I need some help with some homework as classmates are equally stumped and the professor is not responding (yes, bad idea to take this course online but I had no choice as they don't offer it oncampus).
The assignment is: "Rewrite the merge sort algorithm (as described below) as a template function. Use two template parameters, one to set the element type, and the second to define the ordering algorithm."
First off, I thought that the point of a template was so that you can write one 'universal' class/function that could be used for any data type?? So my first question is why would I want to set an element type?
Secondly, why would I (in this case) pass an ordering algorithm into a function that merges??
Thirdly, is it possible to pass an algorithm as a parameter? How would one do this?
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/**
Sorts the elements in a range of a vector.
@param a the vector with the elements to sort
@param from start of the range to sort
@param to end of the range to sort
*/
template <typename T> //implement of template
void merge_sort(T <int>& a, int from, int to) //Changed vector to typename T
{
if (from == to) return;
int mid = (from + to) / 2;
// Sort the first and the second half
merge_sort(a, from, mid);
merge_sort(a, mid + 1, to);
merge(a, from, mid, to);
}
 
I think I have the implementation correct. So I guess I need help with the second and third parts.
Thanks,
David