## Hackerrank – Problem Statement

A description of the problem can be found on Hackerrank.

## Solution

Calculate a length of a line between each pair of following points `p`

, defined with `x`

and `y`

coordinate:

`(p`

_{0}, p_{1}), (p_{1}, p_{2}), ..., (p_{n-1}, p_{0})

Length of a line between two points:

$$l = \sqrt{{(x_1 – x_2)}^2 + {(y_1 – y_2)}^2}$$

Make sum of the lengths.

I created solution in:

All solutions are also available on my GitHub.

**Scala**

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import scala.io.Source object ComputePolygonPerimeter extends App { val lines = Source.stdin.getLines().toList val n = lines.head.toInt val pairs = lines.tail.map(_.split(" ").map(_.toInt)).map(array => Tuple2(array(0), array(1))) println(perimeter(pairs)) def perimeter(points: List[(Int, Int)]) = { val n = points.length (0 until n).map(i => length(pairs(i % n), pairs((i + 1) % n))).sum } def length(p1: (Int, Int), p2: (Int, Int)) = { Math.sqrt((Math.pow(p2._1 - p1._1, 2)) + (Math.pow(p2._2 - p1._2, 2))) } } |