/**
 * Given two strings, s1 and s2, find and return a list of the common characters in both strings.
 */
fun findCommonCharacters(s1: String, s2: String): List<Char> {

    val commonCharacters = mutableListOf<Char>()

    // Loop through each character in the first string
    for (char1 in s1) {
        // Loop through each character in the second string
        for (char2 in s2) {
            // Check if both characters are equal and not already in the commonCharacters list
            if (char1 == char2 && char1 !in commonCharacters) {
                commonCharacters.add(char1)
            }
        }
    }

    return commonCharacters
}
/**
 * Given two strings, s1 and s2, find and return a list of the common characters in both strings.
 */
fun findCommonCharacters(s1: String, s2: String): List<Char> {
/**
 * Given two strings, s1 and s2, find and return a list of the common characters in both strings.
 */
fun findCommonCharacters(s1: String, s2: String): List<Char> {

    val commonCharacters = mutableListOf<Char>()

    // Loop through each character in the first string
    for (char1 in s1) {
        // Loop through each character in the second string
        for (char2 in s2) {
            // Check if both characters are equal and not already in the commonCharacters list
            if (char1 == char2 && char1 !in commonCharacters) {
                commonCharacters.add(char1)
            }
        }
    }

    return commonCharacters
}