Analysis of xx-top500-403-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 35...2....1.....8.....9.7..4...6.......8...1..3.......6.....2..7.......4...1..... initial

Autosolve

position: 358712...917....82264.987.148..61...57.8...1.13....8..6.1...2.87...8.1.48..1..... autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # D2: 3,5 => CTR => D2: 4,6
* DIS # D7: 3,5 => CTR => D7: 4,9
* DIS # D8: 3,5 => CTR => D8: 2,6,9
* DIS # I5: 6,9 => CTR => I5: 3
* PRF # I5: 3 => SOL
* PRF # I6: 6,9 => SOL
* DIS # I6: 5 => CTR => I6: 6,9
* DIS # I9: 6,9 => CTR => I9: 3,5,7
* DIS # D2: 3,5 => CTR => D2: 4,6
* DIS # H4: 3,5 => CTR => H4: 2,7,9
* DIS # H9: 3,5 => CTR => H9: 6,7,9
* DIS # D4: 2,9 => CTR => D4: 3,5
* DIS # F7: 4,9 => CTR => F7: 3,5,7
* DIS # D8: 3,5 => CTR => D8: 2,6,9
* DIS # E9: 3,5 => CTR => E9: 2,4,7
* DIS # F9: 3,5 => CTR => F9: 4,6,7,9
* DIS # H9: 3,5 => CTR => H9: 6,7,9
* CNT  17 HDP CHAINS /  55 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 # D2: 3,5 => CTR => D2: 4,6
* DIS D2: 4,6 # D7: 3,5 => CTR => D7: 4,9
* DIS D2: 4,6 + D7: 4,9 # D8: 3,5 => CTR => D8: 2,6,9
* DIS D2: 4,6 + D7: 4,9 + D8: 2,6,9 # D4: 2,9 => CTR => D4: 3,5
* DIS D2: 4,6 + D7: 4,9 + D8: 2,6,9 + D4: 3,5 # I5: 6,9 => CTR => I5: 3
* PRF D2: 4,6 + D7: 4,9 + D8: 2,6,9 + D4: 3,5 + I5: 3 => SOL
* STA D2: 4,6 + D7: 4,9 + D8: 2,6,9 + D4: 3,5 + I5: 3
* CNT   6 HDP CHAINS /  13 HYP OPENED

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

Details

Positions

35...2....1.....8.....9.7..4...6.......8...1..3.......6.....2..7.......4...1..... initial
358712...917....82264.987.148..61...57.8...1.13....8..6.1...2.87...8.1.48..1..... autosolve
358712649917634582264598731482361975576829413139457826641973258793285164825146397 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (9)
D3: 3,5
I1: 6,9
G2: 3,5
H3: 3,5
C4: 2,9
B7: 4,9
B8: 2,9
C8: 3,5
C9: 3,5

