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 JAVA (judge verdict: Accepted)

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.IOException;
public class Main {
	public static void main(String[] args) throws IOException {
		BufferedReader input = new BufferedReader(new InputStreamReader(System.in));
		String str = input.readLine();
		
		int n1 = str.indexOf(" ");
		int n2 = str.indexOf(" " , n1 + 1);
		int n3 = str.indexOf(" ", n2 + 1);
		
		double x1 = Double.parseDouble(str.substring(0 , n1));
		double y1 = Double.parseDouble(str.substring(n1 + 1 , n2));
		double x2 = Double.parseDouble(str.substring(n2 + 1 , n3));
		double y2 = Double.parseDouble(str.substring(n3 + 1));
		
		double x = Math.pow(x1 - x2 , 2);
		double y = Math.pow(y1 - y2 , 2);
		
		double det = Math.sqrt(x + y);
		
		System.out.println(det);
		
	}

}