Sorry a little vent out post. Extremely frustrated with myself

Had been feeling a little exhausted lately with all these interviews and prep. Recently gave Databricks screening round interview. Had prepared from leetcode interview experience and to my luck got the same question in the interview as well with only a small variation.

It was a popular question around CIDR block. I had prepared but for some reason just completely misunderstood how CIDR block are actually represented in bits. As I was feeling a bit exhausted I just never deep dived into understanding it properly. While solving the question starting facing issues because of the same and bombed out.

To make it worse, I am always confused whether to code in cpp or java. I started with cpp but didn't completely remember string functions because of which wasted 15 mins or so. Switched to java and by then was already in time trouble.

Got rejected for what should have been an easy screening experience.

Do you you guys have any suggestion for such situations to never happen again. Might require it for Uber which is scheduled soon.