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
H4,H6: 2.. / H4 = 2  => 15 pairs (_) / H6 = 2  => 12 pairs (_)
B8,B9: 2.. / B8 = 2  => 12 pairs (_) / B9 = 2  => 10 pairs (_)
D8,E9: 2.. / D8 = 2  => 10 pairs (_) / E9 = 2  => 12 pairs (_)
C5,E5: 2.. / C5 = 2  => 12 pairs (_) / E5 = 2  => 11 pairs (_)
B8,D8: 2.. / B8 = 2  => 12 pairs (_) / D8 = 2  => 10 pairs (_)
B9,E9: 2.. / B9 = 2  => 10 pairs (_) / E9 = 2  => 12 pairs (_)
G2,H3: 3.. / G2 = 3  =>  0 pairs (X) / H3 = 3  =>  0 pairs (_)
C8,C9: 3.. / C8 = 3  =>  0 pairs (*) / C9 = 3  =>  0 pairs (X)
D3,H3: 3.. / D3 = 3  =>  0 pairs (X) / H3 = 3  =>  0 pairs (_)
G1,H1: 4.. / G1 = 4  => 18 pairs (_) / H1 = 4  => 12 pairs (_)
G5,H6: 4.. / G5 = 4  => 12 pairs (_) / H6 = 4  => 18 pairs (_)
B7,B9: 4.. / B7 = 4  =>  9 pairs (_) / B9 = 4  => 10 pairs (_)
G1,G5: 4.. / G1 = 4  => 18 pairs (_) / G5 = 4  => 12 pairs (_)
H1,H6: 4.. / H1 = 4  => 12 pairs (_) / H6 = 4  => 18 pairs (_)
G2,H3: 5.. / G2 = 5  =>  0 pairs (*) / H3 = 5  =>  0 pairs (X)
C8,C9: 5.. / C8 = 5  =>  0 pairs (X) / C9 = 5  =>  0 pairs (_)
D3,H3: 5.. / D3 = 5  =>  0 pairs (*) / H3 = 5  =>  0 pairs (X)
D2,F2: 6.. / D2 = 6  =>  9 pairs (_) / F2 = 6  => 12 pairs (_)
C5,C6: 6.. / C5 = 6  => 12 pairs (_) / C6 = 6  => 11 pairs (_)
D2,D8: 6.. / D2 = 6  =>  9 pairs (_) / D8 = 6  => 12 pairs (_)
E6,F6: 7.. / E6 = 7  =>  9 pairs (_) / F6 = 7  =>  9 pairs (_)
H4,I4: 7.. / H4 = 7  => 17 pairs (_) / I4 = 7  =>  9 pairs (_)
I4,I9: 7.. / I4 = 7  =>  9 pairs (_) / I9 = 7  => 17 pairs (_)
* DURATION: 0:00:36.735771  START: 16:37:57.335318  END: 16:38:34.071089 2017-05-04
* CP COUNT: (23)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B7,B8,C4,C8,C9,D3,G2,H3,I1)
* 358712...917....82264.987.148..61...57.8...1.13....8..6.1...2.87...8.1.48..1.....
* PAIR D3: 3,5 BLK 2
D2: 3,5,4,6                              # reduction candidate for 3,5
D2: 3,5 => CTR
* 358712.4.917.46.82264.987.1489261...57283.416136...8296.1...2.872.68.1.48..12....
D2: 4,6                                  # 10 pairs
E2: 3,5,4                                # reduction candidate for 3,5
E2: 3,5                                  # 12 pairs
F2: 3,5,4,6                              # reduction candidate for 3,5
F2: 3,5                                  # 11 pairs
* PAIR D3: 3,5 COL D
D4: 3,5,2,9                              # reduction candidate for 3,5
D4: 3,5                                  # 12 pairs
D7: 3,5,4,9                              # reduction candidate for 3,5
D7: 3,5 => CTR
* 358712...917....82264.987.148..61...57.8...1.13....8..6.1...2.87...8.1.48..1.....
D7: 4,9                                  # 10 pairs
D8: 3,5,2,6,9                            # reduction candidate for 3,5
D8: 3,5 => CTR
* 358712.4.9176...82264.987.1489261...5728..416136...8296.1...2.872..8.1.48..12....
D8: 2,6,9                                #  9 pairs
* PAIR I1: 6,9 BLK 3
G1: 6,9,4                                # reduction candidate for 6,9
G1: 6,9                                  # 12 pairs
H1: 6,9,4                                # reduction candidate for 6,9
H1: 6,9                                  # 18 pairs
* PAIR I1: 6,9 COL I
I5: 6,9,3                                # reduction candidate for 6,9
I5: 6,9 => CTR
* 358712649917...382264398751482561973579823416136...8256.1.3.2.87.5.8.1.48.31..5.7
I5: 3 => SOLVED
* 358712649917634582264598731482361975576829413139457826641973258793285164825146397
I6: 6,9,5                                # reduction candidate for 6,9
I6: 6,9 => SOLVED
* 358712649917634582264598731482361975576829413139457826641973258793285164825146397
I6: 5 => CTR
* 358712...917...3822643987514825619..57.823416136...8256.1.352787.528.1348.31..5..
I9: 6,9,3,5,7                            # reduction candidate for 6,9
I9: 6,9 => CTR
* 358712...917....82264.987.148..61..757.8...1313....8.56.1...2.87...8.1.48..1.....
I9: 3,5,7                                #  9 pairs
* PAIR G2: 3,5 ROW 2
