/**
 * Given a list of cities visited (citiesVisited) and a list of all cities (allCities),
 * this function returns a list of unique cities that have not been visited yet.
 *
 * Example:
 * findUniqueCities(listOf("London", "Paris", "Madrid"), listOf("Paris", "Berlin", "London", "Rome", "Madrid"))
 * Output: ["Berlin", "Rome"]
 */
fun findUniqueCities(citiesVisited: List<String>, allCities: List<String>): List<String> {

    val uniqueCities = mutableListOf<String>()

    for (city in allCities) {
        if (city !in citiesVisited) {
            uniqueCities.add(city)
        }
    }

    return uniqueCities
}
/**
 * Given a list of cities visited (citiesVisited) and a list of all cities (allCities),
 * this function returns a list of unique cities that have not been visited yet.
 *
 * Example:
 * findUniqueCities(listOf("London", "Paris", "Madrid"), listOf("Paris", "Berlin", "London", "Rome", "Madrid"))
 * Output: ["Berlin", "Rome"]
 */
fun findUniqueCities(citiesVisited: List<String>, allCities: List<String>): List<String> {
/**
 * Given a list of cities visited (citiesVisited) and a list of all cities (allCities),
 * this function returns a list of unique cities that have not been visited yet.
 *
 * Example:
 * findUniqueCities(listOf("London", "Paris", "Madrid"), listOf("Paris", "Berlin", "London", "Rome", "Madrid"))
 * Output: ["Berlin", "Rome"]
 */
fun findUniqueCities(citiesVisited: List<String>, allCities: List<String>): List<String> {

    val uniqueCities = mutableListOf<String>()

    for (city in allCities) {
        if (city !in citiesVisited) {
            uniqueCities.add(city)
        }
    }

    return uniqueCities
}