최빈 단어 찾기

fun mostFrequentWord(s: String): Pair<String, Int>? {
    val words = s.split(' ')
    val frequencyMap = words.groupingBy { it }.eachCount()
    return frequencyMap.maxByOrNull { it.value }
}

fun main() {
    val (word, frequency) = mostFrequentWord("this is a sample program and it is a sample") ?: Pair("", 0)
    println("$word: $frequency") // "sample: 2"
}