BZOJ 1101 Zap

#include<iostream>
#include<cstdio>
#include<cstring>
#include<cmath>
#define maxn 50050
using namespace std;
int n,a,b,d,pre[maxn],miu[maxn],prime[maxn],cnt=0;
bool vis[maxn];
void make_table()
{
miu[1]=1;
for (int i=2;i<=maxn;i++)
{
if (vis[i]==false)
{
prime[++cnt]=i;
miu[i]=-1;
}
for (int j=1;j<=cnt && i*prime[j]<=maxn;j++)
{
vis[i*prime[j]]=true;
if (i%prime[j]!=0) miu[i*prime[j]]=-miu[i];
else
{
miu[i*prime[j]]=0;
break;
}
}
}
for (int i=1;i<=maxn;i++)
pre[i]=pre[i-1]+miu[i];
}
int find(int a,int b,int d)
{
int i=1,ans=0;
if (a>b) swap(a,b);
while (i<=(a/d))
{
int j;
if ((a/(i*d)==0) || (b/(i*d)==0)) j=0;
else j=min((a/d)/((a/d)/i),(b/d)/((b/d)/i));
ans+=(pre[j]-pre[i-1])*(a/(i*d))*(b/(i*d));
i=j+1;
}
return ans;
}
void work()
{
scanf("%d%d%d",&a,&b,&d);
printf("%d\n",find(a,b,d));
}
int main()
{
scanf("%d",&n);
make_table();
for (int i=1;i<=n;i++)
work();
return 0;
}