在数据加密和数据压缩中常需要对特殊的字符串进行编码。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 产生的所有长度不超过6 的升序字符串按照字典序排列并编码如下。 <img alt="" src="/admin/../upload/pimg1702_1.png" height="42" width="38…

A numeric sequence of ai is ordered if a1 < a2 < ... < aN. Let the subsequence of the given numeric sequence (a1, a2, ..., aN) be any sequence (ai1, ai2, ..., aiK), where 1 <= i1 < i2 < ... < iK <= N. For example, the sequence (1, 7, 3,…

There are another kind of Fibonacci numbers: F(0) = 7, F(1) = 11, F(n) = F(n-1) + F(n-2) (n>=2)

Judge Ito is having a problem with people subpoenaed for jury duty giving rather lame excuses in order to avoid serving. In order to reduce the amount of time required listening to goofy excuses, Judge Ito has asked that you write a program that will search fo…

Given an positive integer A (1 <= A <= 100), output the lowest bit of A. For example, given A = 26, we can write A in binary form as 11010, so the lowest bit of A is 10, so the output should be 2. Another example goes like this: given A = 88, we can writ…

<p>Password security is a tricky thing. Users prefer simple passwords that are easy to remember (like buddy), but such passwords are often insecure. Some sites use random computer-generated passwords (like xvtpzyo), but users have a hard time remembering…