College On-Campus Round: Goldman Sachs

Round 1 - Online coding Round 2 - Face-to-face interview Round 3 - Face-to-face interview Round 4 - Face-to-face interview with the Hiring Manager

Round 1 (Online Coding):

The round was conducted on Hackerrank. 600–700 students sat for the exam. This round comprised a 2-hour online test with 4 sections:

Section 1: 3 coding questions

1. Advertisement Scheduling: You are the owner of a news channel with a show that starts at 0 and ends at M. You have N advertisements, each with an effectiveness value given in an array [v1, v2, ..., vn]. The available time slots for these ads are given as [(x1, y1), (x2, y2), ..., (xn, yn)], where the i-th tuple denotes the timing (startTime, endTime) of the i-th ad. The goal is to maximize the sum of effectiveness values of selected ads, with the condition that there must be a minimum time gap of 4 minutes between any two advertisements. For example, if an ad runs from (1, 5), the next ad cannot start before time 10. Thus, an ad from (9, 14) would not be possible, but an ad from (10, 14) would be. Constraints: M >= xi, yi >= 0.
2. Minimum Cost to Cross Array: This is another DP problem. An array of costs was given. You can move either two steps forward or one step backward. Landing on a particular index incurs its cost. Find the minimum cost to cross or reach the end of the array.
3. Advanced Coding Question: Graph-related. The question was not fully recalled as it was not attempted.

Section 2: 10 MCQs

This section covered DBMS, Operating Systems, OOP's, Data Structures, Algorithms, and Mathematical problems (Probability, etc.). Negative marking was applied.

Section 3: 2 Subjective Questions

1. Describe your experience working in a team where you were not the leader. Detail your contributions.
2. Imagine your final end-semester examinations are scheduled for the next week, coinciding with an interview with your dream company. How would you approach this situation?

Results: The first two DP questions were completed fully, and most MCQs were answered correctly. 32 students were selected for the next round.

Round 2 (F2F):

Question: From every node, starting from the root, you can move to the next layer and to its connected nodes. Find the maximum sum of values obtainable from the root to the last layer.

Solution: A bottom-up DP approach was recommended. Start from the last level (leaves) and add the maximum value obtainable from a particular layer to the upward layer. The formula is: value at node (level i) = Max(value of node1 it is connected to (level i+1), value of node2 it is connected to (level i+1)).

Puzzles:

• A chessboard and dominoes puzzle (similar to https://www.geeksforgeeks.org/puzzle-25-chessboard-and-dominos/).
• Another mathematical puzzle, similar to those found on Geeksforgeeks (https://www.geeksforgeeks.org/puzzles/). It was advised to solve as many puzzles as possible, as similarly modified puzzles might be asked.

Round 3 (F2F Coding Questions):

1. Poisonous Plants (https://www.hackerrank.com/challenges/poisonous-plants/problem)
2. Kth Smallest Element in a BST (Solution reference: https://www.geeksforgeeks.org/kth-smallest-element-in-bst-using-o1-extra-space/)