Analysis of xx-top500-347-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: .2....4.....5.7......3.....5.....713.8..2.............1...6..8.3.7.........4..... initial

Autosolve

position: .2....4.....5.7......3.2...5.2...713.8..2.............1...6..8.3.7.5....2.84..... autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # C1: 1,3 => CTR => C1: 5,9
* DIS # C2: 1,3 => CTR => C2: 4,6,9
* PRF # B6: 7 => SOL
* DIS # B6: 3 => CTR => B6: 1,7
* PRF # A5: 4,9 => SOL
* DIS # C5: 4,9 => CTR => C5: 1,3,6
* DIS # F4: 6,8 => CTR => F4: 4,9
* PRF # B7: 4,9 => SOL
* DIS # D4: 8,9 => CTR => D4: 6
* DIS # F4: 8,9 => CTR => F4: 4,6
* DIS # E1: 8,9 => CTR => E1: 1
* DIS # B6: 1 => CTR => B6: 3,7
* PRF # B7: 4,9 => SOL
* DIS # I7: 4,9 => CTR => I7: 2,5,7
* DIS # C5: 4,9 => CTR => C5: 1,3,6
* PRF # F9: 3,9 => SOL
* DIS # G7: 3,9 => CTR => G7: 2,5
* PRF # G7: 2,5 => SOL
* DIS # F5: 3,9 => CTR => F5: 1,4,5
* DIS # F6: 3,9 => CTR => F6: 1,4,5
* CNT  20 HDP CHAINS /  53 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 # C1: 1,3 => CTR => C1: 5,9
* DIS C1: 5,9 # C2: 1,3 => CTR => C2: 4,6,9
* PRF C1: 5,9 + C2: 4,6,9 # A5: 4,9 => SOL
* STA C1: 5,9 + C2: 4,6,9 + A5: 4,9
* CNT   3 HDP CHAINS /   3 HYP OPENED

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

Details

Positions

.2....4.....5.7......3.....5.....713.8..2.............1...6..8.3.7.........4..... initial
.2....4.....5.7......3.2...5.2...713.8..2.............1...6..8.3.7.5....2.84..... autosolve
725816439936547128814392675592684713483721956671935842149263587367158294258479361 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (8)
B2: 1,3
B3: 1,7
B4: 4,9
E4: 8,9
E6: 3,7
C7: 4,9
F7: 3,9
E9: 3,7

