Introduction - If you have any usage issues, please Google them yourself
1) I: initialization (Initialization). From the terminal read into the character set size, N, and n characters and N weights, the establishment of Huffman tree, and save it in the file hfmTree.
2) E: coding (Encoding). Using the built Huffman tree (if not in memory, then read it from the file hfmTree), encode the text in the file ToBeTran, and then put the results in the file CodeFile.
3) D: decoding (Decoding). Huffman tree has been built using the file CodeFile code for decoding, the results stored in the file TextFile.