Question

I need to do two things to an array in C:

1. Summing its entries.
2. Finding the position of all non-zero entries.

I am doing both by looping through each element of the array. E.g.

int sum_array(int a[], int num_elements)
{
   int i, sum=0;
   for (i=0; i<num_elements; i++)
   {
     sum = sum + a[i];
   }
   return(sum);
}

For task 2, I will be checking if the entry is 0. If not, add its position to another array to mark it as non-zero.

Question

Are there more efficient ways of doing these?

I am also using the GNU Scientific Library (GSL), if there are more efficient solutions in there. I just started C recently.

Answer 1

Based on the comments from Gregor, EvilTeach and some of my own googling, my approach is acceptable.