Java Interview Question; Anagram of a Palindrome

In many interview questions, what they are looking for is a simple solution to an apparently complex problem. Unfortunately, the solutions are usually obvious if you know the solution, but very hard to come up with in an interview situation. ;)

 

Anagram of Palindrome

Write a method to test if a String is an anagram of a palindrome. The method should have O(n) time complexity and O(1) space complexity. You can assume all letters are between ' ' (space) and 'z'. Assume only letters matter and case is ignored.

e.g.
"kayak"
"Rats live on no evil star"
"A man, a plan, a canal, Panama"
"Doc, note: I dissent. A fast never prevents a fatness. I diet on cod."

 

The solution

A brute force approach is to generate anagrams and test if they are a palindromes. This is not required. All you need to test is if the String is the sort of string which can be turned into a palindrome.

Sample solution be given Thursday 15th.

 

From http://vanillajava.blogspot.com/2011/12/java-interview-question-anagram-of.html