Analysis of xx-top500-083-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: ...2...4.8.....3...1.........2..4.......8..5..7....1.....71.6..4..5.............1 initial

Autosolve

position: .572.184.84..5731221.84.7.55821749..1...82457.74..5128.2571.6844.15.827.7.842.5.1 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # C3: 6,9 => CTR => C3: 3
* DIS # C5: 3 => CTR => C5: 6,9
* DIS # E1: 6,9 => CTR => E1: 3
* PRF # D6: 6,9 => SOL
* DIS # E1: 6,9 => CTR => E1: 3
* DIS # C3: 6,9 => CTR => C3: 3
* PRF # A6: 3,9 => SOL
* PRF # D5: 3,9 => SOL
* DIS # B8: 3,9 => CTR => B8: 6
* PRF # D6: 6,9 => SOL
* PRF # A6: 3 => SOL
* DIS # E1: 6,9 => CTR => E1: 3
* DIS # B8: 3,9 => CTR => B8: 6
* PRF # A6: 3,9 => SOL
* DIS # F9: 3,9 => CTR => F9: 6
* DIS # F3: 6 => CTR => F3: 3,9
* DIS # B8: 3,9 => CTR => B8: 6
* DIS # F9: 3,9 => CTR => F9: 6
* CNT  18 HDP CHAINS /  50 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 # C3: 6,9 => CTR => C3: 3
* DIS C3: 3 # D5: 6,9 => CTR => D5: 3
* PRF C3: 3 + D5: 3 => SOL
* STA C3: 3 + D5: 3
* CNT   3 HDP CHAINS /   3 HYP OPENED

