1517.cpp

这是哈尔滨工业大学acmOJ的源代码

/*  This Code is Submitted by wywcgs for Problem 1517 on 2005-12-14 at 20:47:48 */ 
#include <cstdio>
#include <cmath>

const int L_MAX = 128;
const double ERATH_R = 6378;
const double eps = 1e-7;

class Point {
public:
	double x, y, z;
	char name[L_MAX];
	void parse(double, double, double);
	double dist(const Point&) const;
};
void Point::parse(double lon, double lat, double h = ERATH_R) {
	double a = lon * M_PI / 180;
	double b = lat * M_PI / 180;
	x = h * cos(a) * cos(b);
	y = h * sin(a) * cos(b);
	z = h * sin(b);
}
double Point::dist(const Point& p) const {
	return (x-p.x)*(x-p.x)+(y-p.y)*(y-p.y)+(z-p.z)*(z-p.z);
}

const Point CENTER = { 0.0, 0.0, 0.0 };

int main()
{
	Point city, sate;
	int n, i, t;
	double lon, lat, h;
	
	for(t = 1; scanf("%d %lf %lf %lf", &n, &lat, &lon, &h) != EOF && n != 0; t++) {
		sate.parse(lon, lat, h+ERATH_R);
		printf("Test case %d:\n", t);
		for(i = 0; i < n; i++) {
			scanf("%s %lf %lf", city.name, &lat, &lon);
			city.parse(lon, lat);
			if(sate.dist(city)+city.dist(CENTER) -
				sate.dist(CENTER) < eps) {
				printf("%s\n", city.name);
			}
		}
		putchar('\n');
	}
	
	return 0;
}