I\'m new to C/C++ and I\'ve been cracking my head but still got no idea how to make an \"structure\" like this
OK let us take your beginnings
int ***sec = new int**[x];
sec is now an array of int**s of length x, so now I am just going to focus on making the zeroeth element be what you want
sec[0] = new int*[y];
Now sec[0] points to array of int*s of length y, now just need to get the last bit of the tree done, so
sec[0][0] = new int[z];
And finally to get it to the form in your diagram
sec[0][0][z-1] = 0;
This does seem a little like a homework question, make sure you actually understand the answer and why it works.