2016 Update

Task/Zig-zag-matrix/Elixir/zig-zag-matrix.elixir

@@ -1,13 +1,14 @@
 defmodule RC do
   require Integer
   def zigzag(n) do
-    indices = for x <- 1..n, y <- 1..n, do: {x,y}
-    sorted = Enum.sort_by(indices, fn{x,y}->{x+y, if(Integer.is_even(x+y), do: y, else: x)} end)
-    sorted2 = Enum.sort(Enum.with_index(sorted))
-    Enum.each(sorted2, fn {{_x,y},i} ->
-      IO.write "#{i} "
-      if y==n, do: IO.puts ""
-    end)
+    fmt = "~#{to_char_list(n*n-1) |> length}w "
+    (for x <- 1..n, y <- 1..n, do: {x,y})
+      |> Enum.sort_by(fn{x,y}->{x+y, if(Integer.is_even(x+y), do: y, else: x)} end)
+      |> Enum.with_index |> Enum.sort
+      |> Enum.each(fn {{_x,y},i} ->
+           :io.format fmt, [i]
+           if y==n, do: IO.puts ""
+         end)
   end
 end