Meta Software Engineer Interview Questions and Answers

Efficiently calculate the sum of a matrix

• Iterate through each element in the matrix and add them to a running total

• Use parallel processing or multi-threading to calculate the sum faster

• Consider using optimized algorithms like Strassen's algorithm for matrix multiplication

Find and return all substrings in a main string that match a given string.

• Iterate through the main string and check for matches with the given string

• Use substring function to extract potential matches

• Store all matching substrings in an array and return it

A sparse matrix can be represented using a dictionary of dictionaries or a list of lists.

• Use a dictionary of dictionaries where the keys are the row and column indices with non-zero values as values.

• Alternatively, use a list of lists where each inner list represents a row with non-zero values and their column indices.

• Sparse matrices are efficient for large matrices with mostly zero values.

• Example: {0: {1: 5, 3: 7}, 2: {2: 3}} represents a 3x4 matrix with non-zero values at (0...read more

A metrics tracker to monitor and analyze key performance indicators

• Define the key metrics to track (e.g. user engagement, conversion rates)

• Implement a data collection system to gather relevant data

• Create visualizations and reports to analyze the metrics

• Set up alerts for abnormal metric values

• Regularly review and update the metrics based on business goals

Use a stack to ensure balanced parenthesis in a string

• Iterate through each character in the string

• If the character is an opening parenthesis, push it onto the stack

• If the character is a closing parenthesis, pop from the stack and check if they match

• If at the end the stack is empty, the parenthesis are balanced

Find all palindromic substrings in a given string.

• Iterate through each character in the string and expand around it to find palindromic substrings.

• Store all palindromic substrings in an array of strings.

Clean maze using a robot by navigating through paths and avoiding obstacles.

• Create a map of the maze with obstacles and paths.

• Implement a pathfinding algorithm for the robot to navigate through the maze.

• Use sensors or algorithms to detect and avoid obstacles.

• Track the robot's progress and clean the maze efficiently.

Online coding judge to evaluate code submissions and provide feedback.

• Create a web application where users can submit code in various programming languages.

• Implement a compiler or interpreter to execute the code and check for errors.

• Provide feedback on code correctness, efficiency, and style.

• Include test cases to verify the code's functionality.

• Allow users to view their submission history and track their progress.