struct book
{
?? ?char name[20];
?? ?float price;
?? ?int num; ? ? ? ? ?//書的數(shù)量
};
//3 數(shù)據(jù)容器——鏈表
struct Node
{
?? ?struct book data;
?? ?struct Node*next;
};
void printflist(struct Node*headnode);
struct Node*headnode = NULL;
//創(chuàng)建表頭
struct Node*createlisthead()
{
?? ?//動態(tài)內(nèi)存申請
?? ?struct Node*headnode = (struct Node*)malloc(sizeof(struct Node));
?? ?//變量的基本規(guī)則：使用前必須初始化
?? ?headnode->next = NULL;
?? ?return headnode;
}
//創(chuàng)建節(jié)點(diǎn)，為插入做準(zhǔn)備
//把用戶的數(shù)據(jù)變?yōu)榻Y(jié)構(gòu)體變量
struct Node* createnewnode(struct book data)
{
?? ?struct Node*newnode = (struct Node*)malloc(sizeof(struct Node));
?? ?newnode->data = data;
?? ?newnode->next = NULL;
?? ?return newnode;
}
//表頭法插入
void insertbyhead(struct Node*headnode, struct book data)
{
?? ?struct Node* newnode = createnewnode(data);
?? ?//必須先連后斷
?? ?newnode->next = headnode->next;
?? ?headnode->next = newnode;

}
//指定位置刪除
void deletenodebyname(struct Node*headnode, char *bookname)
{
?? ?struct Node*posleftnode = headnode;
?? ?struct Node*posnode = headnode->next;
?? ?//字符串比較函數(shù)
?? ?while (posnode != NULL && strcmp(posnode->data.name,bookname))
?? ?{
?? ??? ?posleftnode = posnode;
?? ??? ?posnode = posnode->next;
?? ?}
?? ?//討論結(jié)果
?? ?if (posnode == NULL)
?? ?{
?? ??? ?printf("未找到數(shù)據(jù)");
?? ??? ?return ;
?? ?}
?? ?else
?? ?{
?? ??? ?posleftnode->next = posnode->next;
?? ??? ?free(posnode);
?? ??? ?posnode = NULL;
?? ?}
?? ?printflist(headnode);
}
//查找書籍
struct Node*searchbyname(struct Node*headnode, char *bookname)
{
?? ?struct Node *posnode = headnode->next;
?? ?while (posnode != NULL &&strcmp(posnode->data.name, bookname))
?? ?{
?? ??? ?posnode = posnode->next;
?? ?}
?? ?return posnode;
}
//打印鏈表——從第二個節(jié)點(diǎn)開始打印
void printflist(struct Node*headnode)
{
?? ?struct Node* pmove = headnode->next;
?? ?printf("書名\t價格\t數(shù)量\n");

?? ?while (pmove!=NULL)
?? ?{
?? ??? ?printf("%s\t%.1f\t%d\n", pmove->data.name,pmove->data.price,pmove->data.num );
?? ??? ?pmove = pmove->next;
?? ?}
?? ?printf("\n");
}

//冒泡排序算法
void bubblesortlist(struct Node*headnode)
{
?? ?for (struct Node*p = headnode->next; p != NULL; p = p->next)
?? ?{
?? ??? ?for (struct Node*q = headnode->next; q->next != NULL; q = q->next)
?? ??? ?{
?? ??? ??? ?if (q->data.price > q->next->data.price)
?? ??? ??? ?{
?? ??? ??? ??? ?//交換
?? ??? ??? ??? ?struct book tempdata = q->data;
?? ??? ??? ??? ?q->data = q->next->data;
?? ??? ??? ??? ?q->next->data = tempdata;
?? ??? ??? ?}
?? ??? ?}
?? ?}
?? ?printflist(headnode);
}

//寫操作
void savefile(const char*filename, struct Node*headnode)
{
?? ?FILE*fp = fopen(filename, "w");
?? ?struct Node*pmove = headnode->next;
?? ?while (pmove != NULL)
?? ?{
?? ??? ?fprintf(fp, "%s\t%.1f\t%d\n", pmove->data.name, pmove->data.price, pmove->data.num);
?? ??? ?pmove = pmove->next;
?? ?}

?? ?fclose(fp);
?? ?fp = NULL;
}

//文件讀操作
void readfile(const char *filename, struct Node*headnode)
{
?? ?FILE*fp = fopen(filename, "r");
?? ?if (fp == NULL)
?? ?{
?? ??? ?//不存在文件則創(chuàng)建
?? ??? ?fp = fopen(filename, "w+");
?? ?}
?? ?struct book tempdata;
?? ?while (fscanf(fp, "%s\t%f\t%d\n", tempdata.name, &tempdata.price, &tempdata.num) != EOF)
?? ?{
?? ??? ?insertbyhead(headnode, tempdata);
?? ?}
?? ?fclose(fp);
?? ?fp = NULL;
}

