BZOJ 1053 [HAOI2007]反素数ant

#include<cstdio>
#include<cmath>
#include<algorithm>
using namespace std;
int cnt=11, prime[12]={1,2,3,5,7,11,13,17,19,23,29,31}, ans=0, pos, n;
void dfs(int now, long long num, int temp)
{
if(now>cnt)
{
if(ans<temp)
{
ans=temp;
pos=num;
}
else if(ans==temp && num<pos)
pos=num;
return;
}
dfs(now+1,num,temp);
for(int i = 1; num*prime[now]<=n; i++)
{
num*=prime[now];
dfs(now+1,num,temp*(i+1));
}
}
int main()
{
scanf("%d",&n);
dfs(1,1,1);
printf("%d\n",pos);
return 0;
}