1.py

from collections import defaultdict 

class Graph: 

	def __init__(self): 


		self.graph = defaultdict(list) 


	def addEdge(self,u,v): 
		self.graph[u].append(v) 


	def DFSUtil(self,v,visited): 


		visited[v]= True
		print (v), 

		for i in self.graph[v]: 
			if visited[i] == False: 
				self.DFSUtil(i, visited) 


	def DFS(self,v): 

		visited = [False]*(len(self.graph)) 


		self.DFSUtil(v,visited) 


 
g = Graph() 
g.addEdge(0, 1) 
g.addEdge(0, 2) 
g.addEdge(1, 2) 
g.addEdge(2, 0) 
g.addEdge(2, 3) 
g.addEdge(3, 3) 

print ("Following is DFS from (starting from vertex 1)")
g.DFS(1)