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Coding & Algorithms Interview Questions
Practice 9403 coding, system design and machine learning questions from 546 companies, sorted by role, topic and interview round. Every question has step-by-step hints, a code runner that supports 8 languages and an AI mentor; members also get the full solution walkthrough.
- 9403
- Questions
- 546
- Companies
- 11
- Topics
- 8
- Languages
Showing 1471–1500 of 1706 results
- TikTokMediumSoftware EngineerDelete nodes in linked list and binary tree
This question evaluates proficiency in mutable data structure operations, specifically linked list node removal and binary tree node replacement/deletion, requiring knowledge of traversal, pointer/reference manipulation, and edge-case handling.
Coding & AlgorithmsTechnical Screen - TikTokMediumSoftware EngineerDesign LRU cache with O(1) operations
This question evaluates a candidate's understanding of data structures and algorithm design, specifically skills in implementing constant-time cache operations, eviction policies, update handling, and concurrency/thread-safety considerations.
Coding & AlgorithmsTechnical Screen - TikTokMediumMachine Learning EngineerDetermine if a string can be segmented
This question evaluates a candidate's understanding of dynamic programming and string-processing skills, along with algorithmic complexity analysis for segmentation problems.
Coding & AlgorithmsTechnical Screen - TikTokMediumMachine Learning EngineerDifferentiate virtual and pure virtual functions
This interview question evaluates algorithm design, data structures, correctness, complexity, edge cases, and implementation details in a realistic interview setting. A strong answer for Differentiate virtual and pure virtual functions states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Coding & AlgorithmsTechnical Screen - TikTokMediumSoftware EngineerExplain Java DI, AOP, and transactions
This question evaluates understanding of Java framework internals and related competencies including dependency injection, aspect-oriented programming and proxy mechanisms, transaction management, annotation processing, bean lifecycle, classpath scanning, bean scopes, and circular dependency detection or resolution.
Coding & AlgorithmsTechnical Screen - TikTokMediumSoftware EngineerFind a valid course order from prerequisites
This problem tests your ability to model dependencies as a directed graph and determine a valid sequence using topological sorting (Kahn's algorithm or DFS).
Coding & AlgorithmsTechnical ScreenGraphTopological SortDFS - TikTokMediumMachine Learning EngineerFind and count target-sum subarrays
Find and count target-sum subarrays evaluates algorithm design, data structures, correctness, complexity, edge cases, and implementation details in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Coding & AlgorithmsTechnical Screen - TikTokEasySoftware EngineerFind first and last index of target
This question evaluates mastery of searching algorithms and algorithmic complexity analysis, particularly the ability to locate boundary positions within a sorted array.
Coding & AlgorithmsTechnical Screen - TikTokMediumSoftware EngineerFind kth smallest in sorted 2D matrix
This question evaluates algorithmic problem-solving and data-structure reasoning, focusing on order statistics and operations on a row- and column-sorted matrix within the Coding & Algorithms domain.
Coding & AlgorithmsTechnical Screen - TikTokMediumMachine Learning EngineerFind length of longest common subsequence
This problem tests your ability to identify overlapping subproblems and optimal substructure by implementing a dynamic programming solution to find the length of the Longest Common Subsequence (LCS) between two strings.
Coding & AlgorithmsTechnical ScreenDynamic ProgrammingStringsOptimization - TikTokHardSoftware EngineerFind longest substring with ≥k repeats
This problem tests your ability to use the sliding window technique combined with frequency maps to find the longest substring containing characters that each appear at least k times.
Coding & AlgorithmsTechnical ScreenStringsSliding WindowTwo Pointers - TikTokEasySoftware EngineerFind start indices of anagram substrings
This question evaluates proficiency in string processing, frequency-based pattern matching, and algorithmic efficiency under length constraints, testing the ability to reason about time and space trade-offs for substring searches.
Coding & AlgorithmsTechnical Screen - TikTokMediumSoftware EngineerFind the Longest Substring with at Most Two Distinct Characters
Tests the ability to use the sliding window technique combined with a hash map to maintain a dynamic character set and determine the maximum length of a valid substring in linear time.
Coding & AlgorithmsTechnical Screensliding-windowhash-tabletwo-pointers - TikTokMediumMachine Learning EngineerFix a BST with two misplaced keys
This interview question evaluates algorithm design, data structures, correctness, complexity, edge cases, and implementation details in a realistic interview setting. A strong answer for Fix a BST with two misplaced keys states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Coding & AlgorithmsTechnical Screen - TikTokMediumSoftware EngineerFlatten object & Promise.all
This question evaluates proficiency in JavaScript data manipulation and asynchronous programming, testing competencies in transforming nested objects into single-level key paths and reproducing Promise.all semantics.