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
D7,D8: 2.. / D7 = 2  =>  0 pairs (*) / D8 = 2  =>  0 pairs (X)
C1,H1: 3.. / C1 = 3  =>  0 pairs (X) / H1 = 3  =>  8 pairs (_)
C5,F5: 3.. / C5 = 3  =>  9 pairs (_) / F5 = 3  =>  0 pairs (X)
F7,G7: 3.. / F7 = 3  =>  0 pairs (*) / G7 = 3  =>  0 pairs (X)
B2,B6: 3.. / B2 = 3  =>  8 pairs (_) / B6 = 3  =>  0 pairs (X)
E6,E9: 3.. / E6 = 3  =>  0 pairs (*) / E9 = 3  =>  0 pairs (X)
E2,E3: 4.. / E2 = 4  =>  8 pairs (_) / E3 = 4  =>  8 pairs (_)
B4,F4: 4.. / B4 = 4  =>  0 pairs (X) / F4 = 4  =>  0 pairs (_)
C1,C3: 5.. / C1 = 5  =>  8 pairs (_) / C3 = 5  =>  8 pairs (_)
F5,F6: 5.. / F5 = 5  =>  0 pairs (X) / F6 = 5  =>  8 pairs (_)
B7,B9: 5.. / B7 = 5  =>  9 pairs (_) / B9 = 5  =>  0 pairs (*)
D1,F1: 6.. / D1 = 6  =>  0 pairs (X) / F1 = 6  =>  9 pairs (_)
D4,F4: 6.. / D4 = 6  =>  9 pairs (_) / F4 = 6  =>  0 pairs (X)
B8,B9: 6.. / B8 = 6  =>  9 pairs (_) / B9 = 6  =>  9 pairs (_)
D1,D4: 6.. / D1 = 6  =>  0 pairs (X) / D4 = 6  =>  9 pairs (_)
F1,F4: 6.. / F1 = 6  =>  9 pairs (_) / F4 = 6  =>  0 pairs (X)
D7,E9: 7.. / D7 = 7  =>  0 pairs (X) / E9 = 7  =>  0 pairs (_)
A5,D5: 7.. / A5 = 7  => 12 pairs (_) / D5 = 7  =>  0 pairs (*)
D7,I7: 7.. / D7 = 7  =>  0 pairs (X) / I7 = 7  =>  0 pairs (_)
B3,B6: 7.. / B3 = 7  => 11 pairs (_) / B6 = 7  =>  0 pairs (*)
E6,E9: 7.. / E6 = 7  =>  0 pairs (X) / E9 = 7  =>  0 pairs (_)
G6,I6: 8.. / G6 = 8  =>  8 pairs (_) / I6 = 8  =>  8 pairs (_)
D8,F8: 8.. / D8 = 8  =>  0 pairs (X) / F8 = 8  => 11 pairs (_)
* DURATION: 0:00:42.281612  START: 14:35:45.246531  END: 14:36:27.528143 2017-05-04
* CP COUNT: (23)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B2,B3,B4,C7,E4,E6,E9,F7)
* .2....4.....5.7......3.2...5.2...713.8..2.............1...6..8.3.7.5....2.84.....
* PAIR B2: 1,3 BLK 1
C1: 1,3,5,9                              # reduction candidate for 1,3
C1: 1,3 => CTR
* .23.164...1.5.7.3..753.2...5.268471378..23....3..75.2.1547693823.7258...2.8431...
C1: 5,9                                  #  9 pairs
C2: 1,3,4,6,9                            # reduction candidate for 1,3
C2: 1,3 => CTR
* .25.16437...5.7....7.3.2...5.268471378..2........7....1547693823.7258...2.8431.7.
C2: 4,6,9                                #  8 pairs
* PAIR B2: 1,3 ROW 2
G2: 1,3,2,6,8,9                          # reduction candidate for 1,3
G2: 1,3                                  #  9 pairs
G2: 2,6,8,9                              #  8 pairs
* PAIR B2: 1,3 COL B
B6: 1,3,7                                # reduction candidate for 1,3
B6: 7 => SOLVED
* 725816439936547128814392675592684713483721956671935842149263587367158294258479361
B6: 1,3                                  # 11 pairs
* PAIR B3: 1,7 ROW 3
I3: 1,7,5,6,8,9                          # reduction candidate for 1,7
I3: 1,7                                  #  9 pairs
I3: 5,6,8,9                              #  8 pairs
* PAIR B3: 1,7 COL B
B6: 1,7,3                                # reduction candidate for 1,7
B6: 3 => CTR
* .2...64...1.5.7....7.3.2...5.268471378..23....3..75...1547693823.7258...2.8431...
B6: 1,7                                  #  8 pairs
* PAIR B4: 4,9 BLK 4
A5: 4,9,6,7                              # reduction candidate for 4,9
A5: 4,9 => SOLVED
* 725816439936547128814392675592684713483721956671935842149263587367158294258479361
A5: 6,7                                  #  9 pairs
C5: 4,9,1,3,6                            # reduction candidate for 4,9
C5: 4,9 => CTR
* .2...64.....5.7....7.3.2...5.268471378.123......975...1547693823.7258...2.8431...
C5: 1,3,6                                #  8 pairs
A6: 4,9,6,7                              # reduction candidate for 4,9
A6: 4,9                                  # 10 pairs
C6: 4,9,1,3,6                            # reduction candidate for 4,9
C6: 4,9                                  # 15 pairs
* PAIR B4: 4,9 ROW 4
F4: 4,9,6,8                              # reduction candidate for 4,9
F4: 6,8 => CTR
* .2....43..3.5.7....7.3.2...542...71378312.....1.73....1.4.6..873.7.5....2.847....
F4: 4,9                                  # 10 pairs
* PAIR B4: 4,9 COL B
B7: 4,9,5                                # reduction candidate for 4,9
B7: 4,9 => SOLVED
* 725816439936547128814392675592684713483721956671935842149263587367158294258479361
B7: 5                                    #  9 pairs
B8: 4,9,6                                # reduction candidate for 4,9
B8: 4,9                                  #  9 pairs
* PAIR E4: 8,9 BLK 5
D4: 8,9,6                                # reduction candidate for 8,9
D4: 8,9 => CTR
* .2.6..43..3.5.7....7.3.2...542..671378312.....1.73....1.4.6..873.7.5....2.847....
D4: 6                                    #  9 pairs
F4: 8,9,4,6                              # reduction candidate for 8,9
F4: 8,9 => CTR
* .2...643..3.5.7....7.3.2...5426..71378312.....1.73....1.4.6..873.7.5....2.847....
F4: 4,6                                  #  9 pairs
* PAIR E4: 8,9 COL E
