Analysis of xx-top500-215-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 6.1.3.......5...7...........7.....4.5....1.......6...82.....6.....7..3...5.4..... initial

Autosolve

position: 641.375.....5...767.56...3..76..5.4.5.4.71.6..1..647582.71536.446.7..3151534.6..7 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # G3: 1,4 => CTR => G3: 2,8,9
* DIS # H1: 2,9 => CTR => H1: 8
* PRF # H1: 8 => SOL
* PRF # G3: 2,9 => SOL
* DIS # I3: 2,9 => CTR => I3: 1
* PRF # D1: 2,9 => SOL
* DIS # D1: 8 => CTR => D1: 2,9
* DIS # G3: 1,4 => CTR => G3: 2,8,9
* DIS # A4: 3,9 => CTR => A4: 8
* PRF # A4: 8 => SOL
* PRF # B5: 3,9 => SOL
* DIS # D6: 2 => CTR => D6: 3,9
* PRF # A2: 3,9 => SOL
* DIS # A2: 8 => CTR => A2: 3,9
* DIS # B5: 2,9 => CTR => B5: 3,8
* DIS # C2: 2,9 => CTR => C2: 8
* PRF # C2: 8 => SOL
* DIS # G4: 2,9 => CTR => G4: 1
* DIS # B5: 2,9 => CTR => B5: 3,8
* DIS # D5: 2,9 => CTR => D5: 3,8
* PRF # G3: 2,9 => SOL
* DIS # G9: 2,9 => CTR => G9: 8
* PRF # G9: 8 => SOL
* DIS # B2: 8,9 => CTR => B2: 2,3
* PRF # B3: 8,9 => SOL
* PRF # E8: 8,9 => SOL
* DIS # C2: 2 => CTR => C2: 8,9
* PRF # E8: 8,9 => SOL
* DIS # H9: 8,9 => CTR => H9: 2
* PRF # E4: 2 => SOL
* DIS # H9: 8,9 => CTR => H9: 2
* DIS # H1: 2 => CTR => H1: 8,9
* CNT  32 HDP CHAINS /  63 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 # G3: 1,4 => CTR => G3: 2,8,9
* DIS G3: 2,8,9 # H1: 2,9 => CTR => H1: 8
* PRF G3: 2,8,9 + H1: 8 => SOL
* STA G3: 2,8,9 + H1: 8
* CNT   3 HDP CHAINS /   2 HYP OPENED

