Analysis of xx-top500-484-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: ...4...3..51........8.............139..5...........68..7...82..4.....5......1.... initial

Autosolve

position: ...4...3..51.......48....5.......9139.65...........685.7...82..4.....5......1.3.. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # F3: 1,7 => CTR => F3: 2,3,6,9
* PRF # D4: 2,8 => SOL
* DIS # D4: 6,7 => CTR => D4: 2,8
* DIS # E4: 2,8 => CTR => E4: 4,6,7
* DIS # F6: 1,7 => CTR => F6: 2,3,4,9
* PRF # C4: 4,7 => SOL
* DIS # E6: 4,7 => CTR => E6: 2,3,9
* DIS # F6: 4,7 => CTR => F6: 1,2,3,9
* PRF # B5: 3,8 => SOL
* DIS # B5: 1 => CTR => B5: 3,8
* DIS # E2: 3,8 => CTR => E2: 2,6,7,9
* DIS # D6: 1,3 => CTR => D6: 2,7,9
* PRF # D6: 2,7,9 => SOL
* DIS # F6: 1,3 => CTR => F6: 2,4,7,9
* DIS # B5: 1,3 => CTR => B5: 8
* PRF # B5: 8 => SOL
* DIS # F3: 1,3 => CTR => F3: 2,6,7,9
* DIS # G2: 4,7 => CTR => G2: 8
* PRF # G2: 8 => SOL
* DIS # B5: 3 => CTR => B5: 1,8
* PRF # I9: 6,9 => SOL
* CNT  21 HDP CHAINS /  38 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 # F3: 1,7 => CTR => F3: 2,3,6,9
* DIS F3: 2,3,6,9 # D3: 2,3,6,9 => CTR => D3: 1,7
* PRF F3: 2,3,6,9 + D3: 1,7 # D4: 2,8 => SOL
* STA F3: 2,3,6,9 + D3: 1,7 + D4: 2,8
* CNT   3 HDP CHAINS /   5 HYP OPENED

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

Details

Positions

...4...3..51........8.............139..5...........68..7...82..4.....5......1.... initial
...4...3..51.......48....5.......9139.65...........685.7...82..4.....5......1.3.. autosolve
769485132251397864348162759527846913986531427134729685673958241412673598895214376 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (16)
B1: 6,9
E1: 5,8
F1: 1,5
G1: 1,8
G3: 1,7
B4: 2,8
A6: 1,7
C6: 4,7
E5: 3,8
F5: 1,3
G5: 4,7
B8: 1,8
B9: 6,9
E7: 4,5
F9: 4,5
I8: 1,8

