Since I wasn't writing an entire operating system in 20 minutes, we decided that we'll treat the directory as a stack. When given the new location, you need to break it up on the slash and then navigate the stack appropriately. If there is a slash in the front, then clear the stack since they want to change to an absolute path and not relative to where you are. You need to keep in mind that a single or double dot can be anywhere and how to handle if they try going above the highest level of the stack