Create 0701-insert-into-a-binary-search-tree.kt

Author: a93a

kotlin/0701-insert-into-a-binary-search-tree.kt

@@ -0,0 +1,57 @@
+/**
+ * Example:
+ * var ti = TreeNode(5)
+ * var v = ti.`val`
+ * Definition for a binary tree node.
+ * class TreeNode(var `val`: Int) {
+ *     var left: TreeNode? = null
+ *     var right: TreeNode? = null
+ * }
+ */
+ 
+ // Recursive solution (Non self balancing)
+class Solution {
+    fun insertIntoBST(root: TreeNode?, value: Int): TreeNode? {
+
+        root?: return TreeNode(value)
+
+        if (value > root.value) root.right = insertIntoBST(root.right, value)
+        else root.left = insertIntoBST(root.left, value)
+
+        return root
+    }
+
+    private val TreeNode.value get() = `val`
+}
+
+// Iterative Solution (Non self balancing)
+class Solution {
+    fun insertIntoBST(root: TreeNode?, value: Int): TreeNode? {
+
+        root?: return TreeNode(value)
+
+        var current = root
+
+        while (current != null) {
+            if (value > current!!.value) {
+                if (current.right != null){
+                    current = current?.right
+                } else {
+                    current.right = TreeNode(value)
+                    break
+                }
+            } else {
+                if (current.left != null){
+                    current = current?.left
+                } else {
+                    current.left = TreeNode(value)
+                    break
+                }
+            }
+        }
+
+        return root
+    }
+
+    private val TreeNode.value get() = `val`
+}