Microsoft Corporation Software Developer Intern Interview Questions, Process, and Tips

Round duration - 90 minutes
Round difficulty - Medium

It started in the evening from around 6 pm and the total duration was 90 minutes. There were 3 coding questions of medium difficulty level. I think from a set of 10-12 questions, each student was given 3 questions randomly from that set. So it was somewhat luck dependent too if you get easy or difficult questions. Tab switching was not allowed during the test, also it was proctored through webcam.

Q1. 
Longest Palindromic Subsequence Problem Statement
Given a string A consisting of lowercase English letters, determine the length of the longest palindromic subsequence within A.
Explanation:
• A subsequ...read more
Add your answer
Q2. 
Find K'th Character of Decrypted String
You are given an encrypted string where repeated substrings are represented by the substring followed by its count. Your task is to find the K'th character of the d...read more
Add your answer
Q3. 
Maximum Subarray Sum Problem Statement
Given an array arr of length N consisting of integers, find the sum of the subarray (including empty subarray) with the maximum sum among all subarrays.
Explanation...read more
Add your answer

Round duration - 50 minutes
Round difficulty - Medium

It was held on the Microsoft teams platform. It started at 5 pm in the evening and lasted till around 5:50 pm. It started with me giving a general introduction about what I had done till now in my college. After that, he started with the coding problems.

Q1. 
Total Area of Overlapping Rectangles Problem Statement
Determine the total area covered by two given rectangles on a 2-D coordinate plane, which may have an overlapping area.
Input:
The first line conta...read more
Add your answer
Q2. Can you explain the basic theory behind mutexes and semaphores?
Add your answer

Round duration - 50 minutes
Round difficulty - Easy

The pattern was similar to the previous round. I started with my general introduction after which he proceeded to problem-solving. Also, there was some discussion about the projects I had done previously and also about my previous internship experience.

Q1. 
Find All Triplets with Zero Sum
Given an array Arr consisting of N integers, find all distinct triplets in the array that sum up to zero.
Explanation:
An array is said to have a triplet {Arr[i], Arr[j],...read more
Add your answer

Round duration - 90 Minutes
Round difficulty - Medium

Conducted on https://tests.mettl.com/ and contains 3 coding questions with different difficulty levels – Basic, Easy, and Medium and carrying marks accordingly.

Those who had solved at least 2 questions were selected for the next round. I was able to solve all of them and around 90 students were selected for the next round.

Q1. 
Division to N Decimal Places
Your task is to compute the division of two integers, X / Y, and output the result formatted to contain exactly N decimal places.
Input:
The first line contains an integer ‘...read more
Ans. 
Compute the division of two integers and output the result formatted to contain exactly N decimal places.
• Read the input values for X, Y, and N

• Perform the division X / Y

• Format the result to contain exactly N decimal places

• Output the result as a string with N decimal places
Answered by AI
Add your answer
Q2. 
Longest Palindromic Substring Problem Statement
You are provided with a string STR of length N. The goal is to identify the longest palindromic substring within this string. In cases where multiple palind...read more
Ans. 
Given a string, find the longest palindromic substring, prioritizing the one with the smallest start index.
• Iterate through the string and expand around each character to find palindromes

• Keep track of the longest palindrome found and its starting index

• Return the longest palindromic substring with the smallest start index
Answered by AI
Add your answer
Q3. 
Smallest Window Problem Statement
Given two strings S and X containing random characters, the task is to find the smallest substring in S which contains all the characters present in X.
Input:
The first...read more
Ans. 
Find the smallest substring in a given string that contains all characters from another given string.
• Use a sliding window approach to find the smallest window in S that contains all characters in X.

• Maintain a frequency map for characters in X and a window map for characters in the current window.

• Slide the window to the right, updating the window map and shrinking the window from the left if all characters in X are pres...read more
Answered by AI
Add your answer

Round duration - 60 Minutes
Round difficulty - Medium

It was a pen and paper-based round. 2 questions were given, and we have to solve them efficiently and specify our approach clearly.

