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
Google logo
Google
Hard
Software Engineer

Find safe travel intervals between planet influences

You are planning a space route along a one-dimensional line (the x-axis). You are given a list of planets. Each planet is represented by an integer pa...

Coding & Algorithms
12
2
88 people solved
Nov 22, 2025
Google logo
Google
Medium
Software Engineer Locked

Solve several coding interview problems

This set of problems evaluates proficiency in string processing and combinatorial parsing, arbitrary-precision arithmetic using string representations...

Coding & Algorithms
10
0
99 people solved
Mar 4, 2026
Google logo
Google
Hard
Machine Learning Engineer

Compute winning probability on 1D dice walk

You are on an infinite 1D number line starting at position 0. Repeatedly roll a fair die that returns an integer uniformly at random from 1 to K (incl...

Coding & Algorithms
17
1
166 people solved
Mar 2, 2026
Google logo
Google
Medium
Software Engineer

Find mode in a trinary search tree

You are given the root of a trinary search tree where each node has up to three children: `text class Node { int val; Node left; // all values ...

Coding & Algorithms
13
0
137 people solved
Nov 16, 2025
Google logo
Google
Medium
Software Engineer

Find largest subset sharing a common digit

You are given an array nums of length N (1 ≤ N ≤ 100). Every element is a two-digit integer between 10 and 99 (inclusive). Select as many elements as ...

Coding & Algorithms
9
0
103 people solved
Feb 25, 2026
Google logo
Google
Hard
Machine Learning Engineer

Can you reach target with distance-threshold edges?

You are given a set of unordered 2D points points[], a start point and an end point (both are included in points), and a function: `text getDistance(p...

Coding & Algorithms
11
1
181 people solved
Feb 22, 2026
Google logo
Google
Medium
Software Engineer Locked

Solve array-sum and city-community problems

This question evaluates array-processing and grid/graph connectivity skills, covering counting subarrays with a target sum and identifying connected b...

Coding & Algorithms
6
0
62 people solved
Feb 20, 2026
Google logo
Google
Medium
Software Engineer

Maximize coins collected by tokens jumping +3

You are given a single-player board game represented by a string board of length N (1 ≤ N ≤ 100). Each character is one of: - '.': empty cell - 'T': a...

Coding & Algorithms
5
0
53 people solved
Feb 13, 2026
Google logo
Google
Medium
Software Engineer Locked

Compute minimum servers for cyclic tasks

This question evaluates understanding of interval scheduling, overlap detection, and handling cyclic time via modular arithmetic for tasks that wrap p...

Coding & Algorithms
20
1
192 people solved
Feb 12, 2026
Google logo
Google
Medium
Software Engineer Locked

Min boards to cover roof holes

This question evaluates competency in combinatorial optimization and problem modeling for coverage constraints, testing algorithmic reasoning, complex...

Coding & Algorithms
16
1
161 people solved
Feb 12, 2026
Google logo
Google
Medium
Software Engineer Locked

Decompress encoded string with nested repeats

This question evaluates string parsing and manipulation skills, particularly handling nested repetition encodings and reasoning about output growth, a...

Coding & Algorithms
27
0
196 people solved
Feb 11, 2026
Google logo
Google
Hard
Software Engineer Locked

Find minimum threshold enabling grid path

This question evaluates a candidate's understanding of grid pathfinding, reachability under constraints, and algorithmic optimization, focusing on ski...

Coding & Algorithms
10
0
153 people solved
Feb 11, 2026
Google logo
Google
Medium
Data Scientist

Implement piecewise linear interpolation for time-to-empty

Time-to-Empty from a Discharge Curve (Piecewise Linear Interpolation) Implement a function time_to_empty(checkpoints, current_soc) that returns the nu...

Coding & Algorithms
4
0
41 people solved
Oct 13, 2025
Google logo
Google
Easy
Data Scientist Locked

Implement sampling, subarray scan, and percentile estimate

This multi-part problem evaluates skills in random sampling and geometric probability for uniform 2D sampling, algorithmic array processing for findin...

Coding & Algorithms
8
1
84 people solved
Feb 1, 2026
Google logo
Google
Easy
Software Engineer AI Locked

Find Feature Activation Order

This question evaluates graph-algorithms and dependency-resolution skills, including reasoning about prerequisite relationships, ordering constraints,...

Coding & Algorithms
9
0
62 people solved
Jan 26, 2026
Google logo
Google
Medium
Software Engineer Locked

Solve matrix groups and recipe inventory

This pair of problems evaluates block-wise grid processing and aggregation for minimum-value selection alongside dependency-resolution and resource-al...

Coding & Algorithms
25
0
216 people solved
Jan 22, 2026
Google logo
Google
Hard
Software Engineer Locked

Compute distance-sum from every tree node

This question evaluates understanding of tree and graph algorithms, including computation of pairwise distances and techniques for aggregating path le...

Coding & Algorithms
20
0
145 people solved
Jan 22, 2026
Google logo
Google
Medium
Software Engineer

Maintain k-th largest in a stream

Design and implement a class KthLargest that, given an integer k and an initial list of integers, supports: ( 1) KthLargest(k, nums): constructor; ( 2...

Coding & Algorithms
7
0
75 people solved
Sep 6, 2025
Google logo
Google
Medium
Software Engineer

Find largest subset sharing a common digit

You are given a list of two-digit integers (each from 10 to 99, inclusive). You want to select as many numbers as possible in one selection such that:...

Coding & Algorithms
6
0
71 people solved
Sep 5, 2025
Google logo
Google
Medium
Software Engineer Locked

Compute distance to nearest taxi in grid

This question evaluates understanding of graph traversal and shortest-path reasoning on grids, algorithmic problem-solving for computing distances fro...

Coding & Algorithms
27
0
213 people solved
Jan 10, 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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