The sudoku 9x9 is counts 6 670 903 752 021 072 936 960 possible combinations (it's about 6671 billions of billions...)
Some are very simple, others very difficult. The difficulty is mostly depending of the quantity of digits given at the beginning and of their positions on the grid.

With the smallest quantity of given digits and the most complicated positions of them on the grid, the hardest sudoku will be obtained. There are more than 527 billions of different grids of this kind - 526 727 577 600 exactly, that is mathematically written "4(9!)²"... - it's about one on thirteen billions ...

So here is one of these grid, extremly hard to solve (even the automated programs work hard to find the solution...)
The sudoku game is given in this first part. If you're stuck to find the solution of the sudoku, you'll find it in the part 2. This second part will allow you to start with a "classical" picross, then to verify your sudoku solution if you think you've found it.

It was already explained here that creating a sudoku grid of 9x9 on a picross grid is not so easy, because the graphical place is not large enough. So, there is need of encoding the digits of tne sudoku grid to make them contained.

The encoding principle is very simple in this game.
Each digit is contained in a zone of 9 cells (3x3). There are 81 zones in the picross (9x9).
If you look and give a name to the cells of a zone you'll obtain :
A B C
D E F
G H I
The digit 1 will be represented by a black cell in A and all the others stay white.
The digit 2 will be represented by a black cell in B and all others stay white.
The digit 3 will be represented by a black cell in C etc ....

Easy principle, no complicated encoding.

Now let you brain work, and do the picross then solve the sudoku.
See you in the part 2 for a new Hanjoku and the solution of the sudoku