函數實現:
- 單鏈表的初始化;
- 單鏈表的判空;
- 單鏈表的長度;
- 單鏈表的插入節點:頭插、尾插、隨機插入;
- 單鏈表的遍歷節點;
- 單鏈表的刪除節點;
- 單鏈表的查找節點(搜索節點);
代碼:
class Node(object):
"""節點"""
def __init__(self, elem):
self.elem = elem
self.next = None
class SingleLinkList(object):
"""單鏈表"""
def __init__(self, node = None):
self.__head = node
def is_empty(self):
"""鏈表是否爲空"""
return self.__head == None
def length(self):
# 遊標用來遍歷節點
cur = self.__head
# 節點計數器,初始值影響while循環的判斷條件
counter = 0
while cur != None :
counter += 1
cur = cur.next
return counter
def travel(self):
cur = self.__head
while cur != None:
print(cur.elem)
cur = cur.next
def add(self, item):
"""鏈表頭部添加元素"""
# print("=====頭插法=====")
node = Node(item)
node.next = self.__head
self.__head = node
def append(self, item):
"""鏈表尾部添加元素"""
node = Node(item)
# print("=====尾插法=====")
# 特殊情況
if self.is_empty():
self.__head = node
else:
cur = self.__head
while cur.next != None:
cur = cur.next
cur.next = node
def insert(self, pos, item):
"""
指定位置添加元素
@pos: 從0開始 例:insert(2,100)
"""
if pos <= 0 :
self.add(item)
elif pos > (self.length() - 1):
self.append(item)
else:
node = Node(item)
pre = self.__head
count = 0
while count < (pos - 1):
pre = pre.next
count += 1
# 當循環退出後,pre指向pos-1位置
node.next = pre.next
pre.next = node
def search(self, item):
"""查找節點是否存在"""
cur = self.__head
while cur != None:
if cur.elem == item:
return True
else:
cur = cur.next
return False
# 難度係數高
def remove(self, item):
cur = self.__head
pre = None
while cur != None:
if cur.elem == item:
# 判斷此節點是否爲頭節點
if cur == self.__head:
self.__head = cur.next
else:
pre.next = cur.next
break
# pass
else:
pre = cur
cur = cur.next