Those who had solved both the problems efficiently and able to explain their ideas clearly were shortlisted for further rounds. 24 students selected for the interviews.

Q1. 
Connect Nodes at the Same Level
Given a binary tree where each node has at most two children, your task is to connect all adjacent nodes at the same level. You should populate each node's 'next' pointer t...read more
Ans. 
Connect adjacent nodes at the same level in a binary tree by populating each node's 'next' pointer.
• Traverse the tree level by level using a queue.

• For each level, connect nodes from left to right using their 'next' pointers.

• Set the 'next' pointer of the rightmost node in each level to NULL.

• Example: For the given binary tree, connect nodes 2->3, 4->5, 5->6, and set 1, 3, 6 'next' pointers to NULL.
Answered by AI
Add your answer
Q2. 
Minimum Number of Platforms Problem
Your task is to determine the minimum number of platforms required at a railway station so that no train has to wait.
Explanation:
Given two arrays:
• AT - represent...read more
Ans. 
Determine the minimum number of platforms needed at a railway station so that no train has to wait.
• Sort the arrival and departure times arrays in ascending order.

• Use two pointers to iterate through the arrays and keep track of the number of platforms needed.

• Increment the number of platforms needed when a train arrives and decrement when a train departs.

• Return the maximum number of platforms needed at any point.
Answered by AI
Add your answer

Round duration - 70 minutes
Round difficulty - Medium

This was an MCQ and coding round. For MCQs this was the distribution : -

Apptitude ( 10 questions)
Maths (10 questions)
Coding Fundamentals (10 questions)

Round duration - 60 minutes
Round difficulty - Hard

This was also an MCQ and coding test. 30 MCQs were asked

Q1. 
Validate BST Problem Statement
Given a binary tree with N nodes, determine whether the tree is a Binary Search Tree (BST). If it is a BST, return true; otherwise, return false.
A binary search tree (BST)...read more
Ans. 
Validate if a binary tree is a Binary Search Tree (BST) or not.
• Check if the left subtree of a node contains only nodes with data less than the node's data.

• Check if the right subtree of a node contains only nodes with data greater than the node's data.

• Ensure that both the left and right subtrees are also binary search trees.

• Traverse the tree in an inorder manner and check if the elements are in sorted order.

• Use recursio...read more
Answered by AI
Add your answer

Round duration - 60 Minutes
Round difficulty - Easy

It was an online technical interview focusing on DS and algorithms. They asked two questions in this round. He also asked me to code both the questions. I solved both questions with confidence.
They also gave a puzzle to solve. Out of 32 they selected 22 students along with me.

Q1. 
Spiral Matrix Problem Statement
You are given a N x M matrix of integers. Your task is to return the spiral path of the matrix elements.
Input
The first line contains an integer 'T' which denotes the nu...read more
Add your answer
Q2. You are given a certain number of eggs and a building with a number of floors. The goal is to find the highest floor from which you can drop an egg without breaking it. What is the optimal strategy to mini...read more
Add your answer

Round duration - 90 minutes
Round difficulty - Medium

The round consists of 3 coding questions and the test was conducted on mettl platform. There was no sectional time limit for the coding questions. Every student got randomly 3 coding questions and none of the students got the same set of questions. The test was online with audio and video both on for continuous monitoring.

Q1. 
Mean, Median, Mode Calculation
You are given an array 'ARR' consisting of 'N' integers. Your task is to calculate the three statistical measures for the given array:
1. Mean - Implement the function mean...read more
Add your answer
Q2. 
Nth Term of Geometric Progression (GP) Series
Determine the Nth term of a geometric progression (GP) series given the first term, common ratio, and the term number.
Explanation:
The general form of a GP...read more
Add your answer
Q3. 
Dice Throw Problem Statement
You are provided with D dice, each having F faces numbered 1 to F, inclusive. Your task is to determine the number of possible ways to roll the dice such that the sum of the f...read more
Add your answer

Round duration - 50 minutes
Round difficulty - Medium

This round was based on data structures and some discussion regarding the projects. The interviewer was very calm and listened very carefully to the solutions. There was a lot of discussion on my projects and the interviewer seems to be very interested in knowing about the workflows of my projects.