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

Details

Positions

6.1.3.......5...7...........7.....4.5....1.......6...82.....6.....7..3...5.4..... initial
641.375.....5...767.56...3..76..5.4.5.4.71.6..1..647582.71536.446.7..3151534.6..7 autosolve
641237589328519476795648231876925143534871962912364758287153694469782315153496827 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (11)
E2: 1,4
E3: 1,4
I1: 2,9
G2: 1,4
A6: 3,9
C6: 2,9
G5: 2,9
B7: 8,9
C8: 8,9
E9: 8,9
H7: 8,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
E2,E3: 1.. / E2 = 1  =>  8 pairs (_) / E3 = 1  =>  0 pairs (X)
G4,I4: 1.. / G4 = 1  =>  8 pairs (_) / I4 = 1  =>  0 pairs (X)
E2,G2: 1.. / E2 = 1  =>  8 pairs (_) / G2 = 1  =>  0 pairs (X)
I3,I4: 1.. / I3 = 1  =>  8 pairs (_) / I4 = 1  =>  0 pairs (X)
B5,C6: 2.. / B5 = 2  =>  0 pairs (X) / C6 = 2  => 12 pairs (_)
E8,F8: 2.. / E8 = 2  => 15 pairs (_) / F8 = 2  =>  0 pairs (*)
G9,H9: 2.. / G9 = 2  =>  0 pairs (X) / H9 = 2  => 13 pairs (_)
C6,D6: 2.. / C6 = 2  => 12 pairs (_) / D6 = 2  =>  0 pairs (X)
C2,C6: 2.. / C2 = 2  =>  0 pairs (X) / C6 = 2  => 12 pairs (_)
E4,E8: 2.. / E4 = 2  =>  0 pairs (*) / E8 = 2  =>  0 pairs (X)
H1,H9: 2.. / H1 = 2  =>  0 pairs (X) / H9 = 2  => 13 pairs (_)
A2,B2: 3.. / A2 = 3  =>  0 pairs (*) / B2 = 3  =>  0 pairs (X)
I4,I5: 3.. / I4 = 3  => 14 pairs (_) / I5 = 3  => 12 pairs (_)
A6,D6: 3.. / A6 = 3  => 13 pairs (_) / D6 = 3  => 13 pairs (_)
B2,B5: 3.. / B2 = 3  => 12 pairs (_) / B5 = 3  =>  0 pairs (*)
E2,E3: 4.. / E2 = 4  =>  0 pairs (X) / E3 = 4  =>  8 pairs (_)
G2,G3: 4.. / G2 = 4  =>  8 pairs (_) / G3 = 4  =>  0 pairs (X)
E2,G2: 4.. / E2 = 4  =>  0 pairs (X) / G2 = 4  =>  8 pairs (_)
E3,G3: 4.. / E3 = 4  =>  8 pairs (_) / G3 = 4  =>  0 pairs (X)
H1,G3: 8.. / H1 = 8  =>  0 pairs (*) / G3 = 8  =>  0 pairs (X)
A4,B5: 8.. / A4 = 8  =>  0 pairs (*) / B5 = 8  =>  0 pairs (X)
B7,C8: 8.. / B7 = 8  =>  0 pairs (*) / C8 = 8  =>  0 pairs (X)
D1,H1: 8.. / D1 = 8  =>  0 pairs (X) / H1 = 8  =>  0 pairs (_)
B5,D5: 8.. / B5 = 8  =>  0 pairs (X) / D5 = 8  =>  0 pairs (_)
B7,H7: 8.. / B7 = 8  =>  0 pairs (*) / H7 = 8  =>  0 pairs (X)
A2,A4: 8.. / A2 = 8  =>  0 pairs (X) / A4 = 8  =>  0 pairs (_)
C2,C8: 8.. / C2 = 8  =>  0 pairs (*) / C8 = 8  =>  0 pairs (X)
G3,G9: 8.. / G3 = 8  =>  0 pairs (X) / G9 = 8  =>  0 pairs (_)
B7,C8: 9.. / B7 = 9  =>  0 pairs (X) / C8 = 9  =>  0 pairs (_)
B7,H7: 9.. / B7 = 9  =>  0 pairs (X) / H7 = 9  =>  0 pairs (_)
* DURATION: 0:00:56.178449  START: 10:09:14.187703  END: 10:10:10.366152 2017-05-04
* CP COUNT: (30)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A6,B7,C6,C8,E2,E3,E9,G2,G5,H7,I1)
* 641.375.....5...767.56...3..76..5.4.5.4.71.6..1..647582.71536.446.7..3151534.6..7
* PAIR E3: 1,4 ROW 3
G3: 1,4,2,8,9                            # reduction candidate for 1,4
G3: 1,4 => CTR
* 641237589.285.9.767956.8.3.876.25.4.5.487126..12.64758287153694469782315153496827
G3: 2,8,9                                #  8 pairs
* PAIR I1: 2,9 BLK 3
H1: 2,9,8                                # reduction candidate for 2,9
H1: 2,9 => CTR
* 6418375.....5...767.56..83..76.85.4.584.71.6..12.647582971536844687293151534.6..7
H1: 8 => SOLVED
* 641237589328519476795648231876925143534871962912364758287153694469782315153496827
G3: 2,9,1,4,8                            # reduction candidate for 2,9
G3: 2,9 => SOLVED
* 641237589328519476795648231876925143534871962912364758287153694469782315153496827
G3: 1,4,8                                # 11 pairs
I3: 2,9,1                                # reduction candidate for 2,9
I3: 2,9 => CTR
* 641.3758..385.2.767256...3..76..5.415.4.71.63.1..647582871536944697..315153496827
I3: 1                                    #  8 pairs
* PAIR I1: 2,9 ROW 1
D1: 2,9,8                                # reduction candidate for 2,9
D1: 2,9 => SOLVED
* 641237589328519476795648231876925143534871962912364758287153694469782315153496827
D1: 8 => CTR
* 6418375.....5...767.56..83..76.85.4.584.71.6..12.647582971536844687293151534.6..7
* PAIR I1: 2,9 COL I
I4: 2,9,1,3                              # reduction candidate for 2,9
I4: 2,9                                  # 10 pairs
I5: 2,9,3                                # reduction candidate for 2,9
