LZ78的编码思想是不断地从字符流中提取新的“缀-符串(String)”（通俗地理解为新“词条”），然后用“代号”也就是码字(Code word)表示这个“词条”。这样一来，对字符流的编码就变成了用码字(Code word)去替换字符流，生成码字流，从而达到压缩数据的目的。 -LZ78 encoding idea is to continually extracted from the character stream the new " infix- character string (String)"　(popularly understood as the new " entry" ), then use the " code"　is code word (Code word) said this " entry."　As a result, the encoding for character stream becomes a code word to use (Code word) to replace the character stream, generate code word stream, so as to achieve the purpose of compressed data.