【反演复习计划】【bzoj3529】数表

Orz PoPoQQQ大爷

按照他ppt的解法，这题可以划归到之前的题了OrzOrz

跪wy写的题解（Stealth Assassin）https://www.luogu.org/wiki/show?name=%E9%A2%98%E8%A7%A3+P3312

 #include<bits/stdc++.h>
 #define N 100005
 #define fi first
 #define sc second
 using namespace std;
 typedef long long ll;
 int Q,maxn,cnt,prime[N],mu[N],d[N];
 int c[*N],ans[N],vis[N];
 pair<int,int> f[N];
 struct Query{int n,m,a,id;}q[N];
 bool operator<(Query x,Query y){return x.a<y.a;}
 inline int lowbit(int x){return (x&(-x));}
 inline void add(int x,int val){
     for(int i=x;i<=maxn;i+=lowbit(i))c[i]+=val;
 }
 inline int query(int x){
     int ans=;
     for(int i=x;i;i-=lowbit(i))ans+=c[i];
     return ans;
 }
 inline void calcmu(){
     cnt=;memset(vis,,sizeof(vis));mu[]=;
     for(int i=;i<=maxn;i++){
         if(vis[i]){prime[++cnt]=i;mu[i]=-;}
         for(int j=;j<=cnt;j++){
             int t=prime[j]*i;if(t>maxn)break;
             vis[t]=;
             if(i%prime[j]==){mu[t]=;break;}
             mu[t]=-mu[i];
         }
     }
     for(int i=;i<=maxn;i++)
     for(int j=i;j<=maxn;j+=i)f[j].fi+=i;
     for(int i=;i<=maxn;i++)f[i].sc=i;
 }
 inline void work(int x){
     int id=q[x].id,n=q[x].n,m=q[x].m;
     for(int i=,j=;i<=n;i=j+){
         j=min(n/(n/i),m/(m/i));
         ans[id]+=(n/i)*(m/i)*(query(j)-query(i-));
     }
 }
 inline int read(){
     int f=,x=;char ch;
     do{ch=getchar();if(ch=='-')f=-;}while(ch<''||ch>'');
     do{x=x*+ch-'';ch=getchar();}while(ch>=''&&ch<='');
     return f*x;
 }
 int main(){
     Q=read();
     for(int i=;i<=Q;i++){
         q[i].n=read();q[i].m=read();q[i].a=read();q[i].id=i;
         if(q[i].n>q[i].m)swap(q[i].n,q[i].m);
         maxn=max(maxn,q[i].n);
     }
     calcmu();
     sort(q+,q+Q+);sort(f+,f+maxn+);int now=;
     for(int i=;i<=Q;i++){
         while(now+<=maxn&&f[now+].fi<=q[i].a){
             ++now;
             for(int j=f[now].sc;j<=maxn;j+=f[now].sc)
             add(j,f[now].fi*mu[j/f[now].sc]);
         }
         work(i);
     }
     for(int i=;i<=Q;i++)printf("%d\n",ans[i]&0x7fffffff);
     return ;
 }