Problem:
Distance

Write a program which calculates the distance between two points P1(x1, y1) and P2(x2, y2).

Input

Four real numbers x1, y1, x2 and y2 are given in a line.

Output

Print the distance in real number. The output should not contain an absolute error greater than 10-4.

Sample Input

0 0 1 1

Sample Output

1.41421356

Solution in C# (judge verdict: Accepted)

using System;
using System.Collections.Generic;
using System.Text;
using System.Linq;

namespace ConsoleApplication2
{
    class Point
    {
        public double X
        {
            set; get;
        }

        public double Y
        {
            set; get;
        }

        public double Distance(Point p2)
        {
            double x = Math.Pow(X - p2.X, 2);
            double y = Math.Pow(Y - p2.Y, 2);
            return Math.Sqrt(x + y);
        }
    }


    class Program
    {
        static void Main(string[] args)
        {
            double[] datas = Console.ReadLine()
                             .Split(' ')
                             .Select(x => double.Parse(x))
                             .ToArray();
            var p1 = new Point()
            {
                X = datas[0],
                Y = datas[1],
            };

            var p2 = new Point()
            {
                X = datas[2],
                Y = datas[3],
            };

            Console.WriteLine(p1.Distance(p2));
        }
    }
}