链表的基本操作

#include <stdio.h>
<span style="font-size:18px;">#include <malloc.h>
#define LEN sizeof(struct student)

/*----------------数据定义----------------------*/ 

//定义一个学生信息的结构体,包括学号,姓名和结构体类型的指针 
struct student
{
    long num;                //学号 
    char name[128];            //姓名 
    struct student *next;    //结构体指针 
};

typedef struct student * stuNode;

int n=0;                    //全局变量,记录链表的长度 
 
/*---------------函数声明---------------------*/
stuNode Create();            //创建一个新的链表                     
void Print(stuNode head);    //通过传入的链表头指针打印整个链表 
stuNode Delete(stuNode head,int num);    //通过传入的链表头指针和学生学号删除节点 
stuNode Insert(stuNode head,stuNode newStu);    //依照学生学号的顺序向链表中插入新元素 


/*---------------函数定义----------------------*/

struct student *Create()
{
    struct student *head,*p1,*p2;
    
    //开辟一个LEN大小的空间,并让p1,p2指针指向它 
    p2=p1=(struct student *)malloc(LEN);
    //将头指针置为NULL 
    head=NULL;
    
    //创建链表节点并给节点的元素赋值 
    printf("请输入学生的学号和姓名:");
    scanf("%ld %s",&p1->num,p1->name);
    while(p1->num!=0)
    {
        n=n+1;
        if(NULL==head)
        {
            head=p1;
        }
        else
        {
            p2->next=p1;
        }
        p2=p1;
        p1=(struct student *)malloc(LEN);
        printf("请输入学生的学号和姓名:");
        scanf("%ld %s",&p1->num,p1->name);
    }
    //将尾节点的指针置为NULL 
    p2->next=NULL;
    return head;
}

void Print(struct student *head)
{
    struct student * p;
    p=head;
    
    //判断链表是否为空 
    if(NULL==head)
    {
        printf("链表为空!
");
        return head;
    }
    else
    {
        //循环打印链表中的元素 
        printf("%d 个记录分别为:
",n);
        while(p!=NULL)
        {
            printf("%ld %s
",p->num,p->name);
            //指针指向下一个节点 
            p=p->next;
        }
    }
}

struct student *Delete(struct student * head,int num)
{
    struct student *p1;
    struct student *p2;
    p1=head;
    //判断链表是否为空 
    if(NULL==head)
    {
        printf("链表为空!
");
        return head;
    }
    //遍历节点,判断当前节点是不是需要删除的节点及是否为尾节点
    //如果找到相应节点,或者已经遍历到尾节点就跳出循环 
    while(p1->num!=num&&p1->next!=NULL)
    {
        p2=p1;
        p1=p1->next;
    }
    //判断是否找到相应节点 
    if(p1->num==num)
    {
        //要删除的节点是不是链表的第一个节点
        //如果是,就将头指针指向该节点的后一个节点
        //如果不是,就将该节点的前一个节点的指针指向该节点的后一个节点 
        if(head==p1)
        {
            head=p1->next;
        }
        else
        {
            p2->next=p1->next;
        }
        n=n-1;
        printf("%ld 节点已删除.
",num);
    }
    else
    {
        printf("链表中没有要删除的元素.
");
    }
    return head;
}

struct student *Insert(struct student * head,struct student * newStu)
{
    struct student *p0;
    struct student *p1;
    struct student *p2;
    p0=newStu;
    p1=head;
    //判断链表是否为空,如果是空链表,就将新节点作为第一个节点 
    if(NULL==head)
    {
        head=p0;
        p0->next=NULL;
    }
    else
    {
        //遍历每一个节点中的学号,与新学号比较大小
        //如果找到一个学号比新学号大,就将新学号的节点插入它之前 
        //如果尾节点的学号仍比新学号小,就将新节点插入到链表尾部 
        while((p0->num > p1->num)&&(p1->next!=NULL))
        {
            p2=p1;
            p1=p1->next;
        }
        //找到一个比新学号大的节点 
        if(p0->num <= p1->num)
        {
            //判断该节点是否为头节点,如果是,则将新节点设置为头节点 
            if(p1==head)
            {
                head=p0;
            }
            else
            {
                p2->next=p0;
            }
              p0->next=p1;
        }
        else
        {
            p1->next=p0;
            p0->next=NULL;
        }
    }
    //链表长度加1 
    n=n+1;
    printf("%ld 插入成功!
",newStu->num);
    return head;
}

