June 2018 Update

Task/Visualize-a-tree/Kotlin/visualize-a-tree.kotlin

@@ -0,0 +1,45 @@
+// version 1.2.0
+
+import java.util.Random
+
+class Stem(var str: String? = null, var next: Stem? = null)
+
+const val SDOWN = "  |"
+const val SLAST = "  `"
+const val SNONE = "   "
+
+val rand = Random()
+
+fun tree(root: Int, head: Stem?) {
+    val col = Stem()
+    var head2 = head
+    var tail = head
+    while (tail != null) {
+        print(tail.str)
+        if (tail.next == null) break
+        tail = tail.next
+    }
+    println("--$root")
+    if (root <= 1) return
+    if (tail != null && tail.str == SLAST) tail.str = SNONE
+    if (tail == null) {
+        head2 = col
+        tail = head2
+    }
+    else {
+        tail.next = col
+    }
+    var root2 = root
+    while (root2 != 0) { // make a tree by doing something random
+        val r = 1 + rand.nextInt(root2)
+        root2 -= r
+        col.str = if (root2 != 0) SDOWN else SLAST
+        tree(r, head2)
+    }
+    tail.next = null
+}
+
+fun main(args: Array<String>) {
+    val n = 8
+    tree(n, null)
+}