AGGRCOW on SPOJ – Maximize the minimum distance between aggressive cows
Well, your indentation gives me a headache. I think there might be a pattern in it, but I don't see it, so I'll reformat it for writing my answer.
&lt;bits/stdc++.h&gt; is non-standard and causes longer compile-times. Maybe just include what you need?
Never use using namespace something_humungeous_and_growing_like_std;, because there might be conflicts, and silent changes of semantics.
There are single-character-names which would actually make sense for your variables: The ones used in the spec. If you don't want to use them, put a bit more effort into finding meaningful names.
You never test whether input succeeds. At the very least, add the following to get an exception (though it messes with the input-processing ordinarily used in bigger / more robust programs):

std::cin.exceptions(std::ios_base::failbit);

Avoid flushing streams (use '\n' instead of std::endl) unless you actually need to flush.
Prefer streaming character literals to size-1-strings. It's potentially marginally more efficient.
Decouple iostreams from stdio.
Refrain from copying expensive things. Every single time you pass your vector by value Needs a copy, thus a useless extra-allocation, -deallocation and block-copy.
Also, while it is generally a good idea to minimize the scope of variables, re-using the same vector over multiple iterations allows you to forego extra-allocations and de-allocations.
You are using extremely dumb brute-force in count() by trying minimal distances starting at zero and then counting up.
Consider using binary-search instead, trivial minimum is \$0\$, maximum is \$(maxpos - minpos) / (cows - 1)\$.
Same in CanBeMin(), use binary-search. std::lower_bound() can help.