Dev上试着可以，但洛谷上报WA和RE

#include<bits/stdc++.h>
using namespace std;
int main()
{
	long long n,i,j,x;
	long long a[n];
	cin>>n;
	for(i=0;i<=n-1;i++)
	{
		cin>>a[i];
		if(a[i]>1)
		{
		    if(a[i]==2)
		    cout<<a[i]<<" ";
		    else
			{
				
				for(j=2;j<=sqrt(a[i])+1;j++)
				{
					x=a[i]%j;
					if(x==0)
					break;
				}
				if(j>sqrt(a[i])+1)
					cout<<a[i]<<" ";
			}	
		}
	}
	return 0;
}