Analysis of xx-top500-338-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: .2.4...6.1...8..........5..5..6.2...7.....1.....3.........1.7...3.....2..6....... initial

Autosolve

position: .2.4.7.611...8.......1..5..5136.2...7.....13....3.1.5.....1.7...317...2..67....1. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # A6: 4,9 => CTR => A6: 2,6,8
* DIS # B7: 4,9 => CTR => B7: 5,8
* DIS # C6: 2,6 => CTR => C6: 4,8,9
* DIS # I6: 2,6 => CTR => I6: 4,7,9
* DIS # F3: 3,6 => CTR => F3: 9
* CNT   5 HDP CHAINS /  19 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 # A6: 4,9 => CTR => A6: 2,6,8
* DIS A6: 2,6,8 # B7: 4,9 => CTR => B7: 5,8
* DIS A6: 2,6,8 + B7: 5,8 # C6: 2,6 => CTR => C6: 4,8,9
* DIS A6: 2,6,8 + B7: 5,8 + C6: 4,8,9 # I6: 2,6 => CTR => I6: 4,7,9
* DIS A6: 2,6,8 + B7: 5,8 + C6: 4,8,9 + I6: 4,7,9 # F3: 3,6 => CTR => F3: 9
* DIS A6: 2,6,8 + B7: 5,8 + C6: 4,8,9 + I6: 4,7,9 + F3: 9 # F2: 6 => CTR => F2: 3,5
* PRF A6: 2,6,8 + B7: 5,8 + C6: 4,8,9 + I6: 4,7,9 + F3: 9 + F2: 3,5 # B6: 4,9 => SOL
* STA A6: 2,6,8 + B7: 5,8 + C6: 4,8,9 + I6: 4,7,9 + F3: 9 + F2: 3,5 + B6: 4,9
* CNT   7 HDP CHAINS /  27 HYP OPENED

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

Details

Positions

.2.4...6.1...8..........5..5..6.2...7.....1.....3.........1.7...3.....2..6....... initial
.2.4.7.611...8.......1..5..5136.2...7.....13....3.1.5.....1.7...317...2..67....1. autosolve
925437861176285394384169572513672489742958136698341257259816743831794625467523918 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (5)
B5: 4,9
C5: 2,6
I5: 2,6
F7: 3,6
I7: 3,6

