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;

class Program
{
    static void Main()
    {
        string str = Console.ReadLine();
        string[] strs = str.Split(' ');

        double x1 = double.Parse(strs[0]);
        double y1 = double.Parse(strs[1]);

        double x2 = double.Parse(strs[2]);
        double y2 = double.Parse(strs[3]);


        double length;

        if (x1 >= x2)
        {
            if (y1 >= y2)
            {
                length = Math.Sqrt(((x1 - x2) * (x1 - x2)) + ((y1 - y2) * (y1 - y2)));
            }
            else
            {
                length = Math.Sqrt(((x1 - x2) * (x1 - x2)) + ((y2 - y1) * (y2 - y1)));
            }
         
        }
        else
        {
            if (y1 >= y2)
            {
                length = Math.Sqrt(((x2 - x1) * (x2 - x1)) + ((y1 - y2) * (y1 - y2)));
            }
            else
            {
                length = Math.Sqrt(((x2 - x1) * (x2 - x1)) + ((y2 - y1) * (y2 - y1)));
            }
        }

        Console.WriteLine(length);
        
        
    }
}