I5: 2,9                                  # 14 pairs
* PAIR G2: 1,4 BLK 3
G3: 1,4,2,8,9                            # reduction candidate for 1,4
G3: 1,4 => CTR
* 641237589.285.9.767956.8.3.876.25.4.5.487126..12.64758287153694469782315153496827
G3: 2,8,9                                #  8 pairs
* PAIR A6: 3,9 BLK 4
A4: 3,9,8                                # reduction candidate for 3,9
A4: 3,9 => CTR
* 6418375..8395.2.767256.9.3..76..5.4.584.71.6..12.647582971536844687..315153486..7
A4: 8 => SOLVED
* 641237589328519476795648231876925143534871962912364758287153694469782315153496827
B5: 3,9,2,8                              # reduction candidate for 3,9
B5: 3,9 => SOLVED
* 641237589328519476795648231876925143534871962912364758287153694469782315153496827
B5: 2,8                                  # 13 pairs
* PAIR A6: 3,9 ROW 6
D6: 3,9,2                                # reduction candidate for 3,9
D6: 2 => CTR
* 641.375.....5...767.56...3..76..5.4.5.4.71.6.319264758297153684468729315153486..7
D6: 3,9                                  # 12 pairs
* PAIR A6: 3,9 COL A
A2: 3,9,8                                # reduction candidate for 3,9
A2: 3,9 => SOLVED
* 641237589328519476795648231876925143534871962912364758287153694469782315153496827
A2: 8 => CTR
* 6418375..8395.2.767256.9.3..76..5.4.584.71.6..12.647582971536844687..315153486..7
* PAIR C6: 2,9 BLK 4
B5: 2,9,3,8                              # reduction candidate for 2,9
B5: 2,9 => CTR
* 641.3758.93.5...767.56...3.8763.5.4.5.4871.6331..647582871536944697..315153496827
B5: 3,8                                  # 14 pairs
* PAIR C6: 2,9 ROW 6
D6: 2,9,3                                # reduction candidate for 2,9
D6: 3                                    # 13 pairs
D6: 2,9                                  # 13 pairs
* PAIR C6: 2,9 COL C
C2: 2,9,8                                # reduction candidate for 2,9
C2: 2,9 => CTR
* 6418375.....5..476725649831876..514.534.71.6.912364758297153684468792315153486..7
C2: 8 => SOLVED
* 641237589328519476795648231876925143534871962912364758287153694469782315153496827
* PAIR G5: 2,9 BLK 6
G4: 2,9,1                                # reduction candidate for 2,9
G4: 2,9 => CTR
* 641.3758..385.2.767256...3..76..5.415.4.71.63.1..647582871536944697..315153496827
G4: 1                                    #  8 pairs
I4: 2,9,1,3                              # reduction candidate for 2,9
I4: 2,9                                  # 10 pairs
I5: 2,9,3                                # reduction candidate for 2,9
I5: 2,9                                  # 14 pairs
* PAIR G5: 2,9 ROW 5
B5: 2,9,3,8                              # reduction candidate for 2,9
B5: 2,9 => CTR
* 641.3758.93.5...767.56...3.8763.5.4.5.4871.6331..647582871536944697..315153496827
B5: 3,8                                  # 14 pairs
D5: 2,9,3,8                              # reduction candidate for 2,9
D5: 2,9 => CTR
* 6418375..8395.2.767256.9.3..76..5.4.584.71.63.12.647582971536844687..315153486..7
D5: 3,8                                  # 12 pairs
* PAIR G5: 2,9 COL G
G3: 2,9,1,4,8                            # reduction candidate for 2,9
G3: 2,9 => SOLVED
* 641237589328519476795648231876925143534871962912364758287153694469782315153496827
G3: 1,4,8                                # 11 pairs
G9: 2,9,8                                # reduction candidate for 2,9
G9: 2,9 => CTR
* 6418375.....5..4767.564.831.76.8514.584.71.6..12.647582971536844687293151534.6..7
G9: 8 => SOLVED
* 641237589328519476795648231876925143534871962912364758287153694469782315153496827
* PAIR B7: 8,9 COL B
B2: 8,9,2,3                              # reduction candidate for 8,9
B2: 8,9 => CTR
* 641.3758.3..5.2.767256.8.3.876295143534871.6.9123647582871536944697..3151534.6..7
B2: 2,3                                  # 12 pairs
B3: 8,9,2                                # reduction candidate for 8,9
B3: 8,9 => SOLVED
* 641237589328519476795648231876925143534871962912364758287153694469782315153496827
B3: 2                                    # 17 pairs
B5: 8,9,2,3                              # reduction candidate for 8,9
B5: 8,9                                  # 19 pairs
* PAIR C8: 8,9 ROW 8