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
D2,E3: 2.. / D2 = 2  => 16 pairs (_) / E3 = 2  =>  0 pairs (X)
E3,I3: 2.. / E3 = 2  =>  0 pairs (X) / I3 = 2  => 16 pairs (_)
C5,I5: 2.. / C5 = 2  => 16 pairs (_) / I5 = 2  =>  0 pairs (X)
E3,E9: 2.. / E3 = 2  =>  0 pairs (X) / E9 = 2  => 16 pairs (_)
G2,G6: 2.. / G2 = 2  =>  0 pairs (X) / G6 = 2  => 16 pairs (_)
A1,A3: 3.. / A1 = 3  =>  0 pairs (X) / A3 = 3  => 16 pairs (_)
F7,I7: 3.. / F7 = 3  =>  0 pairs (X) / I7 = 3  => 16 pairs (_)
B7,C7: 5.. / B7 = 5  =>  5 pairs (_) / C7 = 5  =>  0 pairs (X)
I8,I9: 5.. / I8 = 5  =>  5 pairs (_) / I9 = 5  =>  5 pairs (_)
C1,E1: 5.. / C1 = 5  =>  6 pairs (_) / E1 = 5  =>  0 pairs (X)
B2,B7: 5.. / B2 = 5  =>  0 pairs (X) / B7 = 5  =>  5 pairs (_)
C2,F2: 6.. / C2 = 6  => 16 pairs (_) / F2 = 6  =>  0 pairs (X)
C5,I5: 6.. / C5 = 6  =>  0 pairs (X) / I5 = 6  => 16 pairs (_)
F7,I7: 6.. / F7 = 6  => 16 pairs (_) / I7 = 6  =>  0 pairs (X)
A3,A6: 6.. / A3 = 6  =>  0 pairs (X) / A6 = 6  => 16 pairs (_)
E3,E8: 6.. / E3 = 6  => 16 pairs (_) / E8 = 6  =>  0 pairs (X)
G6,G8: 6.. / G6 = 6  =>  0 pairs (X) / G8 = 6  => 16 pairs (_)
B2,B3: 7.. / B2 = 7  =>  6 pairs (_) / B3 = 7  =>  5 pairs (_)
E4,E6: 7.. / E4 = 7  =>  7 pairs (_) / E6 = 7  =>  6 pairs (_)
E6,I6: 7.. / E6 = 7  =>  6 pairs (_) / I6 = 7  =>  7 pairs (_)
D5,F5: 8.. / D5 = 8  =>  6 pairs (_) / F5 = 8  =>  6 pairs (_)
* DURATION: 0:00:39.546059  START: 14:18:36.892585  END: 14:19:16.438644 2017-05-04
* CP COUNT: (21)
* CLUE FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B5,C5,F7,I5,I7)
* .2.4.7.611...8.......1..5..5136.2...7.....13....3.1.5.....1.7...317...2..67....1.
* PAIR B5: 4,9 BLK 4
A6: 4,9,2,6,8                            # reduction candidate for 4,9
A6: 4,9 => CTR
* 32.4.7.611...862.36..1..5..5136.2...7.....13....3.165.....137.6.3176..2..67....1.
A6: 2,6,8                                #  5 pairs
B6: 4,9,8                                # reduction candidate for 4,9
B6: 4,9                                  #  9 pairs
C6: 4,9,2,6,8                            # reduction candidate for 4,9
C6: 4,9                                  #  7 pairs
* PAIR B5: 4,9 ROW 5
E5: 4,9,5                                # reduction candidate for 4,9
E5: 4,9                                  # 10 pairs
F5: 4,9,5,8                              # reduction candidate for 4,9
F5: 4,9                                  #  8 pairs
* PAIR B5: 4,9 COL B
B2: 4,9,5,7                              # reduction candidate for 4,9
B2: 4,9                                  #  6 pairs
B3: 4,9,7,8                              # reduction candidate for 4,9
B3: 4,9                                  #  7 pairs
B7: 4,9,5,8                              # reduction candidate for 4,9
B7: 4,9 => CTR
* .2.457.6115.28....67.1395.25136.2...7.....13..8.3.165...5.137.6.3176..2..67.2..1.
B7: 5,8                                  #  6 pairs
* PAIR C5: 2,6 BLK 4
A6: 2,6,4,8,9                            # reduction candidate for 2,6
A6: 2,6                                  #  6 pairs
C6: 2,6,4,8,9                            # reduction candidate for 2,6
C6: 2,6 => CTR
* 32.4.7.611...86...6..1395.25136.2...7.....13....3.1.5.....137.6.3176..2..67....1.
C6: 4,8,9                                #  6 pairs
* PAIR I5: 2,6 BLK 6
G6: 2,6,4,9                              # reduction candidate for 2,6
G6: 2,6                                  #  6 pairs
I6: 2,6,4,7,9                            # reduction candidate for 2,6
I6: 2,6 => CTR
* .2.4.7.611...8.2.....12.5..5136.2...7.....13....371.5.....167.3.317..62..67....1.
I6: 4,7,9                                #  6 pairs
* PAIR F7: 3,6 COL F
F2: 3,6,5,9                              # reduction candidate for 3,6
F2: 3,6                                  #  8 pairs
F3: 3,6,9                                # reduction candidate for 3,6
F3: 3,6 => CTR
* .2.4.7.611.6.8.......1..5..5136.2...7.2...1366..3.1.5.....167.3.317..62..67.3..1.
F3: 9                                    #  7 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-338-base-pr-000.dot
* REASONING
* DIS # A6: 4,9 => CTR => A6: 2,6,8
* DIS # B7: 4,9 => CTR => B7: 5,8
* DIS # C6: 2,6 => CTR => C6: 4,8,9
* DIS # I6: 2,6 => CTR => I6: 4,7,9
* DIS # F3: 3,6 => CTR => F3: 9
* CNT   5 HDP CHAINS /  19 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B5,C5,F7,I5,I7)
* .2.4.7.611...8.......1..5..5136.2...7.....13....3.1.5.....1.7...317...2..67....1.
* PAIR B5: 4,9 BLK 4
A6: 4,9,2,6,8                            # reduction candidate for 4,9
A6: 4,9 => CTR
* 32.4.7.611...862.36..1..5..5136.2...7.....13....3.165.....137.6.3176..2..67....1.
B6: 4,9,8                                # reduction candidate for 4,9
B6: 4,9                                  #  9 pairs
C6: 4,9,2,6,8                            # reduction candidate for 4,9
C6: 4,9                                  #  7 pairs
* PAIR B5: 4,9 ROW 5
E5: 4,9,5                                # reduction candidate for 4,9
E5: 4,9                                  # 10 pairs
F5: 4,9,5,8                              # reduction candidate for 4,9
F5: 4,9                                  #  8 pairs
* PAIR B5: 4,9 COL B
B2: 4,9,5,7                              # reduction candidate for 4,9
B2: 4,9                                  #  8 pairs
B3: 4,9,7,8                              # reduction candidate for 4,9
B3: 4,9                                  #  9 pairs
B7: 4,9,5,8                              # reduction candidate for 4,9
B7: 4,9 => CTR
* .2.457.6115..8.....7.16.5.25136.2...7.2...13668.3.125...5.167...317..62..67....1.
* PAIR RESTART
* PAIR B5: 4,9 BLK 4
B6: 4,9,8                                # reduction candidate for 4,9
B6: 4,9                                  #  9 pairs
C6: 4,9,2,6,8                            # reduction candidate for 4,9
C6: 4,9                                  #  7 pairs
* PAIR B5: 4,9 ROW 5
E5: 4,9,5                                # reduction candidate for 4,9
E5: 4,9                                  # 11 pairs
F5: 4,9,5,8                              # reduction candidate for 4,9
F5: 4,9                                  #  8 pairs
* PAIR B5: 4,9 COL B
B2: 4,9,5,7                              # reduction candidate for 4,9
B2: 4,9                                  #  8 pairs
B3: 4,9,7,8                              # reduction candidate for 4,9
B3: 4,9                                  #  9 pairs
* PAIR C5: 2,6 BLK 4
A6: 2,6,8                                # reduction candidate for 2,6
A6: 2,6                                  #  7 pairs
C6: 2,6,4,8,9                            # reduction candidate for 2,6
C6: 2,6 => CTR
* 32.4.7.611...86...6..1395.25136.2...7.....13.8..3.1.5.....137.6.3176..2..67....1.
* RESTART
* PAIR I5: 2,6 BLK 6
G6: 2,6,4,9                              # reduction candidate for 2,6
G6: 2,6                                  #  8 pairs
I6: 2,6,4,7,9                            # reduction candidate for 2,6
I6: 2,6 => CTR
* .2.4.7.611...8.2.....12.5..5136.2...7.....13....371.5.....167.3.317..62..67....1.
* RESTART
* PAIR F7: 3,6 COL F
F2: 3,6,5,9                              # reduction candidate for 3,6
F2: 3,6                                  # 11 pairs
F3: 3,6,9                                # reduction candidate for 3,6
F3: 3,6 => CTR
* .2.4.7.611.6.8.......1..5..5136.2...7.2...1366..3.125.....167.3.317..62..67.3..1.
* RESTART
* PAIR F7: 3,6 COL F
F2: 3,6,5                                # reduction candidate for 3,6
F2: 5                                    # 16 pairs
F2: 3,6                                  # 11 pairs
* PAIR RESTART
* PAIR F7: 3,6 COL F
F2: 3,6,5                                # reduction candidate for 3,6
F2: 5                                    # 16 pairs
F2: 3,6                                  # 11 pairs

