Ideas
- Load files into linked list
- Select function
2.1 Book entry: use head interpolation method to save linked list
2.2 Book list display: circularly output linked list content
2.3 Borrowing books: enter book ID and student number. Determine whether the book can be borrowed, (yes) record the data, and the book inventory is reduced by one; (no) re-select function
2.4 Return the book: enter the book ID and student number. Determine whether the student has borrowed the book and not returned it, (yes) changes the return status, and adds one to the book inventory; (no) reselects the function
2.5 Borrowed book list display: circularly output the contents of the linked list
2.6 Book deletion: enter the book ID. Determine whether the book is still borrowed and has not been returned. (Yes) prohibit deletion; (No) find the book and release the current node.
mind Mapping
code
File loading
student module
void load_studentfile(char *filename,struct student *st){
FILE *fp = fopen(filename,"rb+");
struct student *new_st;
new_st = (struct student*)malloc(sizeof(struct student));
if(fp == NULL) {
printf("加载文件失败\n");
return;
}
while (fread(new_st, sizeof(struct student),1,fp) != 0){
new_st->next = st->next;
st->next = new_st;
new_st = (struct student*)malloc(sizeof(struct student));
}
fclose(fp);
return;
}
book module
void load_bookfile(char *filename,struct book *head){
FILE *fp = fopen(filename,"rb+");
struct book *bk;
bk = (struct book*)malloc(sizeof(struct book));
if(fp == NULL) {
printf("加载文件失败\n");
return;
}
while (fread(bk, sizeof(struct book),1,fp) != 0){
bk->next = head->next;
head->next = bk;
bk = (struct book*)malloc(sizeof(struct book));
}
fclose(fp);
return;
}
main function
int main(int argc,char* argv[])
{
struct book head;
struct student st;
int ncmd;
char ch;
/*初始化头结点*/
head.next = NULL;
st.next = NULL;
load_studentfile("student.bin",&st);
load_bookfile("book.bin",&head);
printf("----------------------------\n");
printf("1. 录入图书\n");
printf("2. 图书列表显示\n");
printf("3. 借书\n");
printf("4. 还书\n");
printf("5. 借书列表显示\n");
printf("6. 删除书籍\n");
printf("7. 退出\n");
printf("----------------------------\n");
scanf("%d",&ncmd);
while(ncmd != 7){
if(ncmd == 1)
{
input_book(&head);
printf("是否继续录入(Y/N)?");
ch = getchar();
while(ch == 'Y')
{
input_book(&head);
printf("是否继续录入(Y/N)?");
ch = getchar();
}
}else if(ncmd == 2){
output_book(head);
}else if(ncmd == 3){
borrow_book(&head,&st);
output_student(st);
}else if(ncmd == 4){
output_student(st);
return_book(&head,&st);
output_student(st);
}else if(ncmd == 5){
output_student(st);
}else if(ncmd == 6){
output_book(head);
del_book(&head,st);
printf("----------------------------\n");
output_book(head);
}
printf("----------------------------\n");
printf("----------------------------\n");
printf("选择功能\n");
scanf("%d",&ncmd);
}
output_book(head);
return 0;
}
Book addition
void input_book(struct book *head)
{
struct book *new_book;
new_book = (struct book*)malloc(sizeof(struct book));
printf("输入图书编号：");
scanf("%s",new_book->id);
printf("输入图书名称:");
scanf("%s",new_book->name);
printf("输入作者：");
scanf("%s",new_book->author);
printf("输入库存：");
scanf("%d",&new_book->quantity);
new_book->status = new_book->quantity;
flushall();
new_book->next = head->next;
head->next = new_book;
}
Book list display
void output_book(struct book head)
{
struct book *p;
FILE *pf;