E8: 8,9,2                                # reduction candidate for 8,9
E8: 8,9 => SOLVED
* 641237589328519476795648231876925143534871962912364758287153694469782315153496827
E8: 2                                    # 15 pairs
F8: 8,9,2                                # reduction candidate for 8,9
F8: 8,9                                  # 15 pairs
* PAIR C8: 8,9 COL C
C2: 8,9,2                                # reduction candidate for 8,9
C2: 2 => CTR
* 641.375....25...767.56...3..76..5.4.524871963.19264758297153684468729315153486297
C2: 8,9                                  # 12 pairs
* PAIR E9: 8,9 BLK 8
E8: 8,9,2                                # reduction candidate for 8,9
E8: 8,9 => SOLVED
* 641237589328519476795648231876925143534871962912364758287153694469782315153496827
E8: 2                                    # 15 pairs
F8: 8,9,2                                # reduction candidate for 8,9
F8: 8,9                                  # 15 pairs
* PAIR E9: 8,9 ROW 9
G9: 8,9,2                                # reduction candidate for 8,9
G9: 8,9                                  # 13 pairs
H9: 8,9,2                                # reduction candidate for 8,9
H9: 8,9 => CTR
* 641837529...51.4767.564.831.76.8514.584.7196..12.6475829715368446.7..3151534.62.7
H9: 2                                    # 13 pairs
* PAIR E9: 8,9 COL E
E4: 8,9,2                                # reduction candidate for 8,9
E4: 2 => SOLVED
* 641237589328519476795648231876925143534871962912364758287153694469782315153496827
E4: 8,9                                  # 15 pairs
* PAIR H7: 8,9 BLK 9
G9: 8,9,2                                # reduction candidate for 8,9
G9: 8,9                                  # 13 pairs
H9: 8,9,2                                # reduction candidate for 8,9
H9: 8,9 => CTR
* 641837529...51.4767.564.831.76.8514.584.7196..12.6475829715368446.7..3151534.62.7
H9: 2                                    # 13 pairs
* PAIR H7: 8,9 COL H
H1: 8,9,2                                # reduction candidate for 8,9
H1: 2 => CTR
* 641837529...5...767.56..831.76.8514.584.7196..12.6475829715368446.7..3151534.6..7
H1: 8,9                                  # 13 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-215-base-pr-000.dot
* REASONING
* DIS # G3: 1,4 => CTR => G3: 2,8,9
* DIS # H1: 2,9 => CTR => H1: 8
* PRF # H1: 8 => SOL
* PRF # G3: 2,9 => SOL
* DIS # I3: 2,9 => CTR => I3: 1
* PRF # D1: 2,9 => SOL
* DIS # D1: 8 => CTR => D1: 2,9
* DIS # G3: 1,4 => CTR => G3: 2,8,9
* DIS # A4: 3,9 => CTR => A4: 8
* PRF # A4: 8 => SOL
* PRF # B5: 3,9 => SOL
* DIS # D6: 2 => CTR => D6: 3,9
* PRF # A2: 3,9 => SOL
* DIS # A2: 8 => CTR => A2: 3,9
* DIS # B5: 2,9 => CTR => B5: 3,8
* DIS # C2: 2,9 => CTR => C2: 8
* PRF # C2: 8 => SOL
* DIS # G4: 2,9 => CTR => G4: 1
* DIS # B5: 2,9 => CTR => B5: 3,8
* DIS # D5: 2,9 => CTR => D5: 3,8
* PRF # G3: 2,9 => SOL
* DIS # G9: 2,9 => CTR => G9: 8
* PRF # G9: 8 => SOL
* DIS # B2: 8,9 => CTR => B2: 2,3
* PRF # B3: 8,9 => SOL
* PRF # E8: 8,9 => SOL
* DIS # C2: 2 => CTR => C2: 8,9
* PRF # E8: 8,9 => SOL
* DIS # H9: 8,9 => CTR => H9: 2
* PRF # E4: 2 => SOL
* DIS # H9: 8,9 => CTR => H9: 2
* DIS # H1: 2 => CTR => H1: 8,9
* CNT  32 HDP CHAINS /  63 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A6,B7,C6,C8,E2,E3,E9,G2,G5,H7,I1)
* 641.375.....5...767.56...3..76..5.4.5.4.71.6..1..647582.71536.446.7..3151534.6..7
* PAIR E3: 1,4 ROW 3
G3: 1,4,2,8,9                            # reduction candidate for 1,4
G3: 1,4 => CTR
* 641237589.285.9.767956.8.3.876.25.4.5.487126..12.64758287153694469782315153496827
* PAIR RESTART
* PAIR I1: 2,9 BLK 3
H1: 2,9,8                                # reduction candidate for 2,9
H1: 2,9 => CTR
* 6418375.....51.4767.564.831.76.8514.584.71.6..12.647582971536844687293151534.6..7
H1: 8 => SOLVED
* 641237589328519476795648231876925143534871962912364758287153694469782315153496827
* DURATION: 0:00:04.151020  START: 10:11:18.918811  END: 10:11:23.069831 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-215-base-pr-001.dot
* REASONING
* DIS # G3: 1,4 => CTR => G3: 2,8,9
* DIS G3: 2,8,9 # H1: 2,9 => CTR => H1: 8
* PRF G3: 2,8,9 + H1: 8 => SOL
* STA G3: 2,8,9 + H1: 8
* CNT   3 HDP CHAINS /   2 HYP OPENED

