Depth-first search (DFS) code in python

Question

Can you please let me know what is incorrect in below DFS code. It\'s giving correct result AFAIK, but I don\'t know when it will fail.

graph1 = {
    \'A\'          


        

Answer 1

DFS implementation in Python

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 = len(self.graph)

        visited = [False]*(V)

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

# Driver code
# Create a graph given in the above diagram
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 Depth First Traversal")
g.DFS()

Source :: this