HDU 3335 Divisibility dancing links 重复覆盖

#include<cstdio>
#include<cstring>
#include<queue>
#include<cstdlib>
#include<algorithm>
#include<vector>
#include<cmath>
using namespace std;
typedef long long LL;
const int N=1e6+5;
const double eps=1e-8;
int n,m,sz,k;
int u[N],l[N],r[N],d[N];
int h[1005],s[1005],col[N];
void init()
{
    for(int i=0; i<=m; ++i)
    {
        s[i]=0;
        u[i]=d[i]=i;
        l[i]=i-1;
        r[i]=i+1;
    }
    r[m]=0;
    l[0]=m;
    sz=m;
    for(int i=1; i<=n; ++i)
        h[i]=-1;
}
void link(int x,int y)
{
    ++sz;
    ++s[y],col[sz]=y;
    u[sz]=u[y],d[u[y]]=sz;
    d[sz]=y,u[y]=sz;
    if(h[x]==-1)h[x]=l[sz]=r[sz]=sz;
    {
        l[sz]=l[h[x]];
        r[l[h[x]]]=sz;
        r[sz]=h[x];
        l[h[x]]=sz;
    }
}
void del(int y)
{
    for(int i=d[y]; i!=y; i=d[i])
        r[l[i]]=r[i],l[r[i]]=l[i];
}
void resume(int y)
{
    for(int i=d[y]; i!=y; i=d[i])
        r[l[i]]=l[r[i]]=i;
}
int f()
{
    int ret=0;
    for(int i=r[0];i;i=r[i])++ret;
    return ret;
}
int ans;
void dance(int pos)
{
    if(pos+f()<=ans)return;
    if(!r[0])
    {
        ans=max(pos,ans);
        return;
    }
    int t=r[0];
    for(int i=r[0]; i!=0; i=r[i])
        if(s[i]<s[t])t=i;
    for(int i=d[t]; i!=t; i=d[i])
    {
        del(i);
        for(int j=r[i]; j!=i; j=r[j])
            del(j);
        dance(pos+1);
        for(int j=l[i]; j!=i; j=l[j])
            resume(j);
        resume(i);
    }
}
LL a[1005];
int main()
{
    int T;
    scanf("%d",&T);
    while(T--)
    {
        scanf("%d",&n);
       for(int i=1;i<=n;++i)
         scanf("%I64d",&a[i]);
       sort(a+1,a+1+n);
       m=n;
       init();
       for(int i=1;i<=n;++i)
        for(int j=1;j<=n;++j)
          if(a[i]%a[j]==0||a[j]%a[i]==0)
            link(i,j);
       ans=0;
       dance(0);
       printf("%d\n",ans);
    }
    return 0;
}