One Solution To Euler 12
Nothing special but play haskell for fun.
Priming is a simple module which can be found at 1
│ module Main where │ │ import Data.List │ import Primeing (primeFactors) │ │ main :: IO () │ main = print $ p12 500 │ │ p12 :: Int -> Int │ p12 n = head $ filter (factorLimit n) [ smartGaus x | x <- [1..]] │ │ smartGaus :: Int -> Int │ smartGaus n = (1+n)*n `div` 2 │ │ {-- | │ Is factor count under the limit │ --} │ factorLimit :: Int -> Int -> Bool │ factorLimit l n │ | 2 * sqrtInt n < l = False │ | otherwise = length (factors n) >= l │ │ │ factors :: Int -> [Int] │ factors n = concat [ [x, n `div` x] | x <- [1..sqrtInt n], n `mod` x == 0 ] │ │ sqrtInt :: Int -> Int │ sqrtInt = truncate . sqrt . fromIntegral