绝对回文和相对回文

我这辈子都不会忘记这两道题目，忘记那些时光...

写于2011-01-23 21:19

题目如下：

 

   Input will contain between 1 and 50 characters, inclusive . Each character of input will be an uppercase letter ('A' - 'Z').

   A:   Examples

        "XBCDEFYWFEDCBZ"

       Return: "BCDEF"

  We see that the reverse of BCDEF is FEDCB, which appears later in the string.

 

B: "ABCABA"

 Return: "ABA"

 The String ABA is a palindrome(it's its own reversal), So it meets the criteria.

 

  这两个题目引出了两个概念：绝对回文 和 相对回文