c语言编写一个学生图书管占座系统

好的，我可以给您提供一个简单的学生图书馆占座系统的C语言实现，如下所示：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define MAX 50

// 学生结构体
struct student {
    char name[MAX];
    int id;
    int seat_number;
    int is_reserved;
};

// 图书馆座位结构体
struct seat {
    int number;
    int is_reserved;
};

// 初始化座位
void init_seats(struct seat seats[], int n) {
    for (int i = 0; i < n; i++) {
        seats[i].number = i + 1;
        seats[i].is_reserved = 0;
    }
}

// 显示座位状态
void show_seats(struct seat seats[], int n) {
    printf("座位状态：\n");
    for (int i = 0; i < n; i++) {
        printf("%d号座位: %s\n", seats[i].number, seats[i].is_reserved ? "已被预定" : "未被预定");
    }
}

// 查找学生
int find_student(struct student students[], int n, int id) {
    for (int i = 0; i < n; i++) {
        if (students[i].id == id) {
            return i;
        }
    }
    return -1;
}

// 预定座位
void reserve_seat(struct student students[], int n, struct seat seats[], int m) {
    int id;
    printf("请输入您的学号：");
    scanf("%d", &id);

    int idx = find_student(students, n, id);
    if (idx == -1) {
        printf("未找到该学生！\n");
        return;
    }

    if (students[idx].is_reserved) {
        printf("您已经预定了座位！\n");
        return;
    }

    int seat_number;
    printf("请输入您要预定的座位号：");
    scanf("%d", &seat_number);

    if (seat_number < 1 || seat_number > m) {
        printf("座位号输入有误！\n");
        return;
    }

    if (seats[seat_number-1].is_reserved) {
        printf("该座位已经被预定了！\n");
        return;
    }

    students[idx].seat_number = seat_number;
    students[idx].is_reserved = 1;
    seats[seat_number-1].is_reserved = 1;

    printf("预定成功！\n");
}

// 取消预定
void cancel_reservation(struct student students[], int n, struct seat seats[], int m) {
    int id;
    printf("请输入您的学号：");
    scanf("%d", &id);

    int idx = find_student(students, n, id);
    if (idx == -1) {
        printf("未找到该学生！\n");
        return;
    }

    if (!students[idx].is_reserved) {
        printf("您还没有预定座位！\n");
        return;
    }

    int seat_number = students[idx].seat_number;

    students[idx].is_reserved = 0;
    students[idx].seat_number = 0;
    seats[seat_number-1].is_reserved = 0;

    printf("取消预定成功！\n");
}

// 显示菜单
void show_menu() {
    printf("\n\n");
    printf("1. 预定座位\n");
    printf("2. 取消预定\n");
    printf("3. 显示座位状态\n");
    printf("4. 退出\n");
    printf("\n\n");
}

int main() {
    printf("欢迎使用学生图书馆占座系统！\n");

    int n;
    printf("请输入学生人数：");
    scanf("%d", &n);

    struct student students[n];

    for (int i = 0; i < n; i++) {
        printf("请输入第%d个学生的姓名和学号：", i+1);
        scanf("%s %d", students[i].name, &students[i].id);
        students[i].seat_number = 0;
        students[i].is_reserved = 0;
    }

    int m;
    printf("请输入座位数量：");
    scanf("%d", &m);

    struct seat seats[m];
    init_seats(seats, m);

    int choice;
    do {
        show_menu();
        printf("请输入您的选择：");
        scanf("%d", &choice);

        switch(choice) {
            case 1:
                reserve_seat(students, n, seats, m);
                break;
            case 2:
                cancel_reservation(students, n, seats, m);
                break;
            case 3:
                show_seats(seats, m);
                break;
            case 4:
                printf("谢谢使用，再见！\n");
                break;
            default:
                printf("输入有误，请重新输入！\n");
                break;
        }
    } while(choice != 4);

    return 0;
}

以上代码实现了一个简单的学生图书馆占座系统，包括了预定座位、取消预定、显示座位状态等功能。用户可以根据自己的需要进行修改和扩展。