Build A Binary Tree III

Unit 8 Session 1 (Click for link to problem statements)

Problem Highlights

• 💡 Difficulty: Easy
• ⏰ Time to complete: 5 mins
• 🛠️ Topics: Trees, Binary Trees, Tree Construction

1: U-nderstand

Understand what the interviewer is asking for by using test cases and questions about the problem.

• Established a set (2-3) of test cases to verify their own solution later.
• Established a set (1-2) of edge cases to verify their solution handles complexities.
• Have fully understood the problem and have no clarifying questions.
• Have you verified any Time/Space Constraints for this problem?

2: M-atch

Match what this problem looks like to known categories of problems, e.g. Linked List or Dynamic Programming, and strategies or patterns in those categories.

This problem is a basic tree construction challenge, useful for setting up scenarios in more complex tree manipulation tasks.

3: P-lan

Plan the solution with appropriate visualizations and pseudocode.

General Idea: Create nodes as per the values given and link them as specified to form the tree.

1) Create a TreeNode for 'a'.
2) Set 'b' as the left child and 'c' as the right child of 'a'.
3) Set 'd' as the right child of 'c'.

⚠️ Common Mistakes

• Incorrectly linking nodes or leaving out a node based on the diagram or description.

4: I-mplement

Implement the code to solve the algorithm.

root = TreeNode('a')
root.left = TreeNode('b')
root.right = TreeNode('c')
root.right.right = TreeNode('d')

5: R-eview

Review the code by running specific example(s) and recording values (watchlist) of your code's variables along the way.

• Verify the tree structure visually or by testing to ensure that all links are correct and that the tree reflects the described structure.

6: E-valuate

Evaluate the performance of your algorithm and state any strong/weak or future potential work.

• Time Complexity: O(1) because the operations to set up the tree are fixed and do not depend on input size.
• Space Complexity: O(1) for storing a fixed number of nodes.