This is a course project for advanced data structure. In the project, three data structures including binary heap, 4-way heap and pairing heap are implemented. The time required for each of the heap to construct the huffman tree was assessed and it proved that 4-way heap is the fastest data structure. Uilization of 4-way heap, huffman encoding and decoding are implemented. You can find project details in the file named COP5536_SP17_Project.pdf.