Solution: Recover a Tree From Preorder Traversal
Explore how to rebuild a binary tree from its preorder traversal string using a depth-first search approach. Understand how counting leading dashes indicates node depth, guiding the parsing and reconstruction of each node. This lesson helps you implement and analyze a DFS solution with optimal time and space complexity for tree recovery problems.
We'll cover the following...
Statement
We perform a preorder depth-first traversal on a binary tree starting from its root.
For each node, we first write D dashes, where D is the depth of the node in the tree, followed by the node’s integer value.
The root node has depth 0.
If a node is at depth D, its children (if any) will appear at depth D + 1.
If a node has only one child, it will always be the left child.
You are given the string representation of this traversal. Your task is to reconstruct the original binary tree and return its root.
Constraints:
The number of nodes in the original binary tree lies within the range
...