Google Coding & Algorithms Interview Questions

Preparing for Google Coding & Algorithms interview questions means getting ready for a rigorous, process-driven evaluation that emphasizes clean problem solving, clear communication, and algorithmic depth. Google tends to focus on core data structures and algorithmic patterns—arrays and strings, trees and graphs, dynamic programming, hashing, and complexity trade-offs—while also assessing how you reason through edge cases, test your ideas, and write production-minded code in a collaborative environment. Expect live coding on a shared document during screens and multiple 45‑minute coding rounds in onsite or virtual loops, with system design and behavioral evaluations added for more senior roles. Effective interview preparation balances breadth and depth: practice medium-to-hard algorithmic problems under timed conditions, review core computer science fundamentals, and rehearse explaining tradeoffs and correctness aloud. Work on structured problem walkthroughs, mock interviews that simulate Google’s collaborative doc format, and concise post-solution optimizations. Also prepare concise, impact‑focused stories for the behavioral round and plan a realistic multi-week schedule that includes focused drills, full mock loops, and targeted review of persistent weak spots.

224 Questions 1 Company08.01.2026
Showing 20 results
Role
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Google
Medium
Software Engineer Locked

Most Active Users in a Live Communication Stream

This question tests practical application of hash-based data structures and stream processing to track and rank user activity with deduplication logic...

Coding & Algorithms
4
0
9 people solved
Jun 9, 2026
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Google
Medium
Software Engineer Locked

Rearrange Tasks With Cooldown

This question evaluates task-scheduling and constraint-handling skills, testing algorithmic reasoning about arranging repeated jobs with cooldown cons...

Coding & Algorithms
3
0
24 people solved
Jun 3, 2026
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Google
Medium
Software Engineer Locked

Implement Employee Management and Expression Evaluation

This question evaluates competency in designing and maintaining hierarchical data structures and in parsing and evaluating nested function-style arith...

Coding & Algorithms
2
0
29 people solved
May 30, 2026
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Google
Medium
Software Engineer Locked

Solve Flower Placement and Directory Deletion

This question evaluates combinatorial constraint-satisfaction and permutation/matching skills for the flower-placement grid alongside filesystem trave...

Coding & Algorithms
5
0
56 people solved
May 8, 2026
Google logo
Google
Medium
Software Engineer

Solve Quickselect, Tree Distance, and Prefix Substrings

You are given three independent coding tasks. 1. Implement Quickselect - Given an unsorted integer array nums and an integer k, return the k-th sma...

Coding & Algorithms
3
0
17 people solved
Apr 25, 2026
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Google
Medium
Software Engineer

Count Spellings Using Chemical Element Symbols

Count Spellings Using Chemical Element Symbols Problem Given a list of valid chemical element symbols and a target word, count how many distinct ways ...

Coding & Algorithms
0
1
7 people solved
Apr 19, 2026
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Google
Medium
Software Engineer

Maximize Boundary-Difference Subarray Sum

Given an integer array nums and an integer k, find the maximum possible sum of a non-empty contiguous subarray whose first and last elements differ by...

Coding & Algorithms
3
0
20 people solved
Apr 11, 2026
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Google
Hard
Software Engineer Locked

Find Maximum Envelope Nesting

This question evaluates algorithmic problem-solving skills, particularly reasoning about multi-dimensional ordering, sequence optimization, and time-c...

Coding & Algorithms
4
0
72 people solved
Mar 18, 2026
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Google
Easy
Software Engineer

Compute minimum rooms for time intervals

You are given a list of meeting time intervals, where each interval is represented as [start, end) (start time inclusive, end time exclusive) and star...

Coding & Algorithms
22
0
161 people solved
Mar 1, 2026
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Google
Medium
Software EngineerNew Grad

Implement an LRU cache

Design a key-value cache with a fixed capacity. It must support: - get(key): return the value for the key if it exists, otherwise return -1. - put(key...

Coding & Algorithms
3
0
40 people solved
Feb 24, 2026
Google logo
Google
Medium
Software Engineer

Determine Reporting Relationships

Build an in-memory organization model that supports three operations on employee IDs: 1. add_manager(a, b): employee a is the direct manager of employ...

Coding & Algorithms
3
0
39 people solved
Feb 22, 2026
Google logo
Google
Medium
Software EngineerNew Grad

Design Tic-Tac-Toe With K Players

Design and implement a Tic-Tac-Toe game engine. You are given: - k players, each with a unique player ID or mark. - An n x n board, initially empty. -...

Coding & Algorithms
3
0
20 people solved
Feb 12, 2026
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Google
Medium
Software Engineer Locked

Find cheapest common ancestor in a tree

This question evaluates understanding of tree data structures and ancestor concepts (such as lowest common ancestor) along with algorithmic skills for...

