Implement Trie with with follow-up
Last updated: November 16, 2025
Quick Overview
Implement a Trie data structure that supports insert, search, and startsWith operations. Your implementation should allow for efficient insertion and retrieval of strings, with each operation running in O(m) time, where m is the length of the string being processed. Additionally, provide a follow-up explanation of how you would optimize the space complexity of your Trie.
TikTok
November 16, 202550
12
4,194 solved
Implement a Trie data structure that supports insert, search, and startsWith operations. Your implementation should allow for efficient insertion and retrieval of strings, with each operation running in O(m) time, where m is the length of the string being processed. Additionally, provide a follow-up explanation of how you would optimize the space complexity of your Trie.
Coding interviews at TikTok focus on problem-solving approach as much as the final solution. The interviewer wants to see you break down the problem, consider edge cases, and optimize iteratively. Communication throughout the process is key.
What the Interviewer Expects
- Identify the correct data structure and algorithm for the problem
- Write clean, bug-free code with proper variable naming
- Analyze time and space complexity correctly
- Handle basic edge cases (empty input, single element)
- Communicate your thought process while coding
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
- What happens if the input contains duplicates?
- How would your solution change if the input was sorted?
- What is the worst-case input for your solution?
- Can you solve this iteratively instead of recursively (or vice versa)?
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Problem Analysis
The problem requires implementing a Trie data structure that supports three primary operations: insert, search, and startsWith. The Trie is a tree-like structure where each node represents a cha...
Approach
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Define the Trie Node: Create a
TrieNodeclass that contains a dictionary to hold children nodes and a boolean flag to indicate the end of a word. -
Implement the Trie Class: Create a...
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