Sudoku - toughie

[Lamp]

I'm finding this one tricky. Any logic puzzle gurus wanna have a stab at this ?

X X X X X X 2 X X
X X 3 4 5 X X 1 X
1 2 X X X 6 X X 9

X X X X X 7 X X 8
X 5 X X 8 X X 7 X
6 X X 9 X X X X X

7 X X 1 X X X 5 6
X 8 X X 2 3 4 X X
X X 9 X X X X X X

Completed 4 numbers and I'm stumped ! Help !

 

[Chrystina]

of teh easy tbh ...

4 6 7 8 1 9 2 3 5
9 6 3 4 5 2 6 1 7
1 2 5 3 7 6 8 4 9

9 3 1 2 4 7 5 6 8
2 5 4 6 8 1 9 7 3
6 7 8 9 3 5 1 2 4

7 4 2 1 9 8 3 5 6
5 8 6 7 2 3 4 9 1
3 1 9 5 6 4 7 8 2

 

[Ame]

of teh easy tbh ...

4 6 7 8 1 9 2 3 5
9 6 3 4 5 2 6 1 7
1 2 5 3 7 6 8 4 9

9 3 1 2 4 7 5 6 8
2 5 4 6 8 1 9 7 3
6 7 8 9 3 5 1 2 4

7 4 2 1 9 8 3 5 6
5 8 6 7 2 3 4 9 1
3 1 9 5 6 4 7 8 2

Wanna do some Sudokus I can't do?

 

[Samaroon EatsCheese]

what the hell? :|

 

[Ame]

5 x x | x x x | x 7 x
x x 8 | x 7 x | x x x
x 3 x | x x x | 5 4 1
-------------------
x x 9 | x x 1 | 3 x x
3 x x | 8 x 6 | x x 2
x x 1 | 5 x x | 8 x x
-------------------
9 1 3 | x x x | x 2 x
x x x | x 2 x | 9 x x
x 4 x | x x x | x x 6

 

[Lamp]

That one's bloody tricky

Completed half of it then realised I'd made a mistake in my logic...
Back to the drawing board....this is one I actually wanna complete now

 

[Ame]

I'm not even sure its possible without guess work.

 

[Roken]

of teh easy tbh ...

4 6 7 8 1 9 2 3 5
9 6* 3 4 5 2 6 1 7
1 2 5 3 7 6 8 4 9

9 3 1 2 4 7 5 6 8
2 5 4 6 8 1 9 7 3
6 7 8 9 3 5 1 2 4

7 4 2 1 9 8 3 5 6
5 8 6 7 2 3 4 9 1
3 1 9 5 6 4 7 8 2

*should be 8

 

[Cozak]

How the hell do you do those things? Just looks like a load of numbers to me =/

 

[Lamp]

DONE IT !!

No guess - pure logic
Happy to tell you how I did it if you want

5 9 4 3 1 2 6 7 8
1 6 8 4 7 5 2 9 3
2 3 7 9 6 8 5 4 1
6 8 9 2 4 1 3 5 7
3 7 5 8 9 6 4 1 2
4 2 1 5 3 7 8 6 9
9 1 3 6 8 4 7 2 5
7 5 6 1 2 3 9 8 4
8 4 2 7 5 9 1 3 6

 

[Lamp]

^^ TBH, that's the hardest one I've done

Gives me confidence to reckon I can do anyone now...!!

 

[Lamp]

How the hell do you do those things? Just looks like a load of numbers to me =/

Sidoku is a type of logic puzzle. The object of the puzzle is to fill in the unpopulated boxes with the correct number. The sidoku puzzle is divided into 9 squares each 3x3. Each of the 81 boxes / spaces has to contain a number from 1 to 9. Within each of the 9 3x3 boxes, you have to write in all of the numbers from 1 to 9 inclusive. No omissions or duplications. Similarly each row and each column must contain all the numbers from 1 to 9 - again no omissions or duplications. Sounds easy ? Give it a go !

When you've mastered the 9 x 3 x 3 puzzles, try the new 25 x 5 x 5 or the 100 x 10 x 10 ones !

 

[Ame]

DONE IT !!

No guess - pure logic
Happy to tell you how I did it if you want

5 9 4 3 1 2 6 7 8
1 6 8 4 7 5 2 9 3
2 3 7 9 6 8 5 4 1
6 8 9 2 4 1 3 5 7
3 7 5 8 9 6 4 1 2
4 2 1 5 3 7 8 6 9
9 1 3 6 8 4 7 2 5
7 5 6 1 2 3 9 8 4
8 4 2 7 5 9 1 3 6

You could tell me .

 

[Ingafgrinn Macabre]

sudoko on te web

here, ye can play for free on the web here, with 4 difficulties

 

[Lamp]

You could tell me .

You could use pencil & paper, but I used Microsoft Excel.

1. Copy the entire sudoku grid onto a fresh Excel worksheet.

2. For each and every blank square, enter all the numbers 1-9 that could be in that space.

3. Analyse each of the nine 3x3 blocks. In respect of the boxes with multiple numbers in them is there a number that appears only once ? If so, it means that that number can only appear in that square. Suppose in a particular 3x3 block, after looking at all the multiple number populated boxes, you find the number 4 in only one square. Well, first write a 4 in that box. Then, remove every other iteration of 4 from all the number permutations in that 3x3 block. Then remove every other iteration of 4 from that square's row and column.

4. Its very important that as you remove redundant iterations that you "clean" the square's column and row BEFORE moving on to another number. Failure to adhere to such methodical logic will result in a flaws.

5. Go as far as you can with this elimination of redundants. Then use "standard" sudoku logic to refine and complete the puzzle, ie "3's there, there, and there, so it can't be here, so has to be here" type stuff. You know what I mean if you can do sudoku ! Also, if, say you're missing a 1,2, and 3 from a column, and you see that both 1 and 2 from a row bisect one of the empty spaces in that column, you know that particular box has to be a 3.

Took me 2 hours and about 7 attempts to get it right.

THE most important thing is to make sure that the first stage is 100% accurate. If you make a mistake putting possible combinations in the squares, and you don't notice it, you're screwed !

All the above might be totally obvious, or like teaching one's grandmother to suck eggs, and if so, forgive me, but it is a foolproof method of completing ANY sudoku / logic puzzle of ANY given difficulty. The beauty of logic puzzles is that no guess work is required at all. Using a consistent algorithmical solving process as outlined above effectively nullifies the difficulty rating (ie. if you use this process for every sudoku, level 5 puzzles are no harder than level 1's).

Good luck !