Python数据结构单链表求解

Question

def insert（i,elem): #在位置i处插入结点
pos＝0
if i<1:
raise IndexError
p = self.head
while p.next is not None:
q=p
#补充
if pos ==i:
#补充
return
return IndexError

Answer 1

pos +=1
#--------------
p.next =elem
elem.next=q.next
p=p.next