HackerRank: Frequency Queries

Posted: 18 February 2019

Seemed easy at the start as I misread query 3. I read it as if there exists at least one of this number in the data structure. I tried coding this immediately without writing it on paper, and was stuck pretty quickly or found out I was heading down in the wrong direction pretty quickly. I can see why you should never code immediately and write the solution out on a piece of paper first. I took a step back, wrote it on paper, and the code was 95% correct. The remaining 5% was syntax errors, and a section where I failed some test cases because I forgot to delete the element from the unordered_map after it reaches 0. It was clear that I needed to maintain 2 dictionaries from the start so this was good.

Code here.