G={'a':set('bcdf'),'b':set('cfe'),'c':set('de'),'d':set('e'),'e':set('f'),
'f':set('cgh'),'g':set('fhi'),'h':set('efgi'),'i':set('h')}
#输入节点
node=input("请输入你要查询的结点:")
outDegree = len(G.get(node,[])) #该方法应用在字典上,可以获取到字典某个键的值,如果不存在该键,则返回你指定的值
for i in G.get(node,[]):
print(node,'-->',i) #如果i在node键所映射的值中,输出node--->i
inDegree = sum(1 for v in G.values() if node in v)
for k,v in G.items():
if node in v:
print(k,'-->',node)
print('入度:',inDegree,'出度:',outDegree)