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Coding questions
Explore algorithm tutorials, coding and system design questions, interview experiences, and computer science study guides.
1,899 resources · Page 9 of 80
Coding questions · Confluent
Check Whether a Partially Filled 9x9 Sudoku Board Is Valid
A coding problem that asks whether a partially filled 9x9 Sudoku board is consistent, meaning no row, column or 3x3 box repeats a digit among its filled cells. It tests careful bookkeeping of row, column and box membership without attempting to solve the puzzle.
Coding questions · LinkedIn
Check Whether a String Is a Signed Decimal Number Without Exponent Notation
Write a function that decides whether a string is a valid plain decimal number with an optional sign and fractional part, rejecting exponents, stray symbols, and repeated decimal points. It tests turning a small grammar into careful character-by-character validation and covering edge cases such as empty strings and bare signs.
Coding questions · ByteDance
Check Whether an n x n Tic-Tac-Toe Game Is Over (Win or Draw)
Given an n x n tic-tac-toe board holding empty cells and two players' marks, decide whether the game is over because one player occupies an entire row, column or diagonal, or because the board is full with no winner. It tests complete line checks, draw detection and edge cases such as all-empty lines and a 1 x 1 board.
Coding questions · Snowflake
Check Whether the Latest Move Creates Four in a Row
Check four-in-a-row through the latest move using four axes, bounded bidirectional counts, edge handling, and constant work for a fixed target length.
Coding questions · Upstart
Check Whether Two Words Are Case-Insensitive Anagrams
Compare letter multiplicities case-insensitively to recognize anagrams, including repeated letters and empty strings.
Coding questions · Microsoft
Choose k Non-Adjacent Servers to Minimize the Largest Chosen Value
A coding problem about choosing exactly k servers from a row so that no two chosen servers are neighbors, while making the largest value among the chosen servers as small as possible. It tests reasoning about a min-max objective under an adjacency restriction and finding an efficient solution for rows of up to 100,000 servers.
Coding questions · Uber
Choose K pickup locations minimizing L1 distance
This question evaluates facility-location and spatial optimization skills under the Manhattan (L1) metric, testing algorithm design, combinatorial optimization, and handling geometric data.
Coding questions · Point72
Classify relationships for multiple circle pairs
This question evaluates computational geometry skills, careful integer arithmetic for numeric precision, case-based classification logic, and analysis of time and space complexity in the Coding & Algorithms domain for Data Scientist roles.
Coding questions · Oracle
Classify Tree Nodes in SQL
Classify each tree node as Root, Inner, or Leaf in PostgreSQL using its parent ID and whether it has children, returning one classification per node.
Coding questions · Roblox
Clean and aggregate factory event data in Pandas
This question evaluates a candidate's ability to clean and aggregate large-scale time-series data in Pandas, emphasizing timezone normalization, deterministic deduplication, DST-aware alignment, event-sequence aggregation, rolling statistical features, anomaly detection, and memory- and performance-conscious ETL techniques.
Coding questions · Pinterest
Clean and Aggregate Transactions for Finance Dashboard
This question evaluates data cleaning and transformation competencies including pandas-based vectorized operations, categorical mapping and feature flagging, as well as aggregation and summarization of transactional data in the data manipulation (SQL/Python) domain.
Coding questions · PayPal
Clean and Analyze User Transactions with Python Functions
This question evaluates proficiency in data manipulation and feature engineering with Python and pandas, specifically cleaning transactional logs and deriving user-level time-based metrics such as inter-event intervals.
Coding questions · PayPal
Clean and Summarize User Purchase Data Efficiently
This question evaluates proficiency in data cleaning, aggregation, and time-series manipulation within the Data Manipulation (SQL/Python) domain, focusing on filtering by group counts and calculating inter-event timing metrics.
Coding questions · Uber
Clean, split, merge, and aggregate with pandas
This question evaluates proficiency with pandas data manipulation and cleaning, including handling missing values, trimming and splitting strings, numeric type conversion, merges, time-aware ordering, and aggregation for per-entity summaries.
Coding questions · ByteDance
Clockwise Spiral Traversal of a Matrix With O(1) Extra Space and No Mutation
From a TikTok backend intern interview: return the elements of an m x n matrix in clockwise spiral order using only constant extra space beyond the output, without a visited marker and without modifying the matrix. It tests careful traversal logic and off-by-one handling when a single row or column remains.
Coding questions · DocuSign
Collapse runs of adjacent anagrams in a word list
Given a list of lowercase words, repeatedly delete any word that is an anagram of the word immediately before it, and return what remains in its original order. The task tests anagram comparison, reasoning about how repeated deletions interact, and producing a unique, order-preserving result.
Coding questions · Goldman Sachs
Collect the Most Rocks with Upward and Rightward Moves
Maximize rocks collected from the bottom-left to the top-right of a grid using only upward and rightward moves.
Coding questions · ByteDance
Combined Median of Two Sorted Integer Lists in Logarithmic Time
From a ByteDance technical screen for a machine learning engineer role: given two sorted integer arrays, return the median of all their elements combined, averaging the two middle values when the total count is even. It tests reasoning about sorted order under a logarithmic time target and edge cases such as an empty array.
Coding questions · Mixpanel
Compare First-Week Retention by Plan Type
Compare first-week retention by recorded plan type with distinct-user counts, inclusive denominators, and four-decimal rates.
Coding questions · Read.Ai
Compare Sentences Using Transitive Synonym Groups
Compare two tokenized sentences using undirected, transitive synonym relationships. Sentence lengths and word positions must match, while a union-find or graph traversal groups chained synonyms and leaves unknown words equivalent only to themselves.
Coding questions · Experian
Compare Spark RDDs, DataFrames, and Spark SQL Benefits
This question evaluates understanding of Apache Spark core abstractions (RDDs, DataFrames, Spark SQL), execution model concepts such as lazy evaluation and optimizer-driven execution, and operational competency with managed cloud cluster job submission and monitoring, categorized under Data Manipulation (SQL/Python) for a Data Scientist role.
Coding questions · Experian
Compare Spark RDDs, DataFrames, and SQL Performance Gains
This question evaluates understanding of Spark abstractions (RDDs, DataFrames, Spark SQL), lazy evaluation, memory management, query optimization, and developer ergonomics within the Data Manipulation (SQL/Python) domain of distributed data processing.
Coding questions · ByteDance
Compare SQL counts, windows, and NULL semantics
This question evaluates understanding of SQL aggregation and NULL semantics, window functions (ROW_NUMBER vs RANK), join behavior to avoid double-counting, and defensive handling of NULLs and divide-by-zero using COALESCE and NULLIF in a data manipulation context.
Coding questions · Meta
Compare two string linked lists
This question evaluates proficiency with linked list manipulation and string sequence comparison, focusing on data structure traversal, character-level comparison, and attention to edge cases. It is commonly asked in the Coding & Algorithms domain to assess practical implementation skills, correctness, and efficiency rather than purely conceptual understanding.