pf = fopen("book.bin","w");
p = head.next;
while(p!=NULL)
{
printf("编号:%10s\t 书名:%10s\t 作者:%10s\t 存入数量:%5d\t 剩余库存:%5d\t 状态:%3s\n",
p->id,
p->name,
p->author,
p->quantity,
p->status,
p->status == 0 ? "不可借" : "可借");
fwrite(p,sizeof(struct book),1,pf);
p = p->next;
}
fclose(pf);
}
Borrow books
Determine whether the book is still in stock and can be borrowed. If so, record the book; otherwise, output a prompt
void borrow_book(struct book *head, struct student *st){
char id[10],name[128];
struct book *p;
int quantity;
struct student *new_st;
new_st = (struct student*)malloc(sizeof(struct student));
p = head->next;
printf("输入书编号:");
scanf("%s",id);
while(p != NULL){
if(strcmp(p->id,id) == 0){
if(p->status > 0){
printf("此书库存量:%d,可借!\n",p->quantity);
printf("输入借书学生学号:");
scanf("%s",new_st->number);
printf("请输入学生姓名:");
scanf("%s",new_st->name);
//状态赋值,借出未还
new_st->status = 1;
quantity = p->status;
quantity = quantity - 1;
p->status = quantity;
strcpy(new_st->bookname,p->name);
//new_st->bookname = name;
strcpy(new_st->id,p->id);
//new_st->id = id;
head = p;
new_st->next = st->next;
st->next = new_st;
return;
}else{
printf("此书无库存不能借出!\n");
return;
}
}
p = p->next;
head = p;
}
printf("没有此书\n");
return;
}
Return the book
void return_book(struct book *head, struct student *st){
char student_id[10],book_id[5];
int book_number;
struct book *p;
struct student *new_st;
new_st = st->next;
p = head->next;
printf("请输入学号:");
scanf("%s",student_id);
printf("请输入书籍id:");
scanf("%s",book_id);
while (new_st != NULL){
if(strcmp(new_st->number,student_id) == 0){
if(strcmp(new_st->id,book_id) == 0){
if(new_st->status == 1){
book_number = p->status;
p->status = book_number + 1;
new_st->status = 0;
printf("归还成功\n");
return;
} else{
printf("此学生该书以归还,无需重复操作\n");
return;
}
}else{
printf("该学生未借此书,无需归还\n");
return;
}
}
new_st = new_st->next;
st = new_st;
p = p->next;
head = p;
}
printf("该学生未借书\n");
return;
}
Borrowed book list display
void output_student(struct student st)
{
struct student *p;
FILE *pf;
pf = fopen("student.bin","w");
p = st.next;
while(p!=NULL)
{
printf("学号:%10s\t 名字:%10s\t 书籍编号:%10s\t 书籍名称:%10s\t 状态:%10s\n",
p->number,
p->name,
p->id,
p->bookname,
p->status == 1 ? "未还" : "已还");
fwrite(p,sizeof(struct student),1,pf);
p = p->next;
}
fclose(pf);
}
book deletion
First determine whether the book has been lent and not returned. No: Find the node and determine whether the node is the head node (yes: set the next node of the previous node to NULL and release the current node; no: assign the next node of the current node to the current node) The previous node next of the node releases the current node)
void del_book(struct book *head, struct student st){
char book_id[5];
struct book *p,*p1;
struct student *new_st;
new_st = st.next;
p = head;
p1 = head->next;
printf("请输入需要删除的书籍id:");
scanf("%s",book_id);
while (p1 != NULL){
if(strcmp(p1->id,book_id) == 0){
while(new_st != NULL){
if(strcmp(new_st->id,book_id)==0 && new_st->status==1){
printf("该书籍还有未还，暂不能删除\n");
return;
}
new_st = new_st->next;
}
if(p1->next == NULL){
p->next = NULL;
free(p1);
printf("删除书籍%s成功\n",book_id);
return;
}else{
p->next = p1->next;
free(p1);
printf("删除书籍%s成功\n",book_id);
return;
}
}
p1 = p1->next;
p = p->next;
}
printf("没有找到该书籍\n");
return;
}
renderings
Code download address
Github address: https://github.com/Ltike/Learning/blob/main/BookManager.c