链表逆序[c]

void reverse(struct list *ls)//链表逆置
{
    if (ls->next == NULL)
        return;//只有一个首节点，不需要逆置

    if (ls->next->next == NULL)
        return;//也不需要逆置

    struct list *last = ls->next;//逆置后ls->next就成了最后一个节点了

    struct list *pre = ls;//上一个节点的指针
    struct list *cur = ls->next;//当前节点的指针
    struct list *next = NULL;//下一个节点的指针
    while(cur)
    {
        next = cur->next;
        cur->next = pre;
        pre = cur;
        cur = next;
    }

    ls->next = pre;
    last->next = NULL;
}