When you're using C as a layer under some other high-level language you get those implemented for you. For instance, if you write Python bindings, you will use

When you're using C as a layer under some other high-level language you get those implemented for you. For instance, if you write Python bindings, you will use Python's data structures from C. If those are too slow for you, you'll want a specialised structure - there are many libraries providing collections for C.