Top 26 coding questions to crack the Microsoft interview

Aiming for a profession at Microsoft is a worthy problem given the corporate’s wonderful monitor file for technological innovation, beneficiant compensation packages, and versatile work-life stability.

As the most important and arguably most influential software program firm on the earth, potential candidates could discover the technical interview course of daunting. Nonetheless, familiarizing your self with the kind of technical questions that will likely be introduced to you and studying to acknowledge coding patterns will provide help to navigate these interviews with larger confidence.

We’ll begin with an introduction to 26 frequent coding questions, transfer on to an outline of the entire interview course of for software program engineers, transfer on to ceaselessly requested technical questions, after which wrap up with extra steering and assets to maximise your probabilities of receiving a suggestion.

Matters coated:

26 frequent coding questions

As you go over every query, get into the behavior of diagramming the issue earlier than leaping straight to writing code. Breaking down an issue first provides you an opportunity to ask questions and get any essential info that you must give you the absolute best resolution. Take a second to elucidate your thought course of to your self as when you had been the interviewer.

Take a while to mirror on the effectivity of your resolution, and attempt to see if you may make your reply extra elegant by simplifying it.

Lastly, all the time bear in mind to validate your options.

Alright, let’s dive in!


1. Discover the lacking quantity in a given array

Downside Assertion: Given an array of optimistic numbers starting from 1 to n, such that every one numbers from 1 to n are current besides one quantity x, discover x. Assume the enter array is unsorted.

2. Decide if the sum of two integers is the same as a given worth

Downside Assertion: Given an array of integers and a price, decide if there are any two integers within the array whose sum is the same as the given worth. Return true if the sum exists, and false if it doesn’t. Take into account the next array and its goal sums:

Integer sums

3. Set columns and rows as zeroes

Downside Assertion: Given a two-dimensional array, if any factor inside is zero, make its complete row and column zero. Take into account the matrix beneath.


There are two zeros within the enter matrix at positions (1,1) and (2,3). The output of this needs to be a matrix through which the primary and second rows turn into zero and the primary and third columns turn into zero. Under is the anticipated output matrix.

Excepted output

Linked Lists

4. Add two integers

Downside Assertion: Given the top pointers of two linked lists the place every linked listing represents an integer quantity (every node is a digit), add them and return the ensuing linked listing. Within the instance beneath, the primary node in an inventory represents the least vital digit.

Linked lists

5. Copy linked listing with arbitrary pointer

Downside Assertion: You’re given a linked listing the place the node has two pointers. The primary is the common subsequent pointer. The second pointer is named arbitrary_pointer and it will possibly level to any node within the linked listing.

Right here, deep copy signifies that any operations on the unique listing (inserting, modifying, and eradicating) mustn’t have an effect on the copied listing.

Right here’s an instance of a linked listing with arbitrary pointers related.

Arbitrary pointer

6. Merge two sorted linked lists

Downside Assertion: Write a perform that takes two sorted linked lists and merges them. The perform ought to return a single, sorted listing comprised of splicing the nodes of the primary two lists collectively.

For instance, if the primary linked listing is 1 -> 2 -> 4 and the second linked listing is 3 -> 5 -> 6, then the output can be 1 -> 2 -> 3 -> 4 -> 5 -> 6


7. Stage order traversal of binary tree

Downside Assertion: Given the basis of a binary tree, show the node values at every stage.

Binary tree

The extent order traversal for this binary tree seems like this:

50, 20
25, 75, 350
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8. Join all siblings

Downside Assertion: Join the sibling pointer to the subsequent node in the identical stage. The final node in every stage ought to level to the primary node of the subsequent stage within the tree.

connected siblings in linked tree

9. Test a given binary tree for symmetry

Downside Assertion: Given a binary tree, write a program that may return true if the binary tree is a mirror picture of itself, and false if it’s not.

Binary tree symmetry

The right output given this binary tree can be true as a result of it’s symmetrical.


10. Reverse phrases in a sentence

Downside Assertion: Reverse the order of phrases in a given sentence.

"sphinx of black quartz decide my vow" ought to output as "vow my decide quartz black of sphinx"

11. Discover all palindrome substrings

Downside Assertion: Given a string, discover all non-single letter substrings which might be palindromes.


An string enter of "poppopo" would return "pop", "opo", "oppo", and "poppop".

12. String segmentation

Downside Assertion: Given a dictionary of phrases and a big enter string, discover whether or not or not the enter string could be utterly segmented into the phrases of that dictionary.

Dynamic Programming

13. Discover the utmost single promote revenue

Downside Assertion: Given an inventory of each day inventory costs (integers for simplicity), return the purchase and promote costs that may maximize the only purchase/promote revenue. If you cannot make any revenue, attempt to reduce the loss.

