IST238: Algorithms. Project #5.

1. Implement priority queue template class PQueue with the following public methods:
   • default constructor PQueue() and constructor that allows to specify the amount of memory allocated for the queue PQueue(int N)
   • destructor ~PQueue()
   • method void (Node node) that adds an item to the queue
   • method Node get_top() that returns the highest priority item and removes it from the queue
   • Boolean method bool empty() that returns true if the queue is empty and false otherwise
   • method int Size() that returns the current size of the queue
   Note: you should use the heap structure to implement this class.
2. Implement the Huffman code to construct the optimal prefix tree. To complete this, you need:
   • read all characters from the specified file
   • count their frequencies
   • create the as many nodes of the type Node as you have read distinct characters
   • run the Huffman's algorithm to construct the optimal prefix tree
   • based on the prefix tree build the coding table that specifies variable length code for each character from the file
3. Re-read the file and print the sequence of zeros and ones corresponding to the file contents. The coded version of the text should be written in another file.
4. Read the newly created "compressed" file and decode it using the prefix tree. Print the text on the screen.