Analysis of xx-top500-440-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: ..4...53..8..6........1....1..5..7..2.......6.....8....3.4...8.6..1.............. initial

Autosolve

position: .648..531.81.654...2..1486.1965..7.82.8..13.64.36.8.1..3.4.618.64.18...381.2..6.4 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # A2: 7,9 => CTR => A2: 3
* DIS # A3: 7,9 => CTR => A3: 3,5
* DIS # A7: 5 => CTR => A7: 7,9
* DIS # A3: 7,9 => CTR => A3: 3,5
* DIS # D3: 7,9 => CTR => D3: 3
* DIS # D3: 7,9 => CTR => D3: 3
* DIS # I6: 2,9 => CTR => I6: 5
* DIS # E6: 7 => CTR => E6: 2,9
* DIS # E9: 7,9 => CTR => E9: 3,5
* CNT   9 HDP CHAINS /  43 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 # A2: 7,9 => CTR => A2: 3
* DIS A2: 3 # A3: 7,9 => CTR => A3: 5
* DIS A2: 3 + A3: 5 # I6: 2,9 => CTR => I6: 5
* DIS A2: 3 + A3: 5 + I6: 5 # E7: 7,9 => CTR => E7: 5
* DIS A2: 3 + A3: 5 + I6: 5 + E7: 5 # E9: 7,9 => CTR => E9: 3
* DIS A2: 3 + A3: 5 + I6: 5 + E7: 5 + E9: 3 # H8: 2,9 => CTR => H8: 5,7
* DIS A2: 3 + A3: 5 + I6: 5 + E7: 5 + E9: 3 + H8: 5,7 # I7: 7 => CTR => I7: 2,9
* DIS A2: 3 + A3: 5 + I6: 5 + E7: 5 + E9: 3 + H8: 5,7 + I7: 2,9 # C8: 5 => CTR => C8: 2,9
* PRF A2: 3 + A3: 5 + I6: 5 + E7: 5 + E9: 3 + H8: 5,7 + I7: 2,9 + C8: 2,9 # C7: 7,9 => SOL
* STA A2: 3 + A3: 5 + I6: 5 + E7: 5 + E9: 3 + H8: 5,7 + I7: 2,9 + C8: 2,9 + C7: 7,9
* CNT   9 HDP CHAINS /  26 HYP OPENED

