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 JavaScript (judge verdict: Accepted)

var reader = require('readline').createInterface({
  input: process.stdin,
  output: process.stdout
});
reader.on('line', function (line) {
  var a = line.split(' ');
  var b = Number(a[0]);
  var c = Number(a[1]);
  var d = Number(a[2]);
  var e = Number(a[3]);
  b = Math.sqrt((b-d)*(b-d)+(c-e)*(c-e));
  console.log(b.toFixed(8));
  process.exit();
});
process.stdin.on('end', function () {
});