Update kth-distinct-string-in-an-array.py

Author: kamyu104

Python/kth-distinct-string-in-an-array.py

@@ -1,6 +1,9 @@
 # Time:  O(n)
 # Space: O(n)
 
+import collections
+
+
 class Solution(object):
     def kthDistinct(self, arr, k):
         """