Data commit

Task/Display-a-linear-combination/Elixir/display-a-linear-combination.elixir

@@ -0,0 +1,32 @@
+defmodule Linear_combination do
+  def display(coeff) do
+    Enum.with_index(coeff)
+    |> Enum.map_join(fn {n,i} ->
+         {m,s} = if n<0, do: {-n,"-"}, else: {n,"+"}
+         case {m,i} do
+           {0,_} -> ""
+           {1,i} -> "#{s}e(#{i+1})"
+           {n,i} -> "#{s}#{n}*e(#{i+1})"
+         end
+       end)
+    |> String.trim_leading("+")
+    |> case do
+         ""  -> IO.puts "0"
+         str -> IO.puts str
+       end
+  end
+end
+
+coeffs =
+  [ [1, 2, 3],
+    [0, 1, 2, 3],
+    [1, 0, 3, 4],
+    [1, 2, 0],
+    [0, 0, 0],
+    [0],
+    [1, 1, 1],
+    [-1, -1, -1],
+    [-1, -2, 0, -3],
+    [-1]
+  ]
+Enum.each(coeffs, &Linear_combination.display(&1))