Analysis of xx-top500-230-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: ...8...5.7.....3.....2.....1.....7.4.2.13..........6..6....4....1.....2.....7.... initial

Autosolve

position: 9438672517.241.36..612.347.1.6..2734427136..5.3.74.61267..241.33146...272..371.46 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # B9: 5,8 => CTR => B9: 9
* PRF # F8: 5,9 => SOL
* PRF # E4: 5,9 => SOL
* DIS # C6: 5,8 => CTR => C6: 9
* DIS # F6: 9 => CTR => F6: 5,8
* PRF # E4: 5,9 => SOL
* PRF # B4: 8 => SOL
* PRF # G9: 5 => SOL
* PRF # F8: 5,9 => SOL
* PRF # G9: 5 => SOL
* PRF # C7: 5 => SOL
* PRF # F8: 5,9 => SOL
* CNT  12 HDP CHAINS /  35 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 # B9: 5,8 => CTR => B9: 9
* PRF B9: 9 # F8: 5,9 => SOL
* STA B9: 9 + F8: 5,9
* CNT   2 HDP CHAINS /   3 HYP OPENED

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

Details

Positions

...8...5.7.....3.....2.....1.....7.4.2.13..........6..6....4....1.....2.....7.... initial
9438672517.241.36..612.347.1.6..2734427136..5.3.74.61267..241.33146...272..371.46 autosolve
943867251752419368861253479186592734427136895539748612675924183314685927298371546 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (13)
B2: 5,8
A3: 5,8
F2: 5,9
E3: 5,9
I2: 8,9
I3: 8,9
A6: 5,8
D4: 5,9
G5: 8,9
H5: 8,9
D7: 5,9
H7: 8,9
G8: 5,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
B2,A3: 5.. / B2 = 5  =>  0 pairs (*) / A3 = 5  =>  0 pairs (X)
F2,E3: 5.. / F2 = 5  =>  0 pairs (X) / E3 = 5  =>  0 pairs (_)
G8,G9: 5.. / G8 = 5  => 12 pairs (_) / G9 = 5  =>  0 pairs (*)
B2,F2: 5.. / B2 = 5  =>  0 pairs (*) / F2 = 5  =>  0 pairs (X)
A3,E3: 5.. / A3 = 5  =>  0 pairs (X) / E3 = 5  =>  0 pairs (_)
C7,D7: 5.. / C7 = 5  =>  0 pairs (*) / D7 = 5  =>  0 pairs (X)
A3,A6: 5.. / A3 = 5  =>  0 pairs (X) / A6 = 5  =>  0 pairs (_)
D4,D7: 5.. / D4 = 5  =>  0 pairs (*) / D7 = 5  =>  0 pairs (X)
B2,A3: 8.. / B2 = 8  =>  0 pairs (X) / A3 = 8  =>  0 pairs (_)
I2,I3: 8.. / I2 = 8  =>  0 pairs (*) / I3 = 8  =>  0 pairs (X)
E4,F6: 8.. / E4 = 8  => 16 pairs (_) / F6 = 8  =>  0 pairs (*)
G5,H5: 8.. / G5 = 8  => 12 pairs (_) / H5 = 8  => 12 pairs (_)
E8,F8: 8.. / E8 = 8  =>  0 pairs (*) / F8 = 8  =>  0 pairs (X)
H7,G9: 8.. / H7 = 8  => 12 pairs (_) / G9 = 8  => 12 pairs (_)
B2,I2: 8.. / B2 = 8  =>  0 pairs (X) / I2 = 8  =>  0 pairs (_)
A3,I3: 8.. / A3 = 8  =>  0 pairs (*) / I3 = 8  =>  0 pairs (X)
B4,E4: 8.. / B4 = 8  =>  0 pairs (*) / E4 = 8  =>  0 pairs (X)
C7,H7: 8.. / C7 = 8  => 12 pairs (_) / H7 = 8  => 12 pairs (_)
A3,A6: 8.. / A3 = 8  =>  0 pairs (*) / A6 = 8  =>  0 pairs (X)
E4,E8: 8.. / E4 = 8  => 16 pairs (_) / E8 = 8  =>  0 pairs (*)
F6,F8: 8.. / F6 = 8  =>  0 pairs (*) / F8 = 8  =>  0 pairs (X)
G5,G9: 8.. / G5 = 8  => 12 pairs (_) / G9 = 8  => 12 pairs (_)
H5,H7: 8.. / H5 = 8  => 12 pairs (_) / H7 = 8  => 12 pairs (_)
F2,E3: 9.. / F2 = 9  =>  0 pairs (*) / E3 = 9  =>  0 pairs (X)
I2,I3: 9.. / I2 = 9  =>  0 pairs (X) / I3 = 9  =>  0 pairs (_)
B4,C6: 9.. / B4 = 9  =>  0 pairs (X) / C6 = 9  => 18 pairs (_)
G5,H5: 9.. / G5 = 9  => 12 pairs (_) / H5 = 9  => 12 pairs (_)
F2,I2: 9.. / F2 = 9  =>  0 pairs (*) / I2 = 9  =>  0 pairs (X)
E3,I3: 9.. / E3 = 9  =>  0 pairs (X) / I3 = 9  =>  0 pairs (_)
C6,F6: 9.. / C6 = 9  => 18 pairs (_) / F6 = 9  =>  0 pairs (X)
B4,B9: 9.. / B4 = 9  =>  0 pairs (X) / B9 = 9  => 18 pairs (_)
D4,D7: 9.. / D4 = 9  => 12 pairs (_) / D7 = 9  =>  0 pairs (*)
H5,H7: 9.. / H5 = 9  => 12 pairs (_) / H7 = 9  => 12 pairs (_)
* DURATION: 0:00:55.682199  START: 10:42:03.488967  END: 10:42:59.171166 2017-05-04
* CP COUNT: (33)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A3,A6,B2,D4,D7,E3,F2,G5,G8,H5,H7,I2,I3)
* 9438672517.241.36..612.347.1.6..2734427136..5.3.74.61267..241.33146...272..371.46
* PAIR B2: 5,8 COL B
B4: 5,8,9                                # reduction candidate for 5,8
B4: 5,8                                  # 18 pairs
B9: 5,8,9                                # reduction candidate for 5,8
B9: 5,8 => CTR
* 9438672517.241.36..612.347.196582734427136..5.3.749612675924183314658927289371546
B9: 9                                    # 18 pairs
* PAIR F2: 5,9 COL F
F6: 5,9,8                                # reduction candidate for 5,9
F6: 5,9                                  # 16 pairs
F8: 5,9,8                                # reduction candidate for 5,9
F8: 5,9 => SOLVED
* 943867251752419368861253479186592734427136895539748612675924183314685927298371546
F8: 8                                    # 16 pairs
* PAIR E3: 5,9 COL E
E4: 5,9,8                                # reduction candidate for 5,9
E4: 5,9 => SOLVED
* 943867251752419368861253479186592734427136895539748612675924183314685927298371546
