пирамидальная сортировка

#include <iostream>
#include <vector>

using namespace std;

class Pyramid {
    int n;
    vector<int> arr;

    void siftDown(int root, int bottom) {
        int maxChild;
        bool done = false;
        while ((root * 2 <= bottom) && (!done)) {
            if (root * 2 == bottom || arr[root * 2] > arr[root * 2 + 1]) {
                maxChild = root * 2;
            } else {
                maxChild = root * 2 + 1;
            }
            if (arr[root] < arr[maxChild]) {
                swap(arr[root], arr[maxChild]);
                root = maxChild;
            } else {
                done = true;
            }
        }
    }

public:

    explicit Pyramid(const vector<int> &_arr) {
        arr = _arr;
        n = _arr.size();
    }

    void sort() {
        for (int i = (n / 2); i >= 0; i--)
            siftDown(i, n - 1);
        for (int i = n - 1; i >= 1; i--) {
            swap(arr[0], arr[i]);
            siftDown(0, i - 1);
        }
    }

    vector<int> getSorted() {
        return arr;
    }
};

int main() {
    int n;
    cin >> n;
    vector<int> v(n);
    for (int &i: v)
        cin >> i;

    Pyramid pyramid(v);
    pyramid.sort();
    v = pyramid.getSorted();

    for (int &i: v)
        cout << i << ' ';


}