【数据布局】双向循环链表实现浅易图书管理系统的增删改查 - IT评测·应用市场-qidao123.com

#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;
}

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