c语言双向链表的实现

1. dlist.h

 1 #ifndef _DLIST_H
 2 #define _DLIST_H
 3 
 4 
 5 typedef struct _dlist_node
 6 {
 7     struct _dlist_node *p_next; /* 指向下一个结点的指针 */
 8     struct _dlist_node *p_prev; /* 指向上一个结点的指针 */
 9 }dlist_node_t;
10 
11 typedef dlist_node_t dlist_head_t;
12 typedef int (*dlist_node_process_t)(void *p_arg, dlist_node_t *p_node);
13 
14 int dlist_init(dlist_head_t *p_head);
15 int dlist_add(dlist_head_t *p_head, dlist_node_t *p_pos, dlist_node_t *p_node);
16 int dlist_add_tail(dlist_head_t *p_head, dlist_node_t *p_node);
17 int dlist_add_head(dlist_head_t *p_head, dlist_node_t *p_node);
18 int dlist_del(dlist_head_t *p_head, dlist_node_t *p_node);
19 
20 dlist_node_t *dlist_prev_get(dlist_head_t *p_head, dlist_node_t *p_pos);
21 dlist_node_t *dlist_next_get(dlist_head_t *p_head, dlist_node_t *p_pos);
22 dlist_node_t *dlist_tail_get(dlist_head_t *p_head);
23 dlist_node_t *dlist_begin_get(dlist_head_t *p_head);
24 dlist_node_t *dlist_end_get (dlist_head_t *p_head);
25 int dlist_foreach(dlist_head_t *p_head,
26                 dlist_node_process_t pfn_node_process,
27                 void *p_arg);
28 
29 #endif

2. dlist.c

  1 #include "dlist.h"
  2 #include <stdlib.h>
  3 
  4 int dlist_init(dlist_head_t *p_head)
  5 {
  6     if (p_head == NULL)
  7     {
  8         return -1;
  9     }
 10     p_head->p_next = p_head;
 11     p_head->p_prev = p_head;
 12     return 0;
 13 }
 14 
 15 int dlist_add(dlist_head_t *p_head, dlist_node_t *p_pos, dlist_node_t *p_node)
 16 {
 17     if ((p_head == NULL) || (p_pos == NULL) || (p_node == NULL))
 18     {
 19         return -1;
 20     }
 21     p_node->p_prev = p_pos;
 22     p_node->p_next = p_pos->p_next;
 23     p_pos->p_next->p_prev = p_node;
 24     p_pos->p_next = p_node;
 25     return 0;
 26 }
 27 
 28 int dlist_add_tail(dlist_head_t *p_head, dlist_node_t *p_node)
 29 {
 30     return dlist_add(p_head, p_head->p_prev, p_node);
 31 }
 32 
 33 int dlist_add_head(dlist_head_t *p_head, dlist_node_t *p_node)
 34 {
 35     return dlist_add(p_head, p_head, p_node);    
 36 }
 37 
 38 int dlist_del(dlist_head_t *p_head, dlist_node_t *p_node)
 39 {
 40     if ((p_head == NULL) || (p_node == NULL) || (p_node == p_head))
 41     {
 42         return -1;
 43     }
 44     p_node->p_prev->p_next = p_node->p_next;
 45     p_node->p_next->p_prev = p_node->p_prev;
 46     p_node->p_next = NULL;
 47     p_node->p_prev = NULL;
 48     return 0;
 49 }
 50 
 51 dlist_node_t *dlist_prev_get(dlist_head_t *p_head, dlist_node_t *p_pos)
 52 {
 53     if (p_pos != NULL)
 54     {
 55         return p_pos->p_prev;
 56     }
 57     return NULL;    
 58 }
 59 
 60 dlist_node_t *dlist_next_get(dlist_head_t *p_head, dlist_node_t *p_pos)
 61 {
 62     if (p_pos != NULL)
 63     {
 64         return p_pos->p_next;
 65     }
 66     return NULL;   
 67 }
 68 
 69 dlist_node_t *dlist_tail_get(dlist_head_t *p_head)
 70 {
 71     if (p_head != NULL) 
 72     {
 73         return p_head->p_prev;
 74     }
 75     return NULL;
 76 }
 77 
 78 dlist_node_t *dlist_begin_get(dlist_head_t *p_head)
 79 {
 80     if (p_head != NULL)
 81     {
 82         return p_head->p_next;
 83     }
 84     return NULL;
 85 }
 86 
 87 dlist_node_t *dlist_end_get (dlist_head_t *p_head)
 88 {
 89     return p_head;
 90     /*
 91     if (p_head != NULL) 
 92     {
 93         return p_head->p_prev;
 94     }
 95     return NULL;
 96     */
 97 }
 98 
 99 int dlist_foreach(dlist_head_t *p_head,
100                   dlist_node_process_t pfn_node_process,
101                   void *p_arg)
102 {
103     dlist_node_t *p_tmp, *p_end;
104     int ret;
105 
106     if ((p_head == NULL) || (pfn_node_process == NULL)) 
107     {
108         return -1;
109     }
110 
111     p_tmp = dlist_begin_get(p_head);
112     p_end = dlist_end_get(p_head);
113 
114     while (p_tmp != p_end) 
115     {
116         ret = pfn_node_process(p_arg, p_tmp);
117         if (ret < 0) 
118         {
119             return ret;
120         }
121         p_tmp = dlist_next_get(p_head, p_tmp);
122     }
123 //    pfn_node_process(p_arg, p_tmp);
124     return 0;
125 }

3. demo

 1 #include <stdio.h>
 2 #include "dlist.h"
 3 
 4 typedef struct _dlist_int 
 5 {
 6     dlist_node_t node; /* 包含链表结点 */
 7     int data; /* int类型数据 */
 8 }dlist_int_t;
 9 
10 int list_node_process(void *p_arg, dlist_node_t *p_node)
11 {
12     printf("%d ", ((dlist_int_t *)p_node)->data);
13     return 0;
14 }
15 
16 int main(void)
17 {
18     dlist_head_t head; /* 定义链表头结点 */
19     dlist_int_t node1, node2, node3;
20     dlist_init(&head);
21 
22     node1.data = 1;
23     dlist_add(&head, &head, &(node1.node));
24     node2.data = 2;
25     dlist_add(&head, &(node1.node), &(node2.node));
26     node3.data = 3;
27     dlist_add(&head, &(node2.node), &(node3.node));
28     printf("Before delete node.\n");
29     dlist_foreach(&head, list_node_process, NULL);
30     dlist_del(&head, &(node2.node));
31     printf("\nAfter delet node.\n");
32     dlist_foreach(&head, list_node_process, NULL); /* 遍历链表，用户参数为NULL */
33     return 0;
34 }