E1: 8,9,1                                # reduction candidate for 8,9
E1: 8,9 => CTR
* 725.96431.3.517....1.342.7.592684713.83721....71935...1.9263.873.7158...2.847.1..
E1: 1                                    #  8 pairs
E2: 8,9,1,4                              # reduction candidate for 8,9
E2: 8,9                                  #  9 pairs
E3: 8,9,1,4                              # reduction candidate for 8,9
E3: 8,9                                  #  9 pairs
* PAIR E6: 3,7 ROW 6
B6: 3,7,1                                # reduction candidate for 3,7
B6: 1 => CTR
* 925816437.3.5.7....7.3.2...59268471378.12.....1.97....154769382367258...2.8431.7.
B6: 3,7                                  # 10 pairs
* PAIR C7: 4,9 BLK 7
B7: 4,9,5                                # reduction candidate for 4,9
B7: 4,9 => SOLVED
* 725816439936547128814392675592684713483721956671935842149263587367158294258479361
B7: 5                                    #  9 pairs
B8: 4,9,6                                # reduction candidate for 4,9
B8: 4,9                                  #  9 pairs
* PAIR C7: 4,9 ROW 7
I7: 4,9,2,5,7                            # reduction candidate for 4,9
I7: 4,9 => CTR
* .2....4.....5.7......3.2...5.2...713.8..2.............1..76.28.3.7258...2.8431...
I7: 2,5,7                                #  9 pairs
* PAIR C7: 4,9 COL C
C2: 4,9,1,3,6                            # reduction candidate for 4,9
C2: 4,9                                  #  9 pairs
C3: 4,9,1,5,6                            # reduction candidate for 4,9
C3: 4,9                                  #  9 pairs
C5: 4,9,1,3,6                            # reduction candidate for 4,9
C5: 4,9 => CTR
* .2...64.....5.7....7.3.2...5.268471378.123......975...1547693823.7258...2.8431...
C5: 1,3,6                                #  8 pairs
C6: 4,9,1,3,6                            # reduction candidate for 4,9
C6: 4,9                                  # 15 pairs
* PAIR F7: 3,9 BLK 8
F9: 3,9,1                                # reduction candidate for 3,9
F9: 3,9 => SOLVED
* 725816439936547128814392675592684713483721956671935842149263587367158294258479361
F9: 1                                    #  9 pairs
* PAIR F7: 3,9 ROW 7
G7: 3,9,2,5                              # reduction candidate for 3,9
G7: 3,9 => CTR
* .2....43..3.5.7....7.3.2...542...71378312.....1.73....15426..873.7.5....2.847....
G7: 2,5 => SOLVED
* 725816439936547128814392675592684713483721956671935842149263587367158294258479361
* PAIR F7: 3,9 COL F
F5: 3,9,1,4,5                            # reduction candidate for 3,9
F5: 3,9 => CTR
* .2.8.643..3.5.7....7.3.2...5926847137831296...1.735...149263587367958...2584713..
F5: 1,4,5                                #  9 pairs
F6: 3,9,1,4,5                            # reduction candidate for 3,9
F6: 3,9 => CTR
* .2.8.6437.3.5.7....7.3.2...592684713783125....1.739...1.92635843.7.58...2.84713..
F6: 1,4,5                                #  8 pairs
* PAIR E9: 3,7 ROW 9
H9: 3,7,5,6,9                            # reduction candidate for 3,7
H9: 3,7                                  # 10 pairs
H9: 5,6,9                                #  8 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-347-base-pr-000.dot
* REASONING
* DIS # C1: 1,3 => CTR => C1: 5,9
* DIS # C2: 1,3 => CTR => C2: 4,6,9
* PRF # B6: 7 => SOL
* DIS # B6: 3 => CTR => B6: 1,7
* PRF # A5: 4,9 => SOL
* DIS # C5: 4,9 => CTR => C5: 1,3,6
* DIS # F4: 6,8 => CTR => F4: 4,9
* PRF # B7: 4,9 => SOL
* DIS # D4: 8,9 => CTR => D4: 6
* DIS # F4: 8,9 => CTR => F4: 4,6
* DIS # E1: 8,9 => CTR => E1: 1
* DIS # B6: 1 => CTR => B6: 3,7
* PRF # B7: 4,9 => SOL
* DIS # I7: 4,9 => CTR => I7: 2,5,7
* DIS # C5: 4,9 => CTR => C5: 1,3,6
* PRF # F9: 3,9 => SOL
* DIS # G7: 3,9 => CTR => G7: 2,5
* PRF # G7: 2,5 => SOL
* DIS # F5: 3,9 => CTR => F5: 1,4,5
* DIS # F6: 3,9 => CTR => F6: 1,4,5
* CNT  20 HDP CHAINS /  53 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B2,B3,B4,C7,E4,E6,E9,F7)
* .2....4.....5.7......3.2...5.2...713.8..2.............1...6..8.3.7.5....2.84.....
* PAIR B2: 1,3 BLK 1
C1: 1,3,5,9                              # reduction candidate for 1,3
C1: 1,3 => CTR
* .23.164...1.5.7.3..753.2...5.268471378..23....3..75.2.1547693823.7258...2.8431...
C2: 1,3,4,6,9                            # reduction candidate for 1,3
C2: 1,3 => CTR
* .25.16437...5.7....7.3.2...5.268471378..2........7....1547693823.7258...2.8431.7.
* PAIR B4: 4,9 BLK 4
A5: 4,9,6,7                              # reduction candidate for 4,9
A5: 4,9 => SOLVED
* 725816439936547128814392675592684713483721956671935842149263587367158294258479361
* DURATION: 0:00:05.268244  START: 14:37:18.017005  END: 14:37:23.285249 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-347-base-pr-001.dot
* REASONING
* DIS # C1: 1,3 => CTR => C1: 5,9
* DIS C1: 5,9 # C2: 1,3 => CTR => C2: 4,6,9
* PRF C1: 5,9 + C2: 4,6,9 # A5: 4,9 => SOL
* STA C1: 5,9 + C2: 4,6,9 + A5: 4,9
* CNT   3 HDP CHAINS /   3 HYP OPENED

