知道地球两点算距离——fzu2016

注意精度高点没错的

#include<stdio.h>
#include<math.h>

#define R 6378.00
#define PI 3.1415926535
#define hu 360/3.1415926535/2

int main()
{
    int t;
    double x1,y1,z1,x2,y2,z2,th1,th2,a1,a2,dis,q;
    scanf("%d",&t);
    while(t--)
    {
        double a=sin(30/hu);
        scanf("%lf%lf%lf%lf",&th1,&a1,&th2,&a2);
        th1/=hu;
        a1/=hu;
        th2/=hu;
        a2/=hu;
        x1=R*cos(th1)*sin(a1);
        y1=R*cos(th1)*cos(a1);
        z1=R*sin(th1);

        x2=R*cos(th2)*sin(a2);
        y2=R*cos(th2)*cos(a2);
        z2=R*sin(th2);

        dis=sqrt((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2)+(z1-z2)*(z1-z2));
        q=2*asin(dis/2.0/R)*R;
        printf("%.2lf\n",q);
    }
}