[Haskell-cafe] Help with division
daniel.carrera at zmsl.com
Mon Dec 19 16:24:38 EST 2005
Playing around with Haskell... I'm writing a 'choose' function:
fac :: Int -> Int
fac 0 = 1
fac n = n*fac(n-1)
choose :: Int -> Int -> Int
choose n k = fac(n) / (fac(k) * fac(n-k))
I'm having problems with the last line.
Prelude> :l test.hs
Compiling Main ( test.hs, interpreted )
No instance for (Fractional Int)
arising from use of `/' at test.hs:13:20
Probable fix: add an instance declaration for (Fractional Int)
In the definition of `choose':
choose n k = (fac (n)) / ((fac (k)) * (fac (n - k)))
Failed, modules loaded: none.
The problem is that it doesn't like the / sign. For example, if I
replace the / by * the function is compiled just fine.
Does anyone know what I'm missing?
\/_/ I am not over-weight, I am under-tall.
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