Microsoft Interview Experience (Off-Campus)

I got this opportunity through their career page.

Round 1 (Coding Assessment): There were two questions that need to be solved in 120mins.

• The questions were based on DSA.
• Questions were medium-hard level.
• One question is based on the Two-pointer concept, there are N gas stations on a circular path. You will be given two sets of data.
  • The amount of gas that every gas station has.
  • Distance from that gas station to the next gas station.
  • Find a starting point where the truck can start to get through the complete circular path without exhausting its gas in between.

The second question was based on DFS + DP, don’t remember the question exactly, but it was to apply the inclusion-exclusion principle on graph nodes using DFS. 

Round 2 (Technical Interview Round): The first interviewer introduces himself then he asked me to introduce myself after my introduction he asked me about my internship and then jumped into coding questions:

• He shares me codility platform link and then pasted out the question in the left section, question was about Cutting a rod problem, I explained the overlapping subproblems first and optimized using DP. 
• I was asked to run the code and check for many test cases. The interviewer was satisfied with the code and then moves to the second question.
• He asked me about a number of island problems. I solved the question and explained my approach and the time complexity to him.

This round lasted for about 50-55 mins.  

The interviewer looked happy after I solved both questions, So I was pretty sure that I would qualify for the next round. Within one hour I received the call for my second round.

Round 3 (Technical Interview Round): In this round again the first interviewer introduces himself then he asked me to introduce myself and about my experience with the previous round after that, he shares me codility platform link and moved to coding questions.

• He asked me the most common Minimum number of coins DP problem I solved the question using Space Complexity O(n²), then he asked me to do it with O(n) complexity, and he gave me one hint after that hint I was able to solve it very quickly.
• The second question was based on the string question DP + Rabin Karp Hashing. Given a vector of strings, and a target string, find whether a subset of the array of strings could concatenate to the target string, if more than one possible way, return the one with minimum elements in the subset.

 I explained to him first how hashing would help in comparing then overlapping subproblems while making the target string. Then I was asked to write the code for the same.

In the evening time on the same day, I got a call that my last round would happen on next day. 

Round 4 (Technical Interview Round): I was asked to brief about my internship and project experience. 

• Then the interviewer said that my previous round result was quite good so in this round, he would ask me to solve only one problem The problem was based on a string. 
• A string is valid if all the characters have the same frequency or at most two different frequencies. 
• The question was pretty simple, but it took time for me to understand it. I wrote the code and then the interviewer asked me to run it on some test cases.

In the evening time on the same day, I got the mail that I have been selected. I was so happy and started celebrating.