BZOJ 3629 聪明的燕姿

爆搜233。

#include<iostream>
#include<cstdio>
#include<cmath>
#include<cstring>
#include<algorithm>
#define maxn 1000000
using namespace std;
long long prime[maxn+50],cnt=0,s,stack[maxn],top=0,sqrts;
bool vis[maxn+50];
void get_table()
{
    for (long long i=2;i<=maxn;i++)
    {
        if (!vis[i])
            prime[++cnt]=i;
        for (long long j=1;j<=cnt && i*prime[j]<=maxn;j++)
        {
            vis[i*prime[j]]=true;
            if (i%prime[j]==0) break;
        }
    }
}
bool judge(long long x)
{
    if (x<=maxn) return !vis[x];
    long long top=sqrt(x);
    for (long long i=1;prime[i]<=top;i++)
    {
        if (x%prime[i]==0) return false;
    }
    return true;
}
void dfs(long long x,long long s,long long ans)
{
    if (s==1) {stack[++top]=ans;return;}
    if ((s-1>sqrts) && (judge(s-1))) stack[++top]=ans*(s-1);
    for (long long i=x;prime[i]<=sqrts;i++)
    {
        long long ret=1,kr=prime[i];
        for (long long j=1;kr+ret<=s;j++)
        {
            if (s%(kr+ret)==0)
                dfs(i+1,s/(kr+ret),ans*kr);
            ret+=kr;kr*=prime[i];
        }
    }
}
int main()
{
    get_table();
    while (scanf("%lld",&s)!=EOF)
    {
        sqrts=sqrt(s);top=0;
        dfs(1,s,1);
        sort(stack+1,stack+top+1);
        printf("%lld
",top);
        for (long long i=1;i<=top-1;i++)
            printf("%lld ",stack[i]);
        if (top>=1) printf("%lld
",stack[top]);
    }
    return 0;
}