¿Puede usted por favor hágamelo saber lo que es incorrecto en el código DFS abajo. It's dando resultado correcto AFAIK, pero yo don't saber cuándo va a fallar.
graph1 = {
'A' : ['B','S'],
'B' : ['A'],
'C' : ['D','E','F','S'],
'D' : ['C'],
'E' : ['C','H'],
'F' : ['C','G'],
'G' : ['F','S'],
'H' : ['E','G'],
'S' : ['A','C','G']
}
visited = []
def dfs(graph,node):
global visited
if node not in visited:
visited.append(node)
for n in graph[node]:
dfs(graph,n)
dfs(graph1,'A')
print(visited)
Salida:
['A', 'B', 'S', 'C', 'D', 'E', 'H', 'G', 'F']
Creo que tienes un problema de indentación. Suponiendo que su código se parece a esto:
graph1 = {
'A' : ['B','S'],
'B' : ['A'],
'C' : ['D','E','F','S'],
'D' : ['C'],
'E' : ['C','H'],
'F' : ['C','G'],
'G' : ['F','S'],
'H' : ['E','G'],
'S' : ['A','C','G']
}
visited = []
def dfs(graph,node):
global visited
if node not in visited:
visited.append(node)
for n in graph[node]:
dfs(graph,n)
dfs(graph1,'A')
print(visited)
Yo diría un par de cosas:
más:
Código actualizado:
graph1 = {
'A' : ['B','S'],
'B' : ['A'],
'C' : ['D','E','F','S'],
'D' : ['C'],
'E' : ['C','H'],
'F' : ['C','G'],
'G' : ['F','S'],
'H' : ['E','G'],
'S' : ['A','C','G']
}
def dfs(graph, node, visited):
if node not in visited:
visited.append(node)
for n in graph[node]:
dfs(graph,n, visited)
return visited
visited = dfs(graph1,'A', [])
print(visited)
Sin recursividad:
def dfs(grafo, nodo):
visitado = [nodo]
pila = [nodo]
while pila:
nodo = pila[-1]
si nodo no en visitado:
visited.extend(nodo)
remove_from_stack = True
para next en grafo[nodo]:
if next not in visited:
stack.extend(next)
remove_from_stack = False
break
si remove_from_stack:
stack.pop()
return visitado
print (dfs(grafo1, 'A'))
Salida:
['A', 'B', 'S', 'C', 'D', 'E', 'H', 'G', 'F']
Implementación de DFS en Python
from collections import defaultdict
class Graph:
def __init__(self):
self.graph = defaultdict(list)
def addEdge(self, u, v):
self.graph[u].append(v)
def DFSUtil(self, v, visited):
visited[v]=True
print(v)
for i in self.graph[v]:
if visited[i] == False:
self.DFSUtil(i, visited)
def DFS(self):
V = len(self.graph)
visited = [False]*(V)
for i in range(V):
if visited[i] == False:
self.DFSUtil(i, 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 Depth First Traversal")
g.DFS()
Fuente :: this