c++链表基本操作

  1 #include <stdlib.h>
  2 #include <malloc.h>
  3 #include <stdio.h>
  4 
  5 typedef struct Node
  6 {
  7     int data;
  8     struct Node *pNext;
  9 }NODE,*PNODE;
 10 
 11 PNODE create_list(void);
 12 void traverse_list(PNODE);
 13 bool is_empty(PNODE pHead);
 14 int length_list(PNODE);
 15 bool insert_list(PNODE, int, int);
 16 bool delete_list(PNODE,int,int*);
 17 void sort_list(PNODE);
 18 
 19 int main(void)
 20 {
 21     PNODE pHead = NULL;
 22     int val;
 23     pHead = create_list();
 24     sort_list(pHead);
 25     if (delete_list(pHead, 4, &val))
 26     {
 27         printf("delete %d ok!\n",val);
 28     }
 29     else
 30     {
 31         printf("delete wrong");
 32     }
 33     traverse_list(pHead);
 34     int len = length_list(pHead);
 35     if (is_empty(pHead))
 36     {
 37         printf("list is empty!");
 38     }
 39     else
 40     {
 41         printf("list isn't empty！");
 42     }
 43     return 0;
 44 }
 45 
 46 PNODE create_list(void)
 47 {
 48     int len;
 49     int val;//用于存放用户输入的结点的值
 50     printf("请输入链表的长度：len=");
 51     scanf("%d", &len);
 52     PNODE pHead = (PNODE)malloc(sizeof(Node));
 53 
 54     if (NULL == pHead)
 55     {
 56         printf("分配失败，程序终止!");
 57         exit(-1);
 58     }
 59     PNODE pTail = pHead;
 60     pTail->pNext = NULL;
 61 
 62     for (int i = 0; i < len; ++i)
 63     {
 64         printf("请输入第%d个节点的值", i + 1);
 65         scanf("%d", &val);
 66         PNODE pNew = (PNODE)malloc(sizeof(Node));
 67         if (NULL == pNew)
 68         {
 69             printf("分配失败，程序终止!");
 70             exit(-1);
 71         }
 72         pNew->data = val;
 73         pTail->pNext = pNew;
 74         pNew->pNext = NULL;
 75         pTail = pNew;
 76     }
 77     return pHead;
 78 }
 79 
 80 void traverse_list(PNODE pHead)
 81 {
 82     PNODE p = pHead->pNext;
 83     while (NULL != p)
 84     {
 85         printf("%d", p->data);
 86         p = p->pNext;
 87     }
 88     printf("\n");
 89 }
 90 
 91 bool is_empty(PNODE pHead)
 92 {
 93     if (NULL == pHead->pNext)
 94     {
 95         return true;
 96     }
 97     return false;
 98 }
 99 
100 int length_list(PNODE pHead)
101 {
102     int length = 0;
103     PNODE p = pHead->pNext;
104     while (NULL != p)
105     {
106         length++;
107         p = p->pNext;
108     }
109     return length;
110 }
111 
112 void sort_list(PNODE pHead)
113 {
114     int i, j, t;
115     int len = length_list(pHead);
116     PNODE p, q;
117     for (i = 0, p = pHead->pNext; i < len - 1; ++i, p=p->pNext)
118     {
119         for (j = i + 1, q = p->pNext; j < len; ++j, q = q->pNext)
120         {
121             if (p->data > q->data)
122             {
123                 t = p->data;
124                 p->data = q->data;
125                 q->data = t;
126             }
127         }
128     }
129     return;
130 }
131 //在pHead指向链表的第pos个节点的前面插入一个新的节点，该节点的值为value,pos从1开始
132 bool insert_list(PNODE pHead, int pos, int value)
133 {
134     int i = 0;
135     PNODE p = pHead;
136     while (NULL != p && i < pos - 1)
137     {
138         p = p->pNext;
139         ++i;
140     }
141     if (i > pos - 1 || NULL == p)
142         return false;
143     PNODE pNew = (PNODE)malloc(sizeof(NODE));
144     if (NULL == pNew)
145     {
146         printf("动态分配内存失败！\n");
147         exit(-1);
148     }
149     pNew->data = value;
150     PNODE q = p->pNext;
151     p->pNext = pNew;
152     pNew->pNext = q;
153     return true;
154 }
155 
156 bool delete_list(PNODE pHead, int pos, int *pVal)
157 {
158     int i = 0;
159     PNODE p = pHead;
160     while (NULL != p->pNext && i < pos - 1)
161     {
162         p = p->pNext;
163         ++i;
164     }
165     if (i > pos - 1 || NULL == p->pNext)
166     {
167         return false;
168     }
169     PNODE q = p->pNext;
170     *pVal = q->data;
171     //删除p节点后面的节点
172     p->pNext = p->pNext->pNext;
173     free(q);
174     q = NULL;
175     return true;
176 }
177 
178 
179 /*
180 1.链表的删除，比如删除p后的节点，如何操作？有时很容易遗漏free(r)的操作，导致内存泄漏。
181 可以如下操作：
182 r = p->next;
183 p->next = r->next;
184 free(r);
185 */
posted on 2018-09-18 21:21 Worty 阅读(1003) 评论(0) 编辑收藏举报