D2: 3,5,4,6                              # reduction candidate for 3,5
D2: 3,5 => CTR
* 358712.4.917.46.82264.987.1489261...57283.416136...8296.1...2.872.68.1.48..12....
D2: 4,6                                  # 10 pairs
E2: 3,5,4                                # reduction candidate for 3,5
E2: 3,5                                  # 12 pairs
F2: 3,5,4,6                              # reduction candidate for 3,5
F2: 3,5                                  # 11 pairs
* PAIR G2: 3,5 COL G
G4: 3,5,9                                # reduction candidate for 3,5
G4: 3,5                                  # 11 pairs
G9: 3,5,6,9                              # reduction candidate for 3,5
G9: 3,5                                  # 17 pairs
* PAIR H3: 3,5 COL H
H4: 3,5,2,7,9                            # reduction candidate for 3,5
H4: 3,5 => CTR
* 3587126499176...82264.987.1482.619.757.82.41.13.4..82.6419..27879.28.16482.1.6.9.
H4: 2,7,9                                #  9 pairs
H7: 3,5,7,9                              # reduction candidate for 3,5
H7: 3,5                                  # 11 pairs
H8: 3,5,6,9                              # reduction candidate for 3,5
H8: 3,5                                  # 12 pairs
H9: 3,5,6,7,9                            # reduction candidate for 3,5
H9: 3,5 => CTR
* 358712...917....82264.987.148..61...57.8...1.13....8..6.1...2.87...8.1.48..1.....
H9: 6,7,9                                #  9 pairs
* PAIR C4: 2,9 BLK 4
C5: 2,9,6                                # reduction candidate for 2,9
C5: 2,9                                  # 11 pairs
C6: 2,9,6                                # reduction candidate for 2,9
C6: 2,9                                  # 12 pairs
* PAIR C4: 2,9 ROW 4
D4: 2,9,3,5                              # reduction candidate for 2,9
D4: 2,9 => CTR
* 358712...917....82264.987.148..61...57.8...1.13....8..6.1...2.87...8.1.48..1.....
D4: 3,5                                  # 12 pairs
H4: 2,9,3,5,7                            # reduction candidate for 2,9
H4: 2,9                                  # 15 pairs
* PAIR B7: 4,9 BLK 7
B9: 4,9,2                                # reduction candidate for 4,9
B9: 4,9                                  # 12 pairs
B9: 2                                    # 10 pairs
* PAIR B7: 4,9 ROW 7
D7: 4,9,3,5                              # reduction candidate for 4,9
D7: 4,9                                  # 10 pairs
F7: 4,9,3,5,7                            # reduction candidate for 4,9
F7: 4,9 => CTR
* 358712...917....82264.987.148..61...57.8...1.13....8..6.1...2.87...8.1.48..1.....
F7: 3,5,7                                #  9 pairs
* PAIR B8: 2,9 BLK 7
B9: 2,9,4                                # reduction candidate for 2,9
B9: 4                                    # 10 pairs
B9: 2,9                                  #  9 pairs
* PAIR B8: 2,9 ROW 8
D8: 2,9,3,5,6                            # reduction candidate for 2,9
D8: 3,5,6                                # 12 pairs
D8: 2,9                                  # 10 pairs
* PAIR C8: 3,5 ROW 8
D8: 3,5,2,6,9                            # reduction candidate for 3,5
D8: 3,5 => CTR
* 358712.4.9176...82264.987.1489261...5728..416136...8296.1...2.872..8.1.48..12....
D8: 2,6,9                                #  9 pairs
F8: 3,5,6,9                              # reduction candidate for 3,5
F8: 3,5                                  # 11 pairs
H8: 3,5,6,9                              # reduction candidate for 3,5
H8: 3,5                                  # 12 pairs
* PAIR C9: 3,5 ROW 9
E9: 3,5,2,4,7                            # reduction candidate for 3,5
E9: 3,5 => CTR
* 358712.4.91764..82264.987.148..61...57.8..41.13.4..8..641...2.879.2861.482.1.4...
E9: 2,4,7                                #  9 pairs
F9: 3,5,4,6,7,9                          # reduction candidate for 3,5
F9: 3,5 => CTR
* 358712...917....82264.987.148..61...57.8...1.13....8..6.1...2.87...8.1.48..1.....
