Top K Frequent Elements solution

Author: jungsiroo

top-k-frequent-elements/jungsiroo.py

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+class Solution:
+    def topKFrequent(self, nums: List[int], k: int) -> List[int]:
+        # Naive Solution
+        # TC : O(nlogn)
+        # SC : O(n)
+        
+        cnt = dict()
+        for num in nums:
+            cnt[num] = cnt.get(num, 0) + 1
+            
+        """
+        ret = dict(sorted(cnt.items(), key=lambda x:(-x[1], x[0])))
+        return list(ret.keys())[:k]
+        """
+
+        # Follow up Solution
+        # TC : O(nlog(k))
+        # SC : O(n)
+
+        import heapq
+
+        ret = [(-c, num) for num, c in cnt.items()]
+        heapq.heapify(ret)
+
+        return [heapq.heappop(ret)[1] for _ in range(k)]
+