[The problem appeared in TopCoder SRM 274 (Div-2, Level-2) and SRM 274 (Div-1, Level-1)]
Problem link: http://community.topcoder.com/stat?c=problem_statement&pm=5881&rd=8071
A palindrome is a string that is spelled the same forward and backward. We want to rearrange letters of the given string baseString so that it becomes a palindrome.
You will be given a String baseString. Return the palindrome that can be made from baseString. When more than one palindrome can be made, return the lexicographically earliest (i.e., the one that occurs first in alphabetical order). Return “” (the empty string) if no palindromes can be made from baseString.