swimming for fitness

I want to have fitness body of a swimmer. Doeas swimming 3 days a week enough for me. Or I should do some weight work out besides.
I mean doeas swimming seperately gives a well shaped body like a competitor swimmer or It needs to mix ut with gym? if so. at least how much time it takes to get it by only swimming?

3 days a week would give you the physical development of a swimmer. It may not give you the competitive endurance of a swimmer though but that might not be what you are seeking.