* LEVEL 0 PASS 1 ROUND 2 (AUTO SOLVE) (A6,B5,B7,C5,D2,E1,F7,G6,I5,I7)
* .2.4.7.611...8.......1.95..5136.2...7.....13....3.1.5.....1.7...317...2..67....1.
* PAIR E1: 3,5 BLK 2
F2: 3,5,6                                # reduction candidate for 3,5
F2: 6 => CTR
* .2.4.7.611...862.36..1.95..5136.2...7.6...1322..3.165...2.137.6.3176..2..67....1.
* PAIR B5: 4,9 BLK 4
B6: 4,9,8                                # reduction candidate for 4,9
B6: 4,9 => SOLVED
* 925437861176285394384169572513672489742958136698341257259816743831794625467523918
* DURATION: 0:00:29.134344  START: 14:19:33.725448  END: 14:20:02.859792 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-338-base-pr-001.dot
* REASONING
* DIS # A6: 4,9 => CTR => A6: 2,6,8
* DIS A6: 2,6,8 # B7: 4,9 => CTR => B7: 5,8
* DIS A6: 2,6,8 + B7: 5,8 # C6: 2,6 => CTR => C6: 4,8,9
* DIS A6: 2,6,8 + B7: 5,8 + C6: 4,8,9 # I6: 2,6 => CTR => I6: 4,7,9
* DIS A6: 2,6,8 + B7: 5,8 + C6: 4,8,9 + I6: 4,7,9 # F3: 3,6 => CTR => F3: 9
* DIS A6: 2,6,8 + B7: 5,8 + C6: 4,8,9 + I6: 4,7,9 + F3: 9 # F2: 6 => CTR => F2: 3,5
* PRF A6: 2,6,8 + B7: 5,8 + C6: 4,8,9 + I6: 4,7,9 + F3: 9 + F2: 3,5 # B6: 4,9 => SOL
* STA A6: 2,6,8 + B7: 5,8 + C6: 4,8,9 + I6: 4,7,9 + F3: 9 + F2: 3,5 + B6: 4,9
* CNT   7 HDP CHAINS /  27 HYP OPENED

