Errata for "Pearls of Functional Algorithm Design" by Richard Bird, 2010, page 25 #Haskell smallest :: (Ord a) => Int -> (Array Int a, Array Int a) -> a smallest k (xa,ya) = search k (0,m+1) (0,n+1) where (0,m) = bounds xa (0,n) = bounds ya search k (lx,rx) (ly,ry) | lx == rx = ya ! (k+ly) | ly == ry = xa ! (k+lx) | otherwise = case (xa ! mx < ya ! my, k <= mx-lx+my-ly) of (True, True) -> search k (lx,rx) (ly,my) (True, False) -> search (k-(mx-lx)-1) (mx+1,rx) (ly,ry) (False, True) -> search k (lx,mx) (ly,ry) (False, False)-> search (k-(my-ly)-1) (lx,rx) (my+1,ry) where mx = (lx+rx) `div` 2 my = (ly+ry) `div` 2 -- -- Regards, KC