C语言链表如何实现图书管理系统

// MyLibManSys.cpp : Defines the entry point for the console application. 

// 
 
#include "stdafx.h" 
#include "iostream" 
 
struct book{ 
  int id; 
  char title[20]; 
  char author[20]; 
  double price; 
  char state[20]; 
  int student_id; 
  char student_name[20]; 
  struct book* next; 
}; 
 
struct student{ 
  int id; 
  char name[20]; 
  char sex[10]; 
  char borrow_book[30]; 
  struct student* next; 
}; 
void Print_Book(struct book *head_book); 
void Print_Student(struct student *head_student); 
struct book *Create_New_Book();/*创建新的图书库*/  
struct student *Create_New_Student();/*创建新的学生库*/ 
struct book *Insert_Book(struct book *head_book,struct book *new_book);/*增加图书，逐个添加*/  
//void Insert_Book(struct book *head_book,struct book *new_book);/*增加图书，逐个添加*/ 
//函数的参数是一个指针时，不要在函数体内部改变指针所指的地址，那样毫无作用，需要修改的只能是指针所指向的内容。即应把指针当作常量 
struct student *Insert_Student(struct student *head_student,struct student *new_student);/*增加学生，逐个添加*/  
struct book *Search_Book_ById(int id,struct book *head_book);  
struct book *Search_Book_ByTitle(char *title,struct book *head_book);  
struct book *Search_Book_ByPrice(double price_h,double price_l,struct book *head_book); 
//bool Delete_Book(int id,book* head_book); 
struct book* Delete_Book(int id,book* head_book); 
struct student *Search_Student(int id,struct student *head_student); 
struct student* Delete_Student(int id,student* head_student); 
 
void Lent_Book(int id,int student_id,struct book *head_book,struct student *head_student); 
void Back_Book(int id,int student_id,struct book *head_book,struct student *head_student); 
 
