/// <summary>
/// Returns the distance between two world coordinates (input is in degrees, so transformation in radians required)
/// </summary>
/// <returns></returns>
public static float getDistance(float x1, float y1, float x2, float y2)
{
float X1 = Defibrilator.ToRadians(x1);
float X2 = Defibrilator.ToRadians(x2);
float Y1 = Defibrilator.ToRadians(y1);
float Y2 = Defibrilator.ToRadians(y2);
float XX = (X2 - X1) * (float)Math.Cos((Y1 + Y2) / 2.0f);
float YY = Y2 - Y1;
float distance = (float)Math.Sqrt(XX * XX + YY * YY) * 6371.0f;
return(distance);
}
public static void Main(string[] args)
{
// carefull with float parsing, some computers interpret ',' as separation, others the '.' (local settings matter)
float myX = float.Parse(Console.ReadLine().Replace(',', '.')); //the longitude
float myY = float.Parse(Console.ReadLine().Replace(',', '.')); //the latitude
int N = int.Parse(Console.ReadLine()); //nr. of defibrilators
// read the defribrilators data and store it in a list
List <Defibrilator> defribilators = new List <Defibrilator>();
for (int i = 0; i < N; i++)
{
string defString = Console.ReadLine();
string[] defData = defString.Split(new char[] { ';' });
String tempName = defData[1];
float tempX = float.Parse(defData[4].Replace(',', '.'));
float tempY = float.Parse(defData[5].Replace(',', '.'));
Defibrilator d = new Defibrilator(tempName, tempX, tempY);
defribilators.Add(d);
}
// get the result by sorting the list using as criteria the distance between the points and the user position
//we use lambda expression, for demonstration purposes
String result = defribilators.OrderBy(x => x,
Comparer <Defibrilator> .Create(
(d1, d2) =>
{
float dist1 = Defibrilator.getDistance(d1.X, d1.Y, myX, myY);
float dist2 = Defibrilator.getDistance(d2.X, d2.Y, myX, myY);
return(dist1 == dist2 ? 0 : (dist1 < dist2 ? -1 : 1));
}
)).ToList()[0].Name;
Console.WriteLine(result);
Console.ReadKey();
}