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.IO;
using System.Linq;
using System.Text;

namespace _20170409_AOJ
{
    class Program
    {
        static void Main(string[] args)
        {
            double[] dArr = Console.ReadLine().Split(' ').Select(s => double.Parse(s)).ToArray();
            double x1 = dArr[0];
            double y1 = dArr[1];
            double x2 = dArr[2];
            double y2 = dArr[3];
            double d = Math.Sqrt(Math.Pow(x2 - x1, 2) + Math.Pow(y2 - y1, 2));

            Console.WriteLine(d);

            Console.ReadLine();
        }
    }
}