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

Details

Positions

..4...53..8..6........1....1..5..7..2.......6.....8....3.4...8.6..1.............. initial
.648..531.81.654...2..1486.1965..7.82.8..13.64.36.8.1..3.4.618.64.18...381.2..6.4 autosolve
964872531381965427527314869196523748258741396473698215739456182642187953815239674 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (10)
A1: 7,9
I3: 7,9
B5: 5,7
B6: 5,7
F4: 2,3
D5: 7,9
H4: 2,4
G6: 2,9
F8: 7,9
G8: 2,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
E1,F1: 2.. / E1 = 2  => 11 pairs (_) / F1 = 2  => 15 pairs (_)
H2,I2: 2.. / H2 = 2  => 15 pairs (_) / I2 = 2  => 12 pairs (_)
C7,C8: 2.. / C7 = 2  => 10 pairs (_) / C8 = 2  =>  0 pairs (*)
C7,I7: 2.. / C7 = 2  => 10 pairs (_) / I7 = 2  =>  0 pairs (*)
F1,F4: 2.. / F1 = 2  => 15 pairs (_) / F4 = 2  => 11 pairs (_)
G6,G8: 2.. / G6 = 2  => 16 pairs (_) / G8 = 2  => 11 pairs (_)
A2,A3: 3.. / A2 = 3  => 11 pairs (_) / A3 = 3  =>  0 pairs (X)
D2,D3: 3.. / D2 = 3  =>  0 pairs (X) / D3 = 3  => 11 pairs (_)
E4,F4: 3.. / E4 = 3  => 11 pairs (_) / F4 = 3  => 15 pairs (_)
E9,F9: 3.. / E9 = 3  => 15 pairs (_) / F9 = 3  => 11 pairs (_)
A2,D2: 3.. / A2 = 3  => 11 pairs (_) / D2 = 3  =>  0 pairs (X)
A3,D3: 3.. / A3 = 3  =>  0 pairs (X) / D3 = 3  => 11 pairs (_)
E4,E9: 3.. / E4 = 3  => 11 pairs (_) / E9 = 3  => 15 pairs (_)
F4,F9: 3.. / F4 = 3  => 15 pairs (_) / F9 = 3  => 11 pairs (_)
E4,E5: 4.. / E4 = 4  => 12 pairs (_) / E5 = 4  => 12 pairs (_)
H4,H5: 4.. / H4 = 4  => 12 pairs (_) / H5 = 4  => 12 pairs (_)
E4,H4: 4.. / E4 = 4  => 12 pairs (_) / H4 = 4  => 12 pairs (_)
E5,H5: 4.. / E5 = 4  => 12 pairs (_) / H5 = 4  => 12 pairs (_)
A3,C3: 5.. / A3 = 5  => 13 pairs (_) / C3 = 5  =>  0 pairs (X)
B5,B6: 5.. / B5 = 5  => 10 pairs (_) / B6 = 5  =>  0 pairs (X)
H5,I6: 5.. / H5 = 5  =>  0 pairs (X) / I6 = 5  => 10 pairs (_)
E7,E9: 5.. / E7 = 5  => 13 pairs (_) / E9 = 5  => 14 pairs (_)
B5,H5: 5.. / B5 = 5  => 10 pairs (_) / H5 = 5  =>  0 pairs (X)
B6,I6: 5.. / B6 = 5  =>  0 pairs (X) / I6 = 5  => 10 pairs (_)
C8,H8: 5.. / C8 = 5  => 14 pairs (_) / H8 = 5  => 11 pairs (_)
A3,A7: 5.. / A3 = 5  => 13 pairs (_) / A7 = 5  =>  0 pairs (X)
I6,I7: 5.. / I6 = 5  => 10 pairs (_) / I7 = 5  =>  0 pairs (X)
B5,B6: 7.. / B5 = 7  =>  0 pairs (X) / B6 = 7  => 10 pairs (_)
B6,E6: 7.. / B6 = 7  => 10 pairs (_) / E6 = 7  =>  0 pairs (X)
G6,G8: 9.. / G6 = 9  => 11 pairs (_) / G8 = 9  => 16 pairs (_)
* DURATION: 0:00:52.704479  START: 17:48:18.683744  END: 17:49:11.388223 2017-05-04
* CP COUNT: (30)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,B5,B6,D5,F4,F8,G6,G8,H4,I3)
* .648..531.81.654...2..1486.1965..7.82.8..13.64.36.8.1..3.4.618.64.18...381.2..6.4
* PAIR A1: 7,9 BLK 1
A2: 7,9,3                                # reduction candidate for 7,9
A2: 7,9 => CTR
* .648..531.813654..325.1486.196532748258.4139647369821553.47618264.18..5381.2536.4
A2: 3                                    # 11 pairs
A3: 7,9,3,5                              # reduction candidate for 7,9
A3: 7,9 => CTR
* .648..531381.654...2531486.196532748258.4139647369821553.47618264.18..5381.2536.4
A3: 3,5                                  # 11 pairs
C3: 7,9,5                                # reduction candidate for 7,9
C3: 7,9                                  # 13 pairs
* PAIR A1: 7,9 ROW 1
E1: 7,9,2                                # reduction candidate for 7,9
E1: 7,9                                  # 15 pairs
F1: 7,9,2                                # reduction candidate for 7,9
F1: 7,9                                  # 11 pairs
* PAIR A1: 7,9 COL A
A7: 7,9,5                                # reduction candidate for 7,9
A7: 5 => CTR
* .648..531.81.654...25.1486.196532748258.4139647369821553.47618264.18..5381.2536.4
A7: 7,9                                  # 13 pairs
* PAIR I3: 7,9 BLK 3
H2: 7,9,2                                # reduction candidate for 7,9
