What do you mean by "interactive mode"?

Anyway, take a look at the std::priority_queue adapter for an example of what a priority queue interface might be like. To implement with an ordered array or unordered array, you can build your implementation with the help of say, std::vector. To implement with an ordered linked list or unordered linked list, you can build your implementation with the help of say, std::list. To implement with a heap, you could build your implementation with the help of say, a std::vector with std::make_heap, std::push_heap, and std::pop_heap.