c.txt

这是一个用C编写的图书馆管理系统

#include "stdio.h"
#include "stdlib.h"

struct book {
	int id;
	char name[100];
	char author[100];
	int lent_student;
	char time[100];
	struct book *next;
};

struct student {
	int id;
	char name[100];
	struct student *next;
};

struct book *book_head=NULL;
struct student *student_head=NULL;
int inLib=0;

void save()
{
	FILE *fp;
	struct book *p1;
	struct student *p2;
	fp=fopen("books.txt","wb");
	p1=book_head->next;
	while(p1!=NULL)
	{
		fwrite(p1,sizeof(struct book),1,fp);
		p1=p1->next;
	}
	fclose(fp);
	fp=fopen("students.txt","wb");
	p2=student_head->next;
	while(p2!=NULL)
	{
		fwrite(p2,sizeof(struct student),1,fp);
		p2=p2->next;
	}
	fclose(fp);
}

void load()
{
	FILE *fp;
	struct book *p1,*p1_end;
	struct student *p2,*p2_end;
	
	fp=fopen("books.txt","rb");
	if(fp!=NULL)
	{
		p1_end=book_head;
		while(!feof(fp))
		{
			p1=(struct book *)malloc(sizeof(struct book));
			fread(p1,sizeof(struct book),1,fp);
			p1_end->next=p1;
			p1->next=NULL;
			if(p1->lent_student!=0) inLib++;
			p1_end=p1;
		}
		fclose(fp);
	}
	fp=fopen("students.txt","rb");
	if(fp!=NULL)
	{
		p2_end=student_head;
		while(!feof(fp))
		{
			p2=(struct student *)malloc(sizeof(struct student));
			fread(p2,sizeof(struct student),1,fp);
			p2_end->next=p2;
			p2->next=NULL;
			p2_end=p2;
		}
		fclose(fp);
	}
}

void main()
{
	int s;
	struct book *p1,*p3;
	struct student *p2,*p4;
	
	int id;

	book_head=(struct book *)malloc(sizeof(struct book));
	book_head->next=NULL;
	student_head=(struct student *)malloc(sizeof(struct student));
	student_head->next=NULL;
	load();

	do
	{
		printf("\n         图书馆管理             \n");
		printf("1.添加书				2.删除书\n");
		printf("3.添加学生				4.删除学生\n");
		printf("5.借书					6.还书\n");
		printf("0.退出\n");
		printf("目前存书%d册\n",inLib);
		printf("请做选择:");
		scanf("%d",&s);
		switch(s)
		{
			case 1:
				
				p3=(struct book *)malloc(sizeof(struct book));
				printf("请输入书的编号:");
				scanf("%d",&p3->id);
				printf("请输入书名:");
				scanf("%s",p3->name);
				printf("请输入作者:");
				scanf("%s",p3->author);
				p3->lent_student=0;
				p3->next=NULL;
				for(p1=book_head;p1->next!=NULL;p1=p1->next);
				p1->next=p3;
				printf("添加完成！\n");
				inLib++;
				break;
			case 2:
				printf("请输入要删除的书的编号:");
				scanf("%d",&id);
				for(p1=book_head;p1->next!=NULL;p1=p1->next)
				{
					if(p1->next->id==id)
					{
						p3=p1->next;
						p1->next=p3->next;
						free(p3);
						break;
					}
				}
				printf("删除成功\n");
				break;
			case 3:
				p4=(struct student *)malloc(sizeof(struct student));
				printf("请输入学号:");
				scanf("%d",&p4->id);
				printf("请输入姓名:");
				scanf("%s",p4->name);
				for(p2=student_head;p2->next!=NULL;p2=p2->next);
				p2->next=p4;
				p4->next=NULL;
				printf("添加完成！\n");
				inLib--;
				break;
			case 4:
				printf("请输入要删除的学生学号:");
				scanf("%d",&id);
				for(p2=student_head;p2->next!=NULL;p2=p2->next)
				{
					if(p2->next->id==id)
					{
						p4=p2->next;
						p2->next=p4->next;
						free(p4);
						break;
					}
				}
				printf("删除成功\n");
				break;
			case 5:
				printf("请输入要借的书的编号:");
				scanf("%d",&id);
				for(p1=book_head->next;p1!=NULL;p1=p1->next)
				{
					if(p1->id==id) break;
				}
				if(p1==NULL)
				{
					printf("找不到这本书\n");
					break;
				}
				if(p1->lent_student!=0)
				{
					printf("这本书已经被借出了!\n");
					break;
				}
				printf("请输入要借书的学生学号:");
				scanf("%d",&id);
				for(p2=student_head;p2!=NULL;p2=p2->next)
				{
					if(p2->id==id) break;
				}
				if(p2==NULL)
				{
					printf("找不到这名学生\n");
					break;
				}
				printf("请输入借书时间:");
				scanf("%s",p1->time);
				p1->lent_student=id;
				printf("借书成功!\n");
				inLib--;
				break;
			case 6:
				printf("请输入要还的书的编号:");
				scanf("%d",&id);
				for(p1=book_head->next;p1!=NULL;p1=p1->next)
				{
					if(p1->id==id) break;
				}
				if(p1==NULL)
				{
					printf("找不到这本书\n");
					break;
				}
				if(p1->lent_student==0)
				{
					printf("这本书还没有被借出!\n");
					break;
				}
				p1->lent_student=0;
				printf("还书成功\n");
				inLib++;
		}
	}
	while(s!=0);
	save();
	while(book_head!=NULL)
	{
		p1=book_head->next;
		free(book_head);
		book_head=p1;
	}
	while(student_head!=NULL)
	{
		p2=student_head->next;
		free(student_head);
		student_head=p2;
	}
}