Create dfs

Author: visz11

dfs.py

@@ -0,0 +1,59 @@
+from collections import defaultdict
+
+# This class represents a directed graph using
+# adjacency list representation
+class Graph:
+
+    # Constructor
+    def __init__(self):
+
+        # Default dictionary to store graph
+        self.graph = defaultdict(list)
+
+    
+    # Function to add an edge to graph
+    def addEdge(self, u, v):
+        self.graph[u].append(v)
+
+    
+    # A function used by DFS
+    def DFSUtil(self, v, visited):
+
+        # Mark the current node as visited
+        # and print it
+        visited.add(v)
+        print(v, end=' ')
+
+        # Recur for all the vertices
+        # adjacent to this vertex
+        for neighbour in self.graph[v]:
+            if neighbour not in visited:
+                self.DFSUtil(neighbour, visited)
+
+    
+    # The function to do DFS traversal. It uses
+    # recursive DFSUtil()
+    def DFS(self, v):
+
+        # Create a set to store visited vertices
+        visited = set()
+
+        # Call the recursive helper function
+        # to print DFS traversal
+        self.DFSUtil(v, visited)
+
+
+# Driver's code
+if __name__ == "__main__":
+    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 (starting from vertex 2)")
+    
+    # Function call
+    g.DFS(2)