实现Huffman树的创建、编码及译码， 对一个字符串进行Huffman编码与译码，字符串中每个字母的权值自由设置。附有源码、可执行文件与说明文档。-Huffman tree to achieve the creation, encoding and decoding, Huffman for a string of encoding and decoding, the string of each letter of the freedom to set the weight. Wit