Elixir

Other Elixir solutions.

defmodule Darts do
  @type position :: {number, number}

  @doc """
  Calculate the score of a single dart hitting a target
  """
  @spec score(position) :: integer
  def score({x, y}) do
    r = (x ** 2 + y ** 2) ** 0.5

    cond do
      r <= 1 -> 10
      r <= 5 -> 5
      r <= 10 -> 1
      true -> 0
    end
  end
end

Roc

Other Roc solutions.

module [score]

score : F64, F64 -> U64
score = \x, y ->
    r = Num.sqrt (x ^ 2 + y ^ 2)

    when r is
        _ if r <= 1 -> 10
        _ if r <= 5 -> 5
        _ if r <= 10 -> 1
        _ -> 0

C

Other C solutions.

#include "darts.h"
#include <math.h>

uint8_t score(coordinate_t coord)
{
   float hyp = sqrt(pow(coord.x, 2) + pow(coord.y, 2));
   int score = 0;

   if (hyp <= 1.0F)
   {
      score = 10;
   }
   else if (hyp <= 5.0F)
   {
      score = 5;
   }
   else if (hyp <= 10.0F)
   {
      score = 1;
   }

   return score;
}