Google India L4 | Phone Screen | Reject

I was asked the following question:

1. Given an expression evaluate it's value:

Input: add(5,mul(2,pow(5,2))) Output: 55

I asked some clarifying questions about the input and got:

• There can be 5 binary functions: add, mul, div, sub, pow
• div is NOT integer division so need to return double
• Input will have positive integers
• There can be spaces in the input

It's a simple question but implementation gets messier and messier once you start coding. I did a decent attempt at the problem and I was able to provide a working solution. I missed an edge case which the interviewer pointed out and after thinking for a few minutes I fixed it.

Within 5 minutes into the interview, I knew I'm not going to be selected. Because first, I immediately knew this implementation is going to be messy and second, the interviewer was not offering any feedback as I spoke.

In these type of tricky question where you can't formulate a perfect algorithm handling all cases, it's essential for your interviewer to understand and give feedback to your approach. Since he was not doing that I knew I will fail.

The recruiter called 30 minutes after the inteview and informed about the rejection. She said that everything was poor: DSA, implementation, and logic and asked me to try again after a year.