5
D4: 6,9,3,5                              # reduction candidate for 6,9
D4: 6,9 => CTR
* .5716.43....3785..6..5947127.5.3.841...251.733..4872..584.1.3279..725184172843...
D4: 3,5                                  #  9 pairs
E4: 6,9,3,5,8                            # reduction candidate for 6,9
E4: 6,9 => CTR
* .571.24.8....785..6..5.47.27253..841...251.733..4872..584.1.3279..725184172843...
E4: 3,5,8                                #  8 pairs
E5: 6,9,1,5,8                            # reduction candidate for 6,9
E5: 6,9 => CTR
* ..71.24.8....785..6....47.27......41...2.1.733..487...584.1.3279..725184172843...
E5: 1,5,8                                #  8 pairs
F5: 6,9,1,4                              # reduction candidate for 6,9
F5: 6,9 => CTR
* ..71.24.8....785..6....47.27......41...2...733..4.7...584..13279..725184172843...
F5: 1,4                                  #  9 pairs
D6: 6,9,4                                # reduction candidate for 6,9
D6: 6,9 => SOLVED
* 257196438419378562638452719726539841895214673341687295584961327963725184172843956
D6: 4 => CTR
* ..71.24.8....785..6....47.27......41...2...733..4.7...584...3279..725184172843...
E6: 6,9,1,8                              # reduction candidate for 6,9
E6: 6,9 => CTR
* ..71.24.8....785..6....47.27......41...2.1.733..4.7...584.1.3279..725184172843...
E6: 1,8                                  #  9 pairs
* PAIR F4: 6,9 ROW 4
B4: 6,9,2,5                              # reduction candidate for 6,9
B4: 6,9 => CTR
* ..71.24.8....785..6....47.27.....241...2...7332.4.7...584...3279..725184172843...
B4: 2,5                                  #  9 pairs
C4: 6,9,5,8                              # reduction candidate for 6,9
C4: 6,9                                  # 12 pairs
G4: 6,9,2,8                              # reduction candidate for 6,9
G4: 6,9 => CTR
* 8.71..4..2...785..6.....7.872.....414..2..8733..4.72..584...3279..725184172843...
G4: 2,8                                  #  9 pairs
* PAIR F4: 6,9 COL F
F1: 6,9,2                                # reduction candidate for 6,9
F1: 6,9 => SOLVED
* 257196438419378562638452719726539841895214673341687295584961327963725184172843956
F1: 2 => CTR
* 8.71.24..24..785..6....47.27......414..2...733..4.7...584...3279..725184172843...
F7: 6,9,1                                # reduction candidate for 6,9
F7: 6,9 => CTR
* ..71.24.8....785..6....47.27......41...2.1.733..4.7...584.1.3279..725184172843...
F7: 1                                    # 11 pairs
* PAIR D7: 6,9 BLK 8
E7: 6,9,1                                # reduction candidate for 6,9
E7: 6,9                                  # 11 pairs
F7: 6,9,1                                # reduction candidate for 6,9
F7: 6,9 => CTR
* ..71.24.8....785..6....47.27......41...2.1.733..4.7...584.1.3279..725184172843...
F7: 1                                    # 11 pairs
* PAIR D7: 6,9 COL D
D2: 6,9,3,4                              # reduction candidate for 6,9
D2: 6,9 => CTR
* ..71.24.8....785..6....47.27......41...2...733..4.7...584...3279..725184172843...
D2: 3,4                                  # 10 pairs
D4: 6,9,3,5                              # reduction candidate for 6,9
D4: 6,9 => CTR
* .5716.43....3785..6..5947127.5.3.841...251.733..4872..584.1.3279..725184172843...
D4: 3,5                                  #  9 pairs
D6: 6,9,4                                # reduction candidate for 6,9
D6: 6,9 => SOLVED
* 257196438419378562638452719726539841895214673341687295584961327963725184172843956
D6: 4 => CTR
* ..71.24.8....785..6....47.27......41...2...733..4.7...584...3279..725184172843...
* PAIR G9: 6,9 BLK 9
H9: 6,9,5                                # reduction candidate for 6,9
H9: 6,9                                  # 10 pairs
I9: 6,9,5                                # reduction candidate for 6,9
I9: 6,9                                  # 10 pairs
* PAIR G9: 6,9 COL G
G4: 6,9,2,8                              # reduction candidate for 6,9
G4: 6,9 => CTR
* 8.71..4..2...785..6.....7.872.....414..2..8733..4.72..584...3279..725184172843...
G4: 2,8                                  #  9 pairs
G5: 6,9,8                                # reduction candidate for 6,9
G5: 6,9                                  # 11 pairs
G6: 6,9,2,8                              # reduction candidate for 6,9
G6: 6,9 => CTR
* 8.71..4..24..785..6....47..7.....241...2..87332.4.7...584...3279..725184172843...
G6: 2,8                                  #  9 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-416-base-pr-000.dot
* REASONING
* PRF # I1: 2,8 => SOL
* DIS # I1: 6,9 => CTR => I1: 2,8
* DIS # D4: 6,9 => CTR => D4: 3,5
* DIS # E4: 6,9 => CTR => E4: 3,5,8
* DIS # E5: 6,9 => CTR => E5: 1,5,8
* DIS # F5: 6,9 => CTR => F5: 1,4
* PRF # D6: 6,9 => SOL
* DIS # D6: 4 => CTR => D6: 6,9
* DIS # E6: 6,9 => CTR => E6: 1,8
* DIS # B4: 6,9 => CTR => B4: 2,5
* DIS # G4: 6,9 => CTR => G4: 2,8
* PRF # F1: 6,9 => SOL
* DIS # F1: 2 => CTR => F1: 6,9
* DIS # F7: 6,9 => CTR => F7: 1
* DIS # F7: 6,9 => CTR => F7: 1
* DIS # D2: 6,9 => CTR => D2: 3,4
* DIS # D4: 6,9 => CTR => D4: 3,5
* PRF # D6: 6,9 => SOL
* DIS # D6: 4 => CTR => D6: 6,9
* DIS # G4: 6,9 => CTR => G4: 2,8
* DIS # G6: 6,9 => CTR => G6: 2,8
* CNT  21 HDP CHAINS /  39 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,A2,A5,B8,C8,D7,F4,G9)
* ..71..4......785..6.....7..7......41...2...733....7...584...3279..725184172843...
* PAIR A1: 2,8 ROW 1
I1: 2,8,6,9                              # reduction candidate for 2,8
I1: 2,8 => SOLVED
* 257196438419378562638452719726539841895214673341687295584961327963725184172843956
* DURATION: 0:00:02.609072  START: 17:04:06.305713  END: 17:04:08.914785 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-416-base-pr-001.dot
* REASONING
* PRF # I1: 2,8 => SOL
* STA I1: 2,8
* CNT   1 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 416

