用C语言编写一个图书馆占座管理系统

好的，我将为您提供一个简单的图书馆占座管理系统的C语言代码，仅供参考。

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#define MAX_USER 100
#define MAX_SEAT 50
#define MAX_NAME_LEN 20

typedef struct {
    int seat_id;
    char user_name[MAX_NAME_LEN];
    int start_time; // 占座开始时间
    int end_time; // 占座结束时间
} Seat;

typedef struct {
    char user_name[MAX_NAME_LEN];
    char password[MAX_NAME_LEN];
} User;

int login(User users[], int user_num) { // 登录函数
    char name[MAX_NAME_LEN];
    char password[MAX_NAME_LEN];
    printf("请输入用户名：\n");
    scanf("%s", name);
    printf("请输入密码：\n");
    scanf("%s", password);
    for (int i = 0; i < user_num; i++) {
        if (strcmp(users[i].user_name, name) == 0 && strcmp(users[i].password, password) == 0) {
            printf("登录成功！\n");
            return i; // 返回用户在数组中的索引
        }
    }
    printf("用户名或密码错误！\n");
    return -1;
}

void view_seats(Seat seats[], int seat_num) { // 查看座位状态函数
    printf("座位状态如下：\n");
    for (int i = 0; i < seat_num; i++) {
        printf("座位%d：", seats[i].seat_id);
        if (seats[i].user_name[0] != '\0') {
            printf("%s占用，占座时间：%d~%d\n", seats[i].user_name, seats[i].start_time, seats[i].end_time);
        } else {
            printf("空闲\n");
        }
    }
}

void reserve_seat(Seat seats[], int seat_num, int user_index) { // 预约座位函数
    int seat_id;
    printf("请输入要预约的座位号：\n");
    scanf("%d", &seat_id);
    for (int i = 0; i < seat_num; i++) {
        if (seats[i].seat_id == seat_id) {
            if (seats[i].user_name[0] != '\0') { // 座位已被占用
                printf("该座位已被%s占用，占座时间：%d~%d\n", seats[i].user_name, seats[i].start_time, seats[i].end_time);
                return;
            } else { // 预约座位
                printf("预约座位成功！\n");
                strcpy(seats[i].user_name, users[user_index].user_name);
                printf("请输入占座开始时间：\n");
                scanf("%d", &seats[i].start_time);
                printf("请输入占座结束时间：\n");
                scanf("%d", &seats[i].end_time);
                return;
            }
        }
    }
    printf("座位号不存在！\n");
}

void cancel_reserve(Seat seats[], int seat_num, int user_index) { // 取消预约函数
    int seat_id;
    printf("请输入要取消预约的座位号：\n");
    scanf("%d", &seat_id);
    for (int i = 0; i < seat_num; i++) {
        if (seats[i].seat_id == seat_id) {
            if (strcmp(seats[i].user_name, users[user_index].user_name) == 0) { // 取消预约
                printf("取消预约成功！\n");
                seats[i].user_name[0] = '\0';
                seats[i].start_time = 0;
                seats[i].end_time = 0;
                return;
            } else { // 该座位不是该用户预约的
                printf("该座位不是您预约的！\n");
                return;
            }
        }
    }
    printf("座位号不存在！\n");
}

int main() {
    User users[MAX_USER] = {{"user1", "123456"}, {"user2", "123456"}}; // 用户名和密码
    Seat seats[MAX_SEAT];
    int user_num = 2;
    int seat_num = 10;
    for (int i = 0; i < seat_num; i++) {
        seats[i].seat_id = i + 1;
        seats[i].user_name[0] = '\0';
        seats[i].start_time = 0;
        seats[i].end_time = 0;
    }
    int user_index = login(users, user_num); // 用户登录
    if (user_index == -1) {
        return 0;
    }
    while (1) {
        printf("请选择操作：\n1、查看座位状态\n2、预约座位\n3、取消预约\n4、退出\n");
        int choice;
        scanf("%d", &choice);
        switch (choice) { // 根据用户选择进行相应操作
            case 1:
                view_seats(seats, seat_num);
                break;
            case 2:
                reserve_seat(seats, seat_num, user_index);
                break;
            case 3:
                cancel_reserve(seats, seat_num, user_index);
                break;
            case 4:
                printf("退出系统！\n");
                return 0;
            default:
                printf("输入有误，请重新输入！\n");
                break;
        }
    }
    return 0;
}

以上代码仅为示例，实际开发中还需根据具体需求进行修改和完善。