Analysis of xx-top500-394-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: ..74..5..6....2...............71.8..2.....1..3........5......3..4.9............26 initial

Autosolve

position: .2743.56.6....23...3....2....67138.22.....1.33..2..6..562...93..439267..7..3..426 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # F9: 1 => CTR => F9: 5,8
* CNT   1 HDP CHAINS /  35 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 # F9: 1 => CTR => F9: 5,8
* DIS F9: 5,8 # C2: 8,9 => CTR => C2: 4
* PRF F9: 5,8 + C2: 4 => SOL
* STA F9: 5,8 + C2: 4
* CNT   3 HDP CHAINS /  27 HYP OPENED

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

Details

Positions

..74..5..6....2...............71.8..2.....1..3........5......3..4.9............26 initial
.2743.56.6....23...3....2....67138.22.....1.33..2..6..562...93..439267..7..3..426 autosolve
127438569684592371935671284456713892279864153318259647562147938843926715791385426 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (8)
A4: 4,9
B4: 5,9
A8: 1,8
D7: 1,8
E7: 4,7
F7: 4,7
E9: 5,8
I7: 1,8

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
B6,C6: 1.. / B6 = 1  => 10 pairs (_) / C6 = 1  =>  9 pairs (_)
D7,F9: 1.. / D7 = 1  => 16 pairs (_) / F9 = 1  =>  0 pairs (X)
D7,I7: 1.. / D7 = 1  => 16 pairs (_) / I7 = 1  =>  0 pairs (X)
E7,F7: 4.. / E7 = 4  =>  6 pairs (_) / F7 = 4  =>  6 pairs (_)
A4,H4: 4.. / A4 = 4  =>  8 pairs (_) / H4 = 4  =>  9 pairs (_)
A3,A4: 4.. / A3 = 4  =>  9 pairs (_) / A4 = 4  =>  8 pairs (_)
E9,F9: 5.. / E9 = 5  =>  8 pairs (_) / F9 = 5  => 16 pairs (_)
H8,I8: 5.. / H8 = 5  => 16 pairs (_) / I8 = 5  =>  9 pairs (_)
B4,H4: 5.. / B4 = 5  =>  8 pairs (_) / H4 = 5  =>  9 pairs (_)
I6,I8: 5.. / I6 = 5  => 16 pairs (_) / I8 = 5  =>  9 pairs (_)
D3,E3: 6.. / D3 = 6  =>  9 pairs (_) / E3 = 6  =>  8 pairs (_)
D5,E5: 6.. / D5 = 6  =>  8 pairs (_) / E5 = 6  =>  9 pairs (_)
D3,D5: 6.. / D3 = 6  =>  9 pairs (_) / D5 = 6  =>  8 pairs (_)
E3,E5: 6.. / E3 = 6  =>  8 pairs (_) / E5 = 6  =>  9 pairs (_)
B5,B6: 7.. / B5 = 7  =>  8 pairs (_) / B6 = 7  => 10 pairs (_)
E7,F7: 7.. / E7 = 7  =>  6 pairs (_) / F7 = 7  =>  6 pairs (_)
B5,H5: 7.. / B5 = 7  =>  8 pairs (_) / H5 = 7  => 10 pairs (_)
F3,F7: 7.. / F3 = 7  =>  6 pairs (_) / F7 = 7  =>  6 pairs (_)
D7,I7: 8.. / D7 = 8  =>  0 pairs (X) / I7 = 8  => 16 pairs (_)
B9,C9: 9.. / B9 = 9  => 11 pairs (_) / C9 = 9  =>  9 pairs (_)
* DURATION: 0:00:28.247227  START: 16:18:06.841965  END: 16:18:35.089192 2017-05-04
* CP COUNT: (20)
* CLUE FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A4,A8,B4,D7,E7,E9,F7,I7)
* .2743.56.6....23...3....2....67138.22.....1.33..2..6..562...93..439267..7..3..426
* PAIR A4: 4,9 BLK 4
C5: 4,9,5,8                              # reduction candidate for 4,9
C5: 4,9                                  # 11 pairs
C6: 4,9,1,5,8                            # reduction candidate for 4,9
C6: 4,9                                  # 13 pairs
* PAIR A4: 4,9 ROW 4
H4: 4,9,5                                # reduction candidate for 4,9
H4: 5                                    #  9 pairs
H4: 4,9                                  #  8 pairs
* PAIR A4: 4,9 COL A
A3: 4,9,1,8                              # reduction candidate for 4,9
A3: 1,8                                  # 12 pairs
A3: 4,9                                  # 10 pairs
* PAIR B4: 5,9 BLK 4
B5: 5,9,7,8                              # reduction candidate for 5,9