int main() 
{ 
  struct book* head_book,*p_book; 
  struct student* head_student, *p_student; 
  int choice, f, id, student_id; 
  int m = 1; 
  char name[20],sex[10]; 
  char title[20]; 
  double price_h,price_l,price; 
  char author[20]; 
  int size_book=sizeof(struct book); 
  int size_student=sizeof(struct student); 
  printf("n欢迎您第一次进入图书管理系统!nn");  
  printf("----->[向导]----->[新建图书库]nn");  
  printf("注意:当输入图书编号为0时,进入下一步.nn");  
  head_book=Create_New_Book();  
  system("cls"); 
  //Print_Book(head_book); 
  printf("n欢迎您第一次进入图书管理系统!nn");  
  printf("----->[向导]----->[新建会员库]nn");  
  printf("注意:当输入会员学号为0时,进入主菜单.nn"); 
  head_student=Create_New_Student();  
  system("cls"); 
  //Print_Student(head_student); 
  do{ 
    printf("nttt〓〓〓〓〓图书管理系统〓〓〓〓〓nn");  
    printf("n");  
    printf("ttt[1]:借书办理t");printf(" [6]:还书办理n");  
    printf("n");  
    printf("ttt[2]:查询图书t");printf(" [7]:查询学生n");  
    printf("ttt[3]:添加图书t");printf(" [8]:添加学生n");  
    printf("ttt[4]:删除图书t");printf(" [9]:删除学生n");  
    printf("ttt[5]:遍历图书t");printf("[10]:遍历学生nn");  
    printf("ttt〓〓〓〓〓〓〓〓〓〓〓〓〓〓〓〓nn");  
    printf("ttt0:退出nn");  
    printf("请选择<0~10>:");  
    scanf("%d",&choice); 
    switch(choice){ 
    case 0: 
      system("cls");  
      printf("nttt〓〓〓〓〓图书管理系统〓〓〓〓〓nn");  
      printf("n谢谢您的使用!nn");  
      break; 
    case 1: 
      system("cls"); 
      printf("nttt〓〓〓〓〓图书管理系统〓〓〓〓〓nn"); 
      printf("输入借出图书编号:n");  
      scanf("%d",&id); 
      printf("输入借入学生学号：n"); 
      scanf("%d",&student_id); 
      Lent_Book(id,student_id,head_book,head_student); 
      break; 
    case 2: 
      system("cls");  
      printf("nttt〓〓〓〓〓图书管理系统〓〓〓〓〓nn");  
      printf("1.按编号查询nn");  
      printf("2.按名称查询nn");  
      printf("3.按价格区间查询nn");  
      printf("0.返回主菜单nn");  
      printf("请选择:");  
      scanf("%d",&f);  
      if(f==1){  
        printf("请输入查询图书编号:");  
        scanf("%d",&id);  
        printf("相关信息如下:nn");  
        head_book=Search_Book_ById(id,head_book);  
        break;  
      }  
      else if(f==2){ 
        getchar(); 
        printf("请输入查询图书名称:");  
        gets(title); 
        printf("相关信息如下:nn");  
        head_book=Search_Book_ByTitle(title,head_book);  
        break;  
      }  
      else if(f==3){  
        printf("请输入最高价格:");  
        scanf("%lf",&price_h);  
        printf("请输入最低价格:");  
        scanf("%lf",&price_l);  
        printf("相关信息如下:nn");  
        head_book=Search_Book_ByPrice(price_h,price_l,head_book);  
        break;  
      }  
      else if(f==0){  
        break;  
      }  
      break; 
    case 3: 
      system("cls");  
      printf("nttt〓〓〓〓〓图书管理系统〓〓〓〓〓nn");  
      printf("请输入图书编号:");  
      scanf("%d",&id);  
      printf("请输入图书名称:");  
      scanf("%s",title);  
      printf("请输入作者名字:");  
      scanf("%s",author);  
      printf("请输入单价:");  
      scanf("%lf",&price);  
      printf("n"); 
      struct book *ptr_b; 
      for(ptr_b=head_book;ptr_b;ptr_b=ptr_b->next)  
      { 
        if(ptr_b->id==id)  
        {  
          printf("此编号图书已存在n");  
          m=0;  
          break;  
        }  
      }  
      if(m){  
        p_book=(struct book *)malloc(size_book);  
        strcpy(p_book->title,title);  
        p_book->id=id;  
        p_book->price=price;  
        p_book->student_id=-1;  
        strcpy(p_book->author,author);  
        strcpy(p_book->state,"存在");   
        strcpy(p_book->student_name,"待定");  
      // head_book=Insert_Book(head_book,p_book);  
        Insert_Book(head_book,p_book); 
        printf("n添加图书成功!nn");  
      }  
      break; 
    case 4: 
      system("cls");  
      printf("nttt〓〓〓〓〓图书管理系统〓〓〓〓〓nn");  
      printf("输入删除图书编号:n");  
      scanf("%d",&id);  
      /*if(Delete_Book(id,head_book)){ 
        printf("n删除图书成功!nn"); 
      }else{ 
        printf("删除失败"); 
      }*/ 
      head_book = Delete_Book(id,head_book); 
      break; 
    case 5:  
      system("cls");  
      printf("nttt〓〓〓〓〓图书管理系统〓〓〓〓〓nn");  
      Print_Book(head_book);  
      break; 
    case 6: 
      system("cls"); 
      printf("nttt〓〓〓〓〓图书管理系统〓〓〓〓〓nn"); 
      printf("输入归还图书编号:n");  
      scanf("%d",&id); 
      printf("输入归还学生学号：n"); 
      scanf("%d",&student_id); 
      Back_Book(id,student_id,head_book,head_student); 
      break; 
    case 7: 
      system("cls");  
      printf("nttt〓〓〓〓〓图书管理系统〓〓〓〓〓nn");    
      printf("请输入查询学生学号:");  
      scanf("%d",&id);  
      printf("相关信息如下:nn");  
      head_student=Search_Student(id,head_student);  
      break; 
    case 8: 
      system("cls");  
      printf("nttt〓〓〓〓〓图书管理系统〓〓〓〓〓nn");  
      printf("请输入学生编号:");  
      scanf("%d",&id);  
      printf("请输入学生姓名:");  
      scanf("%s",name);  
      printf("请输入学生性别:");  
      scanf("%s",sex);   
      printf("n"); 
      struct student *ptr_s; 
      for(ptr_s=head_student;ptr_s;ptr_s=ptr_s->next)  
      { 
        if(ptr_s->id==id)  
        {  
          printf("此学号学生已存在n");  
          m=0;  
          break;  
        }  
      }  
      if(m){  
        p_student=(struct student *)malloc(size_student);   
        p_student->id=id;   
        strcpy(p_student->name,name);  
        strcpy(p_student->sex,sex);   
        strcpy(p_student->borrow_book,"无");  
        head_student=Insert_Student(head_student,p_student);  
        printf("n添加学生成功!nn");  
      }  
      break; 
    case 9: 
      system("cls");  
      printf("nttt〓〓〓〓〓图书管理系统〓〓〓〓〓nn");  
      printf("输入删除学生学号:n");  
      scanf("%d",&id);  
      head_student = Delete_Student(id,head_student); 
      break; 
    case 10: 
      system("cls");  
      printf("nttt〓〓〓〓〓图书管理系统〓〓〓〓〓nn");  
      Print_Student(head_student); 
    } 
  }while(choice!=0); 
  return 0; 
} 
 
