Update critical-connections-in-a-network.py

Author: kamyu104

Python/critical-connections-in-a-network.py

@@ -1,7 +1,7 @@
 # Time:  O(|V| + |E|)
 # Space: O(|V| + |E|)
 
-# variant of Tarjan's algorithm
+# variant of Tarjan's algorithm (https://www.geeksforgeeks.org/bridge-in-a-graph/)
 class Solution(object):
     def criticalConnections(self, n, connections):
         """