The interviewer had a huge attitude. Initially, he told me my solution, where I used a HashSet, was wrong (mine is the optimal solution). With only 5 minutes left, he offered to give me the correct solution but stated he would rate me very low. He actually presented a slower, albeit easier, two-pointer solution.

He ended the interview wishing me luck for future job opportunities, which I felt was very sarcastic. I later checked the question on LeetCode and confirmed my solution was correct and optimal.

Arrogant interviewer. I will think twice before interviewing for Palo Alto Networks again. The only area where I faltered was not knowing the properties of a tuple in Python.

3Sum Tuple

Given an array nums of n integers, are there elements a, b, c in nums such that a + b + c = 0?

Find all unique triplets in the array which give the sum of zero.