BZOJ 2257 瓶子与燃料

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<cmath>
#define maxn 1050
using namespace std;
int n,k,x,top=0,s[maxn*maxn*10];
int main()
{
scanf("%d%d",&n,&k);
for (int i=1;i<=n;i++)
{
scanf("%d",&x);
int t=sqrt(x);
for (int j=1;j<=t;j++)
{
if (x%j) continue;
s[++top]=j;
if ((x/j)!=j) s[++top]=x/j;
}
}
sort(s+1,s+top+1);int ret=1;
for (int i=top-1;i>=0;i--)
{
if (s[i]==s[i+1]) ret++;
else
{
if (ret>=k) {printf("%d\n",s[i+1]);return 0;}
else ret=1;
}
}
return 0;
}