For the beneath examples, purchase (orange) and promote (inexperienced) costs for making a most revenue are highlighted.

Dynamic programming

14. Size of longest subsequence

Downside Assertion: Given a one-dimensional integer array a of size n, discover the size of the longest subsequence that will increase earlier than lowering.

15. Discover the longest path in a given matrix

Downside Assertion: Given an n*n matrix the place all numbers are distinct, discover the longest path ranging from any cell such that every one cells alongside the trail improve so as by 1.

Advisable Course:

Dynamic Programming (DP) questions could be a number of the most difficult questions you may encounter in your programming interviews. To get extra follow on this space, we advocate testing Grokking Dynamic Programming Patterns for Coding Interviews on Educative.

Math and Statistics

16. Discover the lacking quantity within the array

Downside Assertion: Given an array of optimistic numbers starting from 1 to n, such that every one numbers from 1 to nare current besides one quantity x, discover x.

The enter array will not be sorted.

Array 2

17. Discover all sum combos

Downside Assertion: Given a optimistic integer, goal, print all doable combos of optimistic integers that sum as much as the goal quantity.

For instance, if we’re given enter ‘5’, these are the doable sum combos.

1, 4
2, 3
1, 1, 3
1, 2, 2 
1, 1, 1, 2
1, 1, 1, 1, 1
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The output will likely be within the type of an inventory of lists or an array of arrays. Every factor within the listing will likely be one other listing containing a doable sum mixture.

18. Discover the kth permutation

Downside Assertion: Given a set of n variables, discover their kth permutation. Take into account the next set of variables:

Array 3


19. Common expression matching

Downside Assertion: Given a textual content and a sample, decide if the sample matches the textual content utterly or under no circumstances utilizing common expression matching. Assume the sample incorporates solely two operators: . and *. Operator * within the sample signifies that the character previous * could not seem or could seem any variety of instances within the textual content. Operator . matches with any character within the textual content precisely as soon as.

Under is an instance of a textual content and its matching and non-matching patterns.


20. Rat in a Maze

Downside Assertion: Take into account a rat positioned in a sq. n*n matrix at place (0, 0). Discover all doable paths the rat can take to achieve its vacation spot (N-1, N-1) from its beginning place.

The rat can transfer vertically and horizontally. Cells with a price of 1 could be traversed, whereas cells with a price of 0 can not. The rat can not go to a cell greater than as soon as.

21. Resolve the Sudoku

Downside Assertion: Given a sq. matrix grid of 9*9 and configured to symbolize an incomplete Sudoku puzzle, discover a resolution that returns a real or false worth relying on whether or not or not the Sudoku could be accomplished. If an answer is feasible, your resolution should additionally return the finished grid.


22. Clone a directed graph

Downside Assertion: Given the basis node of a directed graph, clone this graph by creating its deep copy in order that the cloned graph has the identical vertices and edges as the unique graph.

23. Conduct a Breadth-First Traversal of a given graph

Downside Assertion: Ranging from the supply node, traverse a given graph breadthwise to search out the space between the supply node and node n.

24. Test if there’s a path from a supply to its vacation spot

Downside Assertion: Given a graph n*n with every cell containing a price of 0, 1, 2, or 3, return a true or false worth relying on whether or not or not one can discover a path from the supply node to the vacation spot node. Every graph can have one supply node and one vacation spot node. The graph could be traversed horizontally and vertically.

The cell containing a price of 0 is the supply node.
A worth of 1 represents a wall; this node is impassable.
A worth of 2 represents a clean cell that may be traversed.
A worth of 3 represents the vacation spot node.

Kind and Search

25. Discover the closest assembly level

Downside Assertion: Given n individuals on a sq. grid, discover the purpose that requires the least whole distance coated by all individuals to fulfill at that time.

26. Seek for the given key in a two-dimensional matrix

Downside Assertion:
We’re given a two-dimensional array the place all parts in any particular person row or column are sorted. In such a matrix, we have now to look or discover the place of a given key.

Be ready to go over

  • Information buildings: Arrays, strings, queues, lists, linked lists, stacks, timber, heaps, hash tables, hash maps, hash units, graphs, and extra.
  • Algorithms: Breadth-first search, depth-first search, binary search, quicksort, mergesort, dynamic programming, divide-and-conquer, and extra.

You probably have over 3 years of expertise creating software program, it’s extremely probably that you may be requested system design questions, which could be extra open-ended.

To get an concept of what to anticipate from a system design interview, take a look at the High 10 system design interview questions for software program engineers on Educative.