F9: 4,6,7,9                              #  9 pairs
G9: 3,5,6,9                              # reduction candidate for 3,5
G9: 3,5                                  # 17 pairs
H9: 3,5,6,7,9                            # reduction candidate for 3,5
H9: 3,5 => CTR
* 358712...917....82264.987.148..61...57.8...1.13....8..6.1...2.87...8.1.48..1.....
H9: 6,7,9                                #  9 pairs
I9: 3,5,6,7,9                            # reduction candidate for 3,5
I9: 3,5                                  # 11 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-403-base-pr-000.dot
* REASONING
* DIS # D2: 3,5 => CTR => D2: 4,6
* DIS # D7: 3,5 => CTR => D7: 4,9
* DIS # D8: 3,5 => CTR => D8: 2,6,9
* DIS # I5: 6,9 => CTR => I5: 3
* PRF # I5: 3 => SOL
* PRF # I6: 6,9 => SOL
* DIS # I6: 5 => CTR => I6: 6,9
* DIS # I9: 6,9 => CTR => I9: 3,5,7
* DIS # D2: 3,5 => CTR => D2: 4,6
* DIS # H4: 3,5 => CTR => H4: 2,7,9
* DIS # H9: 3,5 => CTR => H9: 6,7,9
* DIS # D4: 2,9 => CTR => D4: 3,5
* DIS # F7: 4,9 => CTR => F7: 3,5,7
* DIS # D8: 3,5 => CTR => D8: 2,6,9
* DIS # E9: 3,5 => CTR => E9: 2,4,7
* DIS # F9: 3,5 => CTR => F9: 4,6,7,9
* DIS # H9: 3,5 => CTR => H9: 6,7,9
* CNT  17 HDP CHAINS /  55 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B7,B8,C4,C8,C9,D3,G2,H3,I1)
* 358712...917....82264.987.148..61...57.8...1.13....8..6.1...2.87...8.1.48..1.....
* PAIR D3: 3,5 BLK 2
D2: 3,5,4,6                              # reduction candidate for 3,5
D2: 3,5 => CTR
* 358712.4.917.46.82264.987.1489261...57283.416136...8296.1...2.872.68.1.48..12....
E2: 3,5,4                                # reduction candidate for 3,5
E2: 3,5                                  # 12 pairs
F2: 3,5,4,6                              # reduction candidate for 3,5
F2: 3,5                                  # 11 pairs
* PAIR D3: 3,5 COL D
D4: 3,5,2,9                              # reduction candidate for 3,5
D4: 3,5                                  # 12 pairs
D7: 3,5,4,9                              # reduction candidate for 3,5
D7: 3,5 => CTR
* 358712...917....82264.987.148..61...57.8...1.13....8..6.1...2.87...8.1.48..1.....
D8: 3,5,2,6,9                            # reduction candidate for 3,5
D8: 3,5 => CTR
* 358712.4.9176...82264.987.1489261...5728..416136...8296.1...2.872..8.1.48..12....
* RESTART
* PAIR D3: 3,5 COL D
D4: 3,5,2,9                              # reduction candidate for 3,5
D4: 2,9 => CTR
* 358712...917...38226439875148..61..357.8...1.13.5..8..6.1...2.87.5.8.1.48.31.....
* PAIR RESTART
* PAIR D3: 3,5 BLK 2
E2: 3,5,4                                # reduction candidate for 3,5
E2: 3,5                                  # 14 pairs
F2: 3,5,4,6                              # reduction candidate for 3,5
F2: 3,5                                  # 16 pairs
* PAIR I1: 6,9 BLK 3
G1: 6,9,4                                # reduction candidate for 6,9
G1: 6,9                                  # 15 pairs
H1: 6,9,4                                # reduction candidate for 6,9
H1: 6,9                                  # 18 pairs
* PAIR I1: 6,9 COL I
I5: 6,9,3                                # reduction candidate for 6,9
I5: 6,9 => CTR
* 358712649917...382264398751482561973579823416136...8256.1.3.2.87.5.8.1.48.31..5.7
I5: 3 => SOLVED
* 358712649917634582264598731482361975576829413139457826641973258793285164825146397
* DURATION: 0:00:12.534549  START: 16:39:18.172517  END: 16:39:30.707066 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-403-base-pr-001.dot
* REASONING
* DIS # D2: 3,5 => CTR => D2: 4,6
* DIS D2: 4,6 # D7: 3,5 => CTR => D7: 4,9
* DIS D2: 4,6 + D7: 4,9 # D8: 3,5 => CTR => D8: 2,6,9
* DIS D2: 4,6 + D7: 4,9 + D8: 2,6,9 # D4: 2,9 => CTR => D4: 3,5
* DIS D2: 4,6 + D7: 4,9 + D8: 2,6,9 + D4: 3,5 # I5: 6,9 => CTR => I5: 3
* PRF D2: 4,6 + D7: 4,9 + D8: 2,6,9 + D4: 3,5 + I5: 3 => SOL
* STA D2: 4,6 + D7: 4,9 + D8: 2,6,9 + D4: 3,5 + I5: 3
* CNT   6 HDP CHAINS /  13 HYP OPENED