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
G1,G3: 1.. / G1 = 1  =>  0 pairs (*) / G3 = 1  =>  0 pairs (X)
A7,B8: 1.. / A7 = 1  =>  0 pairs (X) / B8 = 1  =>  0 pairs (_)
I7,I8: 1.. / I7 = 1  =>  0 pairs (*) / I8 = 1  =>  0 pairs (X)
F1,G1: 1.. / F1 = 1  =>  0 pairs (X) / G1 = 1  =>  0 pairs (_)
B5,F5: 1.. / B5 = 1  =>  0 pairs (X) / F5 = 1  =>  0 pairs (_)
A7,I7: 1.. / A7 = 1  =>  0 pairs (X) / I7 = 1  =>  0 pairs (_)
B8,I8: 1.. / B8 = 1  =>  0 pairs (*) / I8 = 1  =>  0 pairs (X)
A6,A7: 1.. / A6 = 1  =>  0 pairs (*) / A7 = 1  =>  0 pairs (X)
D3,D6: 1.. / D3 = 1  =>  0 pairs (*) / D6 = 1  =>  0 pairs (X)
B4,B6: 2.. / B4 = 2  => 16 pairs (_) / B6 = 2  =>  0 pairs (X)
H5,I5: 2.. / H5 = 2  => 17 pairs (_) / I5 = 2  => 19 pairs (_)
H2,H5: 2.. / H2 = 2  => 19 pairs (_) / H5 = 2  => 17 pairs (_)
A2,A3: 3.. / A2 = 3  => 16 pairs (_) / A3 = 3  => 16 pairs (_)
B5,B6: 3.. / B5 = 3  =>  0 pairs (X) / B6 = 3  => 16 pairs (_)
C7,C8: 3.. / C7 = 3  => 18 pairs (_) / C8 = 3  => 17 pairs (_)
C7,D7: 3.. / C7 = 3  => 18 pairs (_) / D7 = 3  => 17 pairs (_)
C4,C6: 4.. / C4 = 4  =>  0 pairs (X) / C6 = 4  => 16 pairs (_)
E7,F9: 4.. / E7 = 4  =>  0 pairs (X) / F9 = 4  =>  0 pairs (_)
G2,G5: 4.. / G2 = 4  =>  0 pairs (X) / G5 = 4  => 19 pairs (_)
E1,F1: 5.. / E1 = 5  =>  0 pairs (X) / F1 = 5  =>  0 pairs (_)
A4,C4: 5.. / A4 = 5  =>  0 pairs (*) / C4 = 5  =>  0 pairs (X)
E7,F9: 5.. / E7 = 5  =>  0 pairs (*) / F9 = 5  =>  0 pairs (X)
E1,E7: 5.. / E1 = 5  =>  0 pairs (X) / E7 = 5  =>  0 pairs (_)
F1,F9: 5.. / F1 = 5  =>  0 pairs (*) / F9 = 5  =>  0 pairs (X)
B1,B9: 6.. / B1 = 6  =>  0 pairs (*) / B9 = 6  =>  0 pairs (X)
G1,G2: 8.. / G1 = 8  =>  0 pairs (X) / G2 = 8  =>  0 pairs (_)
B8,A9: 8.. / B8 = 8  =>  0 pairs (X) / A9 = 8  =>  0 pairs (_)
I8,I9: 8.. / I8 = 8  =>  0 pairs (*) / I9 = 8  =>  0 pairs (X)
E1,G1: 8.. / E1 = 8  =>  0 pairs (*) / G1 = 8  =>  0 pairs (X)
B5,E5: 8.. / B5 = 8  =>  0 pairs (*) / E5 = 8  =>  0 pairs (X)
B8,I8: 8.. / B8 = 8  =>  0 pairs (X) / I8 = 8  =>  0 pairs (_)
A9,I9: 8.. / A9 = 8  =>  0 pairs (*) / I9 = 8  =>  0 pairs (X)
A4,A9: 8.. / A4 = 8  =>  0 pairs (X) / A9 = 8  =>  0 pairs (_)
D2,D4: 8.. / D2 = 8  =>  0 pairs (X) / D4 = 8  =>  0 pairs (_)
B1,C1: 9.. / B1 = 9  => 16 pairs (_) / C1 = 9  =>  0 pairs (*)
B1,B9: 9.. / B1 = 9  => 16 pairs (_) / B9 = 9  =>  0 pairs (*)
* DURATION: 0:01:12.981062  START: 19:10:17.681038  END: 19:11:30.662100 2017-05-04
* CP COUNT: (36)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A6,B1,B4,B8,B9,C6,E1,E5,E7,F1,F5,F9,G1,G3,G5,I8)
* ...4...3..51.......48....5.......9139.65...........685.7...82..4.....5......1.3..
* PAIR G3: 1,7 ROW 3
D3: 1,7,2,3,6,9                          # reduction candidate for 1,7
D3: 1,7                                  # 17 pairs
F3: 1,7,2,3,6,9                          # reduction candidate for 1,7
F3: 1,7 => CTR
* ...4...3..51.......48....5.825...913916583...7341..68517..582..48....5.1....1.3.8
F3: 2,3,6,9                              # 16 pairs
* PAIR B4: 2,8 ROW 4
D4: 2,8,6,7                              # reduction candidate for 2,8
D4: 2,8 => SOLVED
* 769485132251397864348162759527846913986531427134729685673958241412673598895214376
D4: 6,7 => CTR
* ...45183..518......48...15.......913916583...7341..685175..82..4.....5......1.3..
E4: 2,8,4,6,7                            # reduction candidate for 2,8
E4: 2,8 => CTR
* ...45183..518......48...15.......9139165...........685.7...82..4.....5..8...1.3..
E4: 4,6,7                                # 16 pairs
* PAIR A6: 1,7 ROW 6
D6: 1,7,2,3,9                            # reduction candidate for 1,7
D6: 1,7                                  # 18 pairs
F6: 1,7,2,3,4,9                          # reduction candidate for 1,7
F6: 1,7 => CTR
* ...48513..51...8.4.481..75.5278469139865314..13492768567.35824141....5.88.52143..
F6: 2,3,4,9                              # 16 pairs
* PAIR C6: 4,7 BLK 4
C4: 4,7,5                                # reduction candidate for 4,7
C4: 4,7 => SOLVED
* 769485132251397864348162759527846913986531427134729685673958241412673598895214376
C4: 5                                    # 20 pairs
* PAIR C6: 4,7 ROW 6
E6: 4,7,2,3,9                            # reduction candidate for 4,7
E6: 4,7 => CTR
* ...48513..51...8.4.481..75.52.8..9139865314..13.9.2685679.5824141....5.88.52143..
E6: 2,3,9                                # 16 pairs
F6: 4,7,1,2,3,9                          # reduction candidate for 4,7
F6: 4,7 => CTR
* ...48513..51...8.4.481..75.52.8469139865314..134927685679.5824141....5.88.52143..
F6: 1,2,3,9                              # 16 pairs
* PAIR E5: 3,8 ROW 5
B5: 3,8,1                                # reduction candidate for 3,8
B5: 3,8 => SOLVED
* 769485132251397864348162759527846913986531427134729685673958241412673598895214376
