Analysis of xx-top500-379-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 7.3....8.....12............5..7...3..1..5....4.6.......8....1.5......2.....3..... initial

Autosolve

position: 7235...81....1237.1...37.525927.183.817.53.2.43692851738.27.1.5.7.18.2.32.13..7.8 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # I2: 4 => CTR => I2: 6,9
* PRF # G3: 4,6 => SOL
* PRF # G3: 4,6 => SOL
* PRF # G5: 9 => SOL
* PRF # I5: 4,6 => SOL
* PRF # I5: 4,6 => SOL
* PRF # I2: 9 => SOL
* CNT   7 HDP CHAINS /  36 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 # I2: 4 => CTR => I2: 6,9
* DIS I2: 6,9 # D3: 4,6 => CTR => D3: 8
* PRF I2: 6,9 + D3: 8 => SOL
* STA I2: 6,9 + D3: 8
* CNT   3 HDP CHAINS /   3 HYP OPENED

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

Details

Positions

7.3....8.....12............5..7...3..1..5....4.6.......8....1.5......2.....3..... initial
7235...81....1237.1...37.525927.183.817.53.2.43692851738.27.1.5.7.18.2.32.13..7.8 autosolve
723569481658412379149837652592741836817653924436928517384276195975184263261395748 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (8)
A2: 6,9
B3: 4,6
G1: 4,6
E4: 4,6
D5: 4,6
I4: 4,6
C7: 4,9
A8: 6,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
E4,D5: 4.. / E4 = 4  =>  0 pairs (*) / D5 = 4  =>  0 pairs (X)
E4,I4: 4.. / E4 = 4  =>  0 pairs (*) / I4 = 4  =>  0 pairs (X)
B2,C2: 5.. / B2 = 5  =>  9 pairs (_) / C2 = 5  => 12 pairs (_)
C8,B9: 5.. / C8 = 5  =>  9 pairs (_) / B9 = 5  => 12 pairs (_)
F8,F9: 5.. / F8 = 5  => 12 pairs (_) / F9 = 5  =>  9 pairs (_)
C8,F8: 5.. / C8 = 5  =>  9 pairs (_) / F8 = 5  => 12 pairs (_)
B9,F9: 5.. / B9 = 5  => 12 pairs (_) / F9 = 5  =>  9 pairs (_)
B2,B9: 5.. / B2 = 5  =>  9 pairs (_) / B9 = 5  => 12 pairs (_)
C2,C8: 5.. / C2 = 5  => 12 pairs (_) / C8 = 5  =>  9 pairs (_)
E4,D5: 6.. / E4 = 6  =>  0 pairs (X) / D5 = 6  =>  0 pairs (_)
A8,B9: 6.. / A8 = 6  => 11 pairs (_) / B9 = 6  => 18 pairs (_)
E4,I4: 6.. / E4 = 6  =>  0 pairs (X) / I4 = 6  =>  0 pairs (_)
F7,H7: 6.. / F7 = 6  => 11 pairs (_) / H7 = 6  => 11 pairs (_)
A2,A8: 6.. / A2 = 6  => 18 pairs (_) / A8 = 6  => 11 pairs (_)
C2,C3: 8.. / C2 = 8  => 12 pairs (_) / C3 = 8  => 11 pairs (_)
D2,D3: 8.. / D2 = 8  => 11 pairs (_) / D3 = 8  => 12 pairs (_)
C2,D2: 8.. / C2 = 8  => 12 pairs (_) / D2 = 8  => 11 pairs (_)
C3,D3: 8.. / C3 = 8  => 11 pairs (_) / D3 = 8  => 12 pairs (_)
E1,F1: 9.. / E1 = 9  => 10 pairs (_) / F1 = 9  => 11 pairs (_)
I2,G3: 9.. / I2 = 9  =>  0 pairs (*) / G3 = 9  =>  0 pairs (X)
G5,I5: 9.. / G5 = 9  =>  0 pairs (*) / I5 = 9  =>  0 pairs (X)
C3,G3: 9.. / C3 = 9  =>  0 pairs (*) / G3 = 9  =>  0 pairs (X)
A2,A8: 9.. / A2 = 9  => 11 pairs (_) / A8 = 9  => 18 pairs (_)
E1,E9: 9.. / E1 = 9  => 10 pairs (_) / E9 = 9  => 11 pairs (_)
G3,G5: 9.. / G3 = 9  => 11 pairs (_) / G5 = 9  =>  0 pairs (*)
I2,I5: 9.. / I2 = 9  =>  0 pairs (*) / I5 = 9  =>  0 pairs (X)
* DURATION: 0:00:43.098030  START: 15:50:14.534354  END: 15:50:57.632384 2017-05-04
* CP COUNT: (26)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A2,A8,B3,C7,D5,E4,G1,I4)
* 7235...81....1237.1...37.525927.183.817.53.2.43692851738.27.1.5.7.18.2.32.13..7.8
* PAIR A2: 6,9 ROW 2
I2: 6,9,4                                # reduction candidate for 6,9
I2: 4 => CTR
* 7235.4681....123741...3795259274183681765342943692851738.27.1.5.7.18.2.32.13..7.8
I2: 6,9                                  # 12 pairs
* PAIR B3: 4,6 BLK 1
B2: 4,6,5                                # reduction candidate for 4,6
B2: 4,6                                  # 12 pairs
B2: 5                                    #  9 pairs
* PAIR B3: 4,6 ROW 3
D3: 4,6,8                                # reduction candidate for 4,6
D3: 4,6                                  # 11 pairs
G3: 4,6,9                                # reduction candidate for 4,6
G3: 4,6 => SOLVED
* 723569481658412379149837652592741836817653924436928517384276195975184263261395748
G3: 9                                    # 11 pairs
* PAIR B3: 4,6 COL B
B9: 4,6,5                                # reduction candidate for 4,6
B9: 5                                    # 12 pairs
B9: 4,6                                  #  9 pairs
* PAIR G1: 4,6 BLK 3
I2: 4,6,9                                # reduction candidate for 4,6
I2: 4,6                                  # 11 pairs
G3: 4,6,9                                # reduction candidate for 4,6
G3: 4,6 => SOLVED
