delete pics to save space

2.11800.cpp

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+#include<cstdio>
+#include<cstring>
+#include<cstdlib>
+#include<cmath>
+#include<vector>
+#include<algorithm>
+using std::vector;
+using std::swap;
+
+struct Point
+{
+	double x,y;
+	Point(double x=0,double y=0):x(x),y(y){}
+};
+typedef Point Vector;
+
+inline Point read_point()
+{
+	Point A;
+	scanf("%lf%lf",&A.x,&A.y);
+	return A;
+}
+
+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);
+}
+using namespace std;
+const char* rslts[]={"Square","Rectangle","Rhombus","Parallelogram","Trapezium","Ordinary Quadrilateral"};
+int T,res;
+Point p[4];
+inline bool PingXing
+(const Point &A1,const Point &B1,const Point &A2,const Point &B2)
+{ return dcmp(Cross(B1-A1,B2-A2))==0; }
+bool is_Square()
+{
+	sort(p,p+4);
+	do
+	{
+		for(int i=0;i<4;i++)
+		{
+			Vector v1=p[(i+1)%4]-p[i],v2=p[(i+2)%4]-p[(i+1)%4];
+			v1=Vector(-v1.y,v1.x);
+			if(!(v1==v2)) goto next;
+		}
+		return true;
+next:
+		continue;
+	}
+	while(next_permutation(p,p+4));
+	return false;
+}
+bool is_JuXin()
+{
+	sort(p,p+4);
+	do
+	{
+		for(int i=0;i<4;i++)
+		{
+			Vector v1=p[(i+1)%4]-p[i],v2=p[(i+2)%4]-p[(i+1)%4];
+			if(!(Normal(v1)==Format(v2))) goto next;
+		}
+		return true;
+next:
+		continue;
+	}
+	while(next_permutation(p,p+4));
+	return false;
+}
+bool is_LinXin()
+{
+	sort(p,p+4);
+	do
+	{
+		for(int i=0;i<4;i++)
+		{
+			Vector v1=p[(i+1)%4]-p[i],v2=p[(i+2)%4]-p[(i+1)%4];
+			if(!(PingXing(p[i],p[(i+1)%4],p[(i+2)%4],p[(i+3)%4])
+				&&Length(v1)==Length(v2))) goto next;
+		}
+		return true;
+next:
+		continue;
+	}
+	while(next_permutation(p,p+4));
+	return false;
+}
+bool is_PingXingSiBianXin()
+{
+	sort(p,p+4);
+	do
+	{
+		for(int i=0;i<4;i++)
+		{
+			Vector v1=p[(i+1)%4]-p[i],v2=p[(i+2)%4]-p[(i+1)%4];
+			if(!(PingXing(p[i],p[(i+1)%4],p[(i+2)%4],p[(i+3)%4]))) goto next;
+		}
+		return true;
+next:
+		continue;
+	}
+	while(next_permutation(p,p+4));
+	return false;
+}
+bool is_TiXin()
+{
+	sort(p,p+4);
+	do
+	{
+		for(int i=0;i<4;i++)
+		{
+			Vector v1=p[(i+1)%4]-p[i],v2=p[(i+2)%4]-p[(i+1)%4];
+			if(PingXing(p[i],p[(i+1)%4],p[(i+2)%4],p[(i+3)%4])) return true;
+		}
+	}
+	while(next_permutation(p,p+4));
+	return false;
+}
+int solve()
+{
+	if(is_Square()) return 0;
+	else if(is_JuXin()) return 1;
+	else if(is_LinXin()) return 2;
+	else if(is_PingXingSiBianXin()) return 3;
+	else if(is_TiXin()) return 4;
+	return 5;
+}
+int main()
+{
+#ifdef local
+	freopen("pro.in","r",stdin);
+#endif
+	scanf("%d",&T);
+	for(int kase=1;kase<=T;kase++)
+	{
+		for(int i=0;i<4;i++) p[i]=read_point();
+		printf("Case %d: %s\n",kase,rslts[solve()]);
+	}
+	return 0;
+}