通过关于算法的Udacity课程并创建以下函数来确定给定图形的欧拉路径。虽然我通过了样本测试，但答案是不被接受的。有人知道为什么吗？感谢您的任何指示！
# Find Eulerian Tour
#
# Write a function that takes in a graph
# represented as a list of tuples
# and return a list of nodes that
# you would follow on an Eulerian Tour
#
# For example, if the input graph was
# [(1, 2), (2, 3), (3, 1)]
# A possible Eulerian tour would be [1, 2, 3, 1]
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 find_eulerian_tour(graph):
tour = []
deg = get_degree(graph)
for node in deg:
if deg.get(node)%2==1:
first = node
else:
first = list(deg.keys())[0]
node = first
tour.append(node)
checkpoint=[]
while graph:
edges = [t for t in graph if t[0] == node or t[1] == node]
if not edges:
tour = checkpoint[-1][0]
graph = checkpoint[-1][1]
node = checkpoint[-1][2]
edges = [t for t in graph if (t[0] == node or t[1] == node) and t != checkpoint[-1][3]]
checkpoint.remove(checkpoint[-1])
path = edges[0]
if len(edges) > 1:
checkpoint.append([list(tour), list(graph), int(node), tuple(path)])
if path[0] == node:
node = path[1]
else:
node = path[0]
tour.append(node)
graph.remove(path)
return tour
def test():
tour = [(1, 2), (2, 3), (3, 1)]
tour2 = [(1, 2), (2, 3), (3,4), (4,1), (2,4)]
tour3 = [(1,2),(2,3),(1,3),(2,4),(2,5),(4,5)]
print(find_eulerian_tour(tour))
print(find_eulerian_tour(tour2))
print(find_eulerian_tour(tour3))
test()