Binary Tree Inorder Traversal
EasyP1Coding
Given the root of a binary tree, return the values of its nodes in inorder order: left subtree, node, right subtree.
Tree nodes have val, left and right. The class TreeNode is already defined for you. The tree arrives in level-order form (as in the examples) and you receive its root, which is null for an empty tree. Solve it iteratively with an explicit stack.
Example 1
- Input
- root = [1,null,2,3]
- Output
- [1,3,2]
Example 2
- Input
- root = [3,9,20,null,null,15,7]
- Output
- [9,3,15,20,7]
Example 3
- Input
- root = []
- Output
- []
Constraints
- The number of nodes is in the range [0, 100].
- -100 <= Node.val <= 100
Hints
Give it a real attempt first. Run shows which examples fail.
Saved automatically
Run checks the 3 visible tests, Submit all 9. ⌘Enter runs, ⌘⇧Enter submits.