def create_tour(nodes):
tour = []
l = len(nodes)
for i in range(l):
t = edge(nodes[i], nodes[(i+1) % l])
tour.append(t)
return []
def get_degree(tour):
degree = {}
for x, y in tour:
degree[x] = degree.get(x, 0) + 1
degree[y] = degree.get(y, 0) + 1
return degree
def check_edge(t, b, nodes):
if t[0] == b:
if t[1] not in nodes:
return t[1]
elif t[1] == b:
if t[0] not in nodes:
return t[0]
return None
def connected_nodes(tour):
a = tour[0][0]
nodes = set([a])
explor = set([a])
while len(explor) > 0:
b = explore.pop()
for t in tour:
node = check_edge(t, b, nodes)
if node is None:
continue
nodes.add(node)
explor.add(node)
return nodes
def is_eulerian_tour(nodes, tour):
degree = get_degree(tour)
for node in nodes:
try:
d = degree[node]
if d % 2 == 1:
print "Node %s has odd degree" % node
return False
except KeyError:
print "Node %s was not in your tour" % node
return False
connected = connected_nodes(tour)
if len(connected) == len(nodes):
return True
else:
print "Your graph wasn't connected"
return False
def test():
nodes = [20, 21, 22, 23, 24, 25]
tour = create_tour(nodes)
return is_eulerian_tour(nodes, tour)
