Linda, the closets will have adequate hangers, a lot have drawer space in the closets also, i am sure that if you find you do not have enough hangers in your closet all you need to do is call your cabin steward or houseskeeping and he/she will get you some more.
Ships provide hangers but I always bring extra hangers so I can keep my outfits matched together. I like to bring the ones that do double duty so that you can hang pants and a top on the same one, if you overpack like I do, you will have enough space in the closet.
If you are lucky and are able to pack that day of cruising you can just pack everything on your own hangers and when you get on the ship you just hang everything up and put the ships hangers in the laundry bag, just remember to put them back otherwise they may charge you for them.
I always pack some light wire pants hangers or plastic clip hangers right with the outfits which I cover with the plastic dry cleaner bags to prevent wrinkles. You take the outfits out of the suitcase and put them in the closet. This along with what the ship provides gives me plenty of hangers for the pants and shorts sets that I don't pre-hang.
We like to hang up almost all of our clothes, so there's never enough for us. We take along the metal ones from the dry cleaner to use. That way, we can just throw them away & not have to lug them home.