单项循环链表

pragma once

include

#include "head.h"
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
bool _insert(NODE** head,int index)
{
    NODE* node = (NODE*)malloc(sizeof(NODE));
    memset(node,0x00,sizeof(NODE));
    node->index = index;
    if (*head == NULL)
    {
        *head = node;
        node->next = node;
        return true;
    }
    if ((*head)->index > node->index)
    {
        for (NODE* p = *head;;p=p->next)
        {
            if (p->next==*head)
            {
                node->next = *head;
                p->next = node;
                *head = node;
                return true;
            }
        }
    }   
    for (NODE* p = *head;; p = p->next)
    {
        if (p->next==*head)
        {
            node->next = p->next;
            p->next = node;
            return true;
        }
        if (node->index < p->next->index)
        {
            node->next = p->next;
            p->next = node;
            return true;
        }
    }       
    return NULL;
}

#define q (*list)
void _remove(NODE** list2, int i) 
{
    NODE* list3 = *list2;
    NODE** list = &list3;
    if (q->next == q)
    {
        //printf("%d", LIST->index);
        return;
    }
    else
    {
        if (i == 2)
        {
            NODE* p = q->next;
            q->next = q->next->next;
            free(p);
            _show(q);
            i = 0;
        }
        _remove(&(q->next), i + 1);
    }
}
#undef q;
//q先走一步,然后构造一个删除q->next的方法,(&(q->next), i + 1)从而达到删除第三个节点的目的;
//递归调用不断重复,当满足q->next=q时跳出函数;

void _show(NODE* list_tail)
{
    NODE* p = NULL;
    for (p = list_tail;; p = p->next)
    {
        printf("%d\n", p->index);
        if (p->next == list_tail)
        {
            printf("--------------\n");
            break;
        }
    }
    return;
}

void main()
{
    NODE* p = NULL;
    _insert(&p,9);
    _insert(&p,6);
    _insert(&p,3);
    _insert(&p,7);
    _insert(&p,8);
    _insert(&p,1);
    _show(p);
    _remove(&p,1);
    system("pause");
}