Amazon: Concatenated Words (wrong solution on Interview)

class Solution {

    fun findAllConcatenatedWordsInADict(words: Array<String>): List<String> {
        val result: MutableList<String> = LinkedList()

        val set = words.toSet()
        words.forEach { word ->
            var wordsCnt = 0
            var concatWord = ""
            var part = ""
            word.forEach { ch ->
                part += ch
                if(set.contains(part)) {
                    concatWord += part
                    wordsCnt++
                    part = ""
                }
            }
            if(part.isEmpty() && wordsCnt > 1) result.add(concatWord)
        }

        return result
    }
}