After initial introductions, I was given a vague question during a DSA round. The interviewer himself stuttered and explained it fully over three trials. It was a graph problem. I immediately identified the problem and asked if they had some test cases or if I should code the input logic as well. I was asked to code the input logic.

Regarding the input logic, the interviewer didn't understand how to determine the number of vertices from an adjacency list. I had to explain it for about ten minutes. After I coded the entire solution and ran it with verbally provided test cases, it gave perfect results. I explained the entire logic to him, and he said he partially understood it. It was a basic DFS modification.

Sometime later, I received negative feedback via email: "GRAB - Please don't waste our time with such incompetent interviewers who don't even know the basics, if they themselves don't understand the basics." (They were lead engineers, two people, one of whom was completely silent throughout the interview).

A modified DFS question about graphs.