原程序备份.txt

C实现的单链表

#include<stdio.h>
#include<malloc.h>
#define NULL 0
#define LEN sizeof(struct stu)

struct stu
{
	long num;
	float score;
	struct stu *next;
};
int n;
struct stu * creat(void)
{
	struct stu * head;
	struct stu * p1,* p2;
	n=0;
	p1=p2=(struct stu *)malloc(LEN);
	scanf("%ld%f",&p1->num,&p1->score);
	head=NULL;
	while(p1->num!=0)
	{
		n++;
		if(n==1)
			head=p1;
		else
			p2->next=p1;
		p2=p1;
		p1=(struct stu *)malloc(LEN);
		scanf("%ld%f",&p1->num,&p1->score);
	}
	p2->next=NULL;
	return head;
}
void print(struct stu *head)
{
	struct stu * p;
	printf("\nNow,there are %d students.\n",n);
	p=head;
	if(head!=NULL)
		do
		{
			printf("%ld%5.1f\n",p->num,p->score);
			p=p->next;
		}while(p!=NULL);
}
struct stu *del(struct stu * head,long num)
{
	struct stu * p1,* p2;
	if(head==NULL)
	{
		printf("\nList dose not exist!\n");
		goto end;
	}
	p1=head;
	while(num!=p1->num&&p1->next!=NULL)
	{
		p2=p1;
		p1=p1->next;
	}
	if(num==p1->num)
	{
		if(p1==head)
			head=p1->next;
		else
			p2->next=p1->next;
		printf("delete:%ld\n",num);
		n=n-1;
	}
	else
		printf("%ld has not been found!\n",num);
end:;
	return head;
}
struct stu * in(struct stu *head,struct stu * stud)
{
	struct stu * p0,*p1,*p2;
	p1=head;
	p0=stud;
	if(head==NULL)
	{
		head=p0;
		p0->next=NULL;
	}
	else
	{
		while((p0->num>p1->num)&&(p1->next)!=NULL)
		{
			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+=1;
	}
	return head;
}
void main()
{
	struct stu * head,* stu;
	long del_num;
	printf("Input records:");
	head=creat();
	print(head);
	printf("\ninput the deleted number:\n");
	scanf("%ld",&del_num);
	while(del_num!=0)
	{
		head=del(head,del_num);
		print(head);
		printf("input the deleted number:");
		scanf("%ld",&del_num);
	}
	printf("\ninput the inserted number:\n");
	stu=(struct stu *)malloc(LEN);
	scanf("%ld%f",&stu->num,&stu->score);
	while(stu->num!=0)
	{
		head=in(head,stu);
		print(head);
		printf("\ninput the inserted number:\n");
		stu=(struct stu *)malloc(LEN);
		scanf("%ld%f",&stu->num,&stu->score);
	}
}