adding contains duplicated

Author: daiyongg-kim

contains-duplicate/daiyongg-kim.py

@@ -0,0 +1,9 @@
+class Solution:
+    def containsDuplicate(self, nums: List[int]) -> bool:
+        my_set = set()
+
+        for num in nums:
+            if num in my_set:
+                return True
+            my_set.add(num)
+        return False