Another update from ingydotnet^djgoku

Task/Constrained-random-points-on-a-circle/Elixir/constrained-random-points-on-a-circle-1.elixir

@@ -0,0 +1,21 @@
+defmodule Random do
+  defp generate_point(0, _, _, set), do: set
+  defp generate_point(n, f, range, set) do
+    point = {x,y} = {f.(), f.()}
+    if x*x + y*y in range and not Set.member?(set, point),
+      do:   generate_point(n-1, f, range, Set.put(set, point)),
+      else: generate_point(n,   f, range, set)
+  end
+  def circle do
+    f = fn -> :rand.uniform(31) - 16 end
+    points = generate_point(100, f, 10*10..15*15, HashSet.new)
+    for x <- -15..15 do
+      for y <- -15..15 do
+        IO.write if Set.member?(points, {x,y}), do: "x", else: " "
+      end
+      IO.puts ""
+    end
+  end
+end
+
+Random.circle

Task/Constrained-random-points-on-a-circle/Elixir/constrained-random-points-on-a-circle-2.elixir

@@ -0,0 +1,17 @@
+defmodule Constrain do
+  defp precalculate(range, condition) do
+    for x <- range, y <- range, x*x + y*y in condition, do: {x,y}
+  end
+
+  def circle do
+    range = -15..15
+    all_points = precalculate(range, 10*10..15*15)
+    IO.puts length(all_points)
+    points = Enum.shuffle(all_points) |> Enum.take(100)
+    Enum.each(-15..15, fn x ->
+      IO.puts Enum.map(range, fn y -> if Enum.member?(points, {x,y}), do: "o ", else: "  " end)
+    end)
+  end
+end
+
+Constrain.circle

Task/Constrained-random-points-on-a-circle/Elixir/constrained-random-points-on-a-circle.elixir

@@ -1,30 +0,0 @@
-defmodule Random do
-  def init() do
-    :random.seed(:erlang.now())
-  end
-  def generate_point() do
-    x = :random.uniform(31) - 16
-    y = :random.uniform(31) - 16
-    if 10*10 <= x*x + y*y and x*x + y*y <= 15*15 do
-      {x, y}
-    else
-      generate_point()
-    end
-  end
-  def circle() do
-    points = for _ <- 1..100, do: generate_point()
-    for x <- -15..15 do
-      for y <- -15..15 do
-        if Enum.member?(points, {x, y}) do
-          IO.write "x"
-        else
-          IO.write " "
-        end
-      end
-      IO.puts ""
-    end
-  end
-end
-
-Random.init()
-Random.circle()