delete pics to save space

2.11524.cpp

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+#include<cstdio>
+#include<cstring>
+#include<cstdlib>
+#include<cmath>
+#include<vector>
+#include<algorithm>
+using namespace std;
+struct Point
+{
+	double x,y;
+	Point(double x=0,double y=0):x(x),y(y){}
+};
+typedef Point Vector;
+
+inline Vector operator+(const Vector &A,const Vector &B)
+{ return Vector(A.x+B.x,A.y+B.y); }
+
+inline Vector operator-(const Point &a,const Point &b)
+{ return Vector(a.x-b.x,a.y-b.y); }
+
+inline Vector operator*(const Vector &A,double p)
+{ return Vector(A.x*p,A.y*p); }
+
+inline Vector operator/(const Vector &A,double p)
+{ return Vector(A.x/p,A.y/p); }
+
+inline bool operator<(const Point &a,const Point &b)
+{ return a.x<b.x||(a.x==b.x&&a.y<b.y); }
+
+const double eps=1e-10;
+inline int dcmp(double x)
+{ return (x>0?x:-x)<=eps?0:(x>0?1:-1); }
+
+inline bool operator==(const Point &a,const Point &b)
+{ return dcmp(a.x-b.x)==0&&dcmp(a.y-b.y)==0; }
+
+inline double Dot(const Vector &A,const Vector &B)
+{ return A.x*B.x+A.y*B.y; }
+
+inline double Length(const Vector &A)
+{ return sqrt(Dot(A,A)); }
+
+inline double Cross(const Vector &A,const Vector &B)
+{ return A.x*B.y-A.y*B.x; }
+
+inline Vector Normal(const Vector &A)
+{
+	double L=Length(A);
+	return Vector(-A.y/L,A.x/L);
+}
+inline Vector Format(const Vector &A)
+{
+	double L=Length(A);
+	return Vector(A.x/L,A.y/L);
+}
+
+inline double DistanceToLine
+(const Point &P,const Point &A,const Point &B)
+{
+	Vector v1=B-A,v2=P-A;
+	return fabs(Cross(v1,v2))/Length(v1);
+}
+
+struct Circle
+{
+	Point c;
+	double r;
+	Circle(Point c=Point(),double r=0):c(c),r(r){}
+	inline Point point(double a)
+	{ return Point(c.x+cos(a)*r,c.y+sin(a)*r); }
+};
+
+inline int GetCircleCircleIntersection
+(Circle C1,Circle C2,vector<Point> &sol)
+{
+	if(C1.r<C2.r) swap(C1,C2);//to make sure C1 is bigger than C2
+	double D=Length(C1.c-C2.c);
+	if(dcmp(D)==0)
+		return dcmp(C1.r-C2.r)==0?-1:0;
+	if(dcmp(C1.r+C2.r-D)<0) return 0;
+	if(dcmp(fabs(C1.r-C2.r)-D)>0) return 0;
+	
+	double d1=((C1.r*C1.r-C2.r*C2.r)/D+D)/2;
+	double x=sqrt(C1.r*C1.r-d1*d1);
+	Point O=C1.c+Format(C2.c-C1.c)*d1;
+	Point P1=O+Normal(O-C2.c)*x,P2=O-Normal(O-C2.c)*x;
+	sol.push_back(P1);
+	if(P1==P2) return 1;
+	sol.push_back(P2);
+	return 2;
+}
+
+Circle NeiJieYuan(Point p1,Point p2,Point p3)
+{
+	double a=Length(p2-p3);
+	double b=Length(p3-p1);
+	double c=Length(p1-p2);
+	Point p=(p1*a+p2*b+p3*c)/(a+b+c);
+	return Circle(p,DistanceToLine(p,p1,p2));
+}
+int T;
+double r,a1,b1,a2,b2,a3,b3;
+double a,b,c;
+int main()
+{
+#ifdef local
+	freopen("pro.in","r",stdin);
+#endif
+	scanf("%d",&T);
+	while(T-->0)
+	{
+		scanf("%lf%lf%lf%lf%lf%lf%lf",&r,&a1,&b1,&a2,&b2,&a3,&b3);
+		c=a1+b1;
+		a=b1+b1*b2/a2;
+		b=a1+a1*a3/b3;
+		Point B(0,0),C(a,0),A;
+		vector<Point> v;
+		GetCircleCircleIntersection(Circle(B,c),Circle(C,b),v);
+		A=v[0];
+		Circle O=NeiJieYuan(A,B,C);
+		double d=r/O.r;
+		a*=d;
+		b*=d;
+		c*=d;
+		double p=(a+b+c)/2;
+		printf("%.4lf\n",sqrt(p*(p-a)*(p-b)*(p-c)));
+	}
+	return 0;
+}