struct book *Create_New_Book(){ 
  struct book *head_book,*p_book;  
  int id, tag;  
  double price;  
  char title[20],author[20];  
  int size_book=sizeof(struct book);  
    
  head_book=NULL;  
  printf("请输入图书编号:");  
  scanf("%d",&id);  
  printf("请输入图书名称:");  
  scanf("%s",title);  
  printf("请输入作者名字:");  
  scanf("%s",author);  
  printf("请输入单价:");  
  scanf("%lf",&price);  
  printf("n");  
  while(true){  
    p_book=(struct book *)malloc(size_book);  
    strcpy(p_book->title,title);  
    p_book->id=id;  
    p_book->price=price;  
    p_book->student_id=-1;  
    strcpy(p_book->author,author);  
    strcpy(p_book->state,"存在");   
    strcpy(p_book->student_name,"待定");  
    head_book=Insert_Book(head_book,p_book); 
    printf("是否继续？继续输入1，退出按任意键n"); 
    scanf("%d",&tag); 
    if(tag!=1){ 
      break; 
    } 
    printf("请输入图书编号:");  
    scanf("%d",&id);  
    printf("请输入图书名称:");  
    scanf("%s",title);  
    printf("请输入作者名字:");  
    scanf("%s",author);  
    printf("请输入单价:");  
    scanf("%lf",&price);  
    printf("n");  
  }  
  return head_book; 
} 
 
struct student *Create_New_Student(){ 
  struct student *head_student,*p_student;  
  int id, tag; 
  char sex[10]; 
  char name[20];  
  int size_student=sizeof(struct student);  
    
  head_student=NULL;  
  printf("请输入学生编号:");  
  scanf("%d",&id);  
  printf("请输入学生姓名:");  
  scanf("%s",name);  
  printf("请输入学生性别:");  
  scanf("%s",sex);   
  printf("n");  
  while(true){  
    p_student=(struct student *)malloc(size_student);   
    p_student->id=id;   
    strcpy(p_student->name,name);  
    strcpy(p_student->sex,sex);   
    strcpy(p_student->borrow_book,"无");  
    head_student=Insert_Student(head_student,p_student);  
    printf("是否继续？继续输入1，退出按任意键n"); 
    scanf("%d",&tag); 
    if(tag!=1){ 
      break; 
    } 
    printf("请输入学生编号:");  
    scanf("%d",&id);  
    printf("请输入学生姓名:");  
    scanf("%s",name);  
    printf("请输入学生性别:");  
    scanf("%s",sex);   
    printf("n");  
  }  
  return head_student; 
} 
 
struct book *Insert_Book(struct book *head_book,struct book *new_book){ 
  struct book *p,*q; 
 
  p=q=head_book; 
   
  if(head_book==NULL){  //单向链表为空的情况 
    head_book=new_book; 
    new_book->next = NULL; 
  }else{ 
    while((new_book->id>p->id)&&(p->next!=NULL)){ 
      q = p; 
      p = p->next; 
    } 
    if(new_book->id<=p->id){ 
      new_book->next=p; 
      if(head_book==p) 
        head_book=new_book; 
      else 
        q->next = new_book; 
    }else{ 
      p->next=new_book; 
      new_book->next=NULL; 
    } 
  } 
  return head_book; 
}; 
 
struct student *Insert_Student(struct student *head_student,struct student *new_student){ 
  struct student *p,*q; 
 
  p=q=head_student; 
   
