Coding & Algorithms interview questions

Showing 2281–2310 of 3276 results

• Clockwise Spiral Matrix Traversal That Turns at Blocked CellsMedium

  Return the values of a matrix in clockwise spiral order starting from the top-left cell, then extend the walk so that blocked cells force clockwise turns and can end it early. Tests precise grid simulation, direction rotation, visited and boundary checks, and an unambiguous stopping rule.

  PinduoduoSoftware EngineerCoding & AlgorithmsTechnical Screen
• Compute longest increasing subsequence lengthMedium

  This question tests the ability to solve the Longest Increasing Subsequence (LIS) problem, specifically targeting the transition from a standard dynamic programming approach to an optimized binary search solution.

  PinduoduoSoftware EngineerCoding & AlgorithmsTechnical Screen
• Count Longest Substrings After Character ReplacementsHard

  This problem tests the sliding window technique with dynamic constraints, requiring an efficient way to track window state and calculate valid substring counts.

  PinduoduoSoftware EngineerCoding & AlgorithmsTechnical Screen
• Design a Recency-Eviction CacheMedium

  This problem tests your 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 operations.

  PinduoduoSoftware EngineerCoding & AlgorithmsTechnical Screen
• Find Shortest Square-Sum PathHard

  This problem tests your ability to model a shortest-path graph search problem where states are integers and transitions involve adding perfect squares.

  PinduoduoSoftware EngineerCoding & AlgorithmsTechnical Screen
• Generate a Matrix in Spiral OrderMedium

  This problem tests your ability to simulate a specific traversal pattern in a 2D grid and maintain precise boundary pointers to fill the matrix correctly.

  PinduoduoSoftware EngineerCoding & AlgorithmsTechnical Screen
• Generate a Spiral MatrixEasy

  This problem tests your ability to manage matrix traversal coordinates and maintain state (direction and boundaries) while iteratively filling a grid.

  PinduoduoSoftware EngineerCoding & AlgorithmsTechnical Screen
• Longest Single-Letter Substring After at Most k Character ChangesMedium

  Given a string of uppercase letters and a budget of at most k single-character changes, find the longest run of one repeated letter that can be produced. Tests reasoning about which substrings can be made uniform, efficient counting, and a near-linear solution for strings of up to 100,000 characters.

  PinduoduoSoftware EngineerCoding & AlgorithmsTechnical Screen
• Traverse a Matrix in Spiral OrderMedium

  Traverse a rectangular matrix in clockwise spiral order using shrinking boundaries. Handle empty, single-row, and single-column inputs without duplicates while achieving linear time and constant auxiliary space beyond the result.

  PinduoduoSoftware EngineerCoding & AlgorithmsTechnical Screen
• Answer Policy Violation Log QueriesMedium

  Design an in-memory query engine over a timestamp-sorted policy violation log to support aggregate, point, and range queries efficiently using hash maps and binary search.

  PinterestSoftware EngineerCoding & AlgorithmsTechnical Screen
• Assign Pins to Shortest ColumnsMedium

  This question evaluates understanding of greedy assignment strategies and data structures for maintaining and updating minimums in an online allocation problem, while also testing load-balancing reasoning and analysis of time and space complexity.

  PinterestSoftware EngineerCoding & AlgorithmsTechnical Screen
• Calculate 95% Bootstrap Confidence Interval for Order ValuesMedium

  This question evaluates a data scientist's competence in statistical inference using bootstrap resampling, proficiency with numerical computing for large sample operations, and attention to performance optimization.

  PinterestData ScientistCoding & AlgorithmsOnsite
• Collect Pins from Reachable BoardsMedium

  Implement a breadth-first graph traversal over a collection of boards to collect unique pins in discovery order, handling cycles, shared children, and invalid references.

  PinterestSoftware EngineerCoding & AlgorithmsOnline Assessment
• Compute average unique pins per userEasy

  This question evaluates a candidate's ability to process collections and compute aggregated metrics, including per-user deduplication of items, handling of missing/null entries, numeric averaging and rounding.

  PinterestData ScientistCoding & AlgorithmsTechnical Screen
• Compute reachable cells for a cleaning robotMedium

  This problem tests graph traversal techniques (BFS/DFS) on a 2D grid, focusing on efficient coordinate management and state representation when navigating obstacles.

  PinterestSoftware EngineerCoding & AlgorithmsOnsite
• Count Distinct Active Pins per Time Segment from Overlapping Interaction LogsHard

  Process overlapping pin interaction logs to calculate the number of distinct active pins over continuous time segments. Tests interval merging, line sweep techniques, and boundary handling.

