題面:https://www.luogu.org/problem/P4213

#include<iostream> #include<cstdio> #include<cstdlib> #include<cstring> #include<cmath> #include<algorithm> #include<ctime> #include<queue> #include<map> using namespace std; const int mod=1000000007,N=5000005; long long phi[N]; int t,prime[N],cnt,mobius[N]; bool vis[N]; unordered_map<int,int>ans_mobius; unordered_map<int,long long> ans_phi; inline int read(){int x=0,f=1;char c=getchar();while(c<'0'||c>'9'){if(c=='-'){f=-1;c=getchar();}}while(c>='0'&&c<='9'){x=x*10+c-48;c=getchar();}return x*f; } inline long long get_phi(long long x){if(x<=N){return phi[x];}if(ans_phi[x]){return ans_phi[x];}long long ans=((1+x)*x)/2;for(register int l=2,r;l<=x;l=r+1){r=x/(x/l);ans-=(r-l+1)*get_phi(x/l);}return ans_phi[x]=ans; } inline int get_mobius(int x){if(x<=N){return mobius[x];}if(ans_mobius[x]){return ans_mobius[x];}int ans=1;for(register int l=2,r;l<=x;l=r+1){r=x/(x/l);ans-=(r-l+1)*get_mobius(x/l);}return ans_mobius[x]=ans; } int main(){mobius[1]=phi[1]=1;for(register int i=2;i<=N;++i){if(!vis[i]){prime[++cnt]=i;mobius[i]=-1;phi[i]=i-1;}for(register int j=1;j<=cnt&&prime[j]*i<=N;++j){vis[prime[j]*i]=1;if(i%prime[j]==0){phi[i*prime[j]]=phi[i]*prime[j];break;}phi[i*prime[j]]=phi[prime[j]]*phi[i];mobius[i*prime[j]]=-mobius[i];}}for(register int i=1;i<=N;++i){mobius[i]+=mobius[i-1];phi[i]+=phi[i-1];}int x;t=read();while(t--){x=read();printf("%lld %d\n",get_phi(x),get_mobius(x));}return 0; }

轉(zhuǎn)載于:https://www.cnblogs.com/ukcxrtjr/p/11311269.html

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