法一

#include <iostream>
using namespace std;
const int N = 1e5 + 10;

int n, a[N];

void quick_sort(int l, int r)
{
	if (l >= r) return;
	int i = l - 1, j = r + 1, x = a[l + r >> 1];
	while (i < j)
	{
		do i ++; while (a[i] < x);
		do j --; while (a[j] > x);
		if (i < j) swap(a[i], a[j]);
	}
	quick_sort(l, j); quick_sort(j + 1, r);
}

int main()
{
	cin >> n;
	for (int i = 0; i < n; i ++ ) cin >> a[i];
	quick_sort(0, n - 1);
	for (int i = 0; i < n; i ++ ) cout << a[i] << ' ';
	return 0;
}

法二

#include <iostream>
#include <algorithm>

using namespace std;

int n;
vector<int> a;

int main()
{
	cin >> n;
	while (cin >> n) a.push_back(n);
	sort(a.begin(), a.end());
	for (auto x : a) cout << x << ' ';
	return 0;
}