UVa/10897 - Travelling Distance/10897.cpp

   1 /*
   2   Accepted
   3  */
   4 using namespace std;
   5 #include <algorithm>
   6 #include <iostream>
   7 #include <iterator>
   8 #include <sstream>
   9 #include <fstream>
  10 #include <cassert>
  11 #include <climits>
  12 #include <cstdlib>
  13 #include <cstring>
  14 #include <string>
  15 #include <cstdio>
  16 #include <cmath>
  17 #include <queue>
  18 #include <deque>
  19 #include <stack>
  20 #include <map>
  21 #include <set>
  22
  23 #define D(x) cout << #x " is " << x << endl
  24
  25 const long double rho = 6371.01;//km
  26 const long double pi = 2*acos(0.0);
  27
  28 struct Vector{
  29   long double x, y, z;
  30   long double dot(const Vector &t) const {
  31     return x*t.x + y*t.y + z*t.z;
  32   }
  33   long double mag() const{
  34     return sqrt(x*x + y*y + z*z);
  35   }
  36 };
  37
  38 ostream& operator << (ostream &out, Vector &v){
  39   out << "<" << v.x << ", " << v.y << ", " << v.z << ">";
  40 }
  41
  42 struct point{
  43   long double phi, theta;
  44   Vector toVector() const{
  45     Vector v;
  46     v.x = sin(phi)*cos(theta);
  47     v.y = sin(phi)*sin(theta);
  48     v.z = cos(phi);
  49     return v;
  50   }
  51 };
  52
  53 istream& operator >> (istream &in, point &p){
  54   long double a, b, c, d, e, f;
  55   char X, Y;
  56   in >> a >> b >> c >> X >> d >> e >> f >> Y;
  57
  58   long double latitude, longitude;
  59   latitude = (a + b/60.0 + c/3600.0);
  60   longitude = (d + e/60.0 + f/3600.0);
  61
  62   p.phi = 90 + latitude * (X == 'N' ? -1.0 : 1.0);
  63   p.theta = longitude * (Y == 'E' ? -1.0 : 1.0);
  64
  65   /*
  66   D(p.phi), D(p.theta);
  67   cout << endl;
  68   */
  69
  70   p.phi *= pi/180.0, p.theta *= pi/180.0; //"radianize"
  71
  72   return in;
  73 }
  74
  75 long double dist(point &a, point &b){
  76   Vector va = a.toVector(), vb = b.toVector();
  77
  78   /*
  79   cout << "Point A as a vector = " << va << endl;
  80   cout << "Point B as a vector = " << vb << endl;
  81   cout << endl;
  82
  83   cout << "|A| = " << va.mag() << endl;
  84   cout << "|B| = " << vb.mag() << endl;
  85   */
  86
  87   long double angle = acos(va.dot(vb));
  88   return rho * angle;
  89 }
  90
  91 int main(){
  92   int n;
  93   for (scanf("%d", &n); n--; ){
  94     point a, b;
  95     cin >> a >> b;
  96     printf("%.2llf\n", dist(a, b));
  97   }
  98
  99   return 0;
 100 }