I have around 1.5 years of experience and received a call from a recruiter through LinkedIn.
Round 1 (Difficulty Level - Medium): Codility test of 90minutes comprising 3 coding questions.
- First question: Minimum number of parentheses required to make the string a valid parenthesis.
This question is expected to be solved in a single traversal else it gives TLE. - Second question: Smallest substring occurring only once in a given string
https://www.geeksforgeeks.org/dsa/smallest-substring-occurring-only-once-in-a-given-string/ - Third question: Related to matrix and DP, was hard and time-consuming
- Required to solve 50% to reach the next round
Round 2: (Technical Interview Round-1) Difficulty Level - Medium: The interviewer has provided a codility link and asked me to solve a single problem.
- Question: Given a BST, find two incorrectly placed nodes in the tree.
Note - First solve it using a brute force approach and then provide an optimized solution. I solved it using simple inorder traversal and have given the required output. - The interviewer was very friendly and helped me whenever I got stuck.
Round 3: (Difficulty Level - Hard): The interviewer has given a codility link with two problems and asked me to solve them.
- First Question: https://www.geeksforgeeks.org/dsa/program-generate-possible-valid-ip-addresses-given-string/
- Second Question: Given 2 cities A and B and given an array of pairs (costA, costB) where costA = cost of moving people to city A and costB = cost of moving people to city B. Write a program to move 2N people into both cities A and B such that N people are in A and N people are in B and the cost is minimum.
Approach: I sorted the array based on the difference in the cost of both cities. Sorting can be done using a comparator interface in Java.
Round 4: (Difficulty Level - Medium): This round was taken by the project manager.
- Asked to design a tiny URL system, considering my years of experience, the interviewer has helped me with the basic design problem of getting the requirements and calculating the throughput.
https://www.geeksforgeeks.org/system-design/system-design-url-shortening-service/
Round 5: (Difficulty Level - Hard): This round was taken by Software Engineering Manager. Provided a codility link with 1 problem to solve
- Question: Given 2 values N, Sprint all combinations of N numbers such that their sum is S.
Example: Input - N=2, S=6
Output : [0,6],[1,5],[2,4],[3,3],[4,2],[5,1],[6,0]. - The problem could have been simple if N = 2, but N varies and repetitions are allowed and all combinations are allowed. I solved it using a recursion approach where one number is kept constant and started filling other numbers such that sum equals S.
Round 6: AA round (Difficulty Level - Medium): This is the final round called AA (As Appropriate) . The interviewer has given a codility link with 1 problem to solve.
- Question: Given an array of 2N numbers, rearrange the array such that even numbers are in even indexes and odd numbers are in odd indexes. No extra space to be used.
- Solved it using a single traversal, and the interviewer has tested the code against multiple test cases and all corner cases
Suggestion: Primary focus in Microsoft is on problem-solving and system design skills. Practicing LeetCode and Microsoft tagged questions on gfg helps a lot.
