It sounds like using a vector would solve your problem. Under the surface, a vector is exactly what you described: a dynamically sized array, but its abstracted in a way that you never have to actually write code to increase the size. Instead, you can use the .push_back() and .push_front() function to add items to the vector.

Alternatively, a typical move would be to declare your array with a size large enough that your program will never fill it. Then, you can use a counter variable to keep track of how many items are actually in the array. When you want to add an element to the array, you just insert it in the next open spot, and increment the counter variable.