mohammed-akkad

fun isValidSudoku(board: List<CharArray>): Boolean {
    if (board.isEmpty()) return false
    val boardSize = board.size
    val baseGrid = kotlin.math.sqrt(boardSize.toDouble()).toInt()

    board.forEach { row -> if (boardSize != row.size || row.size <= 1) return false }

    val seenInRow = Array(boardSize) { HashSet<Char>() }
    val seenInColumn = Array(boardSize) { HashSet<Char>() }
    val seenInGrid = Array(boardSize) { HashSet<Char>() }

mohammed-akkad

fun isValidIPv4Address(ipAddress: String): Boolean {
    val segments = ipAddress.split('.')
    val maxNumberOfSegments = 4
    if (ipAddress.isEmpty() || segments.count() != maxNumberOfSegments) return false
    segments.forEach { item ->
        if (!item.all { it.isDigit() }) return false
        val rangeOfSegment = 0..255
        val segment = item.toIntOrNull() ?: return false
        if ((item.count() > 1 && item.startsWith('0')) || segment !in rangeOfSegment) return false
    }