347. Top K Frequent Elements

347. Top K Frequent Elements

將頻率透過

class Solution:
    def topKFrequent(self, nums: List[int], k: int) -> List[int]:

        counter = Counter(nums)

        pq = []

        heapq.heapify(pq)

        for key in counter.keys():
            heapq.heappush(pq, (-counter[key], key))

        res = []

        while k > 0:
            value, key = heapq.heappop(pq)
            res.append(key)
            k -= 1

        return res

class Solution:
    def topKFrequent(self, nums: List[int], k: int) -> List[int]:        
        counter = Counter(nums)
        
        vals = list(counter.values())
        
        heap = []
        for val in vals:
            heapq.heappush(heap, val)
            if len(heap) > k:
                heapq.heappop(heap)
    
        kFreq = heap[0]
    
        res = []
        for key, val in counter.items():
            if val >= kFreq:
                res.append(key)
        
        return res