B5: 5,9                                  # 14 pairs
C5: 5,9,4,8                              # reduction candidate for 5,9
C5: 5,9                                  # 11 pairs
B6: 5,9,1,7,8                            # reduction candidate for 5,9
B6: 5,9                                  # 14 pairs
C6: 5,9,1,4,8                            # reduction candidate for 5,9
C6: 5,9                                  # 13 pairs
* PAIR B4: 5,9 ROW 4
H4: 5,9,4                                # reduction candidate for 5,9
H4: 4                                    #  9 pairs
H4: 5,9                                  #  8 pairs
* PAIR B4: 5,9 COL B
B2: 5,9,1,8                              # reduction candidate for 5,9
B2: 5,9                                  # 12 pairs
B2: 1,8                                  #  9 pairs
* PAIR A8: 1,8 BLK 7
B9: 1,8,9                                # reduction candidate for 1,8
B9: 1,8                                  #  9 pairs
C9: 1,8,9                                # reduction candidate for 1,8
C9: 1,8                                  # 11 pairs
* PAIR A8: 1,8 ROW 8
H8: 1,8,5                                # reduction candidate for 1,8
H8: 1,8                                  #  9 pairs
I8: 1,8,5                                # reduction candidate for 1,8
I8: 1,8                                  # 16 pairs
* PAIR A8: 1,8 COL A
A1: 1,8,9                                # reduction candidate for 1,8
A1: 1,8                                  # 10 pairs
A3: 1,8,4,9                              # reduction candidate for 1,8
A3: 1,8                                  # 12 pairs
* PAIR D7: 1,8 BLK 8
F9: 1,8,5                                # reduction candidate for 1,8
F9: 5                                    # 16 pairs
F9: 1,8                                  #  8 pairs
* PAIR D7: 1,8 COL D
D2: 1,8,5                                # reduction candidate for 1,8
D2: 1,8                                  # 11 pairs
D3: 1,8,5,6                              # reduction candidate for 1,8
D3: 1,8                                  #  9 pairs
* PAIR E9: 5,8 BLK 8
F9: 5,8,1                                # reduction candidate for 5,8
F9: 1 => CTR
* .2743.56.6....23...3....2....67138.22.....1.33..2..6..5628..9311439267..7..351426
F9: 5,8                                  # 16 pairs
* PAIR E9: 5,8 COL E
E2: 5,8,7,9                              # reduction candidate for 5,8
E2: 5,8                                  # 10 pairs
E3: 5,8,6,7,9                            # reduction candidate for 5,8
E3: 5,8                                  # 12 pairs
E5: 5,8,4,6,9                            # reduction candidate for 5,8
E5: 5,8                                  # 11 pairs
E6: 5,8,4,9                              # reduction candidate for 5,8
E6: 5,8                                  # 10 pairs
* PAIR I7: 1,8 BLK 9
H8: 1,8,5                                # reduction candidate for 1,8
H8: 1,8                                  #  9 pairs
I8: 1,8,5                                # reduction candidate for 1,8
I8: 1,8                                  # 16 pairs
* PAIR I7: 1,8 COL I
I1: 1,8,9                                # reduction candidate for 1,8
I1: 1,8                                  # 10 pairs
I2: 1,8,4,7,9                            # reduction candidate for 1,8
I2: 1,8                                  # 15 pairs
I3: 1,8,4,7,9                            # reduction candidate for 1,8
