31 lines
808 B
C++
31 lines
808 B
C++
|
// source file for the `median' function
|
||
|
|
#include <algorithm> // to get the declaration of `sort'
|
||
|
|
#include <stdexcept> // to get the declaration of `domain_error'
|
||
|
|
#include <vector> // to get the declaration of `vector'
|
||
|
|
|
||
|
|
using std::domain_error; using std::sort; using std::vector;
|
||
|
|
|
||
|
|
#include "median.h"
|
||
|
|
|
||
|
|
// compute the median of a `vector<double>'
|
||
|
|
// note that calling this function copies the entire argument `vector'
|
||
|
|
double median(vector<double> vec)
|
||
|
|
{
|
||
|
|
#ifdef _MSC_VER
|
||
|
|
typedef std::vector<double>::size_type vec_sz;
|
||
|
|
#else
|
||
|
|
typedef vector<double>::size_type vec_sz;
|
||
|
|
#endif
|
||
|
|
|
||
|
|
vec_sz size = vec.size();
|
||
|
|
if (size == 0)
|
||
|
|
throw domain_error("median of an empty vector");
|
||
|
|
|
||
|
|
sort(vec.begin(), vec.end());
|
||
|
|
|
||
|
|
vec_sz mid = size/2;
|
||
|
|
|
||
|
|
return size % 2 == 0 ? (vec[mid] + vec[mid-1]) / 2 : vec[mid];
|
||
|
|
}
|
||
|
|
|