1 """
2 单链表学习程序
3 重点程序
4 """
5
6
7 # 创建结点类
8 class Node(object):
9 def __init__(self, val, next=None):
10 self.val = val # 有用数据
11 self.next = next
12
13
14 # 链表的操作
15 class LinkList(object):
16 def __init__(self):
17 self.head = Node(None) # 链表的开头
18
19 def init_list(self, data):
20 p = self.head # 可移动变量ｐ
21
22 for i in data:
23 p.next = Node(i)
24 p = p.next
25
26 def show(self):
27 p = self.head.next
28
29 while p != None:
30 print(p.val, end=' ')
31 p = p.next
32 print()
33
34 # 尾部插入新的结点
35 def append(self, item):
36 p = self.head
37 while p.next is not None:
38 p = p.next
39 p.next = Node(item)
40
41 # 获取链表长度
42 def get_length(self):
43 n = 0
44 p = self.head
45 while p.next is not None:
46 n += 1
47 p = p.next
48 return n
49
50 # 判断链表是否为空
51 def is_empty(self):
52 if self.get_length() == 0:
53 return True
54 else:
55 return False
56
57 # 清空链表
58 def clear(self):
59 self.head.next = None
60
61 # 获取索引值
62 def get_item(self, index):
63 p = self.head.next
64 i = 0
65 # 没有到对应索引号并且遍历索引没有到最后就循环
66 while i < index and p is not None:
67 i += 1
68 p = p.next
69 # 如果因为ｐ到最后了则说明越界
70 if p is None:
71 raise IndexError("list index out of range")
72 # ｉ 不小于 ｉｎｄｅｘ说明找到索引结点了
73 else:
74 return p.val
75
76 def insert(self,index,item):
77 if index < 0 or index > self.get_length():
78 raise IndexError("list index out of range")
79
80 # 让ｐ移动到待插入位置的前一个
81 p = self.head
82 i = 0
83 while i < index:
84 p = p.next
85 i += 1
86
87 node = Node(item) # 创建新的结点
88 node.next = p.next # 插入结点
89 p.next = node
90 #p.next=Node(item,p.next) # 一句话完成
91
92 def delete(self,item):
93 p = self.head
94 while p.next is not None:
95 # 如果值相等则越过中间的结点
96 if p.next.val == item:
97 p.next = p.next.next
98 break
99 p = p.next # 让程序继续前进
100 else:
101 raise ValueError("x not in list")
102
103
104 if __name__ == "__main__":
105 # 创建链表对象
106 link = LinkList()
107
108 # 初始数据
109 l = [1, 2, 3, 4, 5]
110 link.init_list(l) # 将初始数据插入链表
111 link.show() # 遍历链表
112 link.append(6) # 尾部插入结点
113 link.show()
114 print(link.get_length()) # 获取结点个数
115
116 # print(link.is_empty()) # 判断是否为空
117 # link.clear() # 清空链表
118 # print(link.is_empty())
119
120 print(link.get_item(4)) # 获取索引值
121
122 link.insert(1,10) # 在某个索引位置插入数据
123 link.show()
124 link.delete(10000)
125 link.show()
