线性时间内筛素数+欧拉函数+莫比乌斯函数

来源：互联网发布：js原生打开新页面编辑：程序博客网时间：2024/06/09 15:56

从别人博客里摘录过来改写的：https://quartergeek.com/sieve-prime-in-linear-time/

typedef long long LL;#define mn 100000+5LL ph[mn];bool vis[mn];int primes, prime[mn];void Init(){    ph[1] = 1;    primes=0;    for (LL i = 2; i < mn; ++i)    {        if (!vis[i])        {            prime[primes++] = i;            ph[i] = i-1;        }        for (LL j = 0; j < primes && i*prime[j] < mn; ++j)        {            vis[i*prime[j]] = true;            if (i % prime[j])                ph[i*prime[j]] = ph[i]*(prime[j]-1);            else            {                ph[i*prime[j]] = ph[i]*prime[j];                break;            }        }    }}

#include <cstdio>#include <cstring>using namespace std;const int maxn = 60000+5;bool vis[maxn];int prime[maxn],primes,mu[maxn];void init_mu(){    memset(vis,0,sizeof(vis));    mu[1]=1;    primes=0;    for(int i=2; i<maxn; i++)    {        if(!vis[i]){            prime[primes++]=i;            mu[i]=-1;        }        for(int j=0; j<primes&&i*prime[j]<maxn; j++)        {            vis[i*prime[j]]=1;            if(i%prime[j]) mu[i*prime[j]]=-mu[i];            else { mu[i*prime[j]]=0;break;}        }    }}