## It's Monday - I always get stuck on Monday...

Advanced methods and approaches for solving Sudoku puzzles

### It's Monday - I always get stuck on Monday...

Cannot see my way out - what am I missing?
Here it is;

Code: Select all
[64][167][167]   [9][12][3]    [8][5][247]
[459][17][3]      [57][12][8]   [6][49][2479]
[589][2][5789]   [57][6][4]     [1][3][79]

[2][168][168]     [3][5][9]     [4][7][18]
[7][3][59]        [4][8][1]    [59][2][6]
[589][4][1589]   [2][7][6]  [359][189][1389]

[13][5][2]         [8][49][7]   [39][6][1349]
[368][678][678]   [1][49][5]  [2][489][3489]
[18][9][4]         [6][3][2]    [7][18][5]
Kites

Posts: 48
Joined: 20 May 2005

There’s a naked triple box 1 => r1c1 = 4. Then two moves and puzzle solved. Hint - look for hidden singles.
emm

Posts: 987
Joined: 02 July 2005

Thanks em. Now I can see the naked triple... the rest should be easily solved, but not sure what it means to look for 'hidden singles'.
Thanks again.
Kites

Posts: 48
Joined: 20 May 2005

not sure what it means to look for 'hidden singles'
.
em, did you mean the 6 in r8c1 when you refferred to 'hidden singles'?
Kites

Posts: 48
Joined: 20 May 2005

hidden single refers to when a column, row or block only has one possible location for a number.

It's hidden because it's harder to spot that a naked single!

Simes
simes

Posts: 324
Joined: 11 March 2005
Location: UK

Thank you simes.
Kites

Posts: 48
Joined: 20 May 2005

Going back to my original posting, I would like to know if this was a suitable situation for using 'Colouring' technique? Having missed the Naked Triple in Box 1, I thought I would practice Colouring, but didn't get very far. Having no expirience as to where to start, I picked on '1' and it looked like this;

-11 -1- ---
-1- -1- ---
--- --- ---

-11 --- --1
--- --- ---
--1 --- -11

1-- --- --1
--- --- ---
1-- --- -1-

I used Plus and Minus instead of colours.
I started with + r1c5, - r2c5, and + r2c2
but didn't know how to reach other conjugate cells, or eliminate any of them.
Kites

Posts: 48
Joined: 20 May 2005

Have you looked at this thread - colouring - y the confusion?

or it may be easier to understand here Sadman and Simple Sudoku
emm

Posts: 987
Joined: 02 July 2005