void main()
{
    struct student *head;
    struct student *stu;
    int num;
    head=Create();
    Print(head);
    printf("请输入要删除的学号:");
    scanf("%ld",&num);
    while(num!=0)
    {
        head=Delete(head,num);
        Print(head);
        printf("请输入要删除的学号:");
        scanf("%ld",&num);
    }
    printf("请输入要插入的节点:");
    stu=(struct student *)malloc(LEN);
    scanf("%ld %s",&stu->num,stu->name);
    while(stu->num!=0)
    {
        head=Insert(head,stu);
        printf("请输入要插入的节点:");
        stu=(struct student *)malloc(LEN);
        scanf("%ld %s",&stu->num,stu->name);
    }
    Print(head);
}

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


typedef struct node
{
int data;
node* pNext;
}Node;


//链表的操作，以有头节点为例，无头节点类似
Node* head = NULL;


//创建链表，头结点data=0，pNext=NULL;
bool createNodeList()
{
head = (Node*) malloc(sizeof(Node));
if(NULL == head)
{
return false;
}
else
{
head->data = 0;
head->pNext = NULL;
return true;
}
}


//增加节点
bool addNode(Node* node)
{
if(NULL == head)
{
return false;
}
Node* p = head->pNext;
Node* q = head;
while(NULL != p)
{
q = p;
p = p->pNext;
}
q->pNext = node;
node->pNext = NULL;
return true; 
}


//删除节点
bool deleteNode(int index)
{
if(NULL == head)
{
return false;
}
Node* p = head->pNext;

int length = 0;
while(NULL != p)
{
length ++;
p = p->pNext;
}


if(length < index)
{
return false;
}
else
{
Node* q = head;
p = head;
for(int i=0;i<index;i++)
{
q = p;
p = p->pNext;
}
Node* t = p->pNext;
q->pNext = t;
free(p);
return true;
}
}


//逆序
void reverseNodeList()
{
if(NULL == head)
{
return;
}
//如果链表长度为1
if(head->pNext == NULL)
{
return;
}
Node* p = head->pNext;
Node* q = p->pNext;
Node* t = NULL;
while(NULL != q)
{
t = q->pNext;
q->pNext = p;
p = q;
q = t;
}
head->pNext->pNext = NULL;
head->pNext = p;
}


//排序(降序)
void sort()
{
//冒泡排序
Node* pHead = head;
if(head == NULL)
{
return;
}
if(pHead->pNext == NULL)
{
return;
}
Node* pi = pHead->pNext;
Node* pj = pi->pNext;
for(;pi != NULL;pi=pi->pNext)
{
for(pj = pi->pNext;pj != NULL;pj=pj->pNext)
{
if(pj->data>pi->data)
{
int tmp = pj->data;
pj->data = pi->data;
pi->data = tmp;
}
}
}
}
//销毁
void destroyNodeList()
{
if(NULL == head)
{
return;
}
if(NULL == head->pNext)
{
free(head);
head = NULL;
return;
}
Node* p = head->pNext;
while(NULL != p)
{
Node* tmp = p;
p = p->pNext;
free(tmp);
}
free(head);
head = NULL;
}

void main()
{
createNodeList();

Node* node1 = (Node*)malloc(sizeof(Node));
node1->data = 1;
node1->pNext = NULL;

Node* node2 = (Node*)malloc(sizeof(Node));
node2->data = 2;
node2->pNext = NULL;
addNode(node1);
addNode(node2);
reverseNodeList();
Node* node3 = (Node*)malloc(sizeof(Node));
node3->data = 3;
node3->pNext = NULL;

addNode(node3);
sort();
deleteNode(2);

destroyNodeList();
}