Get MutableList<MutableList<Int>> from List<List<Int>> in Kotlin

Question

I have a List<List> and need to form a mutable list of lists out of it.

fun trial (check: List<List<Int>>): Int {
   val mutableCheck : MutableList<MutableList<Int>> = //mutableListOf(check)?
}

I tried various ways, but not able to make it work.

Answer 1

val mutableCheck = check.map { it.toMutableList() }.toMutableList()