考勤系统设计 功能：设计一考勤系统。考勤信息记录了学生的缺课情况，它包括：缺课日期、第几节课、课程名称、学生姓名、学生学号、缺课类型（迟到、早退、请假及旷课）。系统具有以下功能： 1、录入学生的缺课记录； 2、修改某个学生的缺课记录； 3、查询某个学生的缺课情况； 4、统计某段时间内，旷课学生姓名及旷课次数，按旷课次数由多到少排序； 5、统计某段时间内，有学生旷课的课程及旷课人次，按旷课人次由多到少排序； 6、系统以菜单方式工作。c语言

以下是一个简单的C语言考勤系统设计：

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

#define MAX_STUDENTS 100 // 最多学生数
#define MAX_COURSES 10 // 最多课程数
#define MAX_ABSENCES 20 // 最多缺课记录数

struct Absence { // 缺课记录结构体
    int date; // 缺课日期
    int time; // 第几节课
    char type[10]; // 缺课类型
};

struct Student { // 学生结构体
    char name[20]; // 学生姓名
    char id[20]; // 学生学号
    struct Absence absences[MAX_ABSENCES]; // 缺课记录数组
    int num_absences; // 缺课记录数
};

struct Course { // 课程结构体
    char name[20]; // 课程名称
    struct Student students[MAX_STUDENTS]; // 学生数组
    int num_students; // 学生数
};

struct School { // 学校结构体
    struct Course courses[MAX_COURSES]; // 课程数组
    int num_courses; // 课程数
};

void add_absence(struct Absence *absence) { // 录入缺课记录
    printf("请输入缺课日期：");
    scanf("%d", &(absence->date));
    printf("请输入第几节课：");
    scanf("%d", &(absence->time));
    printf("请输入缺课类型（迟到、早退、请假或旷课）：");
    scanf("%s", absence->type);
}

void add_student(struct Course *course) { // 录入学生信息
    struct Student student;
    printf("请输入学生姓名：");
    scanf("%s", student.name);
    printf("请输入学生学号：");
    scanf("%s", student.id);
    course->students[course->num_students] = student;
    course->num_students++;
}

void add_course(struct School *school) { // 录入课程信息
    struct Course course;
    printf("请输入课程名称：");
    scanf("%s", course.name);
    school->courses[school->num_courses] = course;
    school->num_courses++;
}

void add_absence_record(struct School *school) { // 录入缺课记录
    char course_name[20], student_id[20];
    printf("请输入课程名称：");
    scanf("%s", course_name);
    printf("请输入学生学号：");
    scanf("%s", student_id);
    for (int i = 0; i < school->num_courses; i++) {
        if (strcmp(school->courses[i].name, course_name) == 0) { // 找到对应课程
            for (int j = 0; j < school->courses[i].num_students; j++) {
                if (strcmp(school->courses[i].students[j].id, student_id) == 0) { // 找到对应学生
                    struct Absence absence;
                    add_absence(&absence);
                    school->courses[i].students[j].absences[school->courses[i].students[j].num_absences] = absence;
                    school->courses[i].students[j].num_absences++;
                    printf("缺课记录已添加。\n");
                    return;
                }
            }
            printf("未找到该学生。\n");
            return;
        }
    }
    printf("未找到该课程。\n");
}

void modify_absence_record(struct School *school) { // 修改缺课记录
    char course_name[20], student_id[20];
    printf("请输入课程名称：");
    scanf("%s", course_name);
    printf("请输入学生学号：");
    scanf("%s", student_id);
    for (int i = 0; i < school->num_courses; i++) {
        if (strcmp(school->courses[i].name, course_name) == 0) { // 找到对应课程
            for (int j = 0; j < school->courses[i].num_students; j++) {
                if (strcmp(school->courses[i].students[j].id, student_id) == 0) { // 找到对应学生
                    int absence_index;
                    printf("请输入要修改的缺课记录编号（从1开始）：");
                    scanf("%d", &absence_index);
                    if (absence_index > 0 && absence_index <= school->courses[i].students[j].num_absences) {
                        struct Absence absence;
                        add_absence(&absence);
                        school->courses[i].students[j].absences[absence_index - 1] = absence;
                        printf("缺课记录已修改。\n");
                        return;
                    }
                    printf("无效的缺课记录编号。\n");
                    return;
                }
            }
            printf("未找到该学生。\n");
            return;
        }
    }
    printf("未找到该课程。\n");
}

