美素数——Program H

#include <iostream>
#include <cstdio>
#include <cstring>


using namespace std;
const int maxn=1000005;
int vis[maxn],ans[maxn];
void prime()
{
	memset(vis,0,sizeof(vis));
	memset(ans,0,sizeof(ans));
	for(int i=2;i<maxn;i++)
	{
		if(vis[i])
			continue;
		for(int j=i+i;j<maxn;j+=i)
			vis[j]=1;
	} 
}
int count_sum(int a)
{
	int sum=0;
	while(a)
	{
		sum+=a%10;
		a/=10;
	}
	return sum;
}
int main()
{
	prime();
	ans[0]=ans[1]=0;
	for(int i=2;i<maxn;i++)
	{
		if(!vis[i]&&!vis[count_sum(i)])
			ans[i]=ans[i-1]+1;
		else
			ans[i]=ans[i-1];
	}
	int t,kase=0;
	scanf("%d",&t);
	while(t--)
	{
		int l,r;
		scanf("%d%d",&l,&r);
		printf("Case #%d: %d\n",++kase,ans[r]-ans[l-1]);
	}
}