Compact & naive C# function to get the longest palindromic substrings of a string (i.e. all palindromes excluding overlaps). Time complexity is over quadratic.

GetLongestPalindromes.cs

// Naive, suboptimal
IEnumerable<string> GetLongestPalindromes(string s)
{
    List<string> palindromes = new List<string>();
    var len = s.Length;

    for (int i = 0; i < len; i++)
    {
        for (int j = len - 1; j > i; j--)
        {
            for (int k = 0; true; k++)
            {
                if (s[i + k] != s[j - k])
                    break; // Not palindrome

                int dist = (j - k) - (i + k);
                if (dist <= 1) // Center reached, palindrome found; dist = 0 odd length, dist = 1 even length
                {
                    palindromes.Add(s.Substring(i, j - i + 1));
                    i = j; // Skip overlapping palindromes
                    break;
                }
            }
        }
    }

    return palindromes;
}