Coding & AlgorithmsTechnical Screen - TikTokHardMachine Learning EngineerGenerate all safe queen placements on board
This question evaluates algorithm design for constraint-satisfaction problems, testing skills in search, recursion, backtracking, combinatorics, and state-space pruning.
Coding & AlgorithmsTechnical Screen - TikTokMediumData ScientistImplement K-means and run two iterations
This question evaluates understanding of k-means clustering concepts (k-means++ initialization, Lloyd iterations, and SSE) and proficiency in numerical implementation and vectorized array operations.
Coding & AlgorithmsTechnical Screen - TikTokMediumSoftware EngineerImplement O(1) randomized multiset
Implement O(1) randomized multiset evaluates algorithm design, data structures, correctness, complexity, edge cases, and implementation details in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Coding & AlgorithmsTechnical Screen - TikTokMediumSoftware EngineerImplement a match-3 board resolver
TikTok software-engineer technical-screen coding question: implement a match-3 board resolver over an m×n grid. Repeatedly remove connected horizontal/vertical runs of three or more equal cells, apply gravity so survivors fall and blanks rise to the top, cascade until the board is stable, and return the final board plus the total cells removed. It tests grid simulation, run detection via linear scans, per-column gravity, termination reasoning, and time/space complexity analysis.
Coding & AlgorithmsTechnical Screen - TikTokEasySoftware EngineerImplement an LRU cache
This question tests the ability to implement a Least Recently Used (LRU) cache using a combination of a hash map and a doubly linked list to achieve constant time complexity for core operations.
Coding & AlgorithmsTechnical ScreenHash MapLinked ListDesign - TikTokMediumSoftware EngineerImplement binary tree in-order traversal
This question evaluates understanding of binary tree traversal, comparing recursive and iterative (explicit stack) implementations and their time and space complexity. Commonly asked in Coding & Algorithms interviews to assess both practical implementation and conceptual understanding of tree data structures, algorithmic trade-offs, and complexity analysis.
Coding & AlgorithmsTechnical Screen - TikTokMediumSoftware EngineerMaximize min+max of contiguous subarray
This question evaluates understanding of array algorithms and competency in identifying and reasoning about minimum and maximum values within contiguous subarrays, emphasizing extremal value handling.
Coding & AlgorithmsTechnical Screen - TikTokMediumSoftware EngineerParse a nested list from a string
This problem tests your ability to parse recursive nested structures using stack-based iteration or recursion and string manipulation.
Coding & AlgorithmsTechnical ScreenRecursionStackParsing - TikTokMediumSoftware EngineerParse chemical formula with multipliers
Parse chemical formula with multipliers evaluates algorithm design, data structures, correctness, complexity, edge cases, and implementation details in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Coding & AlgorithmsTechnical Screen - TikTokMediumSoftware EngineerReconstruct a tree from two traversals
Reconstruct a tree from two traversals evaluates algorithm design, data structures, correctness, complexity, edge cases, and implementation details in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Coding & AlgorithmsTechnical Screen - TikTokMediumSoftware EngineerRestore Every Valid IP Address
Implement a backtracking algorithm to partition a digit string into four valid IPv4 octets, adhering to numerical range and leading-zero constraints.
Coding & AlgorithmsTechnical ScreenBacktrackingStringRecursion - TikTokMediumSoftware EngineerSolve array and tree algorithm challenges
This question evaluates algorithmic problem-solving skills across array, heap, and tree data structures, testing competencies in duplicate handling, frequency aggregation, and balancing root-to-leaf path sums within the Coding & Algorithms domain.
Coding & AlgorithmsTechnical Screen - TikTokMediumSoftware EngineerSolve common string/DP/stack problems
This problem tests your ability to identify and implement an efficient solution for finding the longest substring that satisfies specific constraints, requiring a sliding window approach.
Coding & AlgorithmsTechnical ScreenSliding WindowHash MapStrings - TikTokHardSoftware EngineerSolve four OA algorithm problems
This problem tests your ability to optimize string manipulation using greedy approaches and Fenwick trees to count minimum adjacent swaps required to transform a string into a palindrome.
Coding & AlgorithmsTechnical ScreenGreedyStringsTwo Pointers - TikTokMediumSoftware EngineerSolve linked list, string filtering, and puzzle
This problem tests your ability to manipulate linked list pointers in-place, apply conditional string filtering with index tracking, and solve a greedy resource partitioning puzzle.
Coding & AlgorithmsTechnical ScreenLinked ListStringsGreedy
TikTok