Q1. 
Identical Trees Problem Statement
Given two binary trees with 'N' and 'M' nodes respectively, determine if the two trees are identical. Return true if they are identical, otherwise return false.
Input:
...read more
Add your answer
Q2. 
Distinct Subsequences of a String
Given a string S of length N that may contain duplicate alphabets, your task is to compute the count of distinct subsequences of this string.
Example:
Input:
S = "deed...read more
Add your answer

Round duration - 50 minutes
Round difficulty - Medium

This round was also based on data structures and the interviewer was not responding as much as in the first round so that I should think on my own that whether I am on right track or not. In this round also there was a deep discussion on one of my web development with machine learning project. So don't panic in these situations If the interviewer is not responding much because he is noting down every tiny detail of your written code.

Q1. 
Delete Kth Node from End of Linked List
This problem requires you to delete the Kth node from the end of a given singly linked list with N nodes containing integer data.
You are asked to efficiently remo...read more
Add your answer

Round duration - 30 minutes
Round difficulty - Medium

This was an HR/Coding round and was the final one. The coding question was to find the nth node from the end of the linked list which is similar to the one asked in the previous round. The interview started with 2-3 HR questions and after I answered all of them, there was a serious discussion on my projects like why did you chose this project, what are its advantages, was it able to solve the existing problem. I answered all the project related queries very calmly and he was satisfied.

Round duration - 60 minutes
Round difficulty - Medium

This was the first round. The interviewer discussed two coding problems with me.

Q1. 
LCA of Binary Tree Problem Statement
You are given a binary tree of distinct integers, along with two nodes, ‘X’ and ‘Y’. Your task is to determine the Lowest Common Ancestor (LCA) of ‘X’ and ‘Y’.
The LC...read more
Ans. 
Find the Lowest Common Ancestor of two nodes in a binary tree.
• Traverse the binary tree to find the paths from the root to nodes X and Y.

• Compare the paths to find the last common node, which is the LCA.

• Handle cases where one node is an ancestor of the other.

• Consider using recursion to solve the problem efficiently.
Answered by AI
Add your answer
Q2. 
Median of Two Sorted Arrays
Given two sorted arrays A and B of sizes N and M, find the median of the merged array formed by combining arrays A and B. If the total number of elements, N + M, is even, the m...read more
Ans. 
Find the median of two sorted arrays by merging them and calculating the middle element(s).
• Merge the two sorted arrays into one sorted array.

• Calculate the median based on the total number of elements in the merged array.

• If the total number of elements is even, take the mean of the two middle elements as the median.
Answered by AI
Add your answer

Round duration - 45 minutes
Round difficulty - Easy

This was the second round. We started with a brief introduction. The interviewer then asked one coding problem and we had a long discussion on that problem only.

Q1. 
Possible Words From A Phone Number
After years of research, Ninja has invented a time machine and found himself in the era where T9 keypads were commonly used in mobile phones. Being curious, Ninja seeks ...read more
Ans. 
Given a string of digits from 2 to 9, determine all possible strings that can be generated using T9 keypad letter mappings.
• Create a mapping of digits to corresponding letters on a T9 keypad

• Use recursion to generate all possible combinations of letters for the input string

• Sort the generated strings lexicographically

• Return the array of generated strings
Answered by AI
Add your answer

Round duration - 40 minutes
Round difficulty - Easy

This was a typical managerial round. We started with a brief introduction. Then, the interviewer moved to my projects and started asking questions on one of the projects that he found interesting. At last, he asked me some questions based on Operating Systems.