Coding & Algorithms
18
1
132 people solved
Feb 12, 2026
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Google
Medium
Software Engineer Locked

Check pivot after removing one element

This question evaluates array-manipulation skills, cumulative-sum/prefix-sum reasoning, and robustness in handling negative values and duplicates, tes...

Coding & Algorithms
8
0
141 people solved
Feb 12, 2026
Google logo
Google
Easy
Software Engineer Locked

Build a next-word frequency predictor

This question evaluates understanding of data structures and algorithms for frequency counting and associative lookups, including preprocessing-versus...

Coding & Algorithms
38
1
272 people solved
Feb 12, 2026
Google logo
Google
Medium
Software Engineer

Compute minimum number of rooms needed

Problem You are given a list of meetings, each with a start time and end time. A single room can host only one meeting at a time. Two meetings overlap...

Coding & Algorithms
25
1
398 people solved
Feb 12, 2026
Google logo
Google
Medium
Software Engineer Locked

Min deletions to avoid overlap in first k

This question evaluates array and sequence manipulation skills, set-based reasoning about value overlap, and the ability to compute minimal edits whil...

Coding & Algorithms
20
0
342 people solved
Feb 12, 2026
Google logo
Google
Medium
Software Engineer

Validate parent array forms a tree

Problem You are given an integer array parent of length n describing a directed parent pointer for each node i (nodes are labeled 0..n-1). - parent[i]...

Coding & Algorithms
13
1
160 people solved
Feb 11, 2026
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Google
Medium
Machine Learning Engineer Locked

Minimize Fence Painting Operations

This question evaluates algorithmic problem-solving and optimization skills, focusing on minimizing painting operations on an array-modeled fence and ...

Coding & Algorithms
3
1
54 people solved
Feb 10, 2026
Google logo
Google
Medium
Machine Learning Engineer Locked

Compute sum over consecutive-step subarrays

This question evaluates proficiency in array processing, detection of consecutive-step arithmetic sequences, and accumulation of subarray sums with at...

Coding & Algorithms
10
1
84 people solved
Feb 8, 2026

Frequently Asked Questions

How difficult are Google Coding & Algorithms interviews?
Google coding and algorithms rounds are typically medium-to-hard on a LeetCode-style scale, with difficulty increasing by level and role. Phone screens usually target solid problem-solving and clean coding at a medium-to-hard level, while onsite/loop rounds expect more polished, optimized solutions and harder algorithmic thinking for senior roles. Interviewers evaluate algorithm design, correct and maintainable code, complexity trade-offs, and communication. Expect follow-ups that push for edge-case handling and performance improvements. Preparing with progressively harder problems and mock interviews helps bridge the gap to the typical onsite bar.
What is the typical Google interview process and where do Coding & Algorithms questions appear?
The process commonly starts with a recruiter screen, followed by one or two technical phone/video screens that include live coding on a shared environment, and then a virtual or onsite loop of four to six interviews that mix coding, system design (for senior candidates), and behavioral assessments. Coding and algorithms questions appear in the phone screens and in multiple onsite rounds, often as one to two algorithmic problems per technical interview. New graduate roles may include an online assessment stage. The shared-coding document or collaborative pad is a common environment for real-time problem solving.
How long should I prepare for Google Coding & Algorithms interviews?
A focused preparation timeline often ranges from six to eight weeks for candidates with solid fundamentals, and from two to four months for those rebuilding skills or targeting senior levels. Early weeks should refresh data structures, complexity analysis, and basic algorithms; middle weeks should emphasize consistent timed practice of medium to hard problems and pattern recognition; final weeks should include mock interviews, whiteboard or shared-doc practice, and review of common failure cases. Allocate regular, spaced practice and iterative feedback to close gaps, and simulate the exact environment (no IDE, shared doc) before real interviews.
What key subtopics within Coding & Algorithms should I focus on for Google interviews?
Focus on core data structures (arrays, strings, linked lists, stacks, queues, trees, graphs, heaps, and hash tables) and algorithms (sorting, searching, DFS/BFS, shortest paths, topological sorts, greedy strategies, and dynamic programming). Master complexity analysis, common patterns like two-pointers, sliding window, recursion/backtracking, and graph traversal. Also practice windowed aggregates, prefix sums, CTE-like problem decomposition in coding interviews, handling NULLs/edge cases, and thinking about performance trade-offs. Clean, testable code and the ability to explain correctness and runtime are as important as finding a working solution.
What standout tips and common pitfalls should I know when preparing for Google Coding & Algorithms interviews?
Standout tips include asking clarifying questions before coding, outlining the approach and complexity up front, writing a correct simple solution before optimizing, and walking through test cases aloud. Practice in a shared-doc or whiteboard style to mirror the interview environment and time-box your practice. Common pitfalls are not communicating thought process, ignoring constraints and edge cases, prematurely optimizing without a correct baseline, and submitting untested code. Also avoid verbose or unreadable code; prioritize clarity. Mock interviews with feedback are one of the fastest ways to fix these recurring mistakes.

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