Insert into BST 15 XP Medium

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Given a BST and a value, insert the value into the BST and return the root. The new node always becomes a leaf — you never need to restructure the tree.

#       4                4
#      / \     insert 5   / \
#     2   7   ────────→  2   7
#    / \                / \ /
#   1   3              1  3 5

The insertion algorithm is just search until you find an empty spot:

If the current node is None, create a new node here
If val < node.val, insert into the left subtree
If val > node.val, insert into the right subtree
Return the (possibly new) root

The recursive solution is beautifully simple — each recursive call either goes deeper or creates the new node.

📋 Instructions

Implement `insert_bst(root, val)` recursively. Insert 5 into the tree and print inorder traversal.

Base case: if not root, return TreeNode(val). If val < root.val, root.left = insert_bst(root.left, val). If val > root.val, root.right = insert_bst(root.right, val). Return root.

🧪 Test Cases

Input

inorder(root)

Expected

[1, 2, 3, 4, 7]

Test case 1

Input

inorder(root)

Expected

[1, 2, 3, 4, 5, 7]

Test case 2

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main.py

Hi! I'm Rex 👋

Output

Ready. Press ▶ Run or Ctrl+Enter.

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