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

Details

Positions

...2...4.8.....3...1.........2..4.......8..5..7....1.....71.6..4..5.............1 initial
.572.184.84..5731221.84.7.55821749..1...82457.74..5128.2571.6844.15.827.7.842.5.1 autosolve
657231849849657312213849765582174936196382457374965128925713684461598273738426591 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (12)
C2: 6,9
D2: 6,9
I1: 6,9
H3: 6,9
B5: 3,9
E6: 6,9
H4: 3,6
I4: 3,6
A7: 3,9
F7: 3,9
I8: 3,9
H9: 3,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
A1,C3: 3.. / A1 = 3  =>  0 pairs (X) / C3 = 3  => 16 pairs (_)
E1,F3: 3.. / E1 = 3  => 16 pairs (_) / F3 = 3  =>  0 pairs (X)
D5,D6: 3.. / D5 = 3  =>  0 pairs (*) / D6 = 3  =>  0 pairs (X)
H4,I4: 3.. / H4 = 3  =>  0 pairs (*) / I4 = 3  =>  0 pairs (X)
I8,H9: 3.. / I8 = 3  =>  0 pairs (*) / H9 = 3  =>  0 pairs (X)
A1,E1: 3.. / A1 = 3  =>  0 pairs (X) / E1 = 3  => 16 pairs (_)
C3,F3: 3.. / C3 = 3  => 16 pairs (_) / F3 = 3  =>  0 pairs (X)
A6,D6: 3.. / A6 = 3  =>  0 pairs (*) / D6 = 3  =>  0 pairs (X)
A7,F7: 3.. / A7 = 3  =>  0 pairs (X) / F7 = 3  =>  0 pairs (_)
C3,C5: 3.. / C3 = 3  => 16 pairs (_) / C5 = 3  =>  0 pairs (X)
E1,E8: 3.. / E1 = 3  => 16 pairs (_) / E8 = 3  =>  0 pairs (X)
H4,H9: 3.. / H4 = 3  =>  0 pairs (*) / H9 = 3  =>  0 pairs (X)
I4,I8: 3.. / I4 = 3  =>  0 pairs (X) / I8 = 3  =>  0 pairs (_)
I1,H3: 6.. / I1 = 6  =>  0 pairs (X) / H3 = 6  =>  0 pairs (_)
C5,A6: 6.. / C5 = 6  =>  0 pairs (*) / A6 = 6  =>  0 pairs (X)
H4,I4: 6.. / H4 = 6  =>  0 pairs (X) / I4 = 6  =>  0 pairs (_)
B8,B9: 6.. / B8 = 6  => 15 pairs (_) / B9 = 6  =>  0 pairs (X)
E8,F9: 6.. / E8 = 6  =>  0 pairs (X) / F9 = 6  => 15 pairs (_)
C2,D2: 6.. / C2 = 6  => 15 pairs (_) / D2 = 6  =>  0 pairs (*)
C5,D5: 6.. / C5 = 6  =>  0 pairs (*) / D5 = 6  =>  0 pairs (X)
B8,E8: 6.. / B8 = 6  => 15 pairs (_) / E8 = 6  =>  0 pairs (X)
B9,F9: 6.. / B9 = 6  =>  0 pairs (X) / F9 = 6  => 15 pairs (_)
A1,A6: 6.. / A1 = 6  =>  0 pairs (*) / A6 = 6  =>  0 pairs (X)
F3,F9: 6.. / F3 = 6  =>  0 pairs (X) / F9 = 6  => 15 pairs (_)
H3,H4: 6.. / H3 = 6  =>  0 pairs (*) / H4 = 6  =>  0 pairs (X)
I1,I4: 6.. / I1 = 6  =>  0 pairs (X) / I4 = 6  =>  0 pairs (_)
I1,H3: 9.. / I1 = 9  =>  0 pairs (*) / H3 = 9  =>  0 pairs (X)
I8,H9: 9.. / I8 = 9  =>  0 pairs (X) / H9 = 9  =>  0 pairs (_)
C2,D2: 9.. / C2 = 9  =>  0 pairs (*) / D2 = 9  =>  0 pairs (X)
A7,F7: 9.. / A7 = 9  =>  0 pairs (*) / F7 = 9  =>  0 pairs (X)
H3,H9: 9.. / H3 = 9  =>  0 pairs (X) / H9 = 9  =>  0 pairs (_)
I1,I8: 9.. / I1 = 9  =>  0 pairs (*) / I8 = 9  =>  0 pairs (X)
* DURATION: 0:00:52.002002  START: 05:37:18.618366  END: 05:38:10.620368 2017-05-04
* CP COUNT: (32)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A7,B5,C2,D2,E6,F7,H3,H4,H9,I1,I4,I8)
* .572.184.84..5731221.84.7.55821749..1...82457.74..5128.2571.6844.15.827.7.842.5.1
* PAIR C2: 6,9 BLK 1
A1: 6,9,3                                # reduction candidate for 6,9
A1: 6,9                                  # 16 pairs
C3: 6,9,3                                # reduction candidate for 6,9
C3: 6,9 => CTR
* 3572.184.84..5731221.8437.55821749..1.368245767439512892571.6844.15.827.7.842.5.1
C3: 3                                    # 16 pairs
* PAIR C2: 6,9 COL C
C5: 6,9,3                                # reduction candidate for 6,9
C5: 3 => CTR
* 357261849846957312219843765582174936193682457674395128.2571.6844.15.827.7.842.5.1
C5: 6,9                                  # 16 pairs
* PAIR D2: 6,9 BLK 2
E1: 6,9,3                                # reduction candidate for 6,9
E1: 6,9 => CTR
* 3572.184.84..5731221.8437.55821749..1.368245767439512892571.6844.15.827.7.842.5.1
E1: 3                                    # 16 pairs
F3: 6,9,3                                # reduction candidate for 6,9
F3: 6,9                                  # 16 pairs
* PAIR D2: 6,9 COL D
D5: 6,9,3                                # reduction candidate for 6,9
D5: 6,9                                  # 14 pairs
D6: 6,9,3                                # reduction candidate for 6,9
D6: 6,9 => SOLVED
* 657231849849657312213849765582174936196382457374965128925713684461598273738426591
D6: 3                                    # 14 pairs
* PAIR I1: 6,9 ROW 1
A1: 6,9,3                                # reduction candidate for 6,9
A1: 6,9                                  # 16 pairs
E1: 6,9,3                                # reduction candidate for 6,9
E1: 6,9 => CTR
* 3572.184.84..5731221.8437.55821749..1.368245767439512892571.6844.15.827.7.842.5.1
E1: 3                                    # 16 pairs
* PAIR H3: 6,9 ROW 3
C3: 6,9,3                                # reduction candidate for 6,9
C3: 6,9 => CTR
* 3572.184.84..5731221.8437.55821749..1.368245767439512892571.6844.15.827.7.842.5.1
C3: 3                                    # 16 pairs
F3: 6,9,3                                # reduction candidate for 6,9
F3: 6,9                                  # 16 pairs
* PAIR B5: 3,9 BLK 4
C5: 3,9,6                                # reduction candidate for 3,9
C5: 3,9                                  # 15 pairs
A6: 3,9,6                                # reduction candidate for 3,9
A6: 3,9 => SOLVED
* 657231849849657312213849765582174936196382457374965128925713684461598273738426591
A6: 6                                    # 15 pairs
* PAIR B5: 3,9 ROW 5
D5: 3,9,6                                # reduction candidate for 3,9