solution: 257196438419378562638452719726539841895214673341687295584961327963725184172843956
info: 95067    FNBXYK   S8.f     14366

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

Solution

position: 257196438419378562638452719726539841895214673341687295584961327963725184172843956 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 # I1: 2,8 => SOL
* DIS # I1: 6,9 => CTR => I1: 2,8
* DIS # D4: 6,9 => CTR => D4: 3,5
* INC # D4: 3,5 => UNS
* DIS # E4: 6,9 => CTR => E4: 3,5,8
* INC # E4: 3,5,8 => UNS
* DIS # E5: 6,9 => CTR => E5: 1,5,8
* INC # E5: 1,5,8 => UNS
* DIS # F5: 6,9 => CTR => F5: 1,4
* INC # F5: 1,4 => UNS
* PRF # D6: 6,9 => SOL
* DIS # D6: 4 => CTR => D6: 6,9
* DIS # E6: 6,9 => CTR => E6: 1,8
* INC # E6: 1,8 => UNS
* DIS # B4: 6,9 => CTR => B4: 2,5
* INC # B4: 2,5 => UNS
* INC # C4: 6,9 => UNS
* DIS # G4: 6,9 => CTR => G4: 2,8
* INC # G4: 2,8 => UNS
* PRF # F1: 6,9 => SOL
* DIS # F1: 2 => CTR => F1: 6,9
* DIS # F7: 6,9 => CTR => F7: 1
* INC # F7: 1 => UNS
* INC # E7: 6,9 => UNS
* DIS # F7: 6,9 => CTR => F7: 1
* INC # F7: 1 => UNS
* DIS # D2: 6,9 => CTR => D2: 3,4
* INC # D2: 3,4 => UNS
* DIS # D4: 6,9 => CTR => D4: 3,5
* INC # D4: 3,5 => UNS
* PRF # D6: 6,9 => SOL
* DIS # D6: 4 => CTR => D6: 6,9
* INC # H9: 6,9 => UNS
* INC # I9: 6,9 => UNS
* DIS # G4: 6,9 => CTR => G4: 2,8
* INC # G4: 2,8 => UNS
* INC # G5: 6,9 => UNS
* DIS # G6: 6,9 => CTR => G6: 2,8
* INC # G6: 2,8 => UNS
* CNT  39 HDP CHAINS /  39 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* PRF # I1: 2,8 => SOL
* STA I1: 2,8
* CNT   1 HDP CHAINS /   1 HYP OPENED