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 EngineerIntern Locked

Maximize sum without choosing adjacent elements

This question evaluates a candidate's understanding of array-based optimization and dynamic programming concepts for computing a maximum sum under non...

Coding & Algorithms
8
0
70 people solved
Jan 6, 2026
Google logo
Google
Hard
Software Engineer Locked

Determine winner in stack-merging game

This question evaluates understanding of combinatorial game theory, impartial game analysis, state-space encoding, and efficient state-space search te...

Coding & Algorithms
10
1
71 people solved
Jan 6, 2026
Google logo
Google
Hard
Software Engineer Locked

Minimize travel time with optional meeting point

This question evaluates a candidate's understanding of graph shortest-path computation and meeting-point optimization, testing skills in handling weig...

Coding & Algorithms
9
0
75 people solved
Jan 6, 2026
Google logo
Google
Medium
Software Engineer Locked

Find where to cut cake into equal areas

This question evaluates geometric area computation, handling of piecewise-constant profiles formed by adjacent rectangles, and attention to numerical ...

Coding & Algorithms
9
0
81 people solved
Jan 6, 2026
Google logo
Google
Medium
Software Engineer Locked

Answer range queries for alternating parity subarrays

This question evaluates understanding of array manipulation, parity properties, efficient range-query processing, and preprocessing techniques for han...

Coding & Algorithms
4
0
73 people solved
Jan 6, 2026
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Google
Medium
Software Engineer Locked

Find longest increasing contiguous subarray

This question evaluates proficiency in array processing and algorithmic optimization, focusing on recognition of contiguous subarray properties and ha...

Coding & Algorithms
14
0
110 people solved
Jan 6, 2026
Google logo
Google
Medium
Software Engineer Locked

Find median of merged RLE arrays

The question evaluates understanding of run-length encoding, order-statistics (median) computation, and efficient merging of frequency-annotated seque...

Coding & Algorithms
12
0
168 people solved
Jan 6, 2026
Google logo
Google
Medium
Software Engineer Locked

Implement iterator merging lists with filtering

This question evaluates iterator/generator design, sequence merging, stateful filtering and deduplication, checking a candidate's ability to maintain ...

Coding & Algorithms
4
0
69 people solved
Jan 6, 2026
Google logo
Google
Easy
Software Engineer Locked

Compute minimum meeting rooms on circular day

This question evaluates a candidate's ability to reason about interval scheduling, circular time wrap-around, and resource allocation for overlapping ...

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

Reconstruct original array from doubled shuffle

This question evaluates array manipulation, multiset/frequency reasoning, pairing logic, and careful handling of edge cases such as zeros and negative...

Coding & Algorithms
6
0
50 people solved
Jan 4, 2026
Google logo
Google
Medium
Software EngineerSenior+

Design set with O(1) random access

Design a data structure ("FancySet") that stores unique integers and supports the following operations, each in average O(1) time: - add(x): Insert va...

Coding & Algorithms
12
0
144 people solved
Jan 1, 2026
Google logo
Google
Medium
Software Engineer

Maintain streaming median and loosemedian

Maintain streaming median and loosemedian Design a data structure for an online stream of positive integers supporting insert (x). After each insertio...

Coding & Algorithms
9
0
64 people solved
Aug 8, 2025
Google logo
Google
Medium
Software Engineer

Solve tree, graph, sliding-window problems

Question LeetCode 103. Binary Tree Zigzag Level Order Traversal – given a binary tree root, return its zigzag level-order traversal. LeetCode 207. Cou...

Coding & Algorithms
12
0
89 people solved
Aug 4, 2025
Google logo
Google
Medium
Software Engineer

Validate course catalog dependencies

Design a function to validate an e-learning course catalog. You are given: ( 1) a set of course IDs, and ( 2) a list of prerequisite pairs (u, v) mean...

Coding & Algorithms
4
0
62 people solved
Aug 1, 2025
Google logo
Google
Medium
Software Engineer

Compute shortest delivery route with dangerous stops

Delivery Route Planning With Dangerous Stops You are given delivery stops (nodes) and a set of routes. Each route is a list of stops, and you can trav...

Coding & Algorithms
15
0
153 people solved
Dec 15, 2025
Google logo
Google
Hard
Software Engineer

Compute city skyline outline

You are given a list of rectangular buildings in a 2D city skyline. Each building is represented by three integers [L, R, H]: - L: the x-coordinate of...

Coding & Algorithms
14
0
132 people solved
Dec 8, 2025
Google logo
Google
Hard
Software Engineer

Shuffle array using random integer API

You are given an array nums of length n representing a deck of distinct cards. You do not have access to a built-in shuffle function, but you are give...

Coding & Algorithms
6
0
80 people solved
Dec 8, 2025
Google logo
Google
Easy
Software Engineer

Solve three coding problems

The interview note described the following coding questions: 1. Find the N-th license plate in lexicographic order - A license plate has exactly 6 ...

Coding & Algorithms
8
0
72 people solved
Jun 15, 2025
Google logo
Google
Medium
Data ScientistSenior+

Simulate Uniform(0,1) from random bits

Assume you have access to a function rand_bit() that returns 0 or 1 with equal probability and independent across calls. How would you generate a rand...

Coding & Algorithms
2
0
37 people solved
Nov 24, 2025
Google logo
Google
Medium
Software Engineer

Add two big integers from digit lists

You are given two non-empty singly linked lists (or arrays) representing two non-negative integers. The digits are stored in reverse order, and each n...

Coding & Algorithms
11
0
102 people solved
Nov 24, 2025

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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