The New Sudoku Players' Forum

[Mats]

Hi, I am a new beginner with sudoku. Need help to understand how to solve the attached puzzle. I can do it by trial and error but not with logic. What is the technique?

[Leren]

Code: Select all

*------------------------------------*
| 3    1-2  9  | 4 12 7  | 8   6  5  |
| 7    8    6  | 9 12 5  | 12  4  3  |
| 4    5   a12 | 6 8  3  | 7  b29 19 |
|--------------+---------+-----------|
| 8    3    5  | 7 46 46 | 9   1  2  |
| 12   6    12 | 5 9  8  | 4   3  7  |
| 9    7    4  | 1 3  2  | 5   8  6  |
|--------------+---------+-----------|
| 16   9    8  | 2 5  16 | 3   7  4  |
| 5   d124  3  | 8 7  14 | 6  c29 19 |
| 126  124  7  | 3 46 9  | 12  5  8  |
*------------------------------------*

A skyscraper will get you home. It's in cells a-b-c-d and it's easy to see that one of cells a or d must be 2, so r1c2 is not 2. You can read up on skyscrapers here.

Leren