#include <stdio.h>
#include <stdlib.h>
#include <string.h>// 书籍结构体
struct book {char name[20];      // 书名char authorname[20]; // 作者名float price;        // 价格int num;            // 总数量int borrowed;       // 已借出数量
};// 双向循环链表节点
struct node {struct book data;struct node *prev;struct node *next;
};// 全局变量：链表头指针
struct node *head = NULL;// 函数声明
void add_book();
void delete_book();
void modify_book();
void search_book();
void borrow_book();
void return_book();
void display_all();
void free_list();
struct node* find_book(char *name);int main() {int choice;while (1) {printf("\n图书管理系统\n");printf("1. 添加书籍\n");printf("2. 删除书籍\n");printf("3. 修改书籍信息\n");printf("4. 查询书籍信息\n");printf("5. 借书\n");printf("6. 还书\n");printf("7. 显示所有书籍\n");printf("0. 退出\n");printf("请选择操作: ");scanf("%d", &choice);switch (choice) {case 1: add_book(); break;case 2: delete_book(); break;case 3: modify_book(); break;case 4: search_book(); break;case 5: borrow_book(); break;case 6: return_book(); break;case 7: display_all(); break;case 0: free_list(); return 0;default: printf("无效选择!\n");}}return 0;
}// 添加书籍
void add_book() {struct node *new_node = (struct node*)malloc(sizeof(struct node));if (!new_node) {printf("内存分配失败!\n");return;}printf("请输入书名: ");scanf("%s", new_node->data.name);printf("请输入作者名: ");scanf("%s", new_node->data.authorname);printf("请输入价格: ");scanf("%f", &new_node->data.price);printf("请输入总数量: ");scanf("%d", &new_node->data.num);new_node->data.borrowed = 0;if (!head) {head = new_node;head->next = head;head->prev = head;} else {new_node->next = head;new_node->prev = head->prev;head->prev->next = new_node;head->prev = new_node;}printf("书籍添加成功!\n");
}// 删除书籍
void delete_book() {if (!head) {printf("没有书籍可删除!\n");return;}char name[20];printf("请输入要删除的书名: ");scanf("%s", name);struct node *current = head;do {if (strcmp(current->data.name, name) == 0) {if (current->data.borrowed > 0) {printf("该书还有借出未还，不能删除!\n");return;}if (current == head) {if (head->next == head) {head = NULL;} else {head = head->next;}}current->prev->next = current->next;current->next->prev = current->prev;free(current);printf("书籍删除成功!\n");return;}current = current->next;} while (current != head);printf("未找到该书!\n");
}// 修改书籍信息
void modify_book() {if (!head) {printf("没有书籍可修改!\n");return;}char name[20];printf("请输入要修改的书名: ");scanf("%s", name);struct node *book = find_book(name);if (!book) {printf("未找到该书!\n");return;}printf("当前信息:\n");printf("书名: %s\n", book->data.name);printf("作者: %s\n", book->data.authorname);printf("价格: %.2f\n", book->data.price);printf("总数量: %d\n", book->data.num);printf("已借出: %d\n", book->data.borrowed);printf("\n请输入新的作者名: ");scanf("%s", book->data.authorname);printf("请输入新的价格: ");scanf("%f", &book->data.price);printf("请输入新的总数量: ");scanf("%d", &book->data.num);printf("书籍信息修改成功!\n");
}// 查询书籍信息
void search_book() {if (!head) {printf("没有书籍可查询!\n");return;}char name[20];printf("请输入要查询的书名: ");scanf("%s", name);struct node *book = find_book(name);if (!book) {printf("未找到该书!\n");return;}printf("\n书籍信息:\n");printf("书名: %s\n", book->data.name);printf("作者: %s\n", book->data.authorname);printf("价格: %.2f\n", book->data.price);printf("总数量: %d\n", book->data.num);printf("可借数量: %d\n", book->data.num - book->data.borrowed);
}// 借书
void borrow_book() {if (!head) {printf("没有书籍可借!\n");return;}char name[20];printf("请输入要借的书名: ");scanf("%s", name);struct node *book = find_book(name);if (!book) {printf("未找到该书!\n");return;}int available = book->data.num - book->data.borrowed;printf("当前可借数量: %d\n", available);if (available <= 0) {printf("该书已全部借出!\n");return;}int quantity;printf("请输入要借的数量: ");scanf("%d", &quantity);if (quantity <= 0) {printf("借书数量必须大于0!\n");return;}if (quantity > available) {printf("借书数量超过可借数量!\n");return;}book->data.borrowed += quantity;printf("借书成功! 当前已借出: %d\n", book->data.borrowed);
}// 还书
void return_book() {if (!head) {printf("没有书籍可还!\n");return;}char name[20];printf("请输入要还的书名: ");scanf("%s", name);struct node *book = find_book(name);if (!book) {printf("未找到该书!\n");return;}if (book->data.borrowed <= 0) {printf("该书没有借出记录!\n");return;}printf("当前已借出数量: %d\n", book->data.borrowed);int quantity;printf("请输入要还的数量: ");scanf("%d", &quantity);if (quantity <= 0) {printf("还书数量必须大于0!\n");return;}if (quantity > book->data.borrowed) {printf("还书数量超过已借出数量!\n");return;}book->data.borrowed -= quantity;printf("还书成功! 当前已借出: %d\n", book->data.borrowed);
}// 显示所有书籍
void display_all() {if (!head) {printf("没有书籍可显示!\n");return;}struct node *current = head;printf("\n所有书籍信息:\n");do {printf("\n书名: %s\n", current->data.name);printf("作者: %s\n", current->data.authorname);printf("价格: %.2f\n", current->data.price);printf("总数量: %d\n", current->data.num);printf("可借数量: %d\n", current->data.num - current->data.borrowed);current = current->next;} while (current != head);
}// 释放链表内存
void free_list() {if (!head) return;struct node *current = head;struct node *temp;do {temp = current;current = current->next;free(temp);} while (current != head);
}// 查找书籍
struct node* find_book(char *name) {if (!head) return NULL;struct node *current = head;do {if (strcmp(current->data.name, name) == 0) {return current;}current = current->next;} while (current != head);return NULL;
}