def __dfs(graph, start, goal, visited):
stack = [start]
parents = {start: -1}
while len(stack) > 0:
v = stack.pop()
visited.append(v)
if v == goal:
break
col = graph[v]
for i, val in enumerate(col):
if val == 1 and i not in visited:
stack.append(i)
parents.update({i: v})
return get_path(parents, goal, start)
def __bfs(graph, start, goal, visited):
q = deque([start])
visited.append(start)
parents = {start: -1}
while len(q) > 0:
if goal in visited:
break
v = q.popleft()
for i, val in enumerate(graph[v]):
if val == 1 and i not in visited:
q.append(i)
visited.append(i)
parents.update({i: v})
if i == goal:
break
return get_path(parents, goal, start)
def dfs(graph, start, goal, visited):
if start not in graph.keys() or goal not in graph.keys():
return None
stack = [start]
parents = {start: 0}
while len(stack) > 0:
v = stack.pop()
visited.append(v)
if v == goal:
break
adjacent = list(graph[v])
for a in adjacent:
if a not in visited:
stack.append(a)
parents.update({a: v})
return get_path(parents, goal, start)
def bfs(graph, start, goal, visited):
q = deque([start])
visited.append(start)
parents = {start: 0}
while len(q) > 0:
if goal in visited:
break
v = q.popleft()
adjacent = [c for c in graph[v] if c not in visited]
for c in adjacent:
q.append(c)
visited.append(c)
parents.update({c: v})
if c == goal:
break
return get_path(parents, goal, start)
def __ucs(graph, start, goal, visited):
q = PriorityQueue()
q.put((0, start))
parents = {start: 0}
cumulative_cost = {start: 0}
while not q.empty():
if goal in visited:
break
[vcost, v] = q.get()
if v in visited:
continue
visited.append(v)
if v == goal:
break
for i, ccost in enumerate(graph[v]):
if ccost > 0 and i not in visited:
ccost += vcost
if i in cumulative_cost.keys() and ccost >= cumulative_cost[i]:
continue
q.put((ccost, i))
parents.update({i: v})
cumulative_cost.update({i: ccost})
return get_path(parents, goal, start)
def ucs(graph, start, goal, visited):
q = PriorityQueue()
q.put((0, start))
parents = {start: 0}
cumulative_cost = {start: 0}
while q:
if goal in visited:
break
[vcost, v] = q.get()
if v in visited:
continue
visited.append(v)
if v == goal:
break
adjacent = [(c, graph[v][c]) for c in graph[v].keys()
if c not in visited]
for (c, ccost) in adjacent:
ccost += vcost
if c in cumulative_cost.keys() and ccost >= cumulative_cost[c]:
continue
q.put((ccost, c))
parents.update({c: v})
cumulative_cost.update({c: ccost})
return get_path(parents, goal, start)