Deleting first and last element of a linked list in C

问题

struct person 
{
    int age;
    char name[100];
    struct person *next;
};

void delfirst(struct person **p)// For deleting the beginning
{
    struct person *tmp,*m;
    m = (*p);
        tmp = (*p)->next;
    free(m);
    return;

}
void delend(struct person **p)// For deleting the end
{
    struct person *tmp,*m;
    tmp=*p; 
    while(tmp->next!=NULL)
    {
        tmp=tmp->next;
    }
    m->next=tmp;
    free(tmp);
    m->next = NULL;
    return;

}

I'm looking for two separate functions to delete the first and last elements of a linked list. Here is what I tried. What do you suggest? Especially deleting first is so problematic for me.

回答1:

    if (!p || !(*p))
       return;
    struct person *tmp;
    tmp = (*p);
    (*p) = (*p)->next;
    free(tmp);
    return;

void delend(struct person **p)// For deleting the end
{
    if (!p || !(*p))
        return;
    if (!(*p)->next)
    {
        *p = NULL;    
    }
    struct person *tmp,*m;
    tmp=*p; 
    while(tmp->next->next!=NULL)
    {
        tmp=tmp->next;
    }
    free(tmp->next);
    tmp->next = NULL;
    return;

}

来源：https://stackoverflow.com/questions/2906636/deleting-first-and-last-element-of-a-linked-list-in-c