83 lines
3.1 KiB
Python
83 lines
3.1 KiB
Python
from graph import Graph, Node, Queue
|
|
from utils import getNode
|
|
|
|
# directed and weighted digraph
|
|
romania = Graph( ['Or', 'Ne', 'Ze', 'Ia', 'Ar', 'Si', 'Fa',
|
|
'Va', 'Ri', 'Ti', 'Lu', 'Pi', 'Ur', 'Hi',
|
|
'Me', 'Bu', 'Dr', 'Ef', 'Cr', 'Gi'],
|
|
[
|
|
('Or', 'Ze', 71), ('Or', 'Si', 151),
|
|
('Ne', 'Ia', 87), ('Ze', 'Ar', 75),
|
|
('Ia', 'Va', 92), ('Ar', 'Si', 140),
|
|
('Ar', 'Ti', 118), ('Si', 'Fa', 99),
|
|
('Si', 'Ri', 80), ('Fa', 'Bu', 211),
|
|
('Va', 'Ur', 142), ('Ri', 'Pi', 97),
|
|
('Ri', 'Cr', 146), ('Ti', 'Lu', 111),
|
|
('Lu', 'Me', 70), ('Me', 'Dr', 75),
|
|
('Dr', 'Cr', 120), ('Cr', 'Pi', 138),
|
|
('Pi', 'Bu', 101), ('Bu', 'Gi', 90),
|
|
('Bu', 'Ur', 85), ('Ur', 'Hi', 98),
|
|
('Hi', 'Ef', 86)
|
|
] )
|
|
|
|
def search(graph, queue, start_node_name, target_node_name):
|
|
visited_nodes = [] # Nodes which have been visited
|
|
path = []
|
|
|
|
start_node = getNode(start_node_name, graph.nodes)
|
|
target_node = getNode(target_node_name, graph.nodes)
|
|
|
|
start_node.value = 0
|
|
|
|
queue.push(start_node)
|
|
|
|
while not queue.empty():
|
|
current_node = queue.pop()
|
|
visited_nodes.append(current_node.name)
|
|
|
|
if not current_node == target_node:
|
|
for edge in current_node.edges:
|
|
neighbor = edge.end
|
|
condition = not visited_nodes.__contains__(neighbor.name)
|
|
new_cost = current_node.value + edge.value
|
|
|
|
# UCS
|
|
if queue.type == 'PRIO':
|
|
condition = not visited_nodes.__contains__(neighbor.name) and new_cost < neighbor.value
|
|
|
|
# works with digraph, because current_node is marked at this point, a cycle is not possible
|
|
if condition:
|
|
neighbor.parent = current_node
|
|
neighbor.value = new_cost
|
|
queue.push(neighbor)
|
|
else:
|
|
path.append(current_node.name)
|
|
while not current_node == start_node:
|
|
current_node = current_node.parent
|
|
path.insert(0, current_node.name)
|
|
|
|
|
|
if path.__len__() == 0:
|
|
print('zwischen ' + start_node_name + ' und ' + target_node_name + ' konnte kein Pfad gefunden werden')
|
|
else:
|
|
print('From ' + start_node_name + ' to ' + target_node_name + ': ')
|
|
print('Path: ' + path.__str__().format())
|
|
print('Cost: ' + target_node.value.__str__())
|
|
|
|
def bfs(graph, start_node_name, target_node_name):
|
|
search(graph,Queue('FIFO'),start_node_name, target_node_name)
|
|
|
|
def dfs(graph, start_node_name, target_node_name):
|
|
search(graph,Queue('LIFO'),start_node_name, target_node_name)
|
|
|
|
def utc(graph, start_node_name, target_node_name):
|
|
search(graph,Queue('PRIO'),start_node_name, target_node_name)
|
|
|
|
|
|
def main():
|
|
bfs(romania, 'Ti', 'Bu')
|
|
dfs(romania, 'Ti', 'Bu')
|
|
utc(romania, 'Or', 'Si')
|
|
|
|
if __name__ == "__main__":
|
|
main() |