Adding the code written during the exercise

Adding code written in the exercise

Adding the code written at the exercise

Fixing a mistake in the example for the task

Making the code a bit cleamer and adding shrinking of the HashMap

Adding some more info to the task description

Fixing some more visual mistakes

Fixing some visual mistakes

Fixing some mistakes in the task

Adding the task for the sixth exercise

Adding a simple implementation of HashMap

Adding link to the table with the results from the tasks for homework

Updating the materials, adding links for stacks and queues

Adding the code written during the exercise

Adding the classes related to the 4-th exercise as well as some other minor changes