Can I Make a Palindrome - Imperative vs Functional

gistfile1.txt

Here's a little programming challenge, the kind you might be asked in a job interview.

Write a function that can tell if a sequence of characters can be rearranged to form a palindrome.

And here's a solution in C (The kind you might be expected to write in a job interview)
http://geeksquiz.com/check-characters-given-string-can-rearranged-form-palindrome/

    bool canFormPalindrome(char *str)
    {
        // Create a count array and initialize all values as 0
        int count[NO_OF_CHARS] = {0};
    
        // For each character in input strings, increment count in
        // the corresponding count array
        for (int i = 0; str[i];  i++)
            count[str[i]]++;
    
        // Count odd occurring characters
        int odd = 0;
        for (int i = 0; i < NO_OF_CHARS; i++)
            if (count[i] & 1)
                odd++;
        
        // Return true if odd count is 0 or 1, otherwise false
        return (odd <= 1);
    }

Here's basically the same algorithm, using LINQ in C#.

    private static bool canFormPalindrome(string s) {
      return s.GroupBy(c => c)
               .Select(c => c.Count())
               .Where(i => i % 2 == 1)
               .Count() <= 1;
    }

Which do you prefer?