字典序解码问题.在数据加密和数据压缩中常需要对特殊的字符串进行数字编号。给定的字母表 A 由26 个小写英文字母组成 A={a,b,…,z}。该字母表产生的升序字符串是指字符串中字母按照

从左到右出现的次序与字母在字母表中出现的次序相同，且每个字符最多出现 1 次。例如，a,b,ab,bc,xyz 等字符串都是升序字符串。现在对字母表 A 产生的升序字符串按照字典序排列并编号。-In the data encryption and data compression often need for a special string figures. A given by the 26 alphabet lowercase English letters A = {a, b, ..., z}. The alphabet ascending resulting string is a string of letters in accordance with the

The order they appear from left to right with the letters in the alphabet appear in the same order, and each character appears at most once. For example, a, b, ab, bc, xyz ascending other strings are strings. Now on the alphabet A string generated by ascending lexicographic order and numbered.