单链表结点删除

/*
    QQ：778138708
    date:2020年5月15日
    单链表结点删除
 */
#include <stdio.h>
#include <stdlib.h>

struct ListNode {
    int data;
    struct ListNode *next;
};
struct ListNode *readlist(void);
struct ListNode *deletem(struct ListNode *L, int m);
void printlist(struct ListNode *L);
int main(void)
{
    int m;
    
    struct ListNode *L = readlist();
    scanf("%d", &m);
    L = deletem(L, m);
    printlist(L);
    
    return 0;
}
//新建一个链表
struct ListNode *readlist(void)
{
    struct ListNode *head, *tail, *p;
    int n;
    
    head = tail = NULL;
    scanf("%d", &n);
    while (n != -1) {
        p = (struct ListNode *)malloc(sizeof(struct ListNode));
        p->data = n;
        p->next = NULL;
        
        if (head == NULL) {
            head = tail = p;
        } else {
            tail->next = p;
            tail = tail->next;
        }
        
        scanf("%d", &n);
    }
    
    return head;
}
//删除，其实是跳过需要删除的结点，重新生成一个新的链表
struct ListNode *deletem(struct ListNode *L, int m)
{
    struct ListNode *head, *tail, *p, *temp;
    
    head = tail = NULL;
    p = L;
    
    while (p) {
        temp = p;
        p = p->next;
        if (temp->data != m) {
            if (head == NULL) {
                head = temp;
                head->next = NULL;
                tail = head;
            } else {
                tail->next = temp;
                tail = tail->next;
                tail->next = NULL;      //tail等于temp，所以tail->next = NULL
            }
        }
    }
    //返回新的链表头
    return head;
}
void printlist(struct ListNode *L)
{
    struct ListNode *p = L;
    
    while (p) {
        printf("%d ", p->data);
        p = p->next;
    }
    
    printf("
");
}