B5: 1 => CTR
* ..745183..518......48...15.825...913916583...7341..68517..482..48....5.15...1.3.8
* PAIR E5: 3,8 COL E
E2: 3,8,2,6,7,9                          # reduction candidate for 3,8
E2: 3,8 => CTR
* ...45183..51.......48...15.......913916583...7341..685175..82..4.....5......1.3..
E2: 2,6,7,9                              # 16 pairs
* PAIR F5: 1,3 BLK 5
D6: 1,3,2,7,9                            # reduction candidate for 1,3
D6: 1,3 => CTR
* ...45183..518......48...15.......913916583...7341..685175..82..4.....5......1.3..
D6: 2,7,9 => SOLVED
* 769485132251397864348162759527846913986531427134729685673958241412673598895214376
F6: 1,3,2,4,7,9                          # reduction candidate for 1,3
F6: 1,3 => CTR
* ...4.513..51...8...481..75....8..9139.65...........685.7...82..4.....5......1.3..
F6: 2,4,7,9                              # 16 pairs
* PAIR F5: 1,3 ROW 5
B5: 1,3,8                                # reduction candidate for 1,3
B5: 1,3 => CTR
* ...45183..518......48...15.......913916583...7341..685175..82..4.....5......1.3..
B5: 8 => SOLVED
* 769485132251397864348162759527846913986531427134729685673958241412673598895214376
* PAIR F5: 1,3 COL F
F3: 1,3,2,6,7,9                          # reduction candidate for 1,3
F3: 1,3 => CTR
* .694851323516..8.42481.375.52.8..9139865314..13....68567..582.14123..5.88952143..
F3: 2,6,7,9                              # 16 pairs
* PAIR G5: 4,7 BLK 6
H5: 4,7,2                                # reduction candidate for 4,7
H5: 4,7                                  # 19 pairs
I5: 4,7,2                                # reduction candidate for 4,7
I5: 4,7                                  # 17 pairs
* PAIR G5: 4,7 COL G
G2: 4,7,8                                # reduction candidate for 4,7
G2: 4,7 => CTR
* ...45183..51.......48...15.825...913916583...7341..68517..482..48....5.15...1.3.8
G2: 8 => SOLVED
* 769485132251397864348162759527846913986531427134729685673958241412673598895214376
* PAIR B8: 1,8 COL B
B5: 1,8,3                                # reduction candidate for 1,8
B5: 3 => CTR
* ...4...3..51.......48....5.......913936581.........685.7...82..4.....5......1.3..
B5: 1,8                                  # 16 pairs
* PAIR B9: 6,9 ROW 9
D9: 6,9,2,7                              # reduction candidate for 6,9
D9: 6,9                                  # 21 pairs
H9: 6,9,4,7                              # reduction candidate for 6,9
H9: 6,9                                  # 19 pairs
I9: 6,9,4,7,8                            # reduction candidate for 6,9
I9: 6,9 => SOLVED
* 769485132251397864348162759527846913986531427134729685673958241412673598895214376
I9: 4,7,8                                # 16 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-484-base-pr-000.dot
* REASONING
* DIS # F3: 1,7 => CTR => F3: 2,3,6,9
* PRF # D4: 2,8 => SOL
* DIS # D4: 6,7 => CTR => D4: 2,8
* DIS # E4: 2,8 => CTR => E4: 4,6,7
* DIS # F6: 1,7 => CTR => F6: 2,3,4,9
* PRF # C4: 4,7 => SOL
* DIS # E6: 4,7 => CTR => E6: 2,3,9
* DIS # F6: 4,7 => CTR => F6: 1,2,3,9
* PRF # B5: 3,8 => SOL
* DIS # B5: 1 => CTR => B5: 3,8
* DIS # E2: 3,8 => CTR => E2: 2,6,7,9
* DIS # D6: 1,3 => CTR => D6: 2,7,9
* PRF # D6: 2,7,9 => SOL
* DIS # F6: 1,3 => CTR => F6: 2,4,7,9
* DIS # B5: 1,3 => CTR => B5: 8
* PRF # B5: 8 => SOL
* DIS # F3: 1,3 => CTR => F3: 2,6,7,9
* DIS # G2: 4,7 => CTR => G2: 8
* PRF # G2: 8 => SOL
* DIS # B5: 3 => CTR => B5: 1,8
* PRF # I9: 6,9 => SOL
* CNT  21 HDP CHAINS /  38 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A6,B1,B4,B8,B9,C6,E1,E5,E7,F1,F5,F9,G1,G3,G5,I8)
* ...4...3..51.......48....5.......9139.65...........685.7...82..4.....5......1.3..
* PAIR G3: 1,7 ROW 3
D3: 1,7,2,3,6,9                          # reduction candidate for 1,7
D3: 1,7                                  # 17 pairs
F3: 1,7,2,3,6,9                          # reduction candidate for 1,7
F3: 1,7 => CTR
* ...4...3..51.......48....5.825...913916583...7341..68517..582..48....5.1....1.3.8
* RESTART
* PAIR G3: 1,7 ROW 3
D3: 1,7,2,3,6,9                          # reduction candidate for 1,7
D3: 2,3,6,9 => CTR
* ...4.183..51.......48...15.......913916583...7341..68517...82..48....5.1....153.8
* PAIR RESTART
* PAIR B4: 2,8 ROW 4
D4: 2,8,6,7                              # reduction candidate for 2,8
D4: 2,8 => SOLVED
* 769485132251397864348162759527846913986531427134729685673958241412673598895214376
* DURATION: 0:00:07.098909  START: 19:12:12.810727  END: 19:12:19.909636 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-484-base-pr-001.dot
* REASONING
* DIS # F3: 1,7 => CTR => F3: 2,3,6,9
* DIS F3: 2,3,6,9 # D3: 2,3,6,9 => CTR => D3: 1,7
* PRF F3: 2,3,6,9 + D3: 1,7 # D4: 2,8 => SOL
* STA F3: 2,3,6,9 + D3: 1,7 + D4: 2,8
* CNT   3 HDP CHAINS /   5 HYP OPENED