Header Info

Top 500 Minimum 17 215

solution: 641237589328519476795648231876925143534871962912364758287153694469782315153496827
info: 1948     FNBHWX   S8.f     35341

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

Solution

position: 641237589328519476795648231876925143534871962912364758287153694469782315153496827 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 # G3: 1,4 => CTR => G3: 2,8,9
* INC # G3: 2,8,9 => UNS
* DIS # H1: 2,9 => CTR => H1: 8
* PRF # H1: 8 => SOL
* PRF # G3: 2,9 => SOL
* INC # G3: 1,4,8 => UNS
* DIS # I3: 2,9 => CTR => I3: 1
* INC # I3: 1 => UNS
* PRF # D1: 2,9 => SOL
* DIS # D1: 8 => CTR => D1: 2,9
* INC # I4: 2,9 => UNS
* INC # I5: 2,9 => UNS
* DIS # G3: 1,4 => CTR => G3: 2,8,9
* INC # G3: 2,8,9 => UNS
* DIS # A4: 3,9 => CTR => A4: 8
* PRF # A4: 8 => SOL
* PRF # B5: 3,9 => SOL
* INC # B5: 2,8 => UNS
* INC # D6: 3,9 => UNS
* DIS # D6: 2 => CTR => D6: 3,9
* PRF # A2: 3,9 => SOL
* DIS # A2: 8 => CTR => A2: 3,9
* DIS # B5: 2,9 => CTR => B5: 3,8
* INC # B5: 3,8 => UNS
* INC # D6: 2,9 => UNS
* INC # D6: 3 => UNS
* DIS # C2: 2,9 => CTR => C2: 8
* PRF # C2: 8 => SOL
* DIS # G4: 2,9 => CTR => G4: 1
* INC # G4: 1 => UNS
* INC # I4: 2,9 => UNS
* INC # I5: 2,9 => UNS
* DIS # B5: 2,9 => CTR => B5: 3,8
* INC # B5: 3,8 => UNS
* DIS # D5: 2,9 => CTR => D5: 3,8
* INC # D5: 3,8 => UNS
* PRF # G3: 2,9 => SOL
* INC # G3: 1,4,8 => UNS
* DIS # G9: 2,9 => CTR => G9: 8
* PRF # G9: 8 => SOL
* DIS # B2: 8,9 => CTR => B2: 2,3
* INC # B2: 2,3 => UNS
* PRF # B3: 8,9 => SOL
* INC # B3: 2 => UNS
* INC # B5: 8,9 => UNS
* PRF # E8: 8,9 => SOL
* INC # E8: 2 => UNS
* INC # F8: 8,9 => UNS
* INC # C2: 8,9 => UNS
* DIS # C2: 2 => CTR => C2: 8,9
* PRF # E8: 8,9 => SOL
* INC # E8: 2 => UNS
* INC # F8: 8,9 => UNS
* INC # G9: 8,9 => UNS
* DIS # H9: 8,9 => CTR => H9: 2
* INC # H9: 2 => UNS
* INC # E4: 8,9 => UNS
* PRF # E4: 2 => SOL
* INC # G9: 8,9 => UNS
* DIS # H9: 8,9 => CTR => H9: 2
* INC # H9: 2 => UNS
* INC # H1: 8,9 => UNS
* DIS # H1: 2 => CTR => H1: 8,9
* CNT  63 HDP CHAINS /  63 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # G3: 1,4 => CTR => G3: 2,8,9
* DIS G3: 2,8,9 # H1: 2,9 => CTR => H1: 8
* PRF G3: 2,8,9 + H1: 8 => SOL
* STA G3: 2,8,9 + H1: 8
* CNT   3 HDP CHAINS /   2 HYP OPENED