问个问题

#include <bits/stdc++.h>
using namespace std;
int t, x;
int cnt = 0;
int ans[10000001];
bool vis[10000001];
inline bool check(int x)
{
	int t = x;
	while(t)
	{
		if(t % 10 == 7) return 1;
		t /= 10;
	}
	return 0;
}
inline void init()
{
	for(int i = 1; i <= 10000000; i++)
	{
		if(vis[i]) continue;
		if(check(i))
		{
			vis[i] = 1;
			for(int j = i << 1; j <= 10000000; j += i)
				vis[j] = 1;
			continue;
		}
		ans[cnt] = i;
		cnt = i;
	}
}
int main()
{
	cin >> t;
	init();
	while(t--)
	{
		cin >> x;
		if(vis[x]) cout << -1 << endl;
		else cout << ans[x] << endl;
	}
	return 0;
}

#include <bits/stdc++.h>
using namespace std;
int t, x;
int cnt = 0;
int ans[10000101]; //这里
bool vis[10000101]; //这里
inline bool check(int x)
{
	int t = x;
	while(t)
	{
		if(t % 10 == 7) return 1;
		t /= 10;
	}
	return 0;
}
inline void init()
{
	for(int i = 1; i <= 10000090; i++) //i的范围
	{
		if(vis[i]) continue;
		if(check(i))
		{
			vis[i] = 1;
			for(int j = i << 1; j <= 10000090; j += i) //j的范围
				vis[j] = 1;
			continue;
		}
		ans[cnt] = i;
		cnt = i;
	}
}
int main()
{
	cin >> t;
	init();
	while(t--)
	{
		cin >> x;
		if(vis[x]) cout << -1 << endl;
		else cout << ans[x] << endl;
	}
	return 0;
}