Top K Frequent Elements

class Solution:
    def topKFrequent(self, nums: List[int], k: int) -> List[int]:
        freq = collections.defaultdict(int)
        heap = []

        for num in nums:
            freq[num] += 1

        for key, val in freq.items():
            heapq.heappush(heap, (val, key))

        return [x[1] for x in heapq.nlargest(k, heap)]