fun flattenMatrix(matrix: List<List<Char>>): String =
matrix.flatten().joinToString("")
fun main() {
val matrix = listOf(
listOf('H', 'e', 'l', 'l', 'o'),
listOf(' ', 'W', 'o', 'r', 'l', 'd'),
listOf('!')
)
val output = flattenMatrix(matrix)
println("Flattened string: $output")
}
/*
run:
Flattened string: Hello World!
*/