Dfs

code/algorithm_applications/src/depth_first_search/README.md

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+# Depth-First Search (DFS) 
+
+is a graph traversal algorithm that explores a graph or tree data structure by visiting as far down a branch as possible before backtracking. It's called "depth-first" because it explores as deeply as possible along each branch before moving to a sibling branch. DFS can be implemented using both iterative and recursive methods. It is a fundamental algorithm for many graph-related tasks, including searching for paths, determining connectivity, and exploring tree structures.
+
+# For further reading about this you can visit : https://www.geeksforgeeks.org/python-program-for-depth-first-search-or-dfs-for-a-graph/

code/algorithm_applications/src/depth_first_search/dfs.py

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+# Python3 program to print DFS traversal
+# from a given given graph
+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 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 DFS from (starting from vertex 2)")
+g.DFS(2)