标签：des http os io ar for art sp 代码
给出经纬度，算球面距和圆弧的弦长
我的做法：
设好三维坐标系，利用投影算出两点坐标
利用余弦定理算出圆弧对应圆心角，再算出球面距
我的代码：
#include<iostream>
#include<map>
#include<string>
#include<cstring>
#include<cstdio>
#include<cstdlib>
#include<cmath>
#include<queue>
#include<vector>
#include<algorithm>
using namespace std;
const double pi=acos(-1),r=6371009;
double cg(double a)
{
return a/180*pi;
}
int main()
{
int t;
double a,b,c,d,x[2],y[2],z[2];
scanf("%d",&t);
while(t--)
{
scanf("%lf%lf%lf%lf",&a,&b,&c,&d);
a=cg(a);b=cg(b);c=cg(c);d=cg(d);
z[0]=r*sin(a);z[1]=r*sin(c);
y[0]=r*cos(a)*sin(b);y[1]=r*cos(c)*sin(d);
x[0]=r*cos(a)*cos(b);x[1]=r*cos(c)*cos(d);
a=pow(x[0]-x[1],2)+pow(y[0]-y[1],2)+pow(z[0]-z[1],2);
b=acos(1-a/2/r/r);
b=r*b;
a=sqrt(a);
printf("%.0lf\n",b-a);
}
}
There are different methods of transporting people fromplace to place: cars, bikes, boats, trains, planes, etc.For very long distances, people generally fly in a plane.But this
has the disadvantage that the plane must fly aroundthe curved surface of the earth. A distance travelled wouldbe shorter if the traveller followed a straight line fromone point to the other through a tunnel through the earth.
For example, travelling from Waterloo to Cairo requires adistance of 9293521 metres following the great circle route aroundthe earth, but only 8491188 metres following the straight linethrough the earth.
For this problem, assume that the earth is a perfect sphere withradius of 6371009 metres.
1 43.466667 -80.516667 30.058056 31.228889
802333
UVA11817 - Tunnelling the Earth
标签：des http os io ar for art sp 代码
原文地址：http://blog.csdn.net/stl112514/article/details/39135421