E4: 8                                    # 16 pairs
E8: 5,9,8                                # reduction candidate for 5,9
E8: 5,9                                  # 16 pairs
* PAIR A6: 5,8 BLK 4
B4: 5,8,9                                # reduction candidate for 5,8
B4: 5,8                                  # 18 pairs
C6: 5,8,9                                # reduction candidate for 5,8
C6: 5,8 => CTR
* 9438672517.241.36..612.347.196582734427136..5.3.749612675924183314658927289371546
C6: 9                                    # 18 pairs
* PAIR A6: 5,8 ROW 6
F6: 5,8,9                                # reduction candidate for 5,8
F6: 9 => CTR
* 9438672517.24153695612934781.6.82734427136..5.3.74961267.9241833146589272.9371546
F6: 5,8                                  # 18 pairs
* PAIR D4: 5,9 BLK 5
E4: 5,9,8                                # reduction candidate for 5,9
E4: 5,9 => SOLVED
* 943867251752419368861253479186592734427136895539748612675924183314685927298371546
E4: 8                                    # 16 pairs
F6: 5,9,8                                # reduction candidate for 5,9
F6: 5,9                                  # 16 pairs
* PAIR D4: 5,9 ROW 4
B4: 5,9,8                                # reduction candidate for 5,9
B4: 8 => SOLVED
* 943867251752419368861253479186592734427136895539748612675924183314685927298371546
B4: 5,9                                  # 16 pairs
* PAIR G5: 8,9 COL G
G9: 8,9,5                                # reduction candidate for 8,9
G9: 5 => SOLVED
* 943867251752419368861253479186592734427136895539748612675924183314685927298371546
G9: 8,9                                  # 12 pairs
* PAIR D7: 5,9 BLK 8
E8: 5,9,8                                # reduction candidate for 5,9
E8: 5,9                                  # 16 pairs
F8: 5,9,8                                # reduction candidate for 5,9
F8: 5,9 => SOLVED
* 943867251752419368861253479186592734427136895539748612675924183314685927298371546
F8: 8                                    # 16 pairs
* PAIR D7: 5,9 ROW 7
C7: 5,9,8                                # reduction candidate for 5,9
C7: 8                                    # 12 pairs
C7: 5,9                                  # 12 pairs
* PAIR H7: 8,9 BLK 9
G9: 8,9,5                                # reduction candidate for 8,9
G9: 5 => SOLVED
* 943867251752419368861253479186592734427136895539748612675924183314685927298371546
G9: 8,9                                  # 12 pairs
* PAIR H7: 8,9 ROW 7
C7: 8,9,5                                # reduction candidate for 8,9
C7: 5 => SOLVED
* 943867251752419368861253479186592734427136895539748612675924183314685927298371546
C7: 8,9                                  # 12 pairs
* PAIR G8: 5,9 BLK 9
G9: 5,9,8                                # reduction candidate for 5,9
G9: 8                                    # 12 pairs
G9: 5,9                                  # 12 pairs
* PAIR G8: 5,9 ROW 8
E8: 5,9,8                                # reduction candidate for 5,9
E8: 5,9                                  # 16 pairs
F8: 5,9,8                                # reduction candidate for 5,9
F8: 5,9 => SOLVED
* 943867251752419368861253479186592734427136895539748612675924183314685927298371546
F8: 8                                    # 16 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-230-base-pr-000.dot
* REASONING
* DIS # B9: 5,8 => CTR => B9: 9
* PRF # F8: 5,9 => SOL
* PRF # E4: 5,9 => SOL
* DIS # C6: 5,8 => CTR => C6: 9
* DIS # F6: 9 => CTR => F6: 5,8
* PRF # E4: 5,9 => SOL
* PRF # B4: 8 => SOL
* PRF # G9: 5 => SOL
* PRF # F8: 5,9 => SOL
* PRF # G9: 5 => SOL
* PRF # C7: 5 => SOL
* PRF # F8: 5,9 => SOL
* CNT  12 HDP CHAINS /  35 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A3,A6,B2,D4,D7,E3,F2,G5,G8,H5,H7,I2,I3)
* 9438672517.241.36..612.347.1.6..2734427136..5.3.74.61267..241.33146...272..371.46
* PAIR B2: 5,8 COL B
B4: 5,8,9                                # reduction candidate for 5,8
B4: 5,8                                  # 18 pairs
B9: 5,8,9                                # reduction candidate for 5,8
B9: 5,8 => CTR
* 9438672517.241.36..612.347.196582734427136..5.3.749612675924183314658927289371546
* RESTART
* PAIR RESTART
* PAIR F2: 5,9 COL F
F8: 5,9,8                                # reduction candidate for 5,9
F8: 5,9 => SOLVED
* 943867251752419368861253479186592734427136895539748612675924183314685927298371546
* DURATION: 0:00:04.095801  START: 10:43:35.664904  END: 10:43:39.760705 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-230-base-pr-001.dot
* REASONING
* DIS # B9: 5,8 => CTR => B9: 9
* PRF B9: 9 # F8: 5,9 => SOL
* STA B9: 9 + F8: 5,9
* CNT   2 HDP CHAINS /   3 HYP OPENED