H2: 7,9                                  # 12 pairs
I2: 7,9,2                                # reduction candidate for 7,9
I2: 7,9                                  # 15 pairs
* PAIR I3: 7,9 ROW 3
A3: 7,9,3,5                              # reduction candidate for 7,9
A3: 7,9 => CTR
* .648..531381.654...2531486.196532748258.4139647369821553.47618264.18..5381.2536.4
A3: 3,5                                  # 11 pairs
C3: 7,9,5                                # reduction candidate for 7,9
C3: 7,9                                  # 13 pairs
D3: 7,9,3                                # reduction candidate for 7,9
D3: 7,9 => CTR
* .648..531.813654..325.1486.196532748258.4139647369821553.47618264.18..5381.2536.4
D3: 3                                    # 11 pairs
* PAIR I3: 7,9 COL I
I7: 7,9,2,5                              # reduction candidate for 7,9
I7: 7,9                                  # 12 pairs
I7: 2,5                                  # 12 pairs
* PAIR F4: 2,3 BLK 5
E4: 2,3,4                                # reduction candidate for 2,3
E4: 4                                    # 12 pairs
E4: 2,3                                  # 12 pairs
* PAIR D5: 7,9 BLK 5
E5: 7,9,4                                # reduction candidate for 7,9
E5: 7,9                                  # 12 pairs
E6: 7,9,2                                # reduction candidate for 7,9
E6: 7,9                                  # 12 pairs
* PAIR D5: 7,9 COL D
D2: 7,9,3                                # reduction candidate for 7,9
D2: 7,9                                  # 11 pairs
D3: 7,9,3                                # reduction candidate for 7,9
D3: 7,9 => CTR
* .648..531.813654..325.1486.196532748258.4139647369821553.47618264.18..5381.2536.4
D3: 3                                    # 11 pairs
* PAIR H4: 2,4 ROW 4
E4: 2,4,3                                # reduction candidate for 2,4
E4: 2,4                                  # 15 pairs
E4: 3                                    # 11 pairs
* PAIR G6: 2,9 BLK 6
I6: 2,9,5                                # reduction candidate for 2,9
I6: 2,9 => CTR
* 7648..531.81.654..52.31486.196532748278941356453678.1..32496185645187..3819253674
I6: 5                                    # 10 pairs
* PAIR G6: 2,9 ROW 6
E6: 2,9,7                                # reduction candidate for 2,9
E6: 7 => CTR
* 7648..531.81.654..52.31486.196532748278941356453678.1..32496185645187..3819253674
E6: 2,9                                  # 10 pairs
* PAIR F8: 7,9 BLK 8
E7: 7,9,5                                # reduction candidate for 7,9
E7: 7,9                                  # 14 pairs
E9: 7,9,3,5                              # reduction candidate for 7,9
E9: 7,9 => CTR
* .6482.531381.654..52.31486.196532748258741396473698215.3.45618.64.189..381.2.36.4
E9: 3,5                                  # 11 pairs
F9: 7,9,3                                # reduction candidate for 7,9
F9: 7,9                                  # 15 pairs
* PAIR F8: 7,9 ROW 8
C8: 7,9,2,5                              # reduction candidate for 7,9
C8: 7,9                                  # 14 pairs
H8: 7,9,2,5                              # reduction candidate for 7,9
H8: 7,9                                  # 16 pairs
* PAIR F8: 7,9 COL F
F1: 7,9,2                                # reduction candidate for 7,9
F1: 2                                    # 15 pairs
F1: 7,9                                  # 11 pairs
* PAIR G8: 2,9 BLK 9
I7: 2,9,5,7                              # reduction candidate for 2,9
I7: 2,9                                  # 14 pairs
H8: 2,9,5,7                              # reduction candidate for 2,9
H8: 2,9                                  # 19 pairs
* PAIR G8: 2,9 ROW 8
C8: 2,9,5,7                              # reduction candidate for 2,9
C8: 2,9                                  # 14 pairs
