1 /*****************************************************
2 Author：Simon_Kly Version:0.1 Date: 20170520
3 Description：带头结点的双向循环链表
4 Mail: degaullekong@gmail.com
5 Funcion List:
6 *****************************************************/
7
8 #include <stdio.h>
9 #include <stdlib.h>
10
11 typedef struct node
12 {
13 int data;
14 struct node *prior, *next;
15 }Node, *Link;
16
17 void is_malloc_ok(Link head)
18 {
19 if (head == NULL)
20 {
21 printf("malloc is error!\n");
22 exit(-1);
23 }
24 }
25
26 /*创建链表*/
27 void create_link(Link * head)
28 {
29 *head = (Link)malloc(sizeof(Node));
30
31 is_malloc_ok(*head);
32
33 (*head)->next = (*head)->prior = *head;//让其指向自己
34 }
35
36 /*创建节点*/
37 void create_node(Link * new_node)
38 {
39 *new_node = (Link)malloc(sizeof(Node));
40 is_malloc_ok(*new_node);
41 }
42
43 /*插入节点(头插)*/
44 void insert_node_head(Link head, Link new_node)
45 {
46 new_node->prior = head;
47 new_node->next = (head)->next;
48 (head)->next->prior = new_node;
49 (head)->next = new_node;
50 }
51
52
53 /*插入节点(尾插)*/
54 void insert_node(Link * head, Link new_node)
55 {
56 Link p = NULL;
57
58 p = *head;
59 while (p->next != *head)
60 {
61 p = p->next;
62 }
63
64 new_node->prior = p;
65 new_node->next = p->next;
66 p->next->prior = new_node;
67 p->next = new_node;
68 }
69
70 /*输出链表*/
71 void out_link(Link head)
72 {
73 Link p = NULL;
74 #if 0
75 if (head->next == head)
76 {
77 printf("link is empty\n");
78 return ;
79 }
80 #endif
81
82 if (head == NULL)
83 {
84 printf("link is empty\n");
85 return ;
86 }
87
88 p = (head)->next;
89
90 while (p != head)
91 {
92 printf("%d\n", p->data);
93 p = p->next;
94 }
95 putchar(10);
96 }
97
98 /*变成空链*/
99 void make_empty(Link * head)
100 {
101 Link p = NULL;
102
103 p = (*head)->next;
104
105 while (*head != (*head)->next)
106 {
107 (*head)->next = p->next;//head移动
108 free(p);//释放head之前的节点
109 p = (*head)->next;
110 }
111 }
112
113 /*释放链表*/
114 void release_link(Link * head)
115 {
116 make_empty(head);
117
118 free(*head);
119
120 *head = NULL;
121 }
122
123 /*删除节点*/
124 void delete_node(Link * head, int data)
125 {
126 Link p = NULL;
127
128 p = (*head)->next;
129
130 if (p == *head)//空链
131 {
132 printf("link is empty!\n");
133 return ;
134 }
135
136 /*非空链*/
137 while (p != *head && p->data != data)
138 {
139 p = p->next;//找那个节点
140 }
141
142 if (p == *head)//找一圈没找到
143 {
144 printf("No such node!\n");
145 return ;
146 }
147 else//找到并改变指向
148 {
149 p->prior->next = p->next;
150 p->next->prior = p->prior;
151
152 free(p);
153 }
154 }
155
156 void insert_node_seq(Link * head, Link new_node)
157 {
158 Link p = NULL;
159
160 p = (*head);
161
162 while (p->next != *head && new_node->data < p->next->data)//找到该位置的前一个位置
163 {
164 p = p->next;
165 }
166 #if 0
167 if (p == *head)//找到尾部
168 {
169 new_node->prior = p->prior;
170 new_node->next = p;
171 p->prior->next = new_node;
172 p->prior = new_node;
173 return ;
174 }
175 #endif
176 new_node->prior = p;
177 new_node->next = p->next;
178 p->next->prior = new_node;
179 p->next = new_node;
180
181 }
182
183 int main()
184 {
185 int i;
186 Link head = NULL;
187 Link new_node = NULL;
188 create_link(&head);
189
190 out_link(head);
191
192 for (i = 0; i < 10; i++)
193 {
194 create_node(&new_node);
195 new_node->data = i + 1;
196 // insert_node(&head, new_node);
197 insert_node_head(head, new_node);
198 }
199
200 out_link(head);
201
202 #if 1
203 printf("please input i\n");
204 scanf("%d", &i);
205 putchar(10);
206 create_node(&new_node);
207 new_node->data = i;
208 insert_node_seq(&head, new_node);
209 out_link(head);
210 #endif
211
212 #if 0
213 delete_node(&head, 2);
214 out_link(head);
215 #endif
216 release_link(&head);
217 out_link(head);
218 return 0;
219 }
