Coding interview questions for college recruitment

If you’re a college student gearing up for recruitment, you probably know that one of the biggest hurdles you’ll face is the coding interview. These interviews can be intimidating, especially if you’re unfamiliar with the common types of questions asked.

As a college student, you might be wondering: What kind of coding questions should I expect? How do I approach these challenges effectively? What are the best ways to practice and improve? But fear not! In this blog, we’ll provide you with a detailed guide on the coding interview questions for college recruitment.

We’ll cover the most commonly asked questions during college recruitment, along with tips, sample problems, and helpful resources to maximize your preparation. By the end of this guide, you’ll feel more confident and ready to tackle your coding interviews head-on!

Let’s dive in!

Why coding interviews matter#

Before we jump into the questions, let’s first understand why coding interviews are so important in college recruitment. Companies, especially tech giants, use coding interviews to gauge how well you can solve problems under pressure. These interviews aren’t just about how much code you can write, they’re more about your problem-solving skills, logical thinking, and creativity.

Common coding interview questions for college recruitment#

In this section, we’ll break down the key topics you’ll encounter during coding interviews. Each section is designed to help college students understand how to approach these problems in a structured way.

Below are the key coding topics you should focus on, along with sample questions and explanations to help you practice.

Data structures#

Data structures are the bread and butter of coding interviews. They help you organize and store data efficiently so that your algorithms run faster and use less memory. As a college student, you might have learned about data structures in your coursework, but interviews demand more than basic knowledge—you need to know when and how to use them effectively.

Here’s the good news: We have a data structures course that covers everything you need to know. Educative offers challenge lessons in the course where you can apply your knowledge of data structures in real-world scenarios. Plus, our interactive lessons give hands-on experience with coding problems, practical applications of key data structures and opportunities to test and refine your solutions.

We encourage you to visit these lessons and experiment with problems. Here are a few examples to get you started:

• Reversing a Linked List: Learn to reverse a singly linked list in place.

• Finding Duplicates in an Array: Practice finding duplicate elements without using extra space.

Don’t forget to refer to our data structures cheatsheets which provide you concise summaries of the important fundamentals of data structures. They are handy before an interview when you need a quick refresher on key concepts:

• CS101 - Data Structures

• CS201 - Data Structures

Below is a screenshot from our CS201 - Data Structures cheatsheet, which gives you a quick overview of the fundamental operations in array.

Algorithms#

Algorithms are at the heart of solving coding problems. They provide step-by-step instructions to achieve a task or solve a problem efficiently. As a college student preparing for coding interviews, you’ll need to understand how to implement algorithms and optimize them for performance.

If you’re just starting out or looking to improve your algorithm skills, our algorithms course will walk you through key concepts like sorting, searching, dynamic programming, and greedy algorithms.

Here are some sample questions:

• Merge two sorted arrays

• Longest increasing subsequence

You can review common algorithms in our algorithms cheatsheet.

Recursion#

Recursion is a method where a function calls itself to solve smaller subproblems. While it’s a powerful tool, it can be tricky to implement correctly, especially when it comes to avoiding infinite loops or stack overflow errors. Here are some sample questions:

• Generate all subsets of a set

• Fibonacci sequence

You can refer to our blog on recursion as a pithy refresher.

Graph theory#

Graph questions test your ability to traverse and manage complex structures where elements are interconnected in non-linear ways. These questions are popular for companies hiring students for advanced roles. Here are some sample questions:

• Clone a directed graph

• Paths in Maze That Lead to Same Room

You can refer to our blog on graph algorithms for a quick refresher.

Bit manipulation#

Bit manipulation problems focus on optimizing how data is stored and processed at the binary level. These questions are less common but can be a huge plus if you can solve them. Here are some sample questions:

• Check if two numbers differ at one bit position only

• Count the number of 1s in a binary representation

Whiteboard challenges and independent coding interview questions#

In many coding interviews, especially during college recruitment, you’ll encounter whiteboard challenges or independent coding tests. These tests are designed to assess how well you can solve problems without relying on an IDE. You need to demonstrate your ability to write code, handle errors, and optimize your solution without real-time debugging.

What are whiteboard challenges?
In a whiteboard challenge, you’re typically given a coding problem and asked to solve it on a whiteboard in front of the interviewer. This can feel intimidating because you’re writing without the help of an IDE, but it’s an excellent opportunity to showcase your problem-solving approach.

In independent coding tests, the focus remains on solving coding problems, but in an online setting, you're expected to write fully functional code.

Here are some example questions that you can get in a whiteboard challenge or independent coding test:

1. How do you reverse a string?

2. How do you determine if a string is a palindrome?

3. How do you count the occurrences of each character in a string?

4. How to check unique characters in a string?

5. How do you find out if the two given strings are anagrams?

6. How do you reverse an array?

7. How do you find the maximum element in an array?

8. How do you sort an array of integers in ascending order?

9. How to get an nth number in a Fibonacci sequence using recursion?

10. How do you calculate the sum of two integers?

11. How do you find the average of numbers in a list?

12. How do you check if an integer is even or odd?

13. How do you find the middle element of a linked list?

14. How do you remove a loop in a linked list?

15. How do you merge two sorted linked lists?

16. What is a binary search?

17. What is the difference between a binary tree and a binary search tree?

18. How do you print a binary tree in vertical order?

Tips to prepare for coding interviews#

Just knowing these coding questions isn’t enough. Let’s see how you should approach preparation.

Consistency is key: Practice coding questions every day. You don’t need to solve a dozen problems at once—just focus on 1–2 high-quality problems each day and make sure you understand them fully. You may explore our must-know coding problems cheatsheet to ensure you cover the most commonly asked questions in coding interviews.

Understand the problem, don’t memorize: Memorizing solutions won’t help in a real interview. Make sure you understand the underlying logic behind each problem. If you can solve a problem in multiple ways, you’re on the right track.

Focus on time and space complexity: After solving a problem, take the time to optimize it. Can you make your solution faster or use less memory? This is important in real-world applications and interviews alike. For a quick review of common time and space complexities, refer to our Big O notation cheatsheet to ensure you're making efficient choices.

Below is a screenshot from our Big O notation cheatsheet, which shows you a visual representation of complexity chart of constant time towards factorial time.

Mock interviews: Simulate real coding interviews using our AI Mock Interviews. Mock interviews help you practice under pressure and improve communication, which is a big part of the interview process. For more detailed guidance, check out our blog on mock interviews for software developers to learn how to prepare and make the most out of these simulations.

Explain your thought process: In coding interviews, interviewers care as much about how you approach the problem as they do about whether you solve it. Talk through your thought process, explain why you chose a particular approach, and discuss any trade-offs.

Final thoughts#

Coding interviews can seem intimidating, especially for college recruitment, but the truth is they are a test of skills that you can absolutely learn and improve upon. With consistent practice, understanding the fundamentals, and developing a problem-solving mindset, you can not only ace these interviews but also set yourself up for a successful career in tech.

To further enhance your preparation, explore these courses to crack the interviews:

• Grokking Coding Interview Patterns

• Data Structures for Coding Interviews

• Grokking the Behavioral Interview

Good luck with your coding interviews!