根据给定的信源概率分布，编程实现霍夫曼编码和二次扩展信源霍夫曼编码，并和信源的熵进行比较，体会霍夫曼编码的编码效果。(According to the given probability distribution of the source, Hoffman encoding and two extended source Hoffman coding are programmed and compared with the entropy of the source to realize th