24 lines
683 B
Elixir
24 lines
683 B
Elixir
defmodule Grains do
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@doc """
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Calculate two to the power of the input minus one.
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"""
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@spec square(pos_integer()) :: {:ok, pos_integer()} | {:error, String.t()}
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def square(number) when number < 1 or number > 64 do
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{:error, "The requested square must be between 1 and 64 (inclusive)"}
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end
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def square(number), do: {:ok, 2**(number-1)}
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@doc """
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Adds square of each number from 1 to 64.
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"""
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@spec total :: {:ok, pos_integer()}
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def total do
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Enum.reduce_while(1..64, {:ok, 0}, fn n, {:ok, sum} ->
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case square(n) do
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{:ok, squared} -> {:cont, {:ok, squared + sum}}
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{:error, error} -> {:halt, {:error, error}}
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end
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end)
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end
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end
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