Header Info

Top 500 Minimum 17 347

solution: 725816439936547128814392675592684713483721956671935842149263587367158294258479361
info: 3682     FNBHXY   S8.f     47303

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

Solution

position: 725816439936547128814392675592684713483721956671935842149263587367158294258479361 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 # C1: 1,3 => CTR => C1: 5,9
* INC # C1: 5,9 => UNS
* DIS # C2: 1,3 => CTR => C2: 4,6,9
* INC # C2: 4,6,9 => UNS
* INC # G2: 1,3 => UNS
* INC # G2: 2,6,8,9 => UNS
* INC # B6: 1,3 => UNS
* PRF # B6: 7 => SOL
* INC # I3: 1,7 => UNS
* INC # I3: 5,6,8,9 => UNS
* INC # B6: 1,7 => UNS
* DIS # B6: 3 => CTR => B6: 1,7
* PRF # A5: 4,9 => SOL
* INC # A5: 6,7 => UNS
* DIS # C5: 4,9 => CTR => C5: 1,3,6
* INC # C5: 1,3,6 => UNS
* INC # A6: 4,9 => UNS
* INC # C6: 4,9 => UNS
* INC # F4: 4,9 => UNS
* DIS # F4: 6,8 => CTR => F4: 4,9
* PRF # B7: 4,9 => SOL
* INC # B7: 5 => UNS
* INC # B8: 4,9 => UNS
* DIS # D4: 8,9 => CTR => D4: 6
* INC # D4: 6 => UNS
* DIS # F4: 8,9 => CTR => F4: 4,6
* INC # F4: 4,6 => UNS
* DIS # E1: 8,9 => CTR => E1: 1
* INC # E1: 1 => UNS
* INC # E2: 8,9 => UNS
* INC # E3: 8,9 => UNS
* INC # B6: 3,7 => UNS
* DIS # B6: 1 => CTR => B6: 3,7
* PRF # B7: 4,9 => SOL
* INC # B7: 5 => UNS
* INC # B8: 4,9 => UNS
* DIS # I7: 4,9 => CTR => I7: 2,5,7
* INC # I7: 2,5,7 => UNS
* INC # C2: 4,9 => UNS
* INC # C3: 4,9 => UNS
* DIS # C5: 4,9 => CTR => C5: 1,3,6
* INC # C5: 1,3,6 => UNS
* INC # C6: 4,9 => UNS
* PRF # F9: 3,9 => SOL
* INC # F9: 1 => UNS
* DIS # G7: 3,9 => CTR => G7: 2,5
* PRF # G7: 2,5 => SOL
* DIS # F5: 3,9 => CTR => F5: 1,4,5
* INC # F5: 1,4,5 => UNS
* DIS # F6: 3,9 => CTR => F6: 1,4,5
* INC # F6: 1,4,5 => UNS
* INC # H9: 3,7 => UNS
* INC # H9: 5,6,9 => UNS
* CNT  53 HDP CHAINS /  53 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # C1: 1,3 => CTR => C1: 5,9
* DIS C1: 5,9 # C2: 1,3 => CTR => C2: 4,6,9
* PRF C1: 5,9 + C2: 4,6,9 # A5: 4,9 => SOL
* STA C1: 5,9 + C2: 4,6,9 + A5: 4,9
* CNT   3 HDP CHAINS /   3 HYP OPENED