# * Q[i, j] = 1 if there is a link from i to j

# * Q[i, j] = 0 otherwise

Q = np.zeros((n, n), dtype=int)

f = open(infile, 'r')

edges = f.readlines()

f.close()

with open(infile) as f:

edges = f.readlines()

for edge in edges:

from_node, to_node = re.findall('\w', edge)

i, j = alphabet.index(from_node), alphabet.index(to_node)

Q = np.full((num_nodes, num_nodes), np.inf)

# Now we read in the data and modify Q

infile = open(in_file)

for line in infile:

elements = line.split(',')

node = elements.pop(0)

node = int(node[4:]) # convert node description to integer

if node != destination_node:

for element in elements:

destination, cost = element.split()

destination = int(destination[4:])

Q[node, destination] = float(cost)

Q[destination_node, destination_node] = 0

infile.close()

with open(in_file) as infile:

for line in infile:

elements = line.split(',')

node = elements.pop(0)

node = int(node[4:]) # convert node description to integer

if node != destination_node:

for element in elements:

destination, cost = element.split()

destination = int(destination[4:])

Q[node, destination] = float(cost)

Q[destination_node, destination_node] = 0

return Q

```