Count minimum cost in binary tree
Last updated: August 30, 2025
Quick Overview
Given a binary tree where each node has a cost associated with it, write a function to calculate the minimum cost required to traverse from the root node to any leaf node. The function should take the root of the binary tree as input and return an integer representing the minimum cost.
Jump Trading
August 30, 202515
9
2,003 solved
Given a binary tree where each node has a cost associated with it, write a function to calculate the minimum cost required to traverse from the root node to any leaf node. The function should take the root of the binary tree as input and return an integer representing the minimum cost.
Jump Trading uses this problem in the Take-home Project to evaluate your algorithmic thinking. They expect you to discuss multiple approaches, analyze trade-offs between them, and implement the optimal solution with clean, readable code.
What the Interviewer Expects
- Recognize the underlying problem pattern (sliding window, two pointers, BFS/DFS, etc.)
- Discuss multiple approaches and trade-offs before coding
- Implement an optimal solution with clean, production-quality code
- Handle all edge cases including boundary conditions and invalid input
- Optimize both time and space complexity with clear justification
- Test your solution systematically with well-chosen examples
Key Topics to Cover
How to Approach This
- Clarify input constraints and edge cases before writing code.
- Walk through your approach verbally and confirm with the interviewer before coding.
- Start with a brute force solution, then optimize. Mention time and space complexity.
- Test your solution with examples, including edge cases like empty input or duplicates.
- Consider common patterns: sliding window, two pointers, hash map, BFS/DFS, dynamic programming.
Possible Follow-up Questions
- How would you modify your solution to handle streaming input?
- What if the input doesn't fit in memory?
- How would your solution change if the input was sorted?
- Can you solve this in a single pass?
Sharpen Your Skills on Codemia
Practice similar problems with our interactive workspace, get AI feedback, and track your progress.
Practice DSA ProblemsSample Answer
Problem Analysis
This problem is best approached using Depth-First Search (DFS) because we need to explore each path from the root to the leaves to calculate the total cost associated with traversing through the nodes...
Approach
- Define a recursive function that takes a node as its parameter and returns the minimum cost to reach a leaf from that node.
- Base case: If the node is null, return infinity (or a very lar...
Submit Your Answer
