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19 lines
663 B
Haskell
19 lines
663 B
Haskell
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module Util.Triangle where
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-- |A triangle consisting of three integral sides
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data Triangle = Triangle Int Int Int
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deriving(Show, Eq)
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-- |Find all right triangles having sum of sides 'sum' and side c length of 'c'
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right_triangles :: Int -> Int -> [Triangle]
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right_triangles sum c = do
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let diff = sum - c
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let range = [1..(floor ((fromIntegral diff) / 2)) + 1]
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let triangles = filter is_right_triangle (map (\x -> Triangle x (diff - x) c) range)
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triangles
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-- |Return whether the provided triangle is a right triangle using the pythagorean theorem
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is_right_triangle :: Triangle -> Bool
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is_right_triangle (Triangle a b c) =
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a^2 + b^2 == c^2
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