Header Info

Top 500 Minimum 17 338

solution: 925437861176285394384169572513672489742958136698341257259816743831794625467523918
info: 3118     FNBHWXY  S8.f     16758

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

Solution

position: 925437861176285394384169572513672489742958136698341257259816743831794625467523918 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 # A6: 4,9 => CTR => A6: 2,6,8
* INC # A6: 2,6,8 => UNS
* INC # B6: 4,9 => UNS
* INC # C6: 4,9 => UNS
* INC # E5: 4,9 => UNS
* INC # F5: 4,9 => UNS
* INC # B2: 4,9 => UNS
* INC # B3: 4,9 => UNS
* DIS # B7: 4,9 => CTR => B7: 5,8
* INC # B7: 5,8 => UNS
* INC # A6: 2,6 => UNS
* DIS # C6: 2,6 => CTR => C6: 4,8,9
* INC # C6: 4,8,9 => UNS
* INC # G6: 2,6 => UNS
* DIS # I6: 2,6 => CTR => I6: 4,7,9
* INC # I6: 4,7,9 => UNS
* INC # F2: 3,6 => UNS
* DIS # F3: 3,6 => CTR => F3: 9
* INC # F3: 9 => UNS
* CNT  19 HDP CHAINS /  19 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # A6: 4,9 => CTR => A6: 2,6,8
* INC A6: 2,6,8 # B6: 4,9 => UNS
* INC A6: 2,6,8 # C6: 4,9 => UNS
* INC A6: 2,6,8 # E5: 4,9 => UNS
* INC A6: 2,6,8 # F5: 4,9 => UNS
* INC A6: 2,6,8 # B2: 4,9 => UNS
* INC A6: 2,6,8 # B3: 4,9 => UNS
* DIS A6: 2,6,8 # B7: 4,9 => CTR => B7: 5,8
* INC A6: 2,6,8 + B7: 5,8 # B6: 4,9 => UNS
* INC A6: 2,6,8 + B7: 5,8 # C6: 4,9 => UNS
* INC A6: 2,6,8 + B7: 5,8 # E5: 4,9 => UNS
* INC A6: 2,6,8 + B7: 5,8 # F5: 4,9 => UNS
* INC A6: 2,6,8 + B7: 5,8 # B2: 4,9 => UNS
* INC A6: 2,6,8 + B7: 5,8 # B3: 4,9 => UNS
* INC A6: 2,6,8 + B7: 5,8 # A6: 2,6 => UNS
* DIS A6: 2,6,8 + B7: 5,8 # C6: 2,6 => CTR => C6: 4,8,9
* INC A6: 2,6,8 + B7: 5,8 + C6: 4,8,9 # G6: 2,6 => UNS
* DIS A6: 2,6,8 + B7: 5,8 + C6: 4,8,9 # I6: 2,6 => CTR => I6: 4,7,9
* INC A6: 2,6,8 + B7: 5,8 + C6: 4,8,9 + I6: 4,7,9 # F2: 3,6 => UNS
* DIS A6: 2,6,8 + B7: 5,8 + C6: 4,8,9 + I6: 4,7,9 # F3: 3,6 => CTR => F3: 9
* INC A6: 2,6,8 + B7: 5,8 + C6: 4,8,9 + I6: 4,7,9 + F3: 9 # F2: 3,6 => UNS
* INC A6: 2,6,8 + B7: 5,8 + C6: 4,8,9 + I6: 4,7,9 + F3: 9 # F2: 5 => UNS
* INC A6: 2,6,8 + B7: 5,8 + C6: 4,8,9 + I6: 4,7,9 + F3: 9 # F2: 3,6 => UNS
* INC A6: 2,6,8 + B7: 5,8 + C6: 4,8,9 + I6: 4,7,9 + F3: 9 # F2: 5 => UNS
* INC A6: 2,6,8 + B7: 5,8 + C6: 4,8,9 + I6: 4,7,9 + F3: 9 # F2: 3,5 => UNS
* DIS A6: 2,6,8 + B7: 5,8 + C6: 4,8,9 + I6: 4,7,9 + F3: 9 # F2: 6 => CTR => F2: 3,5
* PRF A6: 2,6,8 + B7: 5,8 + C6: 4,8,9 + I6: 4,7,9 + F3: 9 + F2: 3,5 # B6: 4,9 => SOL
* STA A6: 2,6,8 + B7: 5,8 + C6: 4,8,9 + I6: 4,7,9 + F3: 9 + F2: 3,5 + B6: 4,9
* CNT  27 HDP CHAINS /  27 HYP OPENED