Visible Lattice Points SPOJ - VLATTICE 三维+莫比乌斯反演

#include<bits/stdc++.h>
#define ll long long
using namespace std;
const int maxn=1e7+;
int vis[maxn];
int mu[maxn];
int prime[maxn];
int tot=;
int sum1[maxn];
int sum2[maxn];
void get_mu()
{
    mu[]=; vis[]=;
    for(int i=;i<maxn;i++)
    {
        if(!vis[i]) {mu[i]=-; prime[++tot]=i; }
        for(int j=;j<=tot && i*prime[j]<maxn;j++)
        {
            vis[i*prime[j]]=;
            if(i%prime[j]==) break;
            mu[i*prime[j]]=-mu[i];
        }
    }
    for(int i=;i<maxn;i++)
        sum2[i]=sum2[i-]+mu[i];
}
int main()
{
    get_mu();
    int T; cin>>T;
    while(T--)
    {
        int n; cin>>n;
        ll ans=;
        for(int l=,r;l<=n;l=r+)
        {
            r=n/(n/l);
            ans+=(sum2[r]-sum2[l-])*1ll*(n/l)*(n/l)*(n/l);
            ans+=(sum2[r]-sum2[l-])*1ll*(n/l)*(n/l)*;
        }
        cout<<ans+<<endl;
    }
}