UVALive7461 - Separating Pebbles 判断两个凸包相交

 //UVALive7461 - Separating Pebbles 判断两个凸包相交

 #include <bits/stdc++.h>
 using namespace std;
 #define LL long long
 typedef pair<int,int> pii;
 const int inf = 0x3f3f3f3f;
 const int N =1e5+;
 #define clc(a,b) memset(a,b,sizeof(a))
 const double eps = 1e-;
 const int MOD = 1e9+;
 void fre() {freopen("in.txt","r",stdin);}
 void freout() {freopen("out.txt","w",stdout);}
 inline int read() {int x=,f=;char ch=getchar();while(ch>''||ch<'') {if(ch=='-') f=-;ch=getchar();}while(ch>=''&&ch<='') {x=x*+ch-'';ch=getchar();}return x*f;}

 int sgn(double x) {
     if(fabs(x) < eps)return ;
     if(x < )return -;
     else return ;
 }

 struct Point {
     int x,y;
     Point() {}
     Point(int _x,int _y) {
         x = _x;
         y = _y;
     }
     Point operator -(const Point &b)const {
         return Point(x - b.x,y - b.y);
     }
     int operator ^(const Point &b)const {
         return x*b.y - y*b.x;
     }
     int operator *(const Point &b)const {
         return x*b.x + y*b.y;
     }
     friend int dis2(Point a) {
         return a.x*a.x+a.y*a.y;
     }
     friend bool operator<(const Point &a,const Point &b){
         if(fabs(a.y-b.y)<eps) return a.x<b.x;
         return a.y<b.y;
     }
 };
 typedef Point Vector;
 double Dot(Point A, Point B){return A.x*B.x+A.y*B.y;}//点积
 double Cross(Vector A,Vector B){return A.x*B.y-A.y*B.x;}//叉积
 double Length(Vector A){return sqrt(Dot(A,A));}//OA长
 double Angle(Point A,Point B){return acos(Dot(A,B)/Length(A)/Length(B));}//OA和OB的夹角
 //判断线段相交,不在端点相交
 bool SegmentProperIntersection(Point a1,Point a2,Point b1,Point b2){
     double c1=Cross(a2-a1,b1-a1),c2=Cross(a2-a1,b2-a1),c3=Cross(b2-b1,a1-b1),c4=Cross(b2-b1,a2-b1);
     return sgn(c1)*sgn(c2)<&&sgn(c3)*sgn(c4)<;
 }

 int graham(Point p[],int n,Point q[]){
      int top=;
      sort(p,p+n);
      if(n==) return ;
      q[]=p[];
      if(n==) return ;
      q[]=p[];
      if(n==) return ;
      q[]=p[];
      for(int i=;i<n;i++){
          while(top&&(Cross(q[top]-q[top-],p[i]-q[top-])<=)) top--;
          q[++top]=p[i];
      }
      int len=top;
      q[++top]=p[n-];
      for(int i=n-;i>=;i--){
          while(top!=len&&(Cross(q[top]-q[top-],p[i]-q[top-])<=)) top--;
          q[++top]=p[i];
      }
      return top;
 }

 bool C_S(Point *ch1,int t1,Point *ch2,int t2)//判断凸包是否相交
 {
     double angle[],x;
     int i,j,k,m;
     if(t1==)return true;
     if(t1==)
     {
         for(i=;i<t2;i++)
         {
             k=sgn(Cross(ch1[]-ch1[],ch2[i]-ch1[]));
             if(k==&&Dot(ch1[]-ch1[],ch2[i]-ch1[])>)
             {
                 if(Length(ch2[i]-ch1[])<Length(ch1[]-ch1[]))break;
             }
         }
         if(i<t2)return false;
         if(t2==&&SegmentProperIntersection(ch1[],ch1[],ch2[],ch2[]))return false;
         return true;
     }
     angle[]=;
     for(i=;i<t1;i++)
     angle[i-]=Angle(ch1[]-ch1[],ch1[i]-ch1[]);
     for(i=;i<t2;i++)
     {
         j=sgn(Cross(ch1[]-ch1[],ch2[i]-ch1[]));
         if(j<||(j==&&Dot(ch1[]-ch1[],ch2[i]-ch1[])<))continue;
         j=sgn(Cross(ch1[t1-]-ch1[],ch2[i]-ch1[]));
         if(j>||(j==&&Dot(ch1[t1-]-ch1[],ch2[i]-ch1[])<))continue;
         x=Angle(ch1[]-ch1[],ch2[i]-ch1[]);
         m=lower_bound(angle,angle+t1-,x)-angle;
         if(m==)j=;
         else j=m-;
         k=sgn(Cross(ch1[j+]-ch2[i],ch1[j+]-ch2[i]));
         if(k>=)break;
     }
     if(i<t2)return false;
     return true;
 }

 Point p1[],p2[],ch1[],ch2[];
 int main(){
     int T;
     scanf("%d",&T);
     while(T--){
         int n;
         scanf("%d",&n);
         int cnt1=,cnt2=;
         for(int i=;i<n;i++){
             int x,y,c;
             scanf("%d%d%d",&x,&y,&c);
             if(c==){
                 p1[cnt1++]=Point(x,y);
             }
             else p2[cnt2++]=Point(x,y);
         }
         int t1=graham(p1,cnt1,ch1);
         int t2=graham(p2,cnt2,ch2);
         if(C_S(ch1,t1,ch2,t2)&&C_S(ch2,t2,ch1,t1)) printf("1\n");
         else printf("0\n");
     }
 }