线性筛+求莫比乌斯函数‘

void get()
{
    int n = 100;
    mu[1]=1;
    for(int i=2;i<=n;i++)
    {
        if(!ol[i])prime[++num]=i,cout<<i<<" ",mu[i]=-1;
        for(int j=1;j<=num&&j*prime[i]<=n;j++)
        {
            ol[i*prime[j]]=1;
            if((i%prime[j])==0)
            {
                mu[i*prime[j]]=0;
                break;
            }
            mu[i*prime[j]]=-mu[i];
        }
    }
    cout<<num<<endl;
}