  if(head_student==NULL){ //单向链表为空的情况 
    head_student=new_student; 
    new_student->next = NULL; 
  }else{ 
    while((new_student->id>p->id)&&(p->next!=NULL)){ 
      q = p; 
      p = p->next; 
    } 
    if(new_student->id<=p->id){ 
      new_student->next=p; 
      if(head_student==p) 
        head_student=new_student; 
      else 
        q->next = new_student; 
    }else{ 
      p->next=new_student; 
      new_student->next=NULL; 
    } 
  } 
  return head_student; 
} 
 
struct book *Search_Book_ById(int id,struct book *head_book){ 
  struct book *ptr_book = head_book;  
  int flag=0;  
  while(ptr_book!=NULL)  
  { 
    if(ptr_book->id==id){ 
      printf("图书编号:%dn",ptr_book->id); 
      printf("图书名称:%sn",ptr_book->title); 
      printf("图书单价:%.2lfn",ptr_book->price); 
      printf("图书作者:%sn",ptr_book->author); 
      printf("存在状态:%sn",ptr_book->state); 
      printf("借书人姓名:%sn",ptr_book->student_name);  
      printf("学号:%dn",ptr_book->student_id); 
      printf("n"); 
      flag++; 
    } 
    if(flag>0) 
    { 
      break; 
    } 
    ptr_book = ptr_book->next; 
  }  
  if(flag==0){  
      printf("暂无此图书信息!nn");  
  }  
  return head_book;  
}; 
 
struct book *Search_Book_ByTitle(char *title,struct book *head_book){ 
  struct book *ptr_book = head_book;  
  int flag=0;  
  while(ptr_book!=NULL)  
  {  
    if(strcmp(ptr_book->title,title)==0){  
      printf("图书编号:%dn",ptr_book->id);  
      printf("图书名称:%sn",ptr_book->title);  
      printf("图书单价:%.2lfn",ptr_book->price);  
      printf("图书作者:%sn",ptr_book->author);  
      printf("存在状态:%sn",ptr_book->state);  
      printf("借书人姓名:%sn",ptr_book->student_name);   
      printf("学号:%dn",ptr_book->student_id);  
      printf("n");  
      flag++;  
    } 
    if(flag>0) 
    { 
      break; 
    } 
    ptr_book = ptr_book->next; 
  }  
  if(flag==0){  
      printf("暂无此图书信息!nn");  
  }  
  return head_book; 
}; 
 
struct book *Search_Book_ByPrice(double price_h,double price_l,struct book *head_book){ 
  struct book *ptr_book = head_book;  
  int flag=0;  
  while(ptr_book!=NULL)  
  {  
    if(ptr_book->price>=price_l&&ptr_book->price<=price_h){  
      printf("图书编号:%dn",ptr_book->id);  
      printf("图书名称:%sn",ptr_book->title);  
      printf("图书单价:%.2lfn",ptr_book->price);  
      printf("图书作者:%sn",ptr_book->author);  
      printf("存在状态:%sn",ptr_book->state);  
      printf("借书人姓名:%sn",ptr_book->student_name);   
      printf("学号:%dn",ptr_book->student_id);  
      printf("n");  
      flag++;  
    } 
    ptr_book = ptr_book->next; 
  }  
  if(flag==0){  
      printf("暂无此图书信息!nn");  
  }  
  return head_book; 
} 
 
/*bool Delete_Book(int id,book* head_book){ 
  bool flag=true; 
  struct book *p,*q; 
  p=q=head_book; 
  if(p->id==id&&p->next==NULL){ 
    head_book=NULL; 
  } 
 
  while(p->id!=id&&p->next!=NULL){ 
    q=p; 
    p=p->next; 
  } 
  if(p->id==id){ 
    if(p==head_book){ 
      head_book=p->next; 
    }else{ 
      q->next=p->next; 
    } 
    free(p); 
  }else{ 
    flag=false; 
    printf("找不到该书"); 
  } 
  return flag; 
};*/ 
 
struct book* Delete_Book(int id,book* head_book){ 
  bool flag=true; 
  struct book *p,*q; 
  p=q=head_book; 
 
  while(p->id!=id&&p->next!=NULL){ 
    q=p; 
    p=p->next; 
  } 
  if(p->id==id){ 
    if(p==head_book){ 
      head_book=p->next; 
    }else{ 
      q->next=p->next; 
    } 
 
