Update snakes-and-ladders.py

rui-yan · Sep 23, 2018 · a77dd92 · a77dd92
1 parent 889f9bb
commit a77dd92
Showing 1 changed file with 3 additions and 0 deletions.
diff --git a/Python/snakes-and-ladders.py b/Python/snakes-and-ladders.py
@@ -53,6 +53,9 @@
 # - The board square with number 1 has no snake or ladder.
 # - The board square with number N*N has no snake or ladder.
 
+import collections
+
+
 class Solution(object):
     def snakesAndLadders(self, board):
         """