http://acm.hdu.edu.cn/showproblem.php?pid=2138
Time Limit: 3000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 19579 Accepted Submission(s): 6696
#include<ctime>
#include<cstdio>
#include<cstdlib>
using namespace std;
typedef long long LL;
int n,ans;
LL p;
LL mul(LL a,LL b)
{
LL r=0;
while(b)
{
if(b&1) b--,r+=a,r%=p;
a<<=1; a%=p; b>>=1;
}
return r;
}
LL qm(LL a,LL b)
{
LL r=1;
while(b)
{
if(b&1) r=mul(r,a);
b>>=1; a=mul(a,a);
}
return r;
}
bool Miller_Rabin()
{
if(p==2) return true;
if(p%2==0) return false;
int T=5;
LL m=p-1,k=0,a,x,y;
while(m%2==0) k++,m>>=1;
while(T--)
{
a=rand()%(p-1)+1;
x=qm(a,m);
for(int i=1;i<=k;i++)
{
y=mul(x,x);
if(x&1 && y==1 && x!=1 && x!=-1) return false;
x=y;
}
if(x!=1) return false;
}
return true;
}
int main()
{
srand(time(0));
while(scanf("%d",&n)!=EOF)
{
ans=0;
while(n--)
{
scanf("%lld",&p);
if(Miller_Rabin()) ans++;
}
printf("%d\n",ans);
}
}
















