solution

Challange.kt

package basics

fun main() {
    val str ="no todos los carros son azules todos los carros son azules lo sabias sabias"
    findRepeatedWords(str)
}

fun findRepeatedWords(str: String) {
    val split = str.split(" ")
    val map = mutableMapOf<String, Int>()

    split.forEach { word ->
        if (map.containsKey(word)) {
            val count = map.getValue(word) + 1
            map[word] = count
        } else {
            map[word] = 1
        }
    }
    println(map.filter { it.value > 1 }.keys.joinToString(", "))
}