C8: 5,7                                  # 11 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-440-base-pr-000.dot
* REASONING
* DIS # A2: 7,9 => CTR => A2: 3
* DIS # A3: 7,9 => CTR => A3: 3,5
* DIS # A7: 5 => CTR => A7: 7,9
* DIS # A3: 7,9 => CTR => A3: 3,5
* DIS # D3: 7,9 => CTR => D3: 3
* DIS # D3: 7,9 => CTR => D3: 3
* DIS # I6: 2,9 => CTR => I6: 5
* DIS # E6: 7 => CTR => E6: 2,9
* DIS # E9: 7,9 => CTR => E9: 3,5
* CNT   9 HDP CHAINS /  43 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,B5,B6,D5,F4,F8,G6,G8,H4,I3)
* .648..531.81.654...2..1486.1965..7.82.8..13.64.36.8.1..3.4.618.64.18...381.2..6.4
* PAIR A1: 7,9 BLK 1
A2: 7,9,3                                # reduction candidate for 7,9
A2: 7,9 => CTR
* .648..531.813654..325.1486.196532748258.4139647369821553.47618264.18..5381.2536.4
A3: 7,9,5                                # reduction candidate for 7,9
A3: 7,9 => CTR
* .648..531381.654...2531486.196532748258.4139647369821553.47618264.18..5381.2536.4
* RESTART
* PAIR A1: 7,9 ROW 1
E1: 7,9,2                                # reduction candidate for 7,9
E1: 7,9                                  # 15 pairs
F1: 7,9,2                                # reduction candidate for 7,9
F1: 7,9                                  # 14 pairs
* PAIR I3: 7,9 BLK 3
H2: 7,9,2                                # reduction candidate for 7,9
H2: 7,9                                  # 15 pairs
I2: 7,9,2                                # reduction candidate for 7,9
I2: 7,9                                  # 18 pairs
* PAIR I3: 7,9 COL I
I7: 7,9,2,5                              # reduction candidate for 7,9
I7: 7,9                                  # 15 pairs
I7: 2,5                                  # 15 pairs
* PAIR F4: 2,3 BLK 5
E4: 2,3,4                                # reduction candidate for 2,3
E4: 2,3                                  # 15 pairs
E4: 4                                    # 12 pairs
* PAIR D5: 7,9 BLK 5
E5: 7,9,4                                # reduction candidate for 7,9
E5: 7,9                                  # 12 pairs
E6: 7,9,2                                # reduction candidate for 7,9
E6: 7,9                                  # 15 pairs
* PAIR H4: 2,4 ROW 4
E4: 2,4,3                                # reduction candidate for 2,4
E4: 2,4                                  # 15 pairs
E4: 3                                    # 14 pairs
* PAIR G6: 2,9 BLK 6
I6: 2,9,5                                # reduction candidate for 2,9
I6: 2,9 => CTR
* .648..5313817654..52.314867196532748278941356453678.1..32496185645187..381.2536.4
* PAIR F8: 7,9 BLK 8
E7: 7,9,5                                # reduction candidate for 7,9
E7: 7,9 => CTR
* .648.953138176542952.31486.1965..7.8258..13.64736.8.15.354.618264218.95381.253674
E9: 7,9,3                                # reduction candidate for 7,9
E9: 7,9 => CTR
* .648..531381.654..52.31486.196532748258.41396473698215.3.45618.64.18.9.381.27.6.4
* RESTART
* PAIR F8: 7,9 ROW 8
C8: 7,9,2,5                              # reduction candidate for 7,9
C8: 7,9                                  # 14 pairs
H8: 7,9,2,5                              # reduction candidate for 7,9
H8: 7,9                                  # 14 pairs
* PAIR G8: 2,9 BLK 9
I7: 2,9,7                                # reduction candidate for 2,9
I7: 2,9                                  # 20 pairs
H8: 2,9,5,7                              # reduction candidate for 2,9
H8: 2,9 => CTR
* .648.2531381.6547252731486.1965.37.8258..13.64736.8.15.3.45618.645187..381.239654
* RESTART
* PAIR G8: 2,9 BLK 9
I7: 2,9,7                                # reduction candidate for 2,9
I7: 7 => CTR
* .648.2531381.654.252.3148691965.3728258..1346473628915.3245618764.18.253815237694
* PAIR G8: 2,9 ROW 8
C8: 2,9,5                                # reduction candidate for 2,9
C8: 5 => CTR
* .648.2531381.654..52.31486.1965.37.8258..13.64736.8.15.3245618964518...381.23.6.4
* PAIR RESTART

