The interviewer had a huge attitude. Initially he told me my solution (where I used HashSet) was wrong (mine is the optimal solution) and with 5 min left, he told me he would give me the correct solution but said he would be rating me very low. He actually gave a slower solution but facier 2 pointer solution. He ended the interview wishing me luck for future job opportunities (which I felt was very sarcastic). I checked the question asked in leetcode and saw my solution was actually correct and the optimal one. Arrogant interviewer. Will think twice before interviewing for Palo Alto networks again. The only place I failed was not knowing the property of tuple in Python.