UVA 11275 3D Triangles

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大白p292

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#include <vector>#include <cstdio>#include <algorithm>#include <cmath>using namespace std;const double eps=1e-10;//精度const int INF=1<<29;const double PI=acos(-1);int dcmp(double x){//判断double等于0或。。。if(fabs(x)<eps)return 0;else return x<0?-1:1;}struct Point{double x,y,z;Point(double x=0,double y=0,double z=0):x(x),y(y),z(z){}};typedef Point Vector;Vector operator+(Vector a,Vector b){return Vector(a.x+b.x,a.y+b.y,a.z+b.z);}Vector operator-(Point a,Point b){return Vector(a.x-b.x,a.y-b.y,a.z-b.z);}Vector operator*(Vector a,double p){return Vector(a.x*p,a.y*p,a.z*p);}Vector operator/(Vector a,double p){return Vector(a.x/p,a.y/p,a.z/p);}bool operator==(Point a,Point b){return dcmp(a.x-b.x)==0&&dcmp(a.y-b.y)==0&&dcmp(a.z-b.z)==0;}double Dot(Vector a,Vector b){return a.x*b.x+a.y*b.y+a.z*b.z;}double Length(Vector a){return sqrt(Dot(a,a));}double Angle(Vector a,Vector b){return acos(Dot(a,b)/Length(a)/Length(b));}double DistanceToPlane(Point p,Point p0,Vector v){//点p到平面p0 n的距离return fabs(Dot(p-p0,v))/Length(v);//fabs取无向距离}Point GetPlaneProjection(Point p,Point p0,Vector v){//点p在平面p0 v上的投影double d=Dot(p-p0,v)/Length(v);return p+v*d;}Point LinePlaneIntersection(Point p1,Point p2,Point p0,Vector n){//直线p1 p2到平面p0 n的交点 交点必须唯一Vector v=p2-p1;double t=(Dot(n,p0-p1)/Dot(n,v));//Dot(n,v)==0时 平行或在平面上return p1+v*t;}Vector Cross(Vector a,Vector b){//三维叉积 右手定则return Vector(a.y*b.z-a.z*b.y,a.z*b.x-a.x*b.z,a.x*b.y-a.y*b.x);}double Area2(Point a,Point b,Point c){return Length(Cross(b-a,c-a));}bool PointInTri(Point p,Point p0,Point p1,Point p2){//点p在三角形p0 p1 p2中double area1=Area2(p,p0,p1);double area2=Area2(p,p1,p2);double area3=Area2(p,p2,p0);return dcmp(area1+area2+area3-Area2(p0,p1,p2))==0;}bool TriSegIntersection(Point a,Point b,Point c,Point p,Point q,Point& Intersection){//三角形abc是否和线段p q相交 Intersection为交点Vector n=Cross(b-a,c-a);if(dcmp(Dot(n,q-p))==0) return false;//三角形和直线平行或共面else{//三角形和直线平行或共面double t=Dot(n,a-p)/Dot(n,q-p);if(dcmp(t)<0||double(t-1)>0) return false;//交点不在线段AB上Intersection=p+(q-p)*t;return PointInTri(Intersection,a,b,c);}}double DistanceToLine(Point p,Point a,Point b){//点p到直线ab的距离Vector v1=b-a,v2=p-a;return Length(Cross(v1,v2))/Length(v1);}double DistanceToSegment(Point p,Point a,Point b){if(a==b) return Length(p-a);Vector v1=b-a,v2=p-a,v3=p-b;if(dcmp(Dot(v1,v2))<0) return Length(v2);else if(dcmp(Dot(v1,v3))>0) return Length(v3);else return Length(Cross(v1,v2))/Length(v1);}//......int main(){int T;scanf("%d",&T);while(T--){bool ok=false;Point T1[3],T2[3],temp;for(int i=0;i<3;i++) scanf("%lf%lf%lf",&T1[i].x,&T1[i].y,&T1[i].z);for(int i=0;i<3;i++) scanf("%lf%lf%lf",&T2[i].x,&T2[i].y,&T2[i].z);for(int i=0;i<3;i++)if(TriSegIntersection(T1[0],T1[1],T1[2],T2[i],T2[(i+1)%3],temp))ok=true;for(int i=0;i<3;i++)if(TriSegIntersection(T2[0],T2[1],T2[2],T1[i],T1[(i+1)%3],temp))ok=true;if(ok) puts("1");else puts("0");}return 0;}