contains duplicate solution

contains-duplicate/EstherKim97.py

@@ -0,0 +1,9 @@
+# Given an integer array nums, return true if any value appears at least twice in the array, and return false if every element is distinct.
+
+def containsDuplicate(nums):
+    seen = set()
+    for num in nums:
+        if num in seen:
+            return True
+        seen.add(num)
+    return False