* LEVEL 0 PASS 1 ROUND 2 (AUTO SOLVE) (A1,A7,C3,C8,D2,D5,E1,E4,E6,G6,G8,H2,H4,H5,I3,I7)
* .648.2531381.654..52.31486.1965.37.8258..13.64736.8.15.3.45618.64.187.53815239674
* PAIR C3: 7,9 COL C
C7: 7,9,2                                # reduction candidate for 7,9
C7: 7,9 => SOLVED
* 964872531381965427527314869196523748258741396473698215739456182642187953815239674
* DURATION: 0:00:31.295480  START: 17:49:51.860538  END: 17:50:23.156018 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-440-base-pr-001.dot
* REASONING
* DIS # A2: 7,9 => CTR => A2: 3
* DIS A2: 3 # A3: 7,9 => CTR => A3: 5
* DIS A2: 3 + A3: 5 # I6: 2,9 => CTR => I6: 5
* DIS A2: 3 + A3: 5 + I6: 5 # E7: 7,9 => CTR => E7: 5
* DIS A2: 3 + A3: 5 + I6: 5 + E7: 5 # E9: 7,9 => CTR => E9: 3
* DIS A2: 3 + A3: 5 + I6: 5 + E7: 5 + E9: 3 # H8: 2,9 => CTR => H8: 5,7
* DIS A2: 3 + A3: 5 + I6: 5 + E7: 5 + E9: 3 + H8: 5,7 # I7: 7 => CTR => I7: 2,9
* DIS A2: 3 + A3: 5 + I6: 5 + E7: 5 + E9: 3 + H8: 5,7 + I7: 2,9 # C8: 5 => CTR => C8: 2,9
* PRF A2: 3 + A3: 5 + I6: 5 + E7: 5 + E9: 3 + H8: 5,7 + I7: 2,9 + C8: 2,9 # C7: 7,9 => SOL
* STA A2: 3 + A3: 5 + I6: 5 + E7: 5 + E9: 3 + H8: 5,7 + I7: 2,9 + C8: 2,9 + C7: 7,9
* CNT   9 HDP CHAINS /  26 HYP OPENED

