added: top k frequent elements

Author: mihirs16

14. Questions/leetcode 347 - top k frequent elements.py

@@ -0,0 +1,25 @@
+# top k frequency elements | leetcode 347 | https://leetcode.com/problems/top-k-frequent-elements/
+# use buckets with each bucket being the frequency of an element
+
+from collections import Counter
+
+class Solution:
+    def topKFrequent(self, nums: list[int], k: int) -> list[int]:
+        freq = Counter(nums)
+        N = len(nums)
+
+        # create buckets where index = frequency of element
+        buckets = [[] for x in range(N + 1)]
+        for f in freq:
+            buckets[freq[f]].append(f)
+
+        # get k elements starting from the end of the bucket
+        k_mf = []
+        for x in buckets[::-1]:
+            if k > 0:
+                if x != []:
+                    k_mf += x
+                    k -= len(x)
+            else:
+                return k_mf
+