Validate graph sorted
Last updated: February 12, 2026
Quick Overview
Given a graph represented as an adjacency list, write a function to determine if the graph is sorted in ascending order based on the values of its vertices. The function should return true if the vertices are sorted, and false otherwise. The input will be a list of lists, where each sublist represents the neighbors of a vertex, and the output should be a boolean value.
Snapchat
February 12, 2026207
7
1,007 solved
Given a graph represented as an adjacency list, write a function to determine if the graph is sorted in ascending order based on the values of its vertices. The function should return true if the vertices are sorted, and false otherwise. The input will be a list of lists, where each sublist represents the neighbors of a vertex, and the output should be a boolean value.
This coding problem is frequently asked during Technical Screen at Snapchat. The interviewer is testing your ability to translate a problem into clean, working code while discussing time and space complexity. Snapchat expects candidates to write production-quality code, not just solve the puzzle.
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
- Can you solve this iteratively instead of recursively (or vice versa)?
- What if the input doesn't fit in memory?
- How would your solution change if the input was sorted?
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
The problem requires us to determine if the vertices of a graph are sorted in ascending order based on their values. The graph is represented as an adjacency list, where each vertex's neighbors are li...
Approach
- Initialize a list to hold the vertex values, extracted from the adjacency list.
- For each vertex represented by its index in the adjacency list, append its value (the index itself) to the list o...
Submit Your Answer
