I was asked one DSA question during the interview: Set Matrix Zeroes. I started by explaining the brute force approach, followed by an optimized solution using O(n) space. Afterward, I presented an optimized solution with O(1) space complexity, utilizing two variables. However, the interviewer asked me to optimize the solution further using only one variable. I implemented the solution, but I missed an edge case which caused one test case to fail. Unfortunately, after that, I was not invited to the further rounds.