18 lines
519 B
Elixir
18 lines
519 B
Elixir
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defmodule LucasNumbers do
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@moduledoc """
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Lucas numbers are an infinite sequence of numbers which build progressively
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which hold a strong correlation to the golden ratio (φ or ϕ)
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E.g.: 2, 1, 3, 4, 7, 11, 18, 29, ...
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"""
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def generate(count) when is_integer(count) and count > 0 do
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{2, 1}
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|> Stream.iterate(fn {a, b} -> {b, a + b} end)
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|> Stream.map(&elem(&1, 0))
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|> Enum.take(count)
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end
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def generate(_count), do: raise(ArgumentError, "count must be specified as an integer >= 1")
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end
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