* 723569481658412379149837652592741836817653924436928517384276195975184263261395748
G3: 9                                    # 11 pairs
* PAIR G1: 4,6 ROW 1
E1: 4,6,9                                # reduction candidate for 4,6
E1: 4,6                                  # 11 pairs
F1: 4,6,9                                # reduction candidate for 4,6
F1: 4,6                                  # 10 pairs
* PAIR G1: 4,6 COL G
G5: 4,6,9                                # reduction candidate for 4,6
G5: 9 => SOLVED
* 723569481658412379149837652592741836817653924436928517384276195975184263261395748
G5: 4,6                                  # 11 pairs
* PAIR E4: 4,6 COL E
E1: 4,6,9                                # reduction candidate for 4,6
E1: 4,6                                  # 11 pairs
E9: 4,6,9                                # reduction candidate for 4,6
E9: 4,6                                  # 10 pairs
* PAIR D5: 4,6 ROW 5
G5: 4,6,9                                # reduction candidate for 4,6
G5: 4,6                                  # 11 pairs
I5: 4,6,9                                # reduction candidate for 4,6
I5: 4,6 => SOLVED
* 723569481658412379149837652592741836817653924436928517384276195975184263261395748
I5: 9                                    # 11 pairs
* PAIR D5: 4,6 COL D
D2: 4,6,8                                # reduction candidate for 4,6
D2: 4,6                                  # 12 pairs
D3: 4,6,8                                # reduction candidate for 4,6
D3: 4,6                                  # 11 pairs
* PAIR I4: 4,6 BLK 6
G5: 4,6,9                                # reduction candidate for 4,6
G5: 4,6                                  # 11 pairs
I5: 4,6,9                                # reduction candidate for 4,6
I5: 4,6 => SOLVED
* 723569481658412379149837652592741836817653924436928517384276195975184263261395748
I5: 9                                    # 11 pairs
* PAIR I4: 4,6 COL I
I2: 4,6,9                                # reduction candidate for 4,6
I2: 9 => SOLVED
* 723569481658412379149837652592741836817653924436928517384276195975184263261395748
I2: 4,6                                  # 11 pairs
* PAIR C7: 4,9 BLK 7
C8: 4,9,5                                # reduction candidate for 4,9
C8: 4,9                                  # 12 pairs
C8: 5                                    #  9 pairs
* PAIR C7: 4,9 ROW 7
F7: 4,9,6                                # reduction candidate for 4,9
F7: 4,9                                  # 11 pairs
H7: 4,9,6                                # reduction candidate for 4,9
H7: 4,9                                  # 11 pairs
* PAIR C7: 4,9 COL C
C2: 4,9,5,8                              # reduction candidate for 4,9
C2: 4,9                                  # 13 pairs
C3: 4,9,8                                # reduction candidate for 4,9
C3: 4,9                                  # 12 pairs
* PAIR A8: 6,9 ROW 8
F8: 6,9,4,5                              # reduction candidate for 6,9
F8: 6,9                                  # 12 pairs
H8: 6,9,4                                # reduction candidate for 6,9
H8: 6,9                                  # 11 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-379-base-pr-000.dot
* REASONING
* DIS # I2: 4 => CTR => I2: 6,9
* PRF # G3: 4,6 => SOL
* PRF # G3: 4,6 => SOL
* PRF # G5: 9 => SOL
* PRF # I5: 4,6 => SOL
* PRF # I5: 4,6 => SOL
* PRF # I2: 9 => SOL
* CNT   7 HDP CHAINS /  36 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A2,A8,B3,C7,D5,E4,G1,I4)
* 7235...81....1237.1...37.525927.183.817.53.2.43692851738.27.1.5.7.18.2.32.13..7.8
* PAIR A2: 6,9 ROW 2
I2: 6,9,4                                # reduction candidate for 6,9
I2: 4 => CTR
* 7235.4681....123741...3795259274183681765342943692851738.27.1.5.7.18.2.32.13..7.8
* PAIR RESTART
* PAIR B3: 4,6 ROW 3
D3: 4,6,8                                # reduction candidate for 4,6
D3: 4,6 => CTR
* 7235..4819..812376168.379525927.183.817.5362943692851738.27.1.5.7.18.2.32.13..7.8
D3: 8 => SOLVED
* 723569481658412379149837652592741836817653924436928517384276195975184263261395748
* DURATION: 0:00:03.665051  START: 15:51:32.169113  END: 15:51:35.834164 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-379-base-pr-001.dot
* REASONING
* DIS # I2: 4 => CTR => I2: 6,9
* DIS I2: 6,9 # D3: 4,6 => CTR => D3: 8
* PRF I2: 6,9 + D3: 8 => SOL
* STA I2: 6,9 + D3: 8
* CNT   3 HDP CHAINS /   3 HYP OPENED

