Find all unique palindromes of any length in a source string

FindAllPalindromes.cs

using System;
using System.Collections.Generic;
using System.Linq;
using NUnit.Framework;

namespace Genetic.Tests
{
    [TestFixture]
    public class PalindromeTests
    {
        [Test]
        public void FindAllPalindromes()
        {
            const string source = "abcdcbaba";

            var palindromes_described = FindAllUniquePalindromes_Described(source);
            var palindromes_better = FindAllUniquePalindromes_Better(source);
            
            Assert.IsTrue(palindromes_described.SequenceEqual(palindromes_better));
            
            foreach (var palindrome in palindromes_described)
            {
                Console.WriteLine(palindrome);
            }

            /*
             * Output:
                        a
                        abcdcba
                        b
                        bcdcb
                        c
                        cdc
                        d
                        bab
                        aba
             */
        }

        /// <summary>
        /// Searches the source string for all unique palindromes of any length
        /// </summary>
        /// <remarks>
        /// This is the implementation described over the phone
        /// </remarks>
        /// <param name="source">The source string to search</param>
        /// <returns>A list of all palindromes found in source</returns>
        private static HashSet<string> FindAllUniquePalindromes_Described(string source)
        {
            // result set
            var palindromes = new HashSet<string>();

            // for each character in source construct each substring and then test for palindrome
            for (int i = 0; i < source.Length; i++)
            {
                var queue = new Queue<char>(source.Length - i);
                for (int j = i; j < source.Length; j++)
                {
                    // add the next character to our consider set
                    queue.Enqueue(source[j]);

                    // determine if this is a palindrome
                    if (queue.SequenceEqual(queue.Reverse()))
                    {
                        palindromes.Add(new string(queue.ToArray()));
                    }
                }
            }
            return palindromes;
        }

        /// <summary>
        /// Searches the source string for all unique palindromes of any length
        /// </summary>
        /// <remarks>
        /// This is a better implementation after looking at the code, and honestly, laid to to
        /// sleep and figured it a good idea to show a better way instead of just the way I initially
        /// described.
        /// </remarks>
        /// <param name="source">The source string to search</param>
        /// <returns>A list of all palindromes found in source</returns>
        private static HashSet<string> FindAllUniquePalindromes_Better(string source)
        {
            // result set
            var palindromes = new HashSet<string>();

            // for each character in source construct each substring and then test for palindrome
            for (int i = 0; i < source.Length; i++)
            {
                for (int j = i; j < source.Length; j++)
                {
                    string consider = source.Substring(i, j - i + 1);

                    // determine if this is a palindrome
                    if (IsPalindrome(consider))
                    {
                        palindromes.Add(consider);
                    }
                }
            }
            return palindromes;
        }

        /// <summary>
        /// Determines if the specified string is a palindrome (mirrored)
        /// </summary>
        /// <param name="source">The source string to check</param>
        /// <returns>True if the string is a palindrome</returns>
        private static bool IsPalindrome(string source)
        {
            for (int i = 0; i < source.Length/2; i++)
            {
                // palindromes are mirrored, so keep comparing the ends until one doesn't match
                if (source[i] != source[source.Length - i - 1])
                {
                    return false;
                }
            }
            return true;
        }
    }
}