Question

Hi I need to calculate matrix size by count elements in array,
for example if I have 25 elements in list, I need get columns = 5 and row 5 in matrix,
If 26 elements 5 columns 6 rows etc.
thank.

Answer 1

I don’t know what your exact requirements are, but if you want to produce a near-square matrix that doesn’t waste much space,

int x = Math.Floor(Math.Sqrt(num_elems));
int y;
if (x*x == num_elems)
{
    y = x;
} else {
    y = x+1;
    if (x*y < num_elems)
    {
        ++x;
    }
}

produces the dimensions of the smallest matrix with the number of rows and columns differing by at most one that can hold num_elems elements.