Triangle Fun

版权声明:本文为博主原创文章,未经博主允许不得转载。 https://blog.csdn.net/HYNU_zhizuzhe/article/details/46290601

Description

In the picture below you can see a triangle ABC. Point D, E and F divides the sides BC, CA and AB into ratio 1:2 respectively. That is CD=2BD, AE=2CE and BF=2AF. A, D; B, E and C, F are connected. AD and BE intersects at P, BE and CF intersects at Q and CF and AD intersects at R.

So now a new triangle PQR is formed. Given triangle ABC your job is to find the area of triangle PQR.

Input

First line of the input file contains an integer N (0<N<1001) which denotes how many sets of inputs are there. Input for each set contains six floating-point number Ax, Ay, Bx, By, Cx, Cy. (0≤Ax, Ay, Bx, By, Cx,Cy≤10000) in one line line. These six numbers denote that the coordinate of points A, B and C are (Ax, Ay), (Bx, By) and (Cx, Cy) respectively. A, B and C will never be collinear.

Output

For each set of input produce one line of output. This one line contains an integer AREA. Here AREA is the area of triangle PQR, rounded to the nearest integer.

Sample Input

2

3994.707 9251.677 4152.916 7157.810 5156.835 2551.972

6903.233 3540.932 5171.382 3708.015 213.959 2519.852

 

Output for Sample Input

98099

206144



#include<iostream>
#include<cstdio>
using namespace std;

struct Point{
	double x,y;
	Point(double x=0,double y=0):x(x),y(y) {}
	Point operator +(const Point &b) const {return Point(x+b.x,y+b.y);}
	Point operator -(const Point &b) const {return Point(x-b.x,y-b.y);}
	Point operator *(const double &b) const {return Point(x*b,y*b);}
	Point operator /(const double &b) const {return Point(x/b,y/b);}
};

double det(const Point &a,const Point &b) {return a.x*b.y-a.y*b.x;}

Point CrossLine(Point s1,Point t1,Point s2,Point t2)
{
	double t=det(t2-s2,s1-s2)/det(t1-s1,t2-s2);
	return s1+(t1-s1)*t;
}

int main()
{
	int T_T;
	scanf("%d",&T_T);
	while(T_T--)
	{
		Point A,B,C,D,E,F,P,Q,R;
		scanf("%lf%lf%lf%lf%lf%lf",&A.x,&A.y,&B.x,&B.y,&C.x,&C.y);
		D=B+(C-B)/3.0; E=C+(A-C)/3.0; F=A+(B-A)/3.0;
		P=CrossLine(A,D,B,E); Q=CrossLine(B,E,C,F); R=CrossLine(C,F,A,D);
		double area=det(Q-P,R-P)/2.0;
		printf("%.0lf\n",area);
	}
	return 0;
}



猜你喜欢

转载自blog.csdn.net/HYNU_zhizuzhe/article/details/46290601
今日推荐