Header Info

Top 500 Minimum 17 484

solution: 769485132251397864348162759527846913986531427134729685673958241412673598895214376
info: 95821    FNBHYK   S8.f     40239

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

Solution

position: 769485132251397864348162759527846913986531427134729685673958241412673598895214376 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 # D3: 1,7 => UNS
* DIS # F3: 1,7 => CTR => F3: 2,3,6,9
* INC # F3: 2,3,6,9 => UNS
* PRF # D4: 2,8 => SOL
* DIS # D4: 6,7 => CTR => D4: 2,8
* DIS # E4: 2,8 => CTR => E4: 4,6,7
* INC # E4: 4,6,7 => UNS
* INC # D6: 1,7 => UNS
* DIS # F6: 1,7 => CTR => F6: 2,3,4,9
* INC # F6: 2,3,4,9 => UNS
* PRF # C4: 4,7 => SOL
* INC # C4: 5 => UNS
* DIS # E6: 4,7 => CTR => E6: 2,3,9
* INC # E6: 2,3,9 => UNS
* DIS # F6: 4,7 => CTR => F6: 1,2,3,9
* INC # F6: 1,2,3,9 => UNS
* PRF # B5: 3,8 => SOL
* DIS # B5: 1 => CTR => B5: 3,8
* DIS # E2: 3,8 => CTR => E2: 2,6,7,9
* INC # E2: 2,6,7,9 => UNS
* DIS # D6: 1,3 => CTR => D6: 2,7,9
* PRF # D6: 2,7,9 => SOL
* DIS # F6: 1,3 => CTR => F6: 2,4,7,9
* INC # F6: 2,4,7,9 => UNS
* DIS # B5: 1,3 => CTR => B5: 8
* PRF # B5: 8 => SOL
* DIS # F3: 1,3 => CTR => F3: 2,6,7,9
* INC # F3: 2,6,7,9 => UNS
* INC # H5: 4,7 => UNS
* INC # I5: 4,7 => UNS
* DIS # G2: 4,7 => CTR => G2: 8
* PRF # G2: 8 => SOL
* INC # B5: 1,8 => UNS
* DIS # B5: 3 => CTR => B5: 1,8
* INC # D9: 6,9 => UNS
* INC # H9: 6,9 => UNS
* PRF # I9: 6,9 => SOL
* INC # I9: 4,7,8 => UNS
* CNT  38 HDP CHAINS /  38 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # D3: 1,7 => UNS
* DIS # F3: 1,7 => CTR => F3: 2,3,6,9
* INC F3: 2,3,6,9 # D3: 1,7 => UNS
* DIS F3: 2,3,6,9 # D3: 2,3,6,9 => CTR => D3: 1,7
* PRF F3: 2,3,6,9 + D3: 1,7 # D4: 2,8 => SOL
* STA F3: 2,3,6,9 + D3: 1,7 + D4: 2,8
* CNT   5 HDP CHAINS /   5 HYP OPENED