C语言-指针

目的：双向链表 -> 实现链表的添加和删除等操作

编译环境：VS2013

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>


typedef enum{
    FALSE = 0,
    TRUE = 1,
}STATUS;

// 1. 定义双向链表的基本结构
typedef struct _DOUBLE_LINK_NODE
{
    int data;
    struct _DOUBLE_LINK_NODE* prev;
    struct _DOUBLE_LINK_NODE* next;
}DOUBLE_LINK_NODE, *DuLinkList;

// 2. 创建双向链表节点
DOUBLE_LINK_NODE* create_double_link_node(int value)
{
    DOUBLE_LINK_NODE* pDLinkNode = NULL;
    pDLinkNode = (DOUBLE_LINK_NODE*)malloc(sizeof(DOUBLE_LINK_NODE));
    assert(NULL != pDLinkNode);

    memset(pDLinkNode, 0, sizeof(DOUBLE_LINK_NODE));
    pDLinkNode->data = value;
    return pDLinkNode;
}

// 3. 删除双向链表
void delete_all_double_link_node(DOUBLE_LINK_NODE** pDLinkNode)
{
    DOUBLE_LINK_NODE* pNode;
    if (NULL == *pDLinkNode)
        return;

    pNode = *pDLinkNode;
    *pDLinkNode = pNode->next;
    free(pNode);
    delete_all_double_link_node(pDLinkNode);
}

// 4. 在双向链表中查找数据
DOUBLE_LINK_NODE* find_data_in_double_link(const DOUBLE_LINK_NODE* pDLinkNode, int data)
{
    DOUBLE_LINK_NODE* pNode = NULL;
    if (NULL == pDLinkNode)
        return NULL;

    pNode = (DOUBLE_LINK_NODE*)pDLinkNode;
    while (NULL != pNode){
        if (data == pNode->data)
            return pNode;
        pNode = pNode->next;
    }

    return NULL;
}

// 5. 双向链表中插入数据
STATUS insert_data_into_double_link(DOUBLE_LINK_NODE** ppDLinkNode, int data)
{
    DOUBLE_LINK_NODE* pNode;
    DOUBLE_LINK_NODE* pIndex;

    if (NULL == ppDLinkNode)
        return FALSE;

    if (NULL == *ppDLinkNode){
        pNode = create_double_link_node(data);
        assert(NULL != pNode);
        *ppDLinkNode = pNode;
        (*ppDLinkNode)->prev = (*ppDLinkNode)->next = NULL;
        return TRUE;
    }

    if (NULL != find_data_in_double_link(*ppDLinkNode, data))
        return FALSE;

    pNode = create_double_link_node(data);
    assert(NULL != pNode);

    pIndex = *ppDLinkNode;
    while (NULL != pIndex->next)
        pIndex = pIndex->next;

    pNode->prev = pIndex;
    pNode->next = pIndex->next;
    pIndex->next = pNode;
    return TRUE;
}

// 6. 双向链表中删除数据
STATUS delete_data_from_double_link(DOUBLE_LINK_NODE** ppDLinkNode, int data)
{
    DOUBLE_LINK_NODE* pNode;
    if (NULL == ppDLinkNode || NULL == *ppDLinkNode)
        return FALSE;

    pNode = find_data_in_double_link(*ppDLinkNode, data);
    if (NULL == pNode)
        return FALSE;

    if (pNode == *ppDLinkNode){
        if (NULL == (*ppDLinkNode)->next){
            *ppDLinkNode = NULL;
        }
        else{
            *ppDLinkNode = pNode->next;
            (*ppDLinkNode)->prev = NULL;
        }

    }
    else{
        if (pNode->next)
            pNode->next->prev = pNode->prev;
        pNode->prev->next = pNode->next;
    }

    free(pNode);
    return TRUE;
}

// 7. 统计双向链表中数据的个数
int count_number_in_double_link(const DOUBLE_LINK_NODE* pDLinkNode)
{
    int count = 0;
    DOUBLE_LINK_NODE* pNode = (DOUBLE_LINK_NODE*)pDLinkNode;

    while (NULL != pNode){
        count++;
        pNode = pNode->next;
    }
    return count;
}

// 8. 打印双向链表中数据
void print_double_link_node(const DOUBLE_LINK_NODE* pDLinkNode)
{
    DOUBLE_LINK_NODE* pNode = (DOUBLE_LINK_NODE*)pDLinkNode;

    while (NULL != pNode){
        printf("%d
", pNode->data);
        pNode = pNode->next;
    }
}

void main()
{
    DOUBLE_LINK_NODE *datlinklist;
    datlinklist = create_double_link_node(22);

    printf("count = %d
", count_number_in_double_link(datlinklist));
    //count_number_in_double_link(datalinklist);
    printf("hello world!
");
    system("pause");
}