1 （1）定义双向链表的基本结构
2 typedef struct _DOUBLE_LINK_NODE
3 {
4 int data;
5 struct _DOUBLE_LINK_NODE* prev;
6 struct _DOUBLE_LINK_NODE* next;
7 }DOUBLE_LINK_NODE;
8
9 （2）创建双向链表节点
10 [cpp] view plaincopy
11
12 DOUBLE_LINK_NODE* create_double_link_node(int value)
13 {
14 DOUBLE_LINK_NODE* pDLinkNode = NULL;
15 pDLinkNode = (DOUBLE_LINK_NODE*)malloc(sizeof(DOUBLE_LINK_NODE));
16 assert(NULL != pDLinkNode);
17
18 memset(pDLinkNode, 0, sizeof(DOUBLE_LINK_NODE));
19 pDLinkNode->data = value;
20 return pDLinkNode;
21 }
22
23 （3）删除双向链表
24 [cpp] view plaincopy
25
26 void delete_all_double_link_node(DOUBLE_LINK_NODE** pDLinkNode)
27 {
28 DOUBLE_LINK_NODE* pNode;
29 if(NULL == *pDLinkNode)
30 return ;
31
32 pNode = *pDLinkNode;
33 *pDLinkNode = pNode->next;
34 free(pNode);
35 delete_all_double_link_node(pDLinkNode);
36 }
37
38 （4）在双向链表中查找数据
39 [cpp] view plaincopy
40
41 DOUBLE_LINK_NODE* find_data_in_double_link(const DOUBLE_LINK_NODE* pDLinkNode, int data)
42 {
43 DOUBLE_LINK_NODE* pNode = NULL;
44 if(NULL == pDLinkNode)
45 return NULL;
46
47 pNode = (DOUBLE_LINK_NODE*)pDLinkNode;
48 while(NULL != pNode){
49 if(data == pNode->data)
50 return pNode;
51 pNode = pNode ->next;
52 }
53
54 return NULL;
55 }
56
57 （5）双向链表中插入数据
58 [cpp] view plaincopy
59
60 STATUS insert_data_into_double_link(DOUBLE_LINK_NODE** ppDLinkNode, int data)
61 {
62 DOUBLE_LINK_NODE* pNode;
63 DOUBLE_LINK_NODE* pIndex;
64
65 if(NULL == ppDLinkNode)
66 return FALSE;
67
68 if(NULL == *ppDLinkNode){
69 pNode = create_double_link_node(data);
70 assert(NULL != pNode);
71 *ppDLinkNode = pNode;
72 (*ppDLinkNode)->prev = (*ppDLinkNode)->next = NULL;
73 return TRUE;
74 }
75
76 if(NULL != find_data_in_double_link(*ppDLinkNode, data))
77 return FALSE;
78
79 pNode = create_double_link_node(data);
80 assert(NULL != pNode);
81
82 pIndex = *ppDLinkNode;
83 while(NULL != pIndex->next)
84 pIndex = pIndex->next;
85
86 pNode->prev = pIndex;
87 pNode->next = pIndex->next;
88 pIndex->next = pNode;
89 return TRUE;
90 }
91
92 （6）双向链表中删除数据
93 [cpp] view plaincopy
94
95 STATUS delete_data_from_double_link(DOUBLE_LINK_NODE** ppDLinkNode, int data)
96 {
97 DOUBLE_LINK_NODE* pNode;
98 if(NULL == ppDLinkNode || NULL == *ppDLinkNode)
99 return FALSE;
100
101 pNode = find_data_in_double_link(*ppDLinkNode, data);
102 if(NULL == pNode)
103 return FALSE;
104
105 if(pNode == *ppDLinkNode){
106 if(NULL == (*ppDLinkNode)->next){
107 *ppDLinkNode = NULL;
108 }else{
109 *ppDLinkNode = pNode->next;
110 (*ppDLinkNode)->prev = NULL;
111 }
112
113 }else{
114 if(pNode->next)
115 pNode->next->prev = pNode->prev;
116 pNode->prev->next = pNode->next;
117 }
118
119 free(pNode);
120 return TRUE;
121 }
122
123 （7）统计双向链表中数据的个数
124 [cpp] view plaincopy
125
126 int count_number_in_double_link(const DOUBLE_LINK_NODE* pDLinkNode)
127 {
128 int count = 0;
129 DOUBLE_LINK_NODE* pNode = (DOUBLE_LINK_NODE*)pDLinkNode;
130
131 while(NULL != pNode){
132 count ++;
133 pNode = pNode->next;
134 }
135 return count;
136 }
137
138 （8）打印双向链表中数据
139 [cpp] view plaincopy
140
141 void print_double_link_node(const DOUBLE_LINK_NODE* pDLinkNode)
142 {
143 DOUBLE_LINK_NODE* pNode = (DOUBLE_LINK_NODE*)pDLinkNode;
144
145 while(NULL != pNode){
146 printf("%d\n", pNode->data);
147 pNode = pNode ->next;
148 }
149 }
150
151 注意：
152
153 今天我们讨论的双向链表是非循环的，大家可以考虑一下如果改成循环双向链表，应该怎么写？如果是有序的循环双向链表，又该怎么写？
