Q1: https://leetcode.com/problems/first-unique-character-in-a-string/\nQ2: https://leetcode.com/problems/top-k-frequent-elements/\n\nGot a rejection notification from my recruiter one week later.\n\nMy mistakes and learning:\n1. I should use minHeap instead of maxHeap for the second question.\n2. I should improve for the second question using bucket sort instead of the heap.\n3. I had a mistake to mention the time complexity of the heap as ```O(n)```. Even though, I clarify ```O(n log n)``` after getting the hints from the interviewer.\n\nAfter I completed my phone screen, 5 minutes later I realized I made those mistakes. I thought like "That was a minor mistake. I think I have a chance to move onsite."\n\n However, I got rejection :)

Q1: https://leetcode.com/problems/first-unique-character-in-a-string/\nQ2: https://leetcode.com/problems/top-k-frequent-elements/\n\nGot a rejection notificatio