我的代码：

#include <iostream>
using namespace std;

bool vis[100000000];
int prime[50000000];

void init(int maxn)
{
	int cnt = 0;
	for (int i = 2; i < maxn; ++i)
	{
		if (vis[i] == false)
		{
			prime[cnt] = i;
			cnt += 1;
		}
		for (int j = 1; j <= cnt && i * prime[j] < maxn; ++j)
		{
			vis[prime[j] * i] = 1;
			if (i % prime[j] == 0)
			{
				break;
			}
		}
	}
}

int main()
{
	std::ios::sync_with_stdio(0);
	int n, q;
	cin >> n >> q;
	init(n);
	int a;
	cout << prime[1] << " " << prime[2] << " " << prime[3];
	for (int i = 0; i < q; ++i)
	{
		cin >> a;
		cout << prime[a] << endl;
	}
	
	return 0;
}

似乎不是因为数组开大了