Upload 10.py

10.py

@@ -0,0 +1,74 @@
+ 
+class Edge: 
+    def __init__(self, u, v): 
+        self.u = u 
+        self.v = v 
+ 
+    def opposite(self, x): 
+        if x == self.u: 
+            return self.v 
+        elif x == self.v: 
+            return self.u 
+        else: 
+            return None 
+ 
+class Graph: 
+    def __init__(self, n): 
+        self.adj = {i: [] for i in range(1,n+1)} 
+ 
+    def add_edge(self, u, v): 
+        e = Edge(u, v) 
+        self.adj[u].append(e) 
+        self.adj[v].append(e)    
+ 
+    def incident_edges(self, u): 
+        return self.adj[u] 
+ 
+    def vertices(self): 
+        return self.adj.keys() 
+ 
+def DFS(g, u, forest): 
+    for e in g.incident_edges(u): 
+        v = e.opposite(u) 
+        if v not in forest: 
+            forest[v] = e 
+            DFS(g, v, forest) 
+ 
+def DFS_complete(g, start): 
+    forest = {} 
+ 
+ 
+ 
+    forest[start] = None 
+    DFS(g, start, forest) 
+ 
+    for u in g.vertices(): 
+        if u not in forest: 
+            forest[u] = None 
+            DFS(g, u, forest) 
+ 
+    return forest 
+ 
+print("\tDepth First Search Tree Traversal\n") 
+n = int(input("Enter number of vertices: ")) 
+m = int(input("Enter number of edges: ")) 
+ 
+g = Graph(n) 
+ 
+print("Give vertex numbers from 1 to ", n) 
+print("Enter edges (u v):") 
+for _ in range(m): 
+    u, v = map(int, input().split()) 
+    g.add_edge(u, v)     
+ 
+start = int(input("Enter starting vertex: ")) 
+ 
+forest = DFS_complete(g, start) 
+ 
+print("\nDFS Tree (vertex : discovered from)") 
+for v in forest: 
+    if forest[v] is None: 
+        print(f"{v} : None (root)") 
+    else: 
+        parent = forest[v].opposite(v) 
+        print(f"{v} : discovered from {parent}")