BZOJ3739: DZY loves math VIII

莫比乌斯反演
可以推出来
不会Markdown。。。。

http://www.cnblogs.com/clrs97/p/5063707.html

#include<cstdio>#include<iostream>#define ll long longchar c;inline void read(ll&a){    a=0;do c=getchar();while(c<'0'||c>'9');    while(c<='9'&&c>='0')a=(a<<3)+(a<<1)+c-'0',c=getchar();}const int Maxn=10000001; int Prime[Maxn],tot;ll S[Maxn];int Mu[Maxn];int Factor[Maxn];bool Check[Maxn];ll B,A;ll ans; int s[Maxn];int Cache[101];inline void Search(int Pos,int Cur){    if(Pos^(tot+1))Search(Pos+1,Cur),Search(Pos+1,Cur*Cache[Pos]);    else         s[Cur]+=A,B+=Mu[Cur]*s[Cur];}int main(){   ll k;  ll T,n,m,i,j;  Mu[1]=1;  Factor[1]=1;  for(i=2;i<Maxn;i++)   {     if(!Check[i])     Factor[i]=Prime[++tot]=i,Mu[i]=-1;     for(j=1;j<=tot;j++)    {       k=i*Prime[j];      if(k>=Maxn)break;       Check[k]=1;       Factor[k]=Prime[j];      if(i%Prime[j])Mu[k]=-Mu[i];        else       {Mu[k]=0;break; }     }   }   //for(i=2;i<Maxn;i++)Mu[i]+=Mu[i-1];   for(i=1;i<Maxn;i++)   {    S[i]+=S[i-1];    if(A=Mu[i])      {         for(B=tot=0,j=i;j^1;j/=Factor[j])Cache[++tot]=Factor[j];                    Search(1,1);         S[i]+=B*Mu[i];      }   }  read(T);  while(T--)  {      read(n);    printf("%lld\n",S[n]);   }  return 0; }