线性结构之单链表

线性结构之单链表基本操作！

/*
    本程序实现单链表的创建、遍历、插入、删除、排序
    C语言在Visual Studio 2013下编译通过
    */

#include <stdint.h>
#include <malloc.h>
#include <stdlib.h>
#include <stdbool.h>


//定义单链表的数据结构
typedef    struct TagNode
{
    int Date;    //数据域定义为int类型

    struct TagNode * pNext;    //指针域为TagNode类型

}Node, *PNode;



//函数声明

int getLength(PNode pHead);
PNode createLinkedListForTail(void);
PNode createLinkedListForHead(void);
bool insertNode(PNode pHead, int i, int data);
bool deleteNode(PNode pHead, int i);
void storeForBubble(PNode pHead);
void traversal(PNode pHead);

//main函数
int main(void)
{
    int pos = 0;
    int newData = 0;

    PNode head = NULL;

    //head = createLinkedListForTail();
    //printf("尾插法排序前：
");
    //traversal(head);

    //storeForBubble(head);
    //printf("尾插法排序后：
");
    //traversal(head);
    //free(head);

    //printf("
");

    //head = createLinkedListForHead();
    //printf("头插法排序前：
");
    //traversal(head);

    //storeForBubble(head);
    //printf("头插法排序后：
");
    //traversal(head);
    //free(head);

    //printf("重新创建链表：
");
    //head = createLinkedListForTail();
    //printf("输入要插入的位置： Pos=");
    //scanf("%d", &pos);
    //printf("输入要插入的新节点数据值： Data=");
    //scanf("%d", &newData);
    //insertNode(head, pos, newData);
    //traversal(head);

    //head = createLinkedListForTail();
    //traversal(head);
    //printf("输入要删除的节点位置： Pos=");
    //scanf("%d", &pos);
    //deleteNode(head, pos);
    //traversal(head);
    //free(head);
    getchar();
}

//求表长
int getLength(PNode pHead)
{
    int length = 0;
    if (NULL == pHead)
    {
        printf("链表不存在啊！
");
        return -1;
    }

    PNode node = pHead->pNext;
    while (NULL != node)
    {
        ++length;
        node = node->pNext;
    }

    return length;
}

//尾插法 创建单链表,并返回该链表的头节点
PNode createLinkedListForTail(void)
{
    int length;    //表长
    int value;    //数据域值

    printf("-----这是尾插法：-----
");

    //创建头节点
    PNode pHead = (PNode)malloc(sizeof(Node));
    if (NULL == pHead)
    {
        printf("初始化链表失败！");
        exit(-1);
    }

    //并初始化一个空链表
    pHead->pNext = NULL;

    //指针pLast，始终指向最后一个节点，开始时指向头节点
    PNode pLast = pHead;


    printf("请输入单链表的长度:Length= ");
    scanf("%d", &length);

    if (length < 0)
    {
        printf("输入不合法！");
        return NULL;
    }
    else if (length == 0)
    {
        printf("只包含头节点的空链表！");
        return pHead;
    }


    for (int i = 0; i < length; i++)
    {
        printf("请输入第%d个节点的值: ", i + 1);

        scanf("%d", &value);

        PNode newNode = (PNode)malloc(sizeof(Node));//新的节点
        if (NULL == newNode)
        {
            printf("创建节点失败!");
            exit(-1);
        }

        newNode->Date = value;
        pLast->pNext = newNode;
        newNode->pNext = NULL;

        pLast = newNode; //指向最后一个节点
    }

    return pHead;
}

//头插法 创建单链表, 并返回该链表的头节点
PNode createLinkedListForHead(void)
{
    int length;    //表长
    int value;    //数据域值

    printf("-----这是头插法：-----
");

    //创建头节点
    PNode pHead = (PNode)malloc(sizeof(Node));
    if (NULL == pHead)
    {
        printf("初始化链表失败！");
        exit(-1);
    }

    //并初始化一个空链表
    pHead->pNext = NULL;

    printf("请输入单链表的长度:Length= ");
    scanf("%d", &length);

    if (length < 0)
    {
        printf("输入不合法！");
        return NULL;
    }
    else if (length == 0)
    {
        printf("只包含头节点的空链表！");
        return pHead;
    }

    for (int i = 0; i < length; i++)
    {
        printf("请输入第%d个节点的值: ", i + 1);

        scanf("%d", &value);

        PNode newNode = (PNode)malloc(sizeof(Node));//新的节点
        if (NULL == newNode)
        {
            printf("创建节点失败!");
            exit(-1);
        }

        newNode->Date = value;
        newNode->pNext = pHead->pNext;

        pHead->pNext = newNode;
    }

    return pHead;
}

//对单链表冒泡排序 升序
void storeForBubble(PNode pHead)
{
    if (NULL == pHead)
    {
        printf("链表不存在啊！
");
        return;
    }

    int tempData = 0;
    PNode pM;
    PNode pN;

    for (pM = pHead->pNext; NULL != pM; pM = pM->pNext)
    {
        for (pN = pM->pNext; NULL != pN; pN = pN->pNext)
        {
            if (pM->Date > pN->Date)
            {
                tempData = pN->Date;
                pN->Date = pM->Date;
                pM->Date = tempData;
            }
        }
    }
}

//在第i个节点之前插入新节点
bool insertNode(PNode pHead, int i, int data)
{
    if (NULL == pHead)
    {
        printf("链表不存在啊！
");
        return false;
    }

    //-----这里不对链表求表长来判断被插入的位置i是否合法，效率高，理解困难！-----

    int k = 0;
    PNode p = pHead->pNext;
    PNode newNode = (PNode)malloc(sizeof(Node));

    while (NULL != p && k < i - 1)
    {
        p = p->pNext;
        ++k;
    }

    if (NULL == p || k > i - 1)
        return false;


    if (NULL == newNode)
    {
        printf("创建节点失败!");
        exit(-1);
    }

    newNode->Date = data;
    PNode tmp = p->pNext;
    p->pNext = newNode;
    newNode->pNext = tmp;

    return true;
}

//删除第i个节点
bool deleteNode(PNode pHead, int i)
{
    if (NULL == pHead)
    {
        printf("链表不存在啊！
");
        return false;
    }


    int k = 0;
    PNode p = pHead;
    PNode pDel = NULL;

    while (NULL != p->pNext && k < i - 1)
    {
        p = p->pNext;
        ++k;
    }

    if (NULL == p->pNext || k > i - 1)
        return false;

    pDel = p->pNext;
    p->pNext = p->pNext->pNext;

    free(pDel);

    return true;
}

//遍历单链表
void traversal(PNode pHead)
{
    if (NULL == pHead)
    {
        printf("链表不存在啊！
");
        return;
    }

    PNode p = pHead->pNext;
    while (NULL != p)
    {
        printf("节点: %d , 地址: %#X , p->next: %#X
", p->Date, p, p->pNext);
        p = p->pNext;
    }
}