2
2
5 10 5 8 3 10 3 8
8 8 8 6 7 8 7 6
1
0 0 2 2 2 0 0 2

Case #1:
17
Case #2:
4

旋转卡壳。和bzoj上那题基本同样

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<iostream>
#include<algorithm>
#include<functional>
#include<cmath>
using namespace std;
#define For(i,n) for(int i=1;i<=n;i++)
#define Fork(i,k,n) for(int i=k;i<=n;i++)
#define Rep(i,n) for(int i=0;i<n;i++)
#define ForD(i,n) for(int i=n;i;i--)
#define RepD(i,n) for(int i=n;i>=0;i--)
#define Forp(x) for(int p=pre[x];p;p=next[p])
#define Forpiter(x) for(int &p=iter[x];p;p=next[p])
#define MAXN (10000+10)
#define INF (1000000000)
#define eps 1e-6
struct P
{  double x,y;  P(){}  P(double _x,double _y):x(_x),y(_y){}  friend bool operator<(P a,P b){return (fabs(a.y-b.y)<eps)?a.x<b.x:a.y<b.y;  }  friend bool operator==(P a,P b){return fabs(a.x-b.x)<eps&&fabs(a.y-b.y)<eps;}  friend bool operator!=(P a,P b){return !(a==b);}  }a[MAXN],s[MAXN],ansp[5];
int size=0;
double ans=INF;
double dis2(P a,P b){return (a.x-b.x)*(a.x-b.x)+(a.y-b.y)*(a.y-b.y);}
struct V
{  double x,y;  V(){}  V(double _x,double _y):x(_x),y(_y){}  V(P a,P b):x(b.x-a.x),y(b.y-a.y){}  friend double operator*(V a,V b){return a.x*b.y-a.y*b.x;}  friend V operator*(double a,V b){return V(a*b.x,a*b.y);}  friend double operator/(V a,V b){return a.x*b.x+a.y*b.y;}  friend P operator+(P a,V b){return P(a.x+b.x,a.y+b.y);}  friend P operator-(P a,V b){return P(a.x-b.x,a.y-b.y);}  friend V operator~(V a){return V(a.y,-a.x);}  double dis2(){return x*x+y*y;   }
};
int cmp(P A,P B)
{  double tmp=V(a[1],A)*V(a[1],B);  if (tmp>0) return 1;  else if (fabs(tmp)<eps) return (-dis2(A,a[1])-dis2(B,a[1])>0);  return 0;
}
int n;  int main()
{
//  freopen("F.in","r",stdin);int T;cin>>T;For(kcase,T){ans=INF;scanf("%d",&n);  n*=4;for(int i=1;i<=n;i++) scanf("%lf%lf",&a[i].x,&a[i].y);  for (int i=2;i<=n;i++) if (a[i]<a[1]) swap(a[1],a[i]);  sort(a+2,a+1+n,cmp);  s[1]=a[1];size=1;  for (int i=2;i<=n;)  if (size<2||V(s[size-1],s[size])*V(s[size],a[i])>eps) s[++size]=a[i++];  else size--;  s[0]=s[size];  int l=1,r=1,t=1;  for (int i=0;i<size;i++)  {  while (V(s[i],s[i+1])*V(s[i],s[t+1])-V(s[i],s[i+1])*V(s[i],s[t])>-eps) t=(t+1)%size;   while (V(s[i],s[i+1])/V(s[i],s[r+1])-V(s[i],s[i+1])/V(s[i],s[r])>-eps) r=(r+1)%size;   if (i==0) l=r;  while (V(s[i],s[i+1])/V(s[i],s[l+1])-V(s[i],s[i+1])/V(s[i],s[l])<eps) l=(l+1)%size;   double Dis2=dis2(s[i],s[i+1]),wlxdis=V(s[i],s[i+1])/V(s[i],s[l]),wrxdis=V(s[i],s[i+1])/V(s[i],s[r]),hxdis=V(s[i],s[i+1])*V(s[i],s[t]);  double tmp=hxdis*(wrxdis-wlxdis)/Dis2;        if (tmp<0) tmp=-tmp;  if (ans>tmp)  {  ans=tmp;  ansp[0]=s[i]-(wlxdis/Dis2)*V(s[i+1],s[i]);  ansp[1]=s[i]+(wrxdis/Dis2)*V(s[i],s[i+1]);  ansp[2]=ansp[1]+(hxdis/Dis2)*(~V(s[i+1],s[i]));           ansp[3]=ansp[0]+(hxdis/Dis2)*(~V(s[i+1],s[i]));           }  }  int p=0;  for (int i=1;i<4;i++) if (ansp[i]<ansp[p]) p=i;//p=0;  printf("Case #%d:\n",kcase);printf("%.0lf\n",ans);    }return 0;
}