32 lines
1000 B
Plaintext
32 lines
1000 B
Plaintext
defmodule My do
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def exp(x,y) when is_integer(x) and is_integer(y) and y>=0 do
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IO.write("int> ") # debug test
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exp_int(x,y)
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end
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def exp(x,y) when is_integer(y) do
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IO.write("float> ") # debug test
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exp_float(x,y)
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end
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def exp(x,y), do: (IO.write(" "); :math.pow(x,y))
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defp exp_int(_,0), do: 1
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defp exp_int(x,y), do: Enum.reduce(1..y, 1, fn _,acc -> x * acc end)
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defp exp_float(_,y) when y==0, do: 1.0
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defp exp_float(x,y) when y<0, do: 1/exp_float(x,-y)
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defp exp_float(x,y), do: Enum.reduce(1..y, 1, fn _,acc -> x * acc end)
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end
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list = [{2,0}, {2,3}, {2,-2},
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{2.0,0}, {2.0,3}, {2.0,-2},
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{0.5,0}, {0.5,3}, {0.5,-2},
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{-2,2}, {-2,3}, {-2.0,2}, {-2.0,3},
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]
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IO.puts " ___My.exp___ __:math.pow_"
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Enum.each(list, fn {x,y} ->
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sxy = "#{x} ** #{y}"
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sexp = inspect My.exp(x,y)
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spow = inspect :math.pow(x,y) # For the comparison
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:io.fwrite("~10s = ~12s, ~12s~n", [sxy, sexp, spow])
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end)
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