Simplify visited list update in DFS

Author: cclauss

graphs/directed_and_undirected_weighted_graph.py

@@ -425,8 +425,7 @@ def dfs(self, s=-2, d=-1):
             s = stack.pop()
             if visited.count(s) == 1:
                 continue
-            else:
-                visited.append(s)
+            visited.append(s)
             # If reached d, return
             if s == d:
                 break