[暴力] HDU 4473 Exam

#include<cstdio>
#include<cstdlib>
#include<algorithm>
using namespace std;
const double eps(1e-8);
typedef long long ll;

ll n,ans;

int main()
{
freopen("t.in","r",stdin);
freopen("t.out","w",stdout);
int T=0;
while(~scanf("%I64d",&n))
{
ans=0;
for(ll a=1;a*a*a<=n;a++)
for(ll b=a;a*b*b<=n;b++)
{
ll c=n/(a*b);
if(c<b) break;
if(a==b)
ans+=(c-b)*3+1;
else
ans+=(c-b)*6+3;
}
printf("Case %d: %I64d\n",++T,ans);
}
return 0;
}