python3 中两个排序链表的交集?

Question

>我的代码无法打印出新列表，该列表是两个排序链表的交集。它无法访问函数内部的列表。请指出我的代码中的错误。我的代码中没有缩进问题，算法似乎也很好。

class Node(object):
def __init__(self,data):
self.data = data
self.next = None
class Linked(object):
def __init__(self):
self.head = None
def push(self,n):
new_node = Node(n)
new_node.next = self.head
self.head = new_node
def print_list(self):
current = self.head
while current:
print(current.data)
current = current.next
def intersect(self,l1,l2):
l1 = l1.head
l2 = l2.head
dummy = cur = Node(0)
while l1 and l2:
if l2.data>l1.data:
l1=l1.next
elif l1.data>l2.data:
l2=l2.next
else:
cur.next = l1 or l2
l1 = l1.next
l2 = l2.next
cur = cur.next
return dummy.next
llist = Linked()
llist1 = Linked()
llist.push(6)
llist.push(4)
llist.push(3)
llist.push(2)
llist.push(1)
llist1.push(8)
llist1.push(6)
llist1.push(4)
llist1.push(2)
l = Linked()
print(l.intersect(llist,llist1).data)

以下是回溯：

Traceback (most recent call last):
File "C:/Users/omsai/Desktop/intersection.py", line 48, in <module>
print(l.intersect(llist,llist1).data)
File "C:/Users/omsai/Desktop/intersection.py", line 26, in intersect
if l2.data>l1.data:
AttributeError: 'Linked' object has no attribute 'data'

Answer 1

您正在使用两个没有data成员的Linked实例调用Linked.intersect。 您需要在intersect方法中获取实际节点：

def intersect(self,l1,l2):
l1 = l1.head
l2 = l2.head
dummy = cur = Node(0)
# ...

您可能不需要用两个参数调用intersect;将一个列表与另一个列表相交就足够了：

def intersect(self, olinked):
thisone = self.head
otherone = olinked.head
retval = Linked()
while thisone and otherone:
if otherone.data > thisone.data:
thisone = thisone.next
elif thisone.data > otherone.data:
otherone = otherone.next
else:  # thisone.data == otherone.data
retval.push(otherone.data)
thisone = thisone.next
otherone = otherone.next
return retval
# ...
llist.intersect(llist1).print_list()