Talk:Euler problems/121 to 130
On the Project Euler Forum I found the following solution for Problem 127, posted there by glguy.
main = print $ solve 99999
rad x = fromIntegral $ product $ map fst $ primePowerFactors $ fromIntegral x
solve :: Int -> Int solve n = sum [ c | (rc,c) <- invrads
, 2 * rc < c , (ra, a) <- takeWhile (\(a,_)->(c > 2*rc*a)) invrads , a < c `div` 2 , gcd ra rc == 1 , ra * rads ! (c - a) < c `div` rc] where rads :: UArray Int Int rads = listArray (1,n) $ map rad [1..n] invrads = sort $ map (\(a,b) -> (b, a)) $ assocs rads
Would responsible people be so kind as to check copyvio for this one? As far as I'm concerned it is. Just another thought: as you have solutions handy for most problems, couldn't those guarding these pages do the copyvio checking themselves? hk
If it was posted by glguy, I'm willing to bet he's okay with it being here, but I'll check with him. CaleGibbard 14:57, 25 February 2008 (UTC)