class Node:
def __init__(self,data):
self.data = data # 数据
self.next = None; # 下一个节点
return
# 对下面这个函数还是有点儿疑问
def has_value(self,value):
if self.data == value:
return True
else:
return False
# 新建一个单链表的类
class singlelink():
def __init__(self):
self.head = None # head 与 tail 都是Node类型的节点
self.tail = None
self.length = 0
return
# 链表是否为空
def isempty(self):
return self.length == 0
def add_node(self,item):
if not isinstance(item,Node): # 如果不是Node型对象，那么就直接实例化一下
item = Node(item)
if self.head is None: # 如果当前这个链表没有头，那么设置为头
self.head = item
self.tail = item; #头尾都是这个
else:
self.tail.next = item
self.tail = item # 始终记录tail
self.length += 1
return
def insert_node(self,index,data):
if self.isempty():
print("this link is empty")
return
if index < 0 or index >= self.length:
print("error:out of index")
return
item = Node(data)
if index == 0:
item.next = self.head
self.head = item
self.length += 1
return
j = 0
node = self.head
prev = self.head
while node.next and j < index:
prev = node
node = node.next
j+=1
if j==index:
item._next = node
prev._next = item
self.length += 1
def print_link(self):
current_node = self.head
while current_node is not None:
print(current_node.data,end=' ')
current_node = current_node.next
return
# 定义几个实例
n1 = Node(1)
n2 = Node(2)
n3 = Node(3)
n4 = Node(4)
# 定义一个单链表
link = singlelink()
# 将得到的实例放到链表中，链表中存储的是节点
for node in [n1,n2,n3,n4]:
link.add_node(node)
# 调用链表的方法输出其中的值
link.print_link()