    free(p); 
    printf("删除成功！n"); 
  }else{ 
    flag=false; 
    printf("找不到该书"); 
  } 
  return head_book; 
}; 
 
struct student* Delete_Student(int id,student* head_student){ 
  bool flag=true; 
  struct student *p,*q; 
  p=q=head_student; 
 
  while(p->id!=id&&p->next!=NULL){ 
    q=p; 
    p=p->next; 
  } 
  if(p->id==id){ 
    if(p==head_student){ 
      head_student=p->next; 
    }else{ 
      q->next=p->next; 
    } 
 
    free(p); 
    printf("删除成功！n"); 
  }else{ 
    flag=false; 
    printf("找不到该学生"); 
  } 
  return head_student; 
}; 
 
struct student *Search_Student(int id,struct student *head_student){ 
  struct student *ptr_student = head_student;  
  int flag=0;  
  while(ptr_student!=NULL)  
  { 
    if(ptr_student->id==id){ 
      printf("学号:%dn",ptr_student->id); 
      printf("姓名:%sn",ptr_student->name); 
      printf("性别:%sn",ptr_student->sex); 
      printf("借书:%sn",ptr_student->borrow_book);  
      printf("n"); 
      flag++; 
    } 
    if(flag>0) 
    { 
      break; 
    } 
    ptr_student = ptr_student->next; 
  }  
  if(flag==0){  
      printf("暂无此学生信息!nn");  
  }  
  return head_student;  
}; 
 
void Lent_Book(int id,int student_id,struct book *head_book,struct student *head_student){ 
  struct book* p=head_book; 
  struct student* q=head_student; 
  if(p==NULL||q==NULL){ 
    printf("书本或学生不存在n"); 
    return; 
  } 
  while(p!=NULL&&q!=NULL){ 
    if(p->id!=id){ 
      p=p->next; 
    } 
    if(q->id!=student_id){ 
      q=q->next; 
    } 
    if(p->id==id&&q->id==student_id){ 
      break; 
    } 
  } 
  if(p==NULL||q==NULL){ 
    printf("书本或学生不存在n"); 
    return; 
  }else{ 
    if(strcmp(p->state,"存在")!=0){ 
      printf("书已借出!抱歉!"); 
      return; 
    }else{ 
      p->student_id=student_id; 
      strcpy(p->student_name,q->name); 
      strcpy(q->borrow_book,p->title); 
      strcpy(p->state,"已借出"); 
      printf("已成功借出!/n"); 
    } 
  } 
}; 
 
void Back_Book(int id,int student_id,struct book *head_book,struct student *head_student){ 
  struct book* p=head_book; 
  struct student* q=head_student; 
  if(p==NULL||q==NULL){ 
    printf("书本或学生不存在n"); 
    return; 
  } 
  while(p!=NULL&&q!=NULL){ 
    if(p->id!=id){ 
      p=p->next; 
    } 
    if(q->id!=student_id){ 
      q=q->next; 
    } 
    if(p->id==id&&q->id==student_id){ 
      break; 
    } 
  } 
  if(p==NULL||q==NULL){ 
    printf("书本或学生不存在n"); 
    return; 
  }else{ 
    if(strcmp(p->state,"存在")==0){ 
      printf("书未借出!抱歉!"); 
      return; 
    }else{ 
      p->student_id=-1; 
      strcpy(p->student_name,"待定"); 
      strcpy(q->borrow_book,"无"); 
      strcpy(p->state,"存在"); 
      printf("已成功归还!/n"); 
    } 
  } 
}; 
 
void Print_Book(struct book *head_book){ 
  struct book* p=head_book; 
 
  if(p==NULL){  
    printf("n无记录nn");  
    return;  
  }  
  printf("n图书编号t图书名称t图书单价t图书作者nn");  
  while (p!=NULL) 
  { 
    printf("%dtt%stt%.2lftt%snn",p->id,p->title,p->price,p->author); 
    p = p->next; 
  } 
} 
 
void Print_Student(struct student *head_student){ 
  struct student* p=head_student; 
 
  if(p==NULL){  
    printf("n无记录nn");  
    return;  
  }  
  printf("n学生姓名t学生性别t学生学号nn");  
  while (p!=NULL) 
  { 
    printf("%stt%stt%dn",p->name,p->sex,p->id); 
    p = p->next; 
  } 
}