quicksort

#include <bits/stdc++.h>
using namespace std;
vector<int> a;
void _swap(int &a, int &b)
{
    printf("swapped %d & %d; ", a, b);
    swap(a, b);
}
void print()
{
    cout << "\ncurrent state: ";
    for (auto x : a)
        cout << x << " ";
    cout << endl
         << endl;
}
int partition(int l, int h)
{
    int pivot = a[l];
    int start = l;
    int end = h;
    printf("pivot %d -> ", pivot);
    while (start < end)
    {
        while (a[start] <= pivot)
            start++;
        while (a[end] > pivot)
            end--;
        if (start < end)
        {
            // printf("i & j: %d %d, ", start, end);
            _swap(a[start], a[end]);
        }
    }
    cout << " pivot ";
    _swap(a[l], a[end]);
    print();
    return end;
}
void quick_sort(int l, int h)
{
    int loc;
    if (l < h)
    {
        loc = partition(l, h);
        quick_sort(l, loc - 1);
        quick_sort(loc + 1, h);
    }
}
int main()
{
    int n;
    // cout << "enter size & elements of the array \n";
    cin >> n;
    a.resize(n);
    for (auto &x : a)
        cin >> x;
    quick_sort(0, n - 1);
    cout << "\n quick sorted array ";
    for (auto x : a)
        cout << x << " ";
    return 0;
}