[Haskell-cafe] Project Euler Problem 357 in Haskell

[Silvio Frischknecht]

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On 11/08/2011 02:19 PM, Ryan Yates wrote:
> If I compile with optimizations:
> 
> ghc --make -O3 primes.hs
> 
> I get an answer that is off by one from the C++ program in a few
> seconds.

nice one. Though i wonder. The problem seems to be that without
optimization sum is not tail-recursive. Is sum meant to not be
tail-recursive?

ghci> sum [1..]

eats up all the memory within seconds while

ghci> foldl' (+) 0 [1..]

does not

So Mukesh if you want your program to run without -Ox you should
probably define your one sum'

import Data.List
sum' = foldl' (+) 0

Silvio
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