std::partial_sort

From Cppreference

Sorts some of the elements in the range [first, last) in ascending order. The first middle - first of these elements are placed in the range [first, middle). The order of equal elements is guaranteed to be preserved. The order of the remaining elements in the range [middle, last) is unspecified. The first version uses operator< to compare the elements, the second version uses the given comparison function comp.

[edit] Parameters

[edit] Return value

(none)

[edit] Complexity

O(N·log²(N)), where N = std::distance(first, last) applications of cmp. If additional memory is available, then the complexity is O(N·log(N))

[edit] Example

#include <algorithm>
#include <functional>
#include <array>
#include <iostream>
 
int main()
{
    std::array<int, 10> s{5, 7, 4, 2, 8, 6, 1, 9, 0, 3};
 
    std::partial_sort(s.begin(), s.begin() + 3, s.end());
    for (int a : s) {
        std::cout << a << " ";
    } 
}

Output:

0 1 2 7 8 6 5 9 4 3

[edit] See also