C语言单链表的创建、输出、插入结点、删除结点

布满荆棘的人生 2022-05-27 11:10 212阅读 0赞

链表对于C语言的学习者来说是一大难点，但链表又是学好数据结构的基础。在此，对单链表的创建、输出、结点的插入、结点的删除进行简要介绍。

**1、首先定义一个结构体数组**

#define LEN sizeof(struct student)
    struct student
    {
    	int num;
    	char name[20];
    	float score;
    	struct student *next;
    };
    int n;

**2、单链表的创建**

struct student *creat(void)//创建链表 
    {
    	n=0;
    	struct student *p1,*p2,*head;
    	head=NULL;
    	p1=p2=(struct student *)malloc(LEN);//开辟新单元
    	scanf("%d,%s,%f",&p1->num,&p1->name,p1->score);//输入数据
    	while(p1->num!=0)//限定当num为0时，链表输入结束
    	{
    		n++;
    		if(n==1)head=p1;
    		else
    		p2->next=p1;
    		p2=p1;
    		p1=(struct student *)malloc(LEN);
    	    scanf("%d,%s,%f",&p1->num,&p1->name,p1->score);
    	 } 
    	 p2->next=NULL;
    	 return head;
    }

**3、单链表的输出**

void print(struct student *head)//输出链表 
    {
    	printf("\nthere are %d records\n",n);
    	struct student *p;
    	p=head;
    	if(head!=NULL)
    		do
    		{
    			printf("%d,%s,%.0f\n",p->num,p->name,p->score);
    			p=p->next;
    			
    		}
    		while(p!=NULL);
    }

**4、单链表结点删除**

struct student *del(struct student *head,int num)//删除一个节点 
    {
    	struct student *p,*p1;
    	p=head;
    	if(head==NULL)//当链表为空时
    	{
    		printf("this table is null\n");
    		goto end;
    	}
    	while(num!=p->num&&p->next!=NULL)//判断链表中是否存在该结点
    	{
    		p1=p;
    		p=p->next;
    	}
    	if(num==p->num)//当结点存在时
    	{
    		if(p==head)head=p->next;
    		else
    		p1->next=p->next;
    		printf("delete\n");
    		n--;//链表中结点个数
    	}
    	else
    	printf("not find");//找不到该结点时
    end: return head;
    }

**5、单链表的插入**

struct student *insert(struct student *head,struct student *stud)//插入一个节点 
    {
    	struct student *p0,*p1,*p2;
    	p1=head;
    	p0=stud;
    	if(head==NULL)
    	{
    		head=p0;
    		p0->next=NULL;
    	}
    	else
    	{
    		while((p0->num>p1->num)&&(p1->next!=NULL))//判断链表位置
    		{
    			p2=p1;
    			p1=p1->next;
    		}
    		if(p0->num<=p1->num)
    		{
    			if(head==p1)head=p0;
    			else p2->next=p0;
    			     p0->next=p1;
    		}
    		else
    		{
    			p1->next=p0;
    			p0->next=NULL;
    		}	
    	}
    	n++;
    	return(head);
     }

**6、main主函数**

int main(int argc, char *argv[]) {
    struct student *head,*stu;
    int del_num;
    printf("input record:\n");//创建链表
    head=creat();
    print(head);//输出链表
    printf("input the deleted number:\n");//删除链表
    scanf("%d",&del_num);//输入要删除的记录
    while(del_num!=0)
    {
    	head=del(head,del_num);
    	print(head);
        printf("input the deleted number:\n"); 
        scanf("%d",&del_num); 
    }
    printf("input the inserted record:\n");//插入结点
    stu=(struct student *)malloc(LEN);
    scanf("%d,%s,%f",&stu->num,&stu->name,&stu->score);
    while(stu->num!=0)
    {
    	head=insert(head,stu);
    	print(head);
    	printf("input the inserted record:\n");
        stu=(struct student *)malloc(LEN);
        scanf("%d,%s,%f",&stu->num,&stu->name,&stu->score);
    }
    }

注：内容来源于谭浩强C语言第二版内容，做了小幅度改正