BFS and DFS

bfs.py

@@ -0,0 +1,29 @@
+class first:
+    def __init__(self,graph,start,goal):
+        self.start = start
+        self.graph = graph
+        self.goal=goal
+
+    def bfs_shortest_path(self):
+        explored=[]
+        queue = [[self.start]]
+        if self.start==self.goal:
+            return "That was easy! start=goal"
+        while queue:
+            path = queue.pop()
+            node = path[-1]
+            if node not in explored:
+                neighbors = self.graph[node]
+                for neighbor in neighbors:
+                    new_path = list(path)
+                    new_path.append(neighbor)
+                    queue.append(new_path)
+            if neighbor == self.goal:
+                return new_path
+            explored.append(node)
+        return "So  sorry, but a connecting path does not exist"
+
+graph = {'A':['Z','S','T'],'B':['U','P','G','F'],'C':['D','R','P'],'D':['M'],'E':['H'],'I':['V','N'],'L':['T','M'],'O':['Z','S'],'P':['R'],'U':['V'],'Z':['O','A'],'S':['O','A','R','F'],'T':['A','L'],'M':['L','D'],'R':['S','P','C'],'F':['S','B']}
+f = first(graph,'A','B')
+print(f.bfs_shortest_path())
+

dfs.py

@@ -0,0 +1,61 @@
+graph = {'Arad': ['Zerind', 'Sibiu', 'Timisoara'],
+
+'Bucharest': ['Urziceni', 'Pitesti', 'Giurgiu', 'Fagaras'],
+
+'Craiova': ['Dobreta', 'Bimnicu Vilcea', 'Pitesti'],
+
+'Dobreta': ['Mehadia'],
+
+'Eforie': ['Hirsoya'],
+
+'Tasai': ['Vaslui', 'Neamt'],
+
+'Lugoj': ['Timisoara', 'Mehadia'],
+
+'Oradea': ['Zerind', 'Sibiu'],
+
+'Pitesti': ['Bimnicu Vilcea'],
+
+'Urziceni': ['Vaslui'],
+
+'Zerind': ['Oradea', 'Arad'],
+
+'Sibiu': ['Oradea', 'Arad', 'Bimnicu Vilcea', 'Fagaras'],
+
+'Timisoara': ['Arad', 'Lugoj'],
+
+'Mehadia': ['Lugoj', 'Dobreta'],
+
+'Bimnicu Vilcea': ['Sibiu', 'Pitesti', 'Craiova'],
+
+'Fagaras': ['Sibiu', 'Bucharest'],
+
+'Giurgiu': ['Bucharest'],
+
+'Vaslui': ['Urziceni','Iasai'],
+
+'Neaput': ['Tagai']
+}
+
+def IDDES(root, goal):
+    depth = 0 
+    while True: 
+        print("Looping at depth %i"%(depth))
+        result = DLS(root, goal, depth)
+        print ("Result: %s, Goal: %s" % (result, goal))
+        if result == goal:
+            return result
+        depth = depth +1
+
+def DLS(node, goal, depth):
+    print ("node: %s, goal %s, depth: %i" % (node, goal, depth))
+    if depth == 0 and node == goal:
+        print("---Found goal, returning ---")
+        return node
+    elif depth > 0:
+        print("Looping through children %s" %(graph.get(node, [])))
+        for child in graph.get(node, []): 
+            if goal == DLS(child, goal, depth-1):
+                return goal
+
+IDDES('Arad', 'Bucharest')