java.lang.Object
g0901_1000.s0919_complete_binary_tree_inserter.CBTInserter

public class CBTInserter extends Object
919 - Complete Binary Tree Inserter\. Medium A **complete binary tree** is a binary tree in which every level, except possibly the last, is completely filled, and all nodes are as far left as possible. Design an algorithm to insert a new node to a complete binary tree keeping it complete after the insertion. Implement the `CBTInserter` class: * `CBTInserter(TreeNode root)` Initializes the data structure with the `root` of the complete binary tree. * `int insert(int v)` Inserts a `TreeNode` into the tree with value `Node.val == val` so that the tree remains complete, and returns the value of the parent of the inserted `TreeNode`. * `TreeNode get_root()` Returns the root node of the tree. **Example 1:** ![](https://assets.leetcode.com/uploads/2021/08/03/lc-treeinsert.jpg) **Input** ["CBTInserter", "insert", "insert", "get\_root"] [[[1, 2]], [3], [4], []] **Output:** [null, 1, 2, [1, 2, 3, 4]] **Explanation:** CBTInserter cBTInserter = new CBTInserter([1, 2]); cBTInserter.insert(3); // return 1 cBTInserter.insert(4); // return 2 cBTInserter.get\_root(); // return [1, 2, 3, 4] **Constraints:** * The number of nodes in the tree will be in the range `[1, 1000]`. * `0 <= Node.val <= 5000` * `root` is a complete binary tree. * `0 <= val <= 5000` * At most 104 calls will be made to `insert` and `get_root`.
  • Constructor Details

    • CBTInserter

      public CBTInserter(TreeNode root)
  • Method Details

    • insert

      public int insert(int val)
    • getRoot

      public TreeNode getRoot()