Goldman Sachs HackerRank Test Questions and Preparation Guide

Goldman Sachs HackerRank Test Questions

The Goldman Sachs HackerRank online assessment is usually built around timed algorithmic problem solving. For engineering roles, candidates often report a programming challenge with two data-structures-and-algorithms questions, while some programs add a math section or multiple-choice reasoning questions. Exact timing, question mix, and program rules can vary by region, role, and recruiting cycle, so always follow the instructions in your own assessment invitation.

This guide rewrites the original candidate-style experience into a practical ExtraBrain preparation article. It focuses on the kinds of patterns you may see, how to reason through them, and how to prepare responsibly before the test.

ExtraBrain can help during preparation by turning practice sessions into searchable transcripts, coaching you through explanations, and helping you review your own mistakes. Use any AI interview assistant only where Goldman Sachs, HackerRank, your school, your employer, and the assessment rules allow it. Do not use AI to bypass proctoring, hide prohibited help, or misrepresent your own work.

Question Pattern 1: Transaction Segments

A common finance-themed coding prompt asks you to analyze consecutive transaction values. One version can be stated like this:

Given an array of transaction values and an integer k, count how many contiguous segments of exactly k transactions are strictly increasing.

For example, if the transaction values are [1, 3, 4, 2, 5, 7] and k = 3, the segment [1, 3, 4] is strictly increasing, while [3, 4, 2] is not. The task is to count every valid length-k window.

How to Solve Transaction Segments

Start with the simplest edge case. If the array length is smaller than k, the answer is 0 because no complete segment exists.

Then compare each transaction with the previous one. Create a helper idea where each adjacent pair is marked as increasing or not increasing. If transactions[i] > transactions[i - 1], that adjacent step contributes 1; otherwise it contributes 0.

A length-k transaction window is strictly increasing only when all k - 1 adjacent comparisons inside that window are increasing. So you can slide a window of size k - 1 over the comparison array and count windows whose sum equals k - 1.

A more efficient version avoids rebuilding or rechecking each window from scratch. Maintain a running count of consecutive increases. When the current value is greater than the previous value, increment the streak. Otherwise, reset the streak to 1 because the current element starts a new possible segment. Whenever the streak is at least k, one more valid increasing segment ends at the current index.

Pseudocode for Transaction Segments

function countIncreasingSegments(transactions, k):
    if k <= 0:
        return 0
    if length(transactions) < k:
        return 0
    if k == 1:
        return length(transactions)

    answer = 0
    streak = 1

    for i from 1 to length(transactions) - 1:
        if transactions[i] > transactions[i - 1]:
            streak = streak + 1
        else:
            streak = 1

        if streak >= k:
            answer = answer + 1

    return answer

This approach runs in O(n) time and uses O(1) extra space. That is usually the kind of improvement interviewers and online assessments reward.

Question Pattern 2: Organize Encyclopedias

Another reported style of question is more graph-heavy. One version can be stated like this:

You are given an n x m bookshelf grid containing encyclopedias written by k authors. When you select one book, all books by the same author in that selected book’s row and column are removed. Find the minimum number of books you need to select to remove every book.

The important insight is that authors do not interfere with one another. You can solve the subproblem for each author independently, then add the answers.

How to Model Organize Encyclopedias

For one author, list every cell where that author’s books appear. Treat every occupied row as a vertex on the left side of a bipartite graph. Treat every occupied column as a vertex on the right side of the graph. Each book becomes an edge connecting its row to its column.

Selecting a book corresponds to choosing one edge, which covers that row and column for that author. The goal is to cover all edges with the fewest selected row-or-column intersections. By Konig’s theorem, in a bipartite graph, the size of the minimum vertex cover equals the size of the maximum matching. That means the minimum number of selections for one author can be found by computing a maximum bipartite matching.

After computing this value for each author, sum the results to get the final answer.

Pseudocode for Organize Encyclopedias

function minimumSelections(grid):
    positionsByAuthor = group all occupied cells by author
    total = 0

    for each author in positionsByAuthor:
        graph = empty bipartite graph

        for each (row, column) in positionsByAuthor[author]:
            add edge from row to column

        total = total + maximumBipartiteMatching(graph)

    return total

In many languages, this can be implemented with DFS-based Kuhn matching for moderate constraints or Hopcroft-Karp for larger constraints. The key is recognizing the bipartite transformation before jumping into brute force.

Goldman Sachs HackerRank Test Overview

Format

Goldman Sachs online assessments are commonly delivered through HackerRank. Candidates may receive a programming-only challenge or a combined math and programming challenge. The exact format can depend on the role, country, seniority level, internship or full-time track, and current recruiting process.

A programming challenge typically focuses on data structures, algorithms, and efficient implementation in the language you choose. A combined challenge may add math multiple-choice questions, probability, logic, or quantitative reasoning.

Typical Time Limits

Treat these as preparation guidelines rather than a guarantee. Your own invitation email and HackerRank dashboard are the source of truth for timing and rules.

Preparation Strategy for the Goldman Sachs HackerRank Test

Build a Focused Resource Stack

You do not need a dozen prep resources. You need a small set that helps you practice under realistic constraints and review your mistakes.

