Problem
1. Complete all functions of class Huffman_Tree and test them out using a document file and a C++ source file on your computer. You can download class Bit_String from the Web site for this textbook.
2. Use a map to store the frequency counts for all the words in a large text document. When you are done, display the contents of this map. Next, store its contents in an array. Sort the array in decreasing order by frequency and display it.