abc

BTreePrinter.kt

object BTreePrinter {

    fun printNode(root: AVLNode, showHeight: Boolean = false) {
        val maxLevel = BTreePrinter.maxLevel(root)

        printNodeInternal(listOf(root), 1, maxLevel, showHeight)
    }

    private fun printNodeInternal(nodes: List<AVLNode?>, level: Int, maxLevel: Int, showHeight: Boolean) {
        if (nodes.isEmpty() || BTreePrinter.isAllElementsNull(nodes))
            return

        val floor = maxLevel - level
        val edgeLines = Math.pow(2.0, Math.max(floor - 1, 0).toDouble()).toInt()
        val firstSpaces = Math.pow(2.0, floor.toDouble()).toInt() - 1
        val betweenSpaces = Math.pow(2.0, (floor + 1).toDouble()).toInt() - 1

        BTreePrinter.printWhitespaces(firstSpaces)

        val newNodes = arrayListOf<AVLNode?>()
        for (node in nodes) {
            if (node != null) {
                if (!showHeight) print("\b\b")
                print(if (showHeight) node.height else node.elem)
                newNodes.add(node.left)
                newNodes.add(node.right)
            } else {
                newNodes.add(null)
                newNodes.add(null)
                print(" ")
            }

            BTreePrinter.printWhitespaces(betweenSpaces)
        }
        println("")

        for (i in 1..edgeLines) {
            for (j in nodes.indices) {
                BTreePrinter.printWhitespaces(firstSpaces - i)
                if (nodes[j] == null) {
                    BTreePrinter.printWhitespaces(edgeLines + edgeLines + i + 1)
                    continue
                }

                if (nodes[j]?.left != null)
                    print("/")
                else
                    BTreePrinter.printWhitespaces(1)

                BTreePrinter.printWhitespaces(i + i - 1)

                if (nodes[j]?.right != null)
                    print("\\")
                else
                    BTreePrinter.printWhitespaces(1)

                BTreePrinter.printWhitespaces(edgeLines + edgeLines - i)
            }

            println("")
        }

        printNodeInternal(newNodes, level + 1, maxLevel, showHeight)
    }

    private fun printWhitespaces(count: Int) {
        for (i in 0 until count)
            print(" ")
    }

    private fun maxLevel(node: AVLNode?): Int {
        return if (node == null) 0 else Math.max(BTreePrinter.maxLevel(node.left), BTreePrinter.maxLevel(node.right)) + 1

    }

    private fun <T> isAllElementsNull(list: List<T>): Boolean {
        for (`object` in list) {
            if (`object` != null)
                return false
        }

        return true
    }

}