ExtraBrain is a free, local-first Mac desktop AI interview assistant and meeting copilot with live transcription, screen-aware context, local Gemma 4 where installed and compatible, bring-your-own AI providers, and privacy controls. For assessment prep, it is most useful before the official test, where you can practice explaining your reasoning, compare solution approaches, and review session notes afterward.

Use a Weekly Prep Schedule

A simple weekly plan can prevent last-minute cramming. Here is a practical schedule for one to three weeks of preparation:

1. Monday to Wednesday: Solve coding problems for 60 to 120 minutes per day. Focus on one topic per day, such as arrays, graphs, or dynamic programming.
2. Thursday: Review math, probability, logic puzzles, and any quantitative concepts relevant to your track.
3. Friday: Take one timed mock assessment. Practice reading carefully, budgeting time, and submitting clean code.
4. Weekend: Review failed cases, rewrite one or two solutions from scratch, and rest enough to avoid burnout.

During review, do not only ask whether your answer passed. Ask why the algorithm works, what its complexity is, and what edge cases could break it. That habit is valuable in both online assessments and follow-up technical interviews.

Test-Day Approach

Manage Time Deliberately

Before writing code, scan both coding questions if the platform allows it. Estimate which one is more familiar and start with the problem where you can secure points fastest.

If you are stuck after 10 to 15 minutes, write down the partial insight and move on. A complete solution to one problem plus a partial solution to another is often better than spending the entire test on one difficult idea.

Leave time at the end for cleanup. Check input parsing, empty cases, one-element cases, duplicate values, large values, and off-by-one boundaries.

Handle Difficult Questions Calmly

When a question looks intimidating, slow down and translate it into a known pattern. Many Goldman Sachs-style coding prompts wrap standard algorithmic ideas in financial or operational language.

Use this sequence:

1. Restate the problem in your own words.
2. Identify the input size and required output.
3. Write a brute-force solution idea.
4. Find the bottleneck in the brute-force approach.
5. Replace the bottleneck with a known tool, such as sorting, prefix sums, hashing, sliding windows, binary search, graph traversal, or matching.
6. Code only after the plan is clear.

This structure also helps in later interviews because it shows how you think, not just whether you memorized an answer.

Common Pitfalls

Mistakes Candidates Make

• Spending too much time on the hardest problem and missing easier points.
• Coding before understanding all constraints and edge cases.
• Ignoring math or logic prep when the role may include a quantitative section.
• Practicing only untimed problems and then freezing under assessment pressure.
• Forgetting to explain time and space complexity during follow-up interviews.
• Adding too many resume projects and then struggling to discuss them clearly.
• Treating AI tools as a shortcut instead of using them to improve real understanding.

Better Habits

1. Practice across several patterns, but spend extra time on your weakest two topics.
2. Keep a mistake log and revisit it every few days.
3. Time your practice so the real test feels familiar.
4. Write pseudocode before coding when the problem has tricky logic.
5. Keep resume projects limited to work you can explain deeply.
6. Practice saying your reasoning aloud during mock interviews.
7. Use ExtraBrain for practice debriefs, transcript review, and structured feedback where allowed.
8. Follow all assessment and proctoring rules exactly.

Responsible AI Use for HackerRank and Interviews

AI can be useful for preparation, but official assessments are governed by the rules of the employer and platform. If an assessment forbids outside help, do not use an AI assistant during the live test. If a mock interview, study session, school exercise, or workplace meeting allows AI notes or coaching, configure your tools transparently and responsibly.

ExtraBrain is designed for local-first workflows on Mac, including local Parakeet transcription and local Gemma 4 on-device AI where installed and compatible. A fully local setup can keep transcription and AI prompts on device, while external providers may receive selected prompts, transcript text, screenshots, audio, or context depending on configuration. You remain responsible for choosing settings that match your privacy expectations and the rules of the situation.

FAQ

Will Goldman Sachs share my HackerRank score after completion?

Goldman Sachs typically communicates application status rather than a detailed numerical HackerRank score breakdown. You may receive an update by email or through the recruiting portal after the assessment is reviewed. The timing can vary by program and recruiting season.

Can I retake the Goldman Sachs HackerRank test if I do poorly?

Retake policies vary by role, region, and recruiting cycle. Many employers restrict immediate retakes for the same role or application period. If you are not selected, you may need to wait before applying again, and there is no guaranteed retake unless the recruiting team offers one.

Are the questions purely theoretical or tied to business scenarios?

The coding ideas are usually standard computer science patterns, but the story can be framed around business, finance, transactions, risk, or operations. For example, a problem may ask about transaction sequences while really testing sliding windows or arrays. Another may describe organizing records while really testing graph modeling or matching.

What topics should I prioritize?

Prioritize arrays, strings, hashing, sorting, two pointers, sliding windows, heaps, binary search, graph traversal, dynamic programming basics, and greedy reasoning. If your assessment includes math, also review probability, combinatorics, algebra, and logic puzzles.

How can ExtraBrain help me prepare?

ExtraBrain can help you run realistic practice sessions on Mac with live transcription, screen-aware context, answer structuring, and post-session review. You can use it to practice explaining a solution, identify unclear reasoning, generate follow-up questions, and build a stronger study loop. Use it only in contexts where AI assistance, transcription, screenshots, and notes are allowed.

See Also

ExtraBrain AI interview assistant

Responsible use guidelines

ExtraBrain privacy controls

ExtraBrain help center