If you're looking for efficiency, I believe you can actually do #1 in constant time:
On Sat, May 7, 2011 at 7:31 AM, <cas...@istar.ca> wrote: > -- Instead of this > -- sumMultiples3or5 s = sum [x | x <- [3..s-1], x `mod` 3 == 0 || x `mod` 5 > == 0] > > > -- Isn't this faster > > sumMultiples3or5 s = sum ([x | x <- [3,6..s-1]] `merge` [x | x <- > [5,10..s-1]]) > > merge xs [] = xs > merge [] ys = ys > merge txs@(x:xs) tys@(y:ys) > | x < y = x : xs `merge` tys > | x > y = y : txs `merge` ys > | otherwise = x : xs `merge` ys > > > > _______________________________________________ > Haskell-Cafe mailing list > Haskell-Cafe@haskell.org > http://www.haskell.org/mailman/listinfo/haskell-cafe > _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
