ci: fix ci

Author: wislertt

leetcode/missing_number/solution.py

@@ -1,7 +1,17 @@
 class Solution:
 
-    # Time: O(?)
-    # Space: O(?)
+    # Time: O(n)
+    # Space: O(1)
     def missing_number(self, nums: list[int]) -> int:
-        # TODO: Implement missing_number
-        return 0
+        """
+        Find the missing number in an array containing n distinct numbers
+        in the range [0, n].
+
+        Approach: Use the mathematical formula for sum of consecutive integers.
+        The sum of numbers from 0 to n is n*(n+1)/2.
+        The missing number = expected_sum - actual_sum.
+        """
+        n = len(nums)
+        expected_sum = n * (n + 1) // 2
+        actual_sum = sum(nums)
+        return expected_sum - actual_sum

leetcode/top_k_frequent_elements/solution.py

@@ -13,11 +13,13 @@ def top_k_frequent(self, nums: List[int], k: int) -> List[int]:
         """
         counter = Counter(nums)
 
-        # Use min heap of size k
+        # Use min heap of size k - keep the k most frequent elements
         heap: list[tuple[int, int]] = []
         for num, count in counter.items():
-            heapq.heappush(heap, (count, num))
-            if len(heap) > k:
-                heapq.heappop(heap)
+            if len(heap) < k:
+                heapq.heappush(heap, (count, num))
+            elif count > heap[0][0]:
+                heapq.heapreplace(heap, (count, num))
 
+        # Extract numbers from heap (order doesn't matter for this problem)
         return [num for _, num in heap]