I3: 1,8                                  # 15 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-394-base-pr-000.dot
* REASONING
* DIS # F9: 1 => CTR => F9: 5,8
* CNT   1 HDP CHAINS /  35 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A4,A8,B4,D7,E7,E9,F7,I7)
* .2743.56.6....23...3....2....67138.22.....1.33..2..6..562...93..439267..7..3..426
* PAIR A4: 4,9 BLK 4
C5: 4,9,5,8                              # reduction candidate for 4,9
C5: 4,9                                  # 11 pairs
C6: 4,9,1,5,8                            # reduction candidate for 4,9
C6: 4,9                                  # 13 pairs
* PAIR A4: 4,9 ROW 4
H4: 4,9,5                                # reduction candidate for 4,9
H4: 5                                    #  9 pairs
H4: 4,9                                  #  8 pairs
* PAIR A4: 4,9 COL A
A3: 4,9,1,8                              # reduction candidate for 4,9
A3: 1,8                                  # 12 pairs
A3: 4,9                                  # 10 pairs
* PAIR B4: 5,9 BLK 4
B5: 5,9,7,8                              # reduction candidate for 5,9
B5: 5,9                                  # 14 pairs
C5: 5,9,4,8                              # reduction candidate for 5,9
C5: 5,9                                  # 11 pairs
B6: 5,9,1,7,8                            # reduction candidate for 5,9
B6: 5,9                                  # 14 pairs
C6: 5,9,1,4,8                            # reduction candidate for 5,9
C6: 5,9                                  # 13 pairs
* PAIR B4: 5,9 ROW 4
H4: 5,9,4                                # reduction candidate for 5,9
H4: 4                                    #  9 pairs
H4: 5,9                                  #  8 pairs
* PAIR B4: 5,9 COL B
B2: 5,9,1,8                              # reduction candidate for 5,9
B2: 5,9                                  # 12 pairs
B2: 1,8                                  #  9 pairs
* PAIR A8: 1,8 BLK 7
B9: 1,8,9                                # reduction candidate for 1,8
B9: 1,8                                  #  9 pairs
C9: 1,8,9                                # reduction candidate for 1,8
C9: 1,8                                  # 11 pairs
* PAIR A8: 1,8 ROW 8
H8: 1,8,5                                # reduction candidate for 1,8
H8: 1,8                                  #  9 pairs
I8: 1,8,5                                # reduction candidate for 1,8
I8: 1,8                                  # 16 pairs
* PAIR A8: 1,8 COL A
A1: 1,8,9                                # reduction candidate for 1,8
A1: 1,8                                  # 10 pairs
A3: 1,8,4,9                              # reduction candidate for 1,8
A3: 1,8                                  # 12 pairs
* PAIR D7: 1,8 BLK 8
F9: 1,8,5                                # reduction candidate for 1,8
F9: 5                                    # 16 pairs
F9: 1,8                                  #  8 pairs
* PAIR D7: 1,8 COL D
D2: 1,8,5                                # reduction candidate for 1,8
D2: 1,8                                  # 11 pairs
D3: 1,8,5,6                              # reduction candidate for 1,8
D3: 1,8                                  #  9 pairs
* PAIR E9: 5,8 BLK 8
F9: 5,8,1                                # reduction candidate for 5,8
F9: 1 => CTR
* .2743.56.6....23...3....2....67138.22.....1.33..2..6..5628..9311439267..7..351426