Header Info

Top 500 Minimum 17 440

solution: 964872531381965427527314869196523748258741396473698215739456182642187953815239674
info: 95271    FNBXK    S8.f     47137

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

Solution

position: 964872531381965427527314869196523748258741396473698215739456182642187953815239674 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 # A2: 7,9 => CTR => A2: 3
* INC # A2: 3 => UNS
* DIS # A3: 7,9 => CTR => A3: 3,5
* INC # A3: 3,5 => UNS
* INC # C3: 7,9 => UNS
* INC # E1: 7,9 => UNS
* INC # F1: 7,9 => UNS
* INC # A7: 7,9 => UNS
* DIS # A7: 5 => CTR => A7: 7,9
* INC # H2: 7,9 => UNS
* INC # I2: 7,9 => UNS
* DIS # A3: 7,9 => CTR => A3: 3,5
* INC # A3: 3,5 => UNS
* INC # C3: 7,9 => UNS
* DIS # D3: 7,9 => CTR => D3: 3
* INC # D3: 3 => UNS
* INC # I7: 7,9 => UNS
* INC # I7: 2,5 => UNS
* INC # E4: 2,3 => UNS
* INC # E4: 4 => UNS
* INC # E5: 7,9 => UNS
* INC # E6: 7,9 => UNS
* INC # D2: 7,9 => UNS
* DIS # D3: 7,9 => CTR => D3: 3
* INC # D3: 3 => UNS
* INC # E4: 2,4 => UNS
* INC # E4: 3 => UNS
* DIS # I6: 2,9 => CTR => I6: 5
* INC # I6: 5 => UNS
* INC # E6: 2,9 => UNS
* DIS # E6: 7 => CTR => E6: 2,9
* INC # E7: 7,9 => UNS
* DIS # E9: 7,9 => CTR => E9: 3,5
* INC # E9: 3,5 => UNS
* INC # F9: 7,9 => UNS
* INC # C8: 7,9 => UNS
* INC # H8: 7,9 => UNS
* INC # F1: 7,9 => UNS
* INC # F1: 2 => UNS
* INC # I7: 2,9 => UNS
* INC # H8: 2,9 => UNS
* INC # C8: 2,9 => UNS
* INC # C8: 5,7 => UNS
* CNT  43 HDP CHAINS /  43 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # A2: 7,9 => CTR => A2: 3
* DIS A2: 3 # A3: 7,9 => CTR => A3: 5
* INC A2: 3 + A3: 5 # E1: 7,9 => UNS
* INC A2: 3 + A3: 5 # F1: 7,9 => UNS
* INC A2: 3 + A3: 5 # H2: 7,9 => UNS
* INC A2: 3 + A3: 5 # I2: 7,9 => UNS
* INC A2: 3 + A3: 5 # I7: 7,9 => UNS
* INC A2: 3 + A3: 5 # I7: 2,5 => UNS
* INC A2: 3 + A3: 5 # E4: 2,3 => UNS
* INC A2: 3 + A3: 5 # E4: 4 => UNS
* INC A2: 3 + A3: 5 # E5: 7,9 => UNS
* INC A2: 3 + A3: 5 # E6: 7,9 => UNS
* INC A2: 3 + A3: 5 # E4: 2,4 => UNS
* INC A2: 3 + A3: 5 # E4: 3 => UNS
* DIS A2: 3 + A3: 5 # I6: 2,9 => CTR => I6: 5
* DIS A2: 3 + A3: 5 + I6: 5 # E7: 7,9 => CTR => E7: 5
* DIS A2: 3 + A3: 5 + I6: 5 + E7: 5 # E9: 7,9 => CTR => E9: 3
* INC A2: 3 + A3: 5 + I6: 5 + E7: 5 + E9: 3 # C8: 7,9 => UNS
* INC A2: 3 + A3: 5 + I6: 5 + E7: 5 + E9: 3 # H8: 7,9 => UNS
* INC A2: 3 + A3: 5 + I6: 5 + E7: 5 + E9: 3 # I7: 2,9 => UNS
* DIS A2: 3 + A3: 5 + I6: 5 + E7: 5 + E9: 3 # H8: 2,9 => CTR => H8: 5,7
* INC A2: 3 + A3: 5 + I6: 5 + E7: 5 + E9: 3 + H8: 5,7 # I7: 2,9 => UNS
* DIS A2: 3 + A3: 5 + I6: 5 + E7: 5 + E9: 3 + H8: 5,7 # I7: 7 => CTR => I7: 2,9
* INC A2: 3 + A3: 5 + I6: 5 + E7: 5 + E9: 3 + H8: 5,7 + I7: 2,9 # C8: 2,9 => UNS
* DIS A2: 3 + A3: 5 + I6: 5 + E7: 5 + E9: 3 + H8: 5,7 + I7: 2,9 # C8: 5 => CTR => C8: 2,9
* PRF A2: 3 + A3: 5 + I6: 5 + E7: 5 + E9: 3 + H8: 5,7 + I7: 2,9 + C8: 2,9 # C7: 7,9 => SOL
* STA A2: 3 + A3: 5 + I6: 5 + E7: 5 + E9: 3 + H8: 5,7 + I7: 2,9 + C8: 2,9 + C7: 7,9
* CNT  26 HDP CHAINS /  26 HYP OPENED