class Node:
def __init__(self, data):
self.data = data
self.next = Noneclass LinkedList:
def __init__(self):
self.head = None
self.tail = None
def is_empty(self):
return self.head is None
def append(self, data):
node = Node(data)
if self.head is None:
self.head = node
self.tail = node
else:
self.tail.next = node
self.tail = node
def iter(self):
if not self.head:
return
cur = self.head
yield cur.data
while cur.next:
cur = cur.next
yield cur.data
def insert(self, idx, value):
cur = self.head
cur_idx = 0
if cur is None: # 判断是否是空链表
raise Exception('The list is an empty list')
while cur_idx < idx-1: # 遍历链表
cur = cur.next
if cur is None: # 判断是不是最后一个元素
raise Exception('list length less than index')
cur_idx += 1
node = Node(value)
node.next = cur.next
cur.next = node
if node.next is None:
self.tail = node
def remove(self, idx):
cur = self.head
cur_idx = 0
if self.head is None: # 空链表时
raise Exception('The list is an empty list')
while cur_idx < idx-1:
cur = cur.next
if cur is None:
raise Exception('list length less than index')
cur_idx += 1
if idx == 0: # 当删除第一个节点时
self.head = cur.next
cur = cur.next
return
if self.head is self.tail: # 当只有一个节点的链表时
self.head = None
self.tail = None
return
cur.next = cur.next.next
if cur.next is None: # 当删除的节点是链表最后一个节点时
self.tail = cur
def size(self):
current = self.head
count = 0
if current is None:
return 'The list is an empty list'
while current is not None:
count += 1
current = current.next
return count
def search(self, item):
current = self.head
found = False
while current is not None and not found:
if current.data == item:
found = True
else:
current = current.next
return found
if __name__ == '__main__':
link_list = LinkedList()
for i in range(150):
link_list.append(i)
# print(link_list.is_empty())
# link_list.insert(10, 30)
# link_list.remove(0)
for node in link_list.iter():
print('node is {0}'.format(node))
print(link_list.size())
# print(link_list.search(20))