* LEVEL 0 PASS 1 ROUND 2 (AUTO SOLVE) (A3,A4,B2,B6,B9,C5,C6,C9,E2,E3,F5,F6,H2,H4,I3,I6)
* 1274385696..5.23.1.356.128..567138.227.86.1533..25.6..5621479388439267157..385426
* PAIR B2: 8,9 BLK 1
C2: 8,9,4                                # reduction candidate for 8,9
C2: 8,9 => CTR
* 1274385696..5.23414356912879567138.227.86.1533..25.6..5621479388439267157..385426
C2: 4 => SOLVED
* 127438569684592371935671284456713892279864153318259647562147938843926715791385426
* DURATION: 0:00:23.919471  START: 16:19:02.845720  END: 16:19:26.765191 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-394-base-pr-001.dot
* REASONING
* DIS # F9: 1 => CTR => F9: 5,8
* DIS F9: 5,8 # C2: 8,9 => CTR => C2: 4
* PRF F9: 5,8 + C2: 4 => SOL
* STA F9: 5,8 + C2: 4
* CNT   3 HDP CHAINS /  27 HYP OPENED

Header Info

Top 500 Minimum 17 394

solution: 127438569684592371935671284456713892279864153318259647562147938843926715791385426
info: 58674    FNBTXK   S8.f     14405

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

Solution

position: 127438569684592371935671284456713892279864153318259647562147938843926715791385426 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 # C5: 4,9 => UNS
* INC # C6: 4,9 => UNS
* INC # H4: 4,9 => UNS
* INC # H4: 5 => UNS
* INC # A3: 4,9 => UNS
* INC # A3: 1,8 => UNS
* INC # B5: 5,9 => UNS
* INC # C5: 5,9 => UNS
* INC # B6: 5,9 => UNS
* INC # C6: 5,9 => UNS
* INC # H4: 5,9 => UNS
* INC # H4: 4 => UNS
* INC # B2: 5,9 => UNS
* INC # B2: 1,8 => UNS
* INC # B9: 1,8 => UNS
* INC # C9: 1,8 => UNS
* INC # H8: 1,8 => UNS
* INC # I8: 1,8 => UNS
* INC # A1: 1,8 => UNS
* INC # A3: 1,8 => UNS
* INC # F9: 1,8 => UNS
* INC # F9: 5 => UNS
* INC # D2: 1,8 => UNS
* INC # D3: 1,8 => UNS
* INC # F9: 5,8 => UNS
* DIS # F9: 1 => CTR => F9: 5,8
* INC # E2: 5,8 => UNS
* INC # E3: 5,8 => UNS
* INC # E5: 5,8 => UNS
* INC # E6: 5,8 => UNS
* INC # H8: 1,8 => UNS
* INC # I8: 1,8 => UNS
* INC # I1: 1,8 => UNS
* INC # I2: 1,8 => UNS
* INC # I3: 1,8 => UNS
* CNT  35 HDP CHAINS /  35 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # C5: 4,9 => UNS
* INC # C6: 4,9 => UNS
* INC # H4: 4,9 => UNS
* INC # H4: 5 => UNS
* INC # A3: 4,9 => UNS
* INC # A3: 1,8 => UNS
* INC # B5: 5,9 => UNS
* INC # C5: 5,9 => UNS
* INC # B6: 5,9 => UNS
* INC # C6: 5,9 => UNS
* INC # H4: 5,9 => UNS
* INC # H4: 4 => UNS
* INC # B2: 5,9 => UNS
* INC # B2: 1,8 => UNS
* INC # B9: 1,8 => UNS
* INC # C9: 1,8 => UNS
* INC # H8: 1,8 => UNS
* INC # I8: 1,8 => UNS
* INC # A1: 1,8 => UNS
* INC # A3: 1,8 => UNS
* INC # F9: 1,8 => UNS
* INC # F9: 5 => UNS
* INC # D2: 1,8 => UNS
* INC # D3: 1,8 => UNS
* INC # F9: 5,8 => UNS
* DIS # F9: 1 => CTR => F9: 5,8
* DIS F9: 5,8 # C2: 8,9 => CTR => C2: 4
* PRF F9: 5,8 + C2: 4 => SOL
* STA F9: 5,8 + C2: 4
* CNT  28 HDP CHAINS /  27 HYP OPENED