实现lzw词典编码方法

Lzw编码算法的设计思路：

　　1.开始时的词典包含所有的根（先将所有单个字符编码），当前缀P时空的；

　　2.当前字符（C）=字符流中的下一个字符；

3.判断缀-符串P+C是否在词典中

A如果“是”：P=P+C//(用C扩展P)

B．如果“否”：

a 把代表当前前缀P的马子输出到码字流；

b 把缀-符串P+C添加到词典；

c 令P=C//（现在的P仅包含一个字符C）；

4. 判断字符流中是否还有码字要译

（1）如果是，就返回到2；

（2）如果否

a 把代表当前前缀P的码字输出到码字流；

b 结束。.

-Coding method to achieve lzw dictionary coding algorithm Lzw design ideas: 1. The beginning of the dictionary contains all the root (first of all a single character encoding), the current time is made up of P　2. The current character (C) = the next character stream character　3. judge up- at string P+ C is in the dictionary, if A " is" : P = P+ C// (use C extension of P) B. If " no" : a prefix P to the representative of the current output of the commode to the code word stream　b put up- at string P+ C added to the dictionary　c so that P = C// (the P now contains only one character C)　4. to determine whether there are character stream code words to translate (1) If yes, on the return to the 2　(2) If it has a prefix P to the representative of the current output of the code word to code word stream　b end. .