Best first search

 import heapq


def best_first_search(graph, start, goal):

    pq = [(0, start)] # Priority queue (cost, node)

    visited = set() # Track visited nodes


    while pq:

        cost, node = heapq.heappop(pq)

        if node in visited:

            continue

        visited.add(node)

        if node == goal:

            return f"Goal {goal} reached with cost {cost}"

        for neighbor, weight in graph[node]:

            if neighbor not in visited:

                heapq.heappush(pq, (weight, neighbor))

    return "Goal not reachable"


graph = {

    'A': [('B', 1), ('C', 4)],

    'B': [('D', 2), ('E', 5)],

    'C': [('F', 1)],

    'D': [], 'E': [], 'F': []

}

print(best_first_search(graph, 'A', 'F'))

BFS

Comments

Post a Comment

Popular posts from this blog

Web

                         STRING   <?php $mystr="php is a server side scripting language"; echo "<strong> the given string is :</strong> $mystr <br>"; echo "<strong> the length of string is :</strong>".strlen($mystr)."<br>"; echo "<strong> the count of string is :</strong>".str_word_count($mystr)."<br>"; echo "<strong> the reverse of string is :</strong>".strrev($mystr)."<br>"; $substr="side"; echo "<strong> the position of string is '$substr' in the string is :</strong>".strpos($mystr,$substr);                     Files <?php $fname="file1.txt"; $fptr=fopen($fname,"r"); $content=fread($fptr,filesize($fname)); $fptw=fopen("file2.txt","w"); fwrite($fptw,$content); echo"<strong>the content copied in file2 is:</strong> <br>".$c...
Read more

Lab 1 ai

 Dfs.pl s[a,b). s(a,c). s(b,d). s(b,e). s(c,f). s(c,g). s(d,h). s(e,i). s(e,j). s(f,k). goal(f). goal(j). solve(Start,Solution):- breadthfirst([[Start]],Solution). breadthfirst([[Node | Path] ].[Node|Path]]:- goal(Node). breadthfirst([Path | Paths] Solution):- extend(Path,NewPaths), write(NewPaths), nl, conc(Paths,NewPaths, Paths1), breadthfirst(Paths1,Solution). extend([NodePath],NewPaths):- bagof([NewNode, Node | Path),(s(Node, NewNode),not(member(NewNode, [Node | Path]))),NewPaths),!. extend([]). conc([],L,L). Scanned with OKEN Scanner bfs.pl s(a,b). s(a,c). s(b,d). s(b,e). s(c,f). s(c,g). / s(d,h). s(e,i). s(e,j). s(f,k). goal(f). goal(j). member(X,[X|_]). member(X,_|Tail]):- member(X,Tail). solve(Node,Solution):- depthfirst([],Node,Solution). depthfirst(Path, Node,[Node | Path]):- goal(Node). depthfirst(Path,Node,Sol):- s(Node,Node1), not(member(Node1,Path)), depthfirst([Node | Path], Node1,Sol). Scanned with OKEN Scanner conc([X/L1],L2,[X|L3]):- write('conc'), write(X), w...
Read more
 def aStarAlgo(start_node, stop_node): open_set = set(start_node) closed_set = set() g={} parents = {} g[start_node] = 0 parents[start_node] = start_node while len(open_set) > 0: n = None for v in open_set: if n == None or g[v] + heuristic(v) <g[n] + heuristic(n): n=v if n stop_node or Graph_nodes[n] == None: pass else: for (m, weight) in get_neighbors(n): open_set.add(m) if m not in open_set and m not in closed_set: parents[m] = n g[m] = g[n] + weight else: if g[m]g[n] + weight: g[m] = g[n] + weight parents[m] = n if m in closed_set: closed_set.remove(m) open_set.add(m) if n == None: print('Path does not exist!") return None if n == stop_node: path = [] while parents[n] != n: path.append(n) n = parents[n] path.append(start_node) path.reverse() print('Path found: {}'.format(path)) return path open_set.remove(n) closed_set.add(n) print('Path does not exist!") return None def get_neighbors(v): if v in Graph_nodes: return Graph_nodes[v] else: return None de...
Read more