32 lines
971 B
Elixir
32 lines
971 B
Elixir
defmodule Polynomial do
|
|
def division(_, []), do: raise ArgumentError, "denominator is zero"
|
|
def division(_, [0]), do: raise ArgumentError, "denominator is zero"
|
|
def division(f, g) when length(f) < length(g), do: {[0], f}
|
|
def division(f, g) do
|
|
{q, r} = division(g, [], f)
|
|
if q==[], do: q = [0]
|
|
if r==[], do: r = [0]
|
|
{q, r}
|
|
end
|
|
|
|
defp division(g, q, r) when length(r) < length(g), do: {q, r}
|
|
defp division(g, q, r) do
|
|
p = hd(r) / hd(g)
|
|
r2 = Enum.zip(r, g)
|
|
|> Enum.with_index
|
|
|> Enum.reduce(r, fn {{pn,pg},i},acc ->
|
|
List.replace_at(acc, i, pn - p * pg)
|
|
end)
|
|
division(g, q++[p], tl(r2))
|
|
end
|
|
end
|
|
|
|
[ { [1, -12, 0, -42], [1, -3] },
|
|
{ [1, -12, 0, -42], [1, 1, -3] },
|
|
{ [1, 3, 2], [1, 1] },
|
|
{ [1, -4, 6, 5, 3], [1, 2, 1] } ]
|
|
|> Enum.each(fn {f,g} ->
|
|
{q, r} = Polynomial.division(f, g)
|
|
IO.puts "#{inspect f} / #{inspect g} => #{inspect q} remainder #{inspect r}"
|
|
end)
|