Previously in this series we explored using a dynamic array to implement a stack. This was pretty straightforward, and only required four functions which made use of the preexisting dynamic array functions

Today, I realized that I forgot to mention anything about bags and how easy they are to implement using a dynamic array. This is pretty quick and will be more like a mini-episode.

The bag is an abstract data type which, well, resembles a physical bag (the classic example is a bag of marbles). There is no order to the elements in the bag, but the bag does support basic operations such as:

1. add (a marble to the bag)
2. remove (a marble from the bag)
3. contains (is this marble in this bag?)

Adding an element to a bag is the same as the prior implemention with the stack. Again, since order doesn’t matter in the bag, we can just push the element into the bag.

What the stack didn’t have was the contains and remove functions.

Let’s implement them here~

All the contains function does is iterate through the dynamic array until it finds the element that we’re looking for and returns a $1$ (or doesn’t and returns a $0$!)

The remove function is slightly spicier, but not by much. Again, the main logic is to iterate through the dynamic array until it finds an element that matches $val$ and then removes it. The function then has to exit, which since it returns void means we just use a simple return; call.