mirror of https://github.com/oxen-io/oxen-core.git
34 lines
1.1 KiB
C++
34 lines
1.1 KiB
C++
// Copyright (c) 2022, The Oxen Project
|
|
|
|
#include <algorithm>
|
|
#include <vector>
|
|
|
|
namespace tools {
|
|
|
|
// Calculate the median element (the middle element, if an odd size, and the mean of the two
|
|
// middle elements if even). Pass first=true if you don't care about the mean of the middle two,
|
|
// in which case you'll get back the value of lower of the two middle elements.
|
|
// This leaves the given range in an indeterminant (partially sorted) order.
|
|
template <typename RandomAccessIter>
|
|
auto median(RandomAccessIter begin, RandomAccessIter end, bool first = false) {
|
|
std::size_t size = end - begin;
|
|
if (size == 0)
|
|
return std::decay_t<decltype(*begin)>{};
|
|
|
|
auto mid = begin + (size - 1) / 2;
|
|
std::nth_element(begin, mid, end);
|
|
|
|
if (first || size % 2)
|
|
return *mid;
|
|
|
|
auto mid2 = std::min_element(mid + 1, end);
|
|
return (*mid + *mid2) / 2;
|
|
}
|
|
|
|
// Same as above, but takes a vector by value or move for convenience.
|
|
template <typename T>
|
|
T median(std::vector<T> v, bool first = false) {
|
|
return median(v.begin(), v.end(), first);
|
|
}
|
|
} // namespace tools
|