data class Node(var prev: Node?, val value: Int, var next: Node?)

fun poisonousPlants(p: Array<Int>): Int {
    // Write your code here


    var toBeDeleted = mutableListOf<Node>()
    var previousNode: Node? = null
    for (value in p.reversed()) {
        val currentNode = Node(previousNode, value, null)
        previousNode?.next = currentNode
        previousNode = currentNode
        currentNode.prev?.let {prev->
            if (prev.value > currentNode.value) toBeDeleted.add(prev)
        }
    }

    var days = 0

    while (toBeDeleted.isNotEmpty()) {
        val toBeDeletedTemp = mutableListOf<Node>()
        toBeDeleted.forEach { nodeToBeDeleted ->
            nodeToBeDeleted.prev?.next = nodeToBeDeleted.next
            nodeToBeDeleted.next?.prev = nodeToBeDeleted.prev
            if (nodeToBeDeleted.next != null && nodeToBeDeleted.prev != null && nodeToBeDeleted.next?.value!! < nodeToBeDeleted.prev!!.value)
                toBeDeletedTemp.add(nodeToBeDeleted.prev!!)      
        }
        toBeDeleted = toBeDeletedTemp
        days++
    }
    return days
}