static double CalcDistance(ReadPoint p1, ReadPoint p2) { int a = p1.X - p2.X; int b = p1.Y - p2.Y; return(Math.Sqrt(a * a + b * b)); }
static void Main() { int[] input1 = Console.ReadLine().Split().Select(int.Parse).ToArray(); int[] input2 = Console.ReadLine().Split().Select(int.Parse).ToArray(); ReadPoint p1 = new ReadPoint { X = input1[0], Y = input1[1] }; ReadPoint p2 = new ReadPoint { X = input2[0], Y = input2[1] }; Console.WriteLine("{0:F3}", CalcDistance(p1, p2)); }