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.Linq;
using System.Text;
using System.Threading.Tasks;

namespace AOJ1_10_A
{
    class Program
    {
        static void Main(string[] args)
        {
            string[] str = Console.ReadLine().Split(' ');
           double[] Num = new double[str.Length];
            for (int i = 0; i < str.Length; i++)
            {
                Num[i] = 0;
                Num[i] = double.Parse(str[i]);
            }
            double Answer = Math.Sqrt((Num[2] - Num[0]) * (Num[2] - Num[0]) + (Num[3] - Num[1]) * (Num[3] - Num[1]));

            Console.WriteLine(Answer);
                    }
    }
}