Header Info

Top 500 Minimum 17 403

solution: 358712649917634582264598731482361975576829413139457826641973258793285164825146397
info: 90611    FNBTXY   S8.f     30038

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

Solution

position: 358712649917634582264598731482361975576829413139457826641973258793285164825146397 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 # D2: 3,5 => CTR => D2: 4,6
* INC # D2: 4,6 => UNS
* INC # E2: 3,5 => UNS
* INC # F2: 3,5 => UNS
* INC # D4: 3,5 => UNS
* DIS # D7: 3,5 => CTR => D7: 4,9
* INC # D7: 4,9 => UNS
* DIS # D8: 3,5 => CTR => D8: 2,6,9
* INC # D8: 2,6,9 => UNS
* INC # G1: 6,9 => UNS
* INC # H1: 6,9 => UNS
* DIS # I5: 6,9 => CTR => I5: 3
* PRF # I5: 3 => SOL
* PRF # I6: 6,9 => SOL
* DIS # I6: 5 => CTR => I6: 6,9
* DIS # I9: 6,9 => CTR => I9: 3,5,7
* INC # I9: 3,5,7 => UNS
* DIS # D2: 3,5 => CTR => D2: 4,6
* INC # D2: 4,6 => UNS
* INC # E2: 3,5 => UNS
* INC # F2: 3,5 => UNS
* INC # G4: 3,5 => UNS
* INC # G9: 3,5 => UNS
* DIS # H4: 3,5 => CTR => H4: 2,7,9
* INC # H4: 2,7,9 => UNS
* INC # H7: 3,5 => UNS
* INC # H8: 3,5 => UNS
* DIS # H9: 3,5 => CTR => H9: 6,7,9
* INC # H9: 6,7,9 => UNS
* INC # C5: 2,9 => UNS
* INC # C6: 2,9 => UNS
* DIS # D4: 2,9 => CTR => D4: 3,5
* INC # D4: 3,5 => UNS
* INC # H4: 2,9 => UNS
* INC # B9: 4,9 => UNS
* INC # B9: 2 => UNS
* INC # D7: 4,9 => UNS
* DIS # F7: 4,9 => CTR => F7: 3,5,7
* INC # F7: 3,5,7 => UNS
* INC # B9: 2,9 => UNS
* INC # B9: 4 => UNS
* INC # D8: 2,9 => UNS
* INC # D8: 3,5,6 => UNS
* DIS # D8: 3,5 => CTR => D8: 2,6,9
* INC # D8: 2,6,9 => UNS
* INC # F8: 3,5 => UNS
* INC # H8: 3,5 => UNS
* DIS # E9: 3,5 => CTR => E9: 2,4,7
* INC # E9: 2,4,7 => UNS
* DIS # F9: 3,5 => CTR => F9: 4,6,7,9
* INC # F9: 4,6,7,9 => UNS
* INC # G9: 3,5 => UNS
* DIS # H9: 3,5 => CTR => H9: 6,7,9
* INC # H9: 6,7,9 => UNS
* INC # I9: 3,5 => UNS
* CNT  55 HDP CHAINS /  55 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # D2: 3,5 => CTR => D2: 4,6
* INC D2: 4,6 # E2: 3,5 => UNS
* INC D2: 4,6 # F2: 3,5 => UNS
* INC D2: 4,6 # D4: 3,5 => UNS
* DIS D2: 4,6 # D7: 3,5 => CTR => D7: 4,9
* DIS D2: 4,6 + D7: 4,9 # D8: 3,5 => CTR => D8: 2,6,9
* INC D2: 4,6 + D7: 4,9 + D8: 2,6,9 # D4: 3,5 => UNS
* DIS D2: 4,6 + D7: 4,9 + D8: 2,6,9 # D4: 2,9 => CTR => D4: 3,5
* INC D2: 4,6 + D7: 4,9 + D8: 2,6,9 + D4: 3,5 # E2: 3,5 => UNS
* INC D2: 4,6 + D7: 4,9 + D8: 2,6,9 + D4: 3,5 # F2: 3,5 => UNS
* INC D2: 4,6 + D7: 4,9 + D8: 2,6,9 + D4: 3,5 # G1: 6,9 => UNS
* INC D2: 4,6 + D7: 4,9 + D8: 2,6,9 + D4: 3,5 # H1: 6,9 => UNS
* DIS D2: 4,6 + D7: 4,9 + D8: 2,6,9 + D4: 3,5 # I5: 6,9 => CTR => I5: 3
* PRF D2: 4,6 + D7: 4,9 + D8: 2,6,9 + D4: 3,5 + I5: 3 => SOL
* STA D2: 4,6 + D7: 4,9 + D8: 2,6,9 + D4: 3,5 + I5: 3
* CNT  14 HDP CHAINS /  13 HYP OPENED