D5: 3,9 => SOLVED
* 657231849849657312213849765582174936196382457374965128925713684461598273738426591
D5: 6                                    # 15 pairs
* PAIR B5: 3,9 COL B
B8: 3,9,6                                # reduction candidate for 3,9
B8: 3,9 => CTR
* 95723184.84..573122138467955821749631...82457.74.95128.2571.684431568279768429531
B8: 6                                    # 15 pairs
B9: 3,9,6                                # reduction candidate for 3,9
B9: 3,9                                  # 15 pairs
* PAIR E6: 6,9 BLK 5
D5: 6,9,3                                # reduction candidate for 6,9
D5: 6,9                                  # 14 pairs
D6: 6,9,3                                # reduction candidate for 6,9
D6: 6,9 => SOLVED
* 657231849849657312213849765582174936196382457374965128925713684461598273738426591
D6: 3                                    # 14 pairs
* PAIR E6: 6,9 ROW 6
A6: 6,9,3                                # reduction candidate for 6,9
A6: 3 => SOLVED
* 657231849849657312213849765582174936196382457374965128925713684461598273738426591
A6: 6,9                                  # 14 pairs
* PAIR E6: 6,9 COL E
E1: 6,9,3                                # reduction candidate for 6,9
E1: 6,9 => CTR
* 3572.184.84..5731221.8437.55821749..1.368245767439512892571.6844.15.827.7.842.5.1
E1: 3                                    # 16 pairs
E8: 6,9,3                                # reduction candidate for 6,9
E8: 6,9                                  # 16 pairs
* PAIR A7: 3,9 BLK 7
B8: 3,9,6                                # reduction candidate for 3,9
B8: 3,9 => CTR
* 95723184.84..573122138467955821749631...82457.74.95128.2571.684431568279768429531
B8: 6                                    # 15 pairs
B9: 3,9,6                                # reduction candidate for 3,9
B9: 3,9                                  # 15 pairs
* PAIR A7: 3,9 COL A
A1: 3,9,6                                # reduction candidate for 3,9
A1: 3,9                                  # 15 pairs
A6: 3,9,6                                # reduction candidate for 3,9
A6: 3,9 => SOLVED
* 657231849849657312213849765582174936196382457374965128925713684461598273738426591
A6: 6                                    # 15 pairs
* PAIR F7: 3,9 BLK 8
E8: 3,9,6                                # reduction candidate for 3,9
E8: 3,9                                  # 15 pairs
F9: 3,9,6                                # reduction candidate for 3,9
F9: 3,9 => CTR
* .5723184684695731221384679558217496319..82457.74..5128.2571.6844.1568279768429531
F9: 6                                    # 15 pairs
* PAIR F7: 3,9 COL F
F3: 3,9,6                                # reduction candidate for 3,9
F3: 6 => CTR
* .5723184.84.9573122138467955821749631.96824576743951283257196844.15682797.842.5.1
F3: 3,9                                  # 15 pairs
* PAIR I8: 3,9 ROW 8
B8: 3,9,6                                # reduction candidate for 3,9
B8: 3,9 => CTR
* 95723184.84..573122138467955821749631...82457.74.95128.2571.684431568279768429531
B8: 6                                    # 15 pairs
E8: 3,9,6                                # reduction candidate for 3,9
E8: 3,9                                  # 15 pairs
* PAIR H9: 3,9 ROW 9
B9: 3,9,6                                # reduction candidate for 3,9
B9: 3,9                                  # 15 pairs
F9: 3,9,6                                # reduction candidate for 3,9
F9: 3,9 => CTR
* .5723184684695731221384679558217496319..82457.74..5128.2571.6844.1568279768429531
F9: 6                                    # 15 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-083-base-pr-000.dot
* REASONING
* DIS # C3: 6,9 => CTR => C3: 3
* DIS # C5: 3 => CTR => C5: 6,9
* DIS # E1: 6,9 => CTR => E1: 3
* PRF # D6: 6,9 => SOL
* DIS # E1: 6,9 => CTR => E1: 3
* DIS # C3: 6,9 => CTR => C3: 3
* PRF # A6: 3,9 => SOL
* PRF # D5: 3,9 => SOL
* DIS # B8: 3,9 => CTR => B8: 6
* PRF # D6: 6,9 => SOL
* PRF # A6: 3 => SOL
* DIS # E1: 6,9 => CTR => E1: 3
* DIS # B8: 3,9 => CTR => B8: 6
* PRF # A6: 3,9 => SOL
* DIS # F9: 3,9 => CTR => F9: 6
* DIS # F3: 6 => CTR => F3: 3,9
* DIS # B8: 3,9 => CTR => B8: 6
* DIS # F9: 3,9 => CTR => F9: 6
* CNT  18 HDP CHAINS /  50 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A7,B5,C2,D2,E6,F7,H3,H4,H9,I1,I4,I8)
* .572.184.84..5731221.84.7.55821749..1...82457.74..5128.2571.6844.15.827.7.842.5.1
* PAIR C2: 6,9 BLK 1
A1: 6,9,3                                # reduction candidate for 6,9
A1: 6,9                                  # 16 pairs
C3: 6,9,3                                # reduction candidate for 6,9
C3: 6,9 => CTR
* 3572.184.84..5731221.8437.55821749..1.368245767439512892571.6844.15.827.7.842.5.1
* RESTART
* PAIR D2: 6,9 COL D
D5: 6,9,3                                # reduction candidate for 6,9
D5: 6,9 => CTR
* .5723184.84..5731221384.7.55821749..13..82457.743.51283257196844.1568273768423591
D5: 3 => SOLVED
* 657231849849657312213849765582174936196382457374965128925713684461598273738426591
* DURATION: 0:00:03.525360  START: 05:38:58.835083  END: 05:39:02.360443 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-083-base-pr-001.dot
* REASONING
* DIS # C3: 6,9 => CTR => C3: 3
* DIS C3: 3 # D5: 6,9 => CTR => D5: 3
* PRF C3: 3 + D5: 3 => SOL
* STA C3: 3 + D5: 3
* CNT   3 HDP CHAINS /   3 HYP OPENED

