11.2 下午考试

 

#include<iostream>
#include<cstdio>
#include<cstring>
#define LL long long
using namespace std;
LL n,ans;
LL init()
{
    LL 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-'0';c=getchar();}
    return x*f;
}
int main()
{
    freopen("phi.in","r",stdin);
    freopen("phi.out","w",stdout);
    n=init();ans=n;
    for(LL i=2;i*i<=n;i++)
    {
        if(n%i==0)
        {
            while(n%i==0)
            n/=i;
            ans=ans/i*(i-1);
        }
    }
    if(n>1)ans=ans/n*(n-1);
    cout<<ans<<endl;
    fclose(stdin);fclose(stdout);
    return 0;
}

#include<iostream>
#include<cstdio>
#include<cstring>
#include<cmath>
#include<ctime>
#include<cstdlib>
#include<algorithm>
#define LL long long
#define maxn 10000000
using namespace std;
LL n,w,tot,topt;
LL prime[maxn],f[maxn],ans[maxn];
LL init()
{
    LL 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-'0';c=getchar();}
    return x*f;
}
void prepare()
{
    for(LL i=2;i<=10000000;i++)
    {
        if(!f[i])prime[++tot]=i;
        for(LL j=1;j<=tot&&prime[j]*i<=10000000;j++)
        {
            f[prime[j]*i]=1;
            if(i%prime[j]==0)break;
        }
    }
}
LL slow_mul(LL a,LL b,LL p)
{
    LL ret=0;
    while(b)
    {
        if(b&1)b--,ret+=a,ret%=p;
        a<<=1;a%=p;b>>=1;
    }
    return ret;
}
LL pow(LL x,LL q,LL p)
{
    if(q==0)return 1;
    LL ha=pow(x,q/2,p);
    ha=slow_mul(ha,ha,p);
    if(q&1)ha=slow_mul(ha,x,p);
    return ha;
}
LL judge(LL x)
{
    LL flag=0;
    for(LL i=1;i<=5;i++)
    {
        LL s=rand();
        if(pow(s,x-1,x)==1)continue;
        flag=1;break;
    }
    return flag==0;
}
void dfs(LL x,LL rest,LL sum)
{
    if(rest==1)
    {
        ans[++topt]=sum;
        return;
    }
    if(rest+1>prime[tot]&&judge(rest+1))
        ans[++topt]=sum*(rest+1);
    for(int i=x;i>=1;i--)
    {
        if(rest%(prime[i]-1)==0)
        {
            LL r=rest,s=sum;
            while(1)
            {
                s*=prime[i];
                dfs(i-1,r/(prime[i]-1),s);
                if(r%prime[i]!=0)break;
                r/=prime[i];
            }
        }
    }
}
int main()
{
    freopen("arc.in","r",stdin);
    freopen("arc.out","w",stdout);
    srand(time(0));
    n=init();w=init();
    prepare();
    dfs(tot,n,1);
    sort(ans+1,ans+topt+1);
    //unique(ans+1,ans+topt+1);
    for(LL i=1;i<=w;i++)
      cout<<ans[i]<<" ";
    return 0;
}

 

暂无正解

60分代码:

/*
60分 
*/
#include<iostream>
#include<cstdio>
#include<cstring>
#define LL long long
using namespace std;
LL n,ans,f[10000010];
LL init()
{
    LL 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-'0';c=getchar();}
    return x*f;
}
void prepare()
{
    f[1]=1;
    for(LL i=2;i<=n;i++)
    {
        if(!f[i])
        {
            f[i]=i-1;
            for(LL j=i*2;j<=n;j+=i)
            {
                if(!f[j])f[j]=j;
                f[j]=f[j]/i*(i-1);
            }
        }
    }
}
int main()
{
    freopen("sum.in","r",stdin);
    freopen("sum.out","w",stdout);
    n=init();
    prepare();
    for(LL i=1;i<=n;i++)
      ans+=f[i];
    cout<<ans<<endl;
    return 0;
}