Header Info

Top 500 Minimum 17 230

solution: 943867251752419368861253479186592734427136895539748612675924183314685927298371546
info: 2065     FNBWXY   S8.f     12064

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

Solution

position: 943867251752419368861253479186592734427136895539748612675924183314685927298371546 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 # B4: 5,8 => UNS
* DIS # B9: 5,8 => CTR => B9: 9
* INC # B9: 9 => UNS
* INC # F6: 5,9 => UNS
* PRF # F8: 5,9 => SOL
* INC # F8: 8 => UNS
* PRF # E4: 5,9 => SOL
* INC # E4: 8 => UNS
* INC # E8: 5,9 => UNS
* INC # B4: 5,8 => UNS
* DIS # C6: 5,8 => CTR => C6: 9
* INC # C6: 9 => UNS
* INC # F6: 5,8 => UNS
* DIS # F6: 9 => CTR => F6: 5,8
* PRF # E4: 5,9 => SOL
* INC # E4: 8 => UNS
* INC # F6: 5,9 => UNS
* INC # B4: 5,9 => UNS
* PRF # B4: 8 => SOL
* INC # G9: 8,9 => UNS
* PRF # G9: 5 => SOL
* INC # E8: 5,9 => UNS
* PRF # F8: 5,9 => SOL
* INC # F8: 8 => UNS
* INC # C7: 5,9 => UNS
* INC # C7: 8 => UNS
* INC # G9: 8,9 => UNS
* PRF # G9: 5 => SOL
* INC # C7: 8,9 => UNS
* PRF # C7: 5 => SOL
* INC # G9: 5,9 => UNS
* INC # G9: 8 => UNS
* INC # E8: 5,9 => UNS
* PRF # F8: 5,9 => SOL
* INC # F8: 8 => UNS
* CNT  35 HDP CHAINS /  35 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # B4: 5,8 => UNS
* DIS # B9: 5,8 => CTR => B9: 9
* PRF B9: 9 # F8: 5,9 => SOL
* STA B9: 9 + F8: 5,9
* CNT   3 HDP CHAINS /   3 HYP OPENED