Header Info

Top 500 Minimum 17 083

solution: 657231849849657312213849765582174936196382457374965128925713684461598273738426591
info: 1552     FNBWXY   S8.f     46913

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

Solution

position: 657231849849657312213849765582174936196382457374965128925713684461598273738426591 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 # A1: 6,9 => UNS
* DIS # C3: 6,9 => CTR => C3: 3
* INC # C3: 3 => UNS
* INC # C5: 6,9 => UNS
* DIS # C5: 3 => CTR => C5: 6,9
* DIS # E1: 6,9 => CTR => E1: 3
* INC # E1: 3 => UNS
* INC # F3: 6,9 => UNS
* INC # D5: 6,9 => UNS
* PRF # D6: 6,9 => SOL
* INC # D6: 3 => UNS
* INC # A1: 6,9 => UNS
* DIS # E1: 6,9 => CTR => E1: 3
* INC # E1: 3 => UNS
* DIS # C3: 6,9 => CTR => C3: 3
* INC # C3: 3 => UNS
* INC # F3: 6,9 => UNS
* INC # C5: 3,9 => UNS
* PRF # A6: 3,9 => SOL
* INC # A6: 6 => UNS
* PRF # D5: 3,9 => SOL
* INC # D5: 6 => UNS
* DIS # B8: 3,9 => CTR => B8: 6
* INC # B8: 6 => UNS
* INC # B9: 3,9 => UNS
* INC # D5: 6,9 => UNS
* PRF # D6: 6,9 => SOL
* INC # D6: 3 => UNS
* INC # A6: 6,9 => UNS
* PRF # A6: 3 => SOL
* DIS # E1: 6,9 => CTR => E1: 3
* INC # E1: 3 => UNS
* INC # E8: 6,9 => UNS
* DIS # B8: 3,9 => CTR => B8: 6
* INC # B8: 6 => UNS
* INC # B9: 3,9 => UNS
* INC # A1: 3,9 => UNS
* PRF # A6: 3,9 => SOL
* INC # A6: 6 => UNS
* INC # E8: 3,9 => UNS
* DIS # F9: 3,9 => CTR => F9: 6
* INC # F9: 6 => UNS
* INC # F3: 3,9 => UNS
* DIS # F3: 6 => CTR => F3: 3,9
* DIS # B8: 3,9 => CTR => B8: 6
* INC # B8: 6 => UNS
* INC # E8: 3,9 => UNS
* INC # B9: 3,9 => UNS
* DIS # F9: 3,9 => CTR => F9: 6
* INC # F9: 6 => UNS
* CNT  50 HDP CHAINS /  50 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # A1: 6,9 => UNS
* DIS # C3: 6,9 => CTR => C3: 3
* DIS C3: 3 # D5: 6,9 => CTR => D5: 3
* PRF C3: 3 + D5: 3 => SOL
* STA C3: 3 + D5: 3
* CNT   4 HDP CHAINS /   3 HYP OPENED