lzhang39 / linked-list

A singly linked list with each node containing integer data. Methods on the singly linked list

Linked-List

Using object oriented design constructs, define a Node class and LinkedList class for a singly linked list. Each node has integer data value and a link to the next node. The linked list class has a head node and the following methods defined.

Getting Started

As usual with a python project, create a virtual environment:

python -m venv venv

Then activate the virtual environment

source venv/bin/activate

Then install the required packages.

pip install -r requirements.txt

Exercise

Design and implement the classes and the methods. Implement the methods within the Linked List class that are currently only contain pass.

Complete the following methods:

• get_first - This method returns the value of the 1st node in the list (head). It returns None if the list is empty.
• add_first - This method adds a new node with the given value to the head of the list.
• search - This method returns True or False if the list contains the given value.
• length - This method returns the size of the list.
• get_at_index - This method returns the value of the node at the given index. It returns None if the list does not have that many elements.
• get_last - This method returns the value of the last node in the list.
• add_last - This method adds a new node to the rear of the list.
• find_max - This method finds the largest value in the list, assuming you can use >, or < to compare each element in the list.
• delete - This method deletes the node at the given index maintaining all the remaining elements in the same order.
• reverse - This method reverses the list.

Going Further

There are a set of advanced methods you can choose to implement for additional practice. Tests are provided, but you will need to unskip them by removing the @pytest.mark.skip decorator.

For more practice complete the following methods:

• find_middle_value - This method returns the value in the middle of the list (rounded down for even length lists).
• find_nth_from_n - This method returns the value of the node which is nth from last in the list.
• has_cycle- This method returns true if there is a loop in the list. I.e. somehow a node's next value is pointing to a prior node.