Writing this post to express my frustration about the Snowflake Internship Core Engineering C++/Java Hackerrank that was recently sent out. I am an undergraduate junior at a school that is ranked 60th by USNews for computer science.

The OA consisted of 1 LC Medium and 2 LC Hards in 90 minutes, that included topics ranging from (two pointers, binary search, dynamic programming, and combinatorics). I was able to pass all the test cases with 2 minutes remaining. One of my solutions was O(nlogn) in time, and O(1) space. I could have used O(n) space to make it O(n) time, but the O(nlogn) solution was running faster on the test cases because lg(n) was smaller than the constant time added by the hashmap.

After completing the OA, I searched for the questions online, and my approach was slightly different but still correct (e.g. I used DP instead of implementing nCr, or lower bound binary search instead of searching for a target), so I could not have been flagged for cheating.

My code was very clean but I did not have time to add comments. I used proper naming of variables though.

A couple hours after submitting the OA, I got a rejection letter. What could have gone wrong? I thought the questions were very interesting and I was glad that I was able to solve them. This makes being rejected feel even worse. Please share your experiences with the Hackerrank as well.