Longest palindromic substring
http://en.wikipedia.org/wiki/Longest_palindromic_substring http://www.leetcode.com/2011/11/longest-palindromic-substring-part-ii.html http://www.felix021.com/blog/read.php?2040 http://zhuhongcheng.wordpress.com/2009/08/02/a-simple-linear-time-algorithm-for-finding-longest-palindrome-sub-string/ http://johanjeuring.blogspot.hk/2007/08/finding-palindromes.html http://www.akalin.cx/longest-palindrome-linear-time http://www.leetcode.com/2011/11/longest-palindromic-substring-part-i.html