Data commit

Task/Population-count/Elixir/population-count.elixir

@@ -0,0 +1,20 @@
+defmodule Population do
+
+  def count(n), do: count(<<n :: integer>>, 0)
+
+  defp count(<<>>, acc), do: acc
+
+  defp count(<<bit :: integer-1, rest :: bitstring>>, sum), do: count(rest, sum + bit)
+
+  def evil?(n), do: n >= 0 and rem(count(n),2) == 0
+
+  def odious?(n), do: n >= 0 and rem(count(n),2) == 1
+
+end
+
+IO.puts "Population count of the first thirty powers of 3:"
+IO.inspect Stream.iterate(1, &(&1*3)) |> Enum.take(30) |> Enum.map(&Population.count(&1))
+IO.puts "first thirty evil numbers:"
+IO.inspect Stream.iterate(0, &(&1+1)) |> Stream.filter(&Population.evil?(&1)) |> Enum.take(30)
+IO.puts "first thirty odious numbers:"
+IO.inspect Stream.iterate(0, &(&1+1)) |> Stream.filter(&Population.odious?(&1)) |> Enum.take(30)