test.cs

private static List<(string word, int charIndex, string replacedWord)> CompareSentences(string sentence1, string sentence2)
{
	string[] words1 = sentence1.Split(' ');
	string[] words2 = sentence2.Split(' ');

	List<(string word, int charIndex, string replacedWord)> differences =
		new List<(string word, int charIndex, string replacedWord)>();

	// Track the character index
	int charIndex = 0;

	// Get the maximum length of the two sentences
	int maxLength = Math.Max(words1.Length, words2.Length);

	// Compare each word in the sentences
	for (int i = 0; i < maxLength; i++)
	{
		// Check if the current word exists in both sentences
		if (i < words1.Length && i < words2.Length)
		{
			// If the words are different, add the word, character index, and replaced word to the list
			if (words1[i] != words2[i])
			{
				differences.Add((words1[i], charIndex, words2[i]));
			}
		}
		// If one of the sentences is shorter, add the extra word to the list
		else if (i < words1.Length)
		{
			differences.Add((words1[i], charIndex, ""));
		}
		else
		{
			differences.Add((words2[i], charIndex, ""));
		}

		// Update the character index for the next word
		if (i < words1.Length)
			charIndex += words1[i].Length + 1; // Add 1 for the space
	}

	return differences;
}