Binary Tree
Detailed guide and Python implementation for the 'Binary Tree' problem.
1. Concept Overview
The 'Binary Tree' problem is a key challenge in the Trees section.
This implementation focuses on medium-level logic in Python.
We prioritize technical accuracy and code readability in our provided solutions.
2. Real-World Applications
3. Visual Intuition
Visualizing the logic flow for Binary Tree.
4. Prerequisites
5. Step-by-Step Thinking
1. Understand the problem
Read the problem statement for Binary Tree carefully.
2. Formulate brute force
Draft a simple iterative solution.
3. Identify inefficiency
Look for redundant calculations.
4. Optimize search path
Use hashing or sorting to speed up the process.
5. Final Implementation
Clean up the code for production standards.
Problem Statement
Write a function is_univalued_binary_tree(tree_arr) that takes an array representation of a binary tree tree_arr (where the root is at index 0, and children of index i are at 2i + 1 and 2i + 2, with None representing empty nodes) and returns True if every node in the tree has the same value, or False otherwise.
- •0 <= len(tree_arr) <= 1000
Examples
tree_arr = [1, 1, 1, 1, 1, None, 1]
True
All nodes in the tree contain the value 1.
tree_arr = [2, 2, 2, 5, 2]
False
One node has value 5, which differs from other nodes (value 2).
Need a Hint?
Edge Cases to Watch
- Empty input structures
- Single element inputs
- Large numerical bounds
Ready to Solve?
Open the problem in PyRun's browser-based Python editor. Your code runs fully offline — no server required.
Interview Insights & Variations
Complexity Analysis Breakdown
Why Time: Directly evaluates all possibilities.
Why Space: Uses standard local memory.
Why Time: Optimized paths reduce total operations.
Why Space: May trade memory for speed.
Optimized Solution Python Code
Optimized Solution Python Code
def create_binary_tree_opt(arr: list) -> list:
root = build_tree(arr)
return tree_to_list(root)Brute Force Code (Spoiler Guarded)
Brute Force Code (Spoiler Guarded)
def create_binary_tree_brute(arr: list) -> list:
root = build_tree(arr)
return tree_to_list(root)Algorithm Pattern Checklist
When dealing with Trees data patterns.
Core Prerequisites
Revision Key Notes
Common Mistakes & Pitfalls
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