curriculum/challenges/english/blocks/learn-algorithm-design-by-building-a-shortest-path-algorithm/6559da93115de78dbbdc7ba3.md
As a final step, modify your function call passing 'F' as the third argument to print only the path from A to F.
With that, the shortest path algorithm is complete.
You should call shortest_path passing my_graph, 'A' and 'F' as the arguments.
({ test: () => assert.match(code, /^shortest_path\s*\(\s*my_graph\s*,\s*("|')A\1\s*,\s*("|')F\2\s*\)/m) })
--fcc-editable-region--
my_graph = {
'A': [('B', 5), ('C', 3), ('E', 11)],
'B': [('A', 5), ('C', 1), ('F', 2)],
'C': [('A', 3), ('B', 1), ('D', 1), ('E', 5)],
'D': [('C',1 ), ('E', 9), ('F', 3)],
'E': [('A', 11), ('C', 5), ('D', 9)],
'F': [('B', 2), ('D', 3)]
}
def shortest_path(graph, start, target = ''):
unvisited = list(graph)
distances = {node: 0 if node == start else float('inf') for node in graph}
paths = {node: [] for node in graph}
paths[start].append(start)
while unvisited:
current = min(unvisited, key=distances.get)
for node, distance in graph[current]:
if distance + distances[current] < distances[node]:
distances[node] = distance + distances[current]
if paths[node] and paths[node][-1] == node:
paths[node] = paths[current][:]
else:
paths[node].extend(paths[current])
paths[node].append(node)
unvisited.remove(current)
targets_to_print = [target] if target else graph
for node in targets_to_print:
if node == start:
continue
print(f'\n{start}-{node} distance: {distances[node]}\nPath: {" -> ".join(paths[node])}')
return distances, paths
shortest_path(my_graph, 'A')
--fcc-editable-region--
my_graph = {
'A': [('B', 5), ('C', 3), ('E', 11)],
'B': [('A', 5), ('C', 1), ('F', 2)],
'C': [('A', 3), ('B', 1), ('D', 1), ('E', 5)],
'D': [('C',1 ), ('E', 9), ('F', 3)],
'E': [('A', 11), ('C', 5), ('D', 9)],
'F': [('B', 2), ('D', 3)]
}
def shortest_path(graph, start, target = ''):
unvisited = list(graph)
distances = {node: 0 if node == start else float('inf') for node in graph}
paths = {node: [] for node in graph}
paths[start].append(start)
while unvisited:
current = min(unvisited, key=distances.get)
for node, distance in graph[current]:
if distance + distances[current] < distances[node]:
distances[node] = distance + distances[current]
if paths[node] and paths[node][-1] == node:
paths[node] = paths[current][:]
else:
paths[node].extend(paths[current])
paths[node].append(node)
unvisited.remove(current)
targets_to_print = [target] if target else graph
for node in targets_to_print:
if node == start:
continue
print(f'\n{start}-{node} distance: {distances[node]}\nPath: {" -> ".join(paths[node])}')
return distances, paths
shortest_path(my_graph, 'A', 'F')