手把手写数据结构之双向链表操作

define NAME_LEN    20    //名字最大长度

//函数入口检测(宏)
#define TEST(arg) if(arg == NULL){\
    printf("Invalid arg..................\n");\
    return -1;\
}

typedef enum sex//性别封装
{
    b ,            //男
    g ,            //女
}E_SEX;

typedef struct stu_info//学生信息封装
{
    int num;                //学号
    char name[NAME_LEN+1];    //姓名
    E_SEX sex;                //性别
}STU_INFO;

typedef struct stu_node//结点信息
{
    STU_INFO stu;            //学生信息
    struct stu_node *prev;    //结点指针前驱
    struct stu_node *next;    //结点指针后驱
}NODE;


typedef struct link_info
{
    int node_count;//结点个数
    NODE *head;        //指向首元结点的指针
}LINK_INFO;







//创建结点
static NODE *__Create_Node__(STU_INFO stu)
{
    NODE *new_node = (NODE *)malloc(sizeof(NODE));
    if(NULL == new_node)
    {
        perror("Create_Node");
        return NULL;
    }

    new_node ->stu = stu;
    new_node->next = NULL;
    new_node->prev = NULL;

    return new_node;
}

/*************************************************
*Des:    查找某个结点是否存在
*Ret:    成功返回结点，失败返回NULL；
**************************************************/
static NODE *__Find_Node__(LINK_INFO *plist, int num)
{
    if(NULL == plist)
    {
        printf("Invalid arg.......\n");
        return NULL;
    }

    NODE *pnode = plist->head;
    while(NULL != pnode)
    {
        if(pnode->stu.num == num)
            break;
        pnode = pnode->next;
    }

    return pnode;
}

/*************************************************
*Des:    创建学生信息链表
*Ret:    成功返回0，失败返回-1；
**************************************************/
int Stu_Ceate_Link(LINK_INFO **plist)
{
    TEST(plist);//函数入口检测

    *plist = (LINK_INFO *)malloc(sizeof(LINK_INFO));
    if(NULL == *plist)
    {
        perror("Create Link");
        return -1;
    }

    (*plist)->node_count = 0;
    (*plist)->head = NULL;
    
    return 0;
}

/*************************************************
*Des:    判断学生信息链表是否为空
*Ret:    真空:1 ,假空:0
**************************************************/
int Stu_Is_Empty(LINK_INFO *plist)
{
    return ((NULL == plist->head) ? 1 : 0);
}

/*************************************************
*Des:    添加结点到链表(按num排好序)
*Ret:    成功返回0，失败返回-1；
**************************************************/
int Stu_Add_Node(LINK_INFO *plist, STU_INFO stu)
{
    TEST(plist);//函数入口检测

    NODE *tmpnode = NULL, *pnode = plist->head;

    if(__Find_Node__(plist, stu.num) != NULL)
    {
        printf("Have this Node!\n");
        return -1;
    }

    //创建结点
    NODE *new_node = __Create_Node__(stu);
    if(NULL == new_node)
        return -1;
    
    if(Stu_Is_Empty(plist))//当链表为空
    {
        plist->head = new_node;
    }
    else    //链表非空
    {
        while(NULL != pnode)
        {
            if(pnode->stu.num > stu.num)
                break;
            tmpnode = pnode;
            pnode = pnode->next;
        }
        if(NULL == pnode)//添加到尾结点后
        {
            tmpnode->next = new_node;
            new_node->prev = tmpnode;
        }
        else
        {
            if(NULL == tmpnode)//添加到头结点前
            {
                new_node->next = plist->head;
                plist->head->prev = new_node;
                plist->head = new_node;
            }
            else//其它
            {
                tmpnode->next = new_node;
                new_node->prev = tmpnode;
                new_node->next = pnode;
                pnode->prev = new_node;
            }
        }
        
    }
    
    plist->node_count++;

    return 0;
}

/*************************************************
*Des:    删除学生信息
*Ret:    成功返回0，失败返回-1；
**************************************************/
int Stu_Delete_Node(LINK_INFO *plist, int num)
{
    TEST(plist);//函数入口检测

    NODE *pnode = NULL;
    if(NULL == (pnode = __Find_Node__(plist, num)))//1
    {
        return -1;
    }

    //只有1个节点
    if(pnode == plist->head && pnode->next == NULL)
    {
        plist->head = NULL;
    }

    //2.是头结点
    else if(pnode == plist->head)
    {
        plist->head = pnode->next;
        pnode->next->prev = NULL;
        //plist->head->prev = NULL;
    }
    //3.是最后一个节点
    else if(pnode->next == NULL)
    {
        pnode->prev->next = NULL;
    }
    //4.其他节点
    else
    {
        pnode->prev->next = pnode->next;
        pnode->next->prev = pnode->prev;
    }

    free(pnode);

    plist->node_count--;

    return 0;
}


/*************************************************
*Des:    遍历学生信息
*Ret:    成功返回0，失败返回-1；
**************************************************/
int Stu_Traverse(LINK_INFO *plist)
{
    TEST(plist);//函数入口检测

    if(Stu_Is_Empty(plist))
    {
        printf("The list is empty!\n");
        return -1;
    }

    NODE *pnode = plist->head;
printf("###################################################\n");
    printf("num\t  name\t\tsex\t\n");
    while(NULL != pnode)
    {
        if(pnode->stu.sex == 0)
            pnode->stu.sex += 98;
        else
            pnode->stu.sex += 102;
        
        printf("%-10d%-10s\t%c\n", pnode->stu.num,
                            pnode->stu.name, pnode->stu.sex);
        pnode = pnode->next;
    }

printf("###################################################\n");
    
    return 0;
}

/*************************************************
*Des:    清空链表操作
*Ret:    成功返回0，失败返回-1；
**************************************************/
int Stu_Empty_Link(LINK_INFO *plist)
{
    TEST(plist);//函数入口检测

    if(Stu_Is_Empty(plist))
    {
        printf("The is list is empty!\n");
        return -1;
    }
    
    NODE *tmpnode = NULL, *pnode = plist->head;
    while(pnode != NULL)
    {
        tmpnode= pnode; 
        pnode = pnode->next;
    }
    
    plist->head = NULL;
    plist->node_count = 0;

    return 0;
}


/*************************************************
*Des:    销毁链表
*Ret:    成功返回0，失败返回-1；
**************************************************/
int Stu_Destory_Link(LINK_INFO **plist)
{
    TEST(plist);

    //清空链表
    if(Stu_Empty_Link(plist) < 0)
        return -1;

    free(*plist);

    *plist = NULL;

    return 0;
}