//1 界面
void menu()
{
?? ?printf("---------------------------------\n");
?? ?printf("\t圖書管理系統(tǒng)\n");
?? ?printf("\t0.退出系統(tǒng)\n");
?? ?printf("\t1.登記書籍\n");
?? ?printf("\t2.瀏覽書籍\n");
?? ?printf("\t3.借閱書籍\n");
?? ?printf("\t4.歸還書籍\n");
?? ?printf("\t5.書籍排序\n");
?? ?printf("\t6.刪除書籍\n");
?? ?printf("\t7.查找書籍\n");
?? ?printf("---------------------------------\n");
?? ?printf("請輸入0~7\n");

}
//2 ?做交互
void keydown()
{
?? ?int input = 0;
?? ?struct book tempbook; ?//創(chuàng)建臨時變量，存儲書籍信息
?? ?struct Node*result = NULL; ? ? //創(chuàng)建臨時指針變量，指向查找書籍的節(jié)點(diǎn)
?? ?scanf("%d", &input);
?? ?switch (input)
?? ?{
?? ?case 0:
?? ??? ?printf("【退出】\n");
?? ??? ?printf("退出成功\n");
?? ??? ?system("pause");
?? ??? ?exit(0); ? //關(guān)閉整個程序
?? ??? ?break;
?? ?case 1:
?? ??? ?printf("【登記】\n");
?? ??? ?printf("輸入書籍的信息（name,price,num）");
?? ??? ?scanf("%s%f%d", tempbook.name, &tempbook.price, &tempbook.num);
?? ??? ?insertbyhead(headnode, tempbook);
?? ??? ?savefile("book.txt", headnode);
?? ??? ?break;
?? ?case 2:
?? ??? ?printf("【瀏覽】\n");
?? ??? ?printflist(headnode);
?? ??? ?break;
?? ?case 3:
?? ??? ?printf("【借閱】\n"); ? ? ? ? ?//書籍存在，數(shù)量-1
?? ??? ?printf("請輸入要借閱的書籍");
?? ??? ?scanf("%s", tempbook.name);
?? ??? ?result = searchbyname(headnode, tempbook.name);
?? ??? ?if (result == NULL)
?? ??? ?{
?? ??? ??? ?printf("沒有相關(guān)書籍，無法借閱");
?? ??? ?}
?? ??? ?else
?? ??? ?{
?? ??? ??? ?if (result->data.num > 0)
?? ??? ??? ?{
?? ??? ??? ??? ?result->data.num--;
?? ??? ??? ??? ?printf("借閱成功");
?? ??? ??? ?}
?? ??? ??? ?else
?? ??? ??? ??? ?printf("無庫存");
?? ??? ??? ?
?? ??? ?}

?? ??? ?break;
?? ?case 4:
?? ??? ?printf("【歸還】\n"); ? ? ?//書記歸還，數(shù)量+1
?? ??? ?printf("請輸入要?dú)w還的書籍");
?? ??? ?scanf("%s", tempbook.name);
?? ??? ?result = searchbyname(headnode, tempbook.name);
?? ??? ?if (result == NULL)
?? ??? ??? ?printf("來源非法");
?? ??? ?else
?? ??? ?{
?? ??? ??? ?result->data.num++;
?? ??? ??? ?printf("書籍歸還成功！");
?? ??? ?}
?? ?
?? ??? ?break;
?? ?case 5:
?? ??? ?printf("【排序】\n");
?? ??? ?bubblesortlist(headnode);
?? ??? ?savefile("book.txt", headnode);
?? ??? ?break;
?? ?case 6:
?? ??? ?printf("【刪除】\n");
?? ??? ?printf("輸入要刪除的書名");
?? ??? ?scanf("%s", tempbook.name);
?? ??? ?deletenodebyname(headnode, tempbook.name);
?? ??? ?savefile("book.txt", headnode);
?? ??? ?break;
?? ?case 7:
?? ??? ?printf("【查找】\n");
?? ??? ?printf("請輸入要查找的書籍");
?? ??? ?scanf("%s", tempbook.name);
?? ??? ?result = searchbyname(headnode, tempbook.name);
?? ??? ?if (result == NULL)
?? ??? ?{
?? ??? ??? ?printf("未找到相關(guān)信息!\n");

?? ??? ?}
?? ??? ?else
?? ??? ?{
?? ??? ??? ?printf("書名\t價格\t數(shù)量\n");
?? ??? ??? ?printf("%s\t%.1f\t%d\t", result->data.name, result->data.price, result->data.num);
?? ??? ?}
?? ??? ?break;
?? ?default:
?? ??? ?printf("選擇錯誤，請重新選擇：>");
?? ??? ?break;
?? ?}
}
int main()
{
?? ?headnode = createlisthead();
?? ?readfile("book.txt", headnode);
?? ?while (1)
?? ?{
?? ??? ?menu();
?? ??? ?keydown();
?? ??? ?system("pause");
?? ??? ?system("cls");

?? ?}
?? ?system("pause");
?? ?return 0;
}