[LC] 240817 add time complexity

Author: HaJunYoo

contains-duplicate/hajunyoo.py

@@ -1,4 +1,5 @@
 class Solution:
+    # Time complexity: O(n)
     def containsDuplicate(self, nums: List[int]) -> bool:
         string_len = len(nums)
         set_len = len(set(nums))

kth-smallest-element-in-a-bst/hajunyoo.py

@@ -8,6 +8,7 @@
 
 
 class Solution:
+    # Time complexity: O(n)
     def kthSmallest(self, root: Optional[TreeNode], k: int) -> int:
 
         self.count = 0

number-of-1-bits/hajunyoo.py

@@ -1,4 +1,5 @@
 class Solution:
+    # Time complexity: O(log n)
     def hammingWeight(self, n: int) -> int:
         n = int(n)
         cnt = 0

palindromic-substrings/hajunyoo.py

@@ -1,4 +1,5 @@
 class Solution:
+    # Time complexity: O(n^2) = O(n) * O(n)
     def countSubstrings(self, s: str) -> int:
         self.count = 0
         n = len(s)

top-k-frequent-elements/hajunyoo.py

@@ -3,6 +3,7 @@
 
 
 class Solution:
+    # Time complexity: O(nlogn) -> O(n) + O(nlogn) + O(k)
     def topKFrequent(self, nums: List[int], k: int) -> List[int]:
         counter_dict = defaultdict(int)