Top K Frequent Elements at Amazon — Interview Guide

• Count frequencies with a hash map in O(n).
• A min-heap of size k keeps the top k by frequency in O(n log k).
• Bucket sort by frequency achieves O(n) when values are bounded.

import heapq, collections
def top_k(nums, k):
    freq = collections.Counter(nums)
    return heapq.nlargest(k, freq.keys(), key=freq.get)

• Customer obsession — start from the customer and work backward.
• Ownership — think long-term and act on behalf of the whole company.
• Bias for action — make decisions with incomplete data and ship.
• Dive deep — understand the details behind any metric you cite.
• Deliver results — focus on the right inputs and hit commitments.