单链表结点删除

Posted 2021-02-19 2018jason

 1 /*
 2     QQ：778138708
 3     date:2020年5月15日
 4     单链表结点删除
 5  */
 6 #include <stdio.h>
 7 #include <stdlib.h>
 8 
 9 struct ListNode {
10     int data;
11     struct ListNode *next;
12 };
13 struct ListNode *readlist(void);
14 struct ListNode *deletem(struct ListNode *L, int m);
15 void printlist(struct ListNode *L);
16 int main(void)
17 {
18     int m;
19     
20     struct ListNode *L = readlist();
21     scanf("%d", &m);
22     L = deletem(L, m);
23     printlist(L);
24     
25     return 0;
26 }
27 //新建一个链表
28 struct ListNode *readlist(void)
29 {
30     struct ListNode *head, *tail, *p;
31     int n;
32     
33     head = tail = NULL;
34     scanf("%d", &n);
35     while (n != -1) {
36         p = (struct ListNode *)malloc(sizeof(struct ListNode));
37         p->data = n;
38         p->next = NULL;
39         
40         if (head == NULL) {
41             head = tail = p;
42         } else {
43             tail->next = p;
44             tail = tail->next;
45         }
46         
47         scanf("%d", &n);
48     }
49     
50     return head;
51 }
52 //删除，其实是跳过需要删除的结点，重新生成一个新的链表
53 struct ListNode *deletem(struct ListNode *L, int m)
54 {
55     struct ListNode *head, *tail, *p, *temp;
56     
57     head = tail = NULL;
58     p = L;
59     
60     while (p) {
61         temp = p;
62         p = p->next;
63         if (temp->data != m) {
64             if (head == NULL) {
65                 head = temp;
66                 head->next = NULL;
67                 tail = head;
68             } else {
69                 tail->next = temp;
70                 tail = tail->next;
71                 tail->next = NULL;      //tail等于temp，所以tail->next = NULL
72             }
73         }
74     }
75     //返回新的链表头
76     return head;
77 }
78 void printlist(struct ListNode *L)
79 {
80     struct ListNode *p = L;
81     
82     while (p) {
83         printf("%d ", p->data);
84         p = p->next;
85     }
86     
87     printf("
");
88 }