Header Info

Top 500 Minimum 17 379

solution: 723569481658412379149837652592741836817653924436928517384276195975184263261395748
info: 32792    FNBO     S8.f     37319

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

Solution

position: 723569481658412379149837652592741836817653924436928517384276195975184263261395748 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 # I2: 6,9 => UNS
* DIS # I2: 4 => CTR => I2: 6,9
* INC # B2: 4,6 => UNS
* INC # B2: 5 => UNS
* INC # D3: 4,6 => UNS
* PRF # G3: 4,6 => SOL
* INC # G3: 9 => UNS
* INC # B9: 4,6 => UNS
* INC # B9: 5 => UNS
* INC # I2: 4,6 => UNS
* PRF # G3: 4,6 => SOL
* INC # G3: 9 => UNS
* INC # E1: 4,6 => UNS
* INC # F1: 4,6 => UNS
* INC # G5: 4,6 => UNS
* PRF # G5: 9 => SOL
* INC # E1: 4,6 => UNS
* INC # E9: 4,6 => UNS
* INC # G5: 4,6 => UNS
* PRF # I5: 4,6 => SOL
* INC # I5: 9 => UNS
* INC # D2: 4,6 => UNS
* INC # D3: 4,6 => UNS
* INC # G5: 4,6 => UNS
* PRF # I5: 4,6 => SOL
* INC # I5: 9 => UNS
* INC # I2: 4,6 => UNS
* PRF # I2: 9 => SOL
* INC # C8: 4,9 => UNS
* INC # C8: 5 => UNS
* INC # F7: 4,9 => UNS
* INC # H7: 4,9 => UNS
* INC # C2: 4,9 => UNS
* INC # C3: 4,9 => UNS
* INC # F8: 6,9 => UNS
* INC # H8: 6,9 => UNS
* CNT  36 HDP CHAINS /  36 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # I2: 6,9 => UNS
* DIS # I2: 4 => CTR => I2: 6,9
* DIS I2: 6,9 # D3: 4,6 => CTR => D3: 8
* PRF I2: 6,9 + D3: 8 => SOL
* STA I2: 6,9 + D3: 8
* CNT   4 HDP CHAINS /   3 HYP OPENED