Evaluate binomial coefficients: Difference between revisions
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PatGarrett (talk | contribs) (→{{header|Batch File}}: Rename the section) |
(→{{header|AppleScript}}: Added a functionally composed variant) |
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=={{header|AppleScript}}== |
=={{header|AppleScript}}== |
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===Imperative=== |
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<lang AppleScript>set n to 5 |
<lang AppleScript>set n to 5 |
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set k to 3 |
set k to 3 |
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return n_factorial / (n_minus_k_factorial) * 1 / (k_factorial) as integer |
return n_factorial / (n_minus_k_factorial) * 1 / (k_factorial) as integer |
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</lang> |
</lang> |
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===Functional=== |
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Using a little more abstraction, for readability and ease of refactoring: |
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<lang applescript>-- factorial :: Int -> Int |
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on factorial(n) |
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product(enumFromTo(1, n)) |
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end factorial |
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-- binomialCoefficient :: Int -> Int -> Int |
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on binomialCoefficient(n, k) |
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factorial(n) div (factorial(n - k) * (factorial(k))) |
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end binomialCoefficient |
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-- TEST ----------------------------------------------------- |
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on run |
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binomialCoefficient(5, 3) |
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--> 10 |
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end run |
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-- GENERAL ------------------------------------------------- |
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-- enumFromTo :: Int -> Int -> [Int] |
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on enumFromTo(m, n) |
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if m ≤ n then |
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set lst to {} |
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repeat with i from m to n |
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set end of lst to i |
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end repeat |
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return lst |
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else |
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return {} |
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end if |
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end enumFromTo |
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-- foldl :: (a -> b -> a) -> a -> [b] -> a |
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on foldl(f, startValue, xs) |
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tell mReturn(f) |
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set v to startValue |
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set lng to length of xs |
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repeat with i from 1 to lng |
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set v to |λ|(v, item i of xs, i, xs) |
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end repeat |
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return v |
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end tell |
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end foldl |
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-- Lift 2nd class handler function into 1st class script wrapper |
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-- mReturn :: First-class m => (a -> b) -> m (a -> b) |
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on mReturn(f) |
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if script is class of f then |
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f |
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else |
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script |
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property |λ| : f |
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end script |
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end if |
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end mReturn |
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-- product :: [Num] -> Num |
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on product(xs) |
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script multiply |
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on |λ|(a, b) |
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a * b |
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end |λ| |
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end script |
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foldl(multiply, 1, xs) |
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end product</lang> |
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{{Out}} |
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<pre>10</pre> |
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=={{header|AutoHotkey}}== |
=={{header|AutoHotkey}}== |
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<lang autohotkey>MsgBox, % Round(BinomialCoefficient(5, 3)) |
<lang autohotkey>MsgBox, % Round(BinomialCoefficient(5, 3)) |
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