Overview of the Microsoft hiring course of

The timeline for the complete course of (from submitting your resume to receiving a job supply) takes roughly 1-2 months You’re inspired to make use of no matter mainstream programming language (e.g., C/C++ or Java) that you’re most snug with to resolve the technical questions.


  • Prescreening: A recruiter contacts you through electronic mail to schedule a 45-minute cellphone name. They are going to spend quarter-hour going over your resume and asking behavioral questions. You’ve gotten the remaining half-hour to resolve a coding query associated to algorithms and knowledge buildings in a shared editor.
  • Telephone interview: The recruiter contacts you inside two weeks to schedule a cellphone interview with a senior developer or engineering supervisor. Details about potential subjects which may be coated throughout this cellphone interview will likely be supplied upfront.
  • On-site or digital interview: After passing the cellphone interview, you may be invited to take part in 4-5 rounds of interviews both in-person on the Microsoft campus or nearly. Every spherical is an hour lengthy and will likely be carried out by two members of the workforce you are seeking to be a part of. These rounds can have each behavioral and technical questions.
  • Lunch interview: Midway by way of the rounds, you may be taken out to lunch for a extra informal dialog. This can happen on the Microsoft campus, or off-campus at a restaurant.
  • Ultimate interview of the day: The final spherical will likely be carried out by an AS-AP (As-Applicable) who can have the ultimate say in hiring you.
  • HR interview: The hiring supervisor will go over any remaining behavioral or technical questions not coated within the earlier rounds of interviews, make a suggestion, and talk about compensation.

Easy methods to put together for the interview

Microsoft develops a holistic view of you as a candidate utilizing competency-based questioning along with your resume. They need candidates with sturdy technical abilities that align properly with the corporate values.

Microsoft interview

Step 1: Replace your resume

The very first thing you need to do is to ensure your resume and LinkedIn profile are updated. Be very particular, and use deliverables and metrics at any time when doable.

Subsequent, you’ll need to take a look at your resume within the context of the Microsoft Core Competencies. Take into account how particular initiatives or experiences could be tied into totally different Core Competencies, and replace them to mirror methods through which you’ve gotten prioritized these values in your work.

Step 2: The 12-week interview prep roadmap

To totally put together your self for the coding interview, we strongly counsel that you simply take three months to go over technical ideas and follow fixing interview questions. Utilizing an interview prep roadmap is a good way to maintain monitor of your progress, and break down what that you must be taught.

You should utilize our Definitive Interview Prep Roadmap on Educative to ensure you’re hitting all the essential subjects that is likely to be coated throughout coding interviews.

  • Week 0 – What programming language must you use?
  • Week 1 – Brush up in your chosen programming language.
  • Weeks 2 & 3 – Information buildings and algorithms.
  • Weeks 4 & 5 – Apply easy knowledge buildings and algorithmic challenges
  • Weeks 6, 7 & 8 – Dive into extra advanced coding interview issues
  • Weeks 9 & 10 – System design interviews
  • Week 11 – OS and concurrency ideas
  • Week 12 – Object-oriented design interviews

Step 3: Put together for the behavioral interview

Behavioral interview questions usually fall into one in every of three classes:

  • Previous experiences
  • Hypothetical conditions
  • Values-based questions

Behavioral interviews assist interviewers determine when you’re somebody they’d need to work with. Replicate on the way you react to optimistic conditions or conflicts in an expert setting, and be sincere about your previous experiences. Primarily, be your genuine self.

Don’t be afraid to convey your distinctive perspective to the desk. Transcend simply answering questions. Actually hear and reply to your interviewers. Present them that you simply’re engaged and tuned into the dialog you’re having with them.

An important factor to remember for any behavioral interview is that your interviewers need to rent you. Should you’re enthusiastic in regards to the know-how you’ll be working with, don’t be afraid to indicate it!

If you wish to brush up on behavioral interview questions, then take a look at Grokking the Behavioral Interview on Educative to be taught extra about what interviewers are in search of, and how one can develop the sort of structured responses that impress them.

You can too learn up in regards to the key attributes that outline the tradition at Microsoft.

Wrapping up and useful assets

Now that you simply’re extra conversant in the Microsoft interview course of, it is time to make a plan and put it into motion! The most effective candidates come totally ready, so it is essential to train due diligence. We have put collectively an intensive course that may provide help to shortly determine any gaps in your data, check your abilities, and follow utilizing a stay, in-browser coding setting.

Take a look at Grokking the Coding Interview: Patterns for Coding Questions on Educative.

You possibly can go to our Decode the Coding Interview library on Educative. The Decode collection exposes you to a number of the most ceaselessly requested questions at tech firms and helps solidify your data by contextualizing these issues in real-world purposes.

Blissful studying!

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