  PinterestSoftware EngineerCoding & AlgorithmsOnsite
• Cross-reference logs to flag spam numbersMedium

  This question evaluates proficiency with data structures (such as hash maps), parsing and deduplication, frequency counting, input validation, and analysis of time and space complexity.

  PinterestSoftware EngineerCoding & AlgorithmsOnsite
• Decide target via subsequence plus/multiply expressionMedium

  A Pinterest software-engineer coding screen: given positive 32-bit integers and a target, decide whether some subsequence with '+'/'*' operators evaluated strictly left to right (equal precedence) hits the target, and return a valid expression. The answer spans forward backtracking, monotonicity-based pruning, a divisibility-guided reverse search from the target, complexity analysis, and 32-bit overflow handling.

  PinterestSoftware EngineerCoding & AlgorithmsTechnical Screen
• Decode and Explain Ambiguity in Compression StringsMedium

  This question evaluates parsing of compact count-value encodings, reasoning about ambiguous encodings, and combinatorial enumeration of all valid decodings.

  PinterestData ScientistCoding & AlgorithmsOnsite
• Delete and Compact a Forest Stored by Parent IndicesMedium

  Implement subtree deletion on a parent-pointer forest array, supporting tombstoning and index compaction with pointer remapping.

  PinterestSoftware EngineerCoding & AlgorithmsTechnical Screen
• Design Algorithm to Minimize Payments in Expense-Sharing AppMedium

  This question evaluates algorithm design and optimization skills, focusing on modeling multi-party transactions and minimizing the number of settlement operations.

  PinterestData ScientistCoding & AlgorithmsOnsite
• Design Data Structure for Sparse Matrices OperationsMedium

  This question evaluates a candidate's ability to design efficient data structures and implement algorithms for sparse matrix storage and operations, emphasizing space-efficient representations, matrix arithmetic, and computational complexity reasoning.

  PinterestData ScientistCoding & AlgorithmsOnsite
• Design Hierarchical Permission ChecksMedium

  This question evaluates understanding of hierarchical access control, tree data structures, and permission inheritance, testing competencies in data modeling and algorithmic reasoning.

  PinterestMachine Learning EngineerCoding & AlgorithmsTechnical Screen
• Design a violation log analyzerMedium

  This question evaluates proficiency in data structures, in-memory indexing and query design, algorithmic time/space complexity analysis, and reasoning about state management for dynamic event streams.

  PinterestSoftware EngineerCoding & AlgorithmsTechnical Screen
• Design adjustable ID allocatorMedium

  A Pinterest software-engineer onsite coding problem: design an adjustable ID allocator over a fixed [0, 999] ID space with named, contiguous, non-overlapping bucket ranges. It covers initial allocation (packing from desired sizes and validating/normalizing proposed ranges), a resize operation that grows or shrinks a bucket by consuming adjacent free space and then minimally shifting or borrowing from neighbors under a deterministic policy, plus complexity analysis, boundary-case testing, and concurrency handling.

  PinterestSoftware EngineerCoding & AlgorithmsOnsite
• Determine Pin Connections Through Common BoardsMedium

  This question evaluates graph modeling and connectivity concepts, including representing boards and pins as relationships and reasoning about reachability and minimal connection paths.

  PinterestData ScientistCoding & AlgorithmsOnsite
• Determine equality of arbitrarily nested setsMedium

  This question evaluates understanding of nested data structures and set semantics, including canonicalization, hashing, recursion, handling of edge cases, unit-test design, and time/space complexity analysis.

  PinterestSoftware EngineerCoding & AlgorithmsTechnical Screen
• Fewest Buses to Ride Between Two Stops on Looping Bus LinesMedium

  A coding problem about bus lines that loop through fixed lists of stops: find the fewest buses a rider must board to travel from a source stop to a target stop, or report that the target cannot be reached. It tests modeling transfers between lines as a graph and keeping the search efficient when many lines share stops.

  PinterestSoftware EngineerCoding & AlgorithmsOnsite
• Find First Prefix-Matching WordMedium

  This problem tests your ability to efficiently search through a collection of strings to find the first element that satisfies a specific prefix condition, emphasizing clean iteration and edge case management.

  PinterestSoftware EngineerCoding & AlgorithmsTechnical Screen
• Find available reservation time slotsMedium

  This question evaluates a candidate's ability to reason about time-interval data and temporal normalization, testing competencies in interval manipulation, conflict detection, and algorithmic problem-solving for scheduling contexts.

  PinterestData ScientistCoding & AlgorithmsOnsite