then this?
template<typename Iter>
typename iterator_traits<Iter>::value_type median(Iter begin, Iter end)
{
typedef typename iterator_traits<Iter>::difference_type diff_t;
diff_t size = end - begin;
if(0 == size )
throw std::runtime_error("median of empty vector");
size 0 ? sort(begin, end) : sort(end, begin);
diff_t mid = size / 2;
return size % 2 == 0 ? (*(begin+mid-1)+*(begin+mid))/2 : *(begin+mid);
}
int main()
{
int arr[] = { 0, 3, 11, 6 };
int arr_size = sizeof(arr) / sizeof(int);
vector<floatvec(arr, arr + arr_size);
cout << "int arr midian: " << median(arr, arr + arr_size) << endl;
cout << "float vec median: " << median(vec.begin(), vec.end()) << endl;
cout << "inverse: " << median(arr + arr_size, arr) << endl;
return 0;
}
jim
Jim Z. Shi 写道:
Quote:
try this:
>
template<typename Iter>
double median(Iter begin, Iter end)
{
typedef typename iterator_traits<Iter>::difference_type diff_t;
diff_t size = end - begin;
if(0 == size )
throw std::runtime_error("median of empty vector");
>
sort(begin, end);
diff_t mid = size / 2;
return size % 2 == 0 ? (*(begin+mid-1)+*(begin+mid))/2 : *(begin+mid);
}
>
int main() {
int arr[] = { 0, 3, 11, 9 };
int arr_size = sizeof(arr)/sizeof(int);
vector<intvec(arr, arr + arr_size);
>
cout << "arr midian: " << median(arr, arr + arr_size) << endl;
cout << "vec median: " << median(vec.begin(), vec.end()) << endl;
>
return 0;
}
>
HTH,
jim
>
utab 写道:
Quote:
>Dear all,
>>
>I have the below template (1) which I would like to implement to
>accept either a vector or an array. I thought on it some time and came
>with a solution as in (2) , however the call of my implementation is
>not natural in the way that I do not supply the vector directly. How
>can I improve on that?
>>
>(1)
>template <class T>
>T median(vector<Tv)
>{
> vec_sz size = v.size();
> if (size == 0)
> throw domain_error("median of an empty vector");
> sort(v.begin(), v.end());
> vec_sz mid = size/2;
> return size % 2 == 0 ? (v[mid] + v[mid-1]) / 2 : v[mid];
>}
>>
>(2)
>template <class T>
>T median( T*v, int n )
>{
> size_t sz = n;
> if (n == 0)
> throw domain_error("median of an empty vector");
> sort(v, v+n);
> size_t mid = sz/2;
> return sz % 2 == 0 ? (v[mid] + v[mid-1]) / 2 : v[mid];
>}
>>
>calls for (2) are
>>
>std::cout << median(a,7) << std::endl; // for array
>...
>std::cout << median(&(*b.begin()),b.size()) << std::endl; // for vector
>>
>Best regards,
>>
