http://acm.hdu.edu.cn/showproblem.php?pid=1071

按要求求出面积即可

View Code
#include <stdio.h>

int main()
{
    int t;
    double x0,y0,x1,y1,x2,y2;
    double k,b;
    double a;
    double s;
    scanf("%d",&t);
    while(t--)
    {
        scanf("%lf%lf%lf%lf%lf%lf",&x0,&y0,&x1,&y1,&x2,&y2);
        k=(y2-y1)/(x2-x1);
        b=y1-k*x1;
        a=(y1-y0)/(x1-x0)/(x1-x0);
        s=(a*x2*x2*x2/3-a*x0*x2*x2+(a*x0*x0+y0)*x2-a*x1*x1*x1/3+a*x0*x1*x1-(a*x0*x0+y0)*x1-k*x2*x2/2-b*x2+k*x1*x1/2+b*x1);
        printf("%.2lf\n",s);
    }
    return 0;
}