Yes I think it was, but the screenplay was not by the novel's author.
The screenplay writer handed in a first draft supposedly and they shot that without asking him for the rewrites he expected to have to do. Given that, it makes you wonder whether all the rewriting that gets done is really worth it half the time.
I suppose it might have been more of a box office hit with the rewrites but possibly a worse film (although I see a lot of critics didn't like it at the time).