void query_absences(struct School *school) { // 查询学生缺课情况
    char course_name[20], student_id[20];
    printf("请输入课程名称：");
    scanf("%s", course_name);
    printf("请输入学生学号：");
    scanf("%s", student_id);
    for (int i = 0; i < school->num_courses; i++) {
        if (strcmp(school->courses[i].name, course_name) == 0) { // 找到对应课程
            for (int j = 0; j < school->courses[i].num_students; j++) {
                if (strcmp(school->courses[i].students[j].id, student_id) == 0) { // 找到对应学生
                    struct Student student = school->courses[i].students[j];
                    printf("学生姓名：%s\n", student.name);
                    printf("学生学号：%s\n", student.id);
                    printf("缺课记录：\n");
                    for (int k = 0; k < student.num_absences; k++) {
                        struct Absence absence = student.absences[k];
                        printf("%d\t%d\t%s\n", absence.date, absence.time, absence.type);
                    }
                    return;
                }
            }
            printf("未找到该学生。\n");
            return;
        }
    }
    printf("未找到该课程。\n");
}

void sort_students_by_absences(struct School *school) { // 按旷课次数排序学生
    char course_name[20];
    printf("请输入课程名称：");
    scanf("%s", course_name);
    for (int i = 0; i < school->num_courses; i++) {
        if (strcmp(school->courses[i].name, course_name) == 0) { // 找到对应课程
            struct Student students[MAX_STUDENTS];
            int num_students = 0;
            for (int j = 0; j < school->courses[i].num_students; j++) {
                int num_absences = 0;
                for (int k = 0; k < school->courses[i].students[j].num_absences; k++) {
                    if (strcmp(school->courses[i].students[j].absences[k].type, "旷课") == 0) {
                        num_absences++;
                    }
                }
                if (num_absences > 0) {
                    students[num_students] = school->courses[i].students[j];
                    students[num_students].num_absences = num_absences;
                    num_students++;
                }
            }
            for (int j = 0; j < num_students - 1; j++) { // 冒泡排序
                for (int k = 0; k < num_students - j - 1; k++) {
                    if (students[k].num_absences < students[k + 1].num_absences) {
                        struct Student temp = students[k];
                        students[k] = students[k + 1];
                        students[k + 1] = temp;
                    }
                }
            }
            printf("旷课学生姓名\t旷课次数\n");
            for (int j = 0; j < num_students; j++) {
                printf("%s\t%d\n", students[j].name, students[j].num_absences);
            }
            return;
        }
    }
    printf("未找到该课程。\n");
}

void sort_courses_by_absences(struct School *school) { // 按旷课人次排序课程
    int start_date, end_date;
    printf("请输入起始日期：");
    scanf("%d", &start_date);
    printf("请输入截止日期：");
    scanf("%d", &end_date);
    struct Course courses[MAX_COURSES];
    int num_courses = 0;
    for (int i = 0; i < school->num_courses; i++) {
        int num_absences = 0;
        for (int j = 0; j < school->courses[i].num_students; j++) {
            for (int k = 0; k < school->courses[i].students[j].num_absences; k++) {
                if (strcmp(school->courses[i].students[j].absences[k].type, "旷课") == 0 && school->courses[i].students[j].absences[k].date >= start_date && school->courses[i].students[j].absences[k].date <= end_date) {
                    num_absences++;
                }
            }
        }
        if (num_absences > 0) {
            courses[num_courses] = school->courses[i];
            courses[num_courses].num_students = num_absences;
            num_courses++;
        }
    }
    for (int i = 0; i < num_courses - 1; i++) { // 冒泡排序
        for (int j = 0; j < num_courses - i - 1; j++) {
            if (courses[j].num_students < courses[j + 1].num_students) {
                struct Course temp = courses[j];
                courses[j] = courses[j + 1];
                courses[j + 1] = temp;
            }
        }
    }
    printf("旷课课程名称\t旷课人次\n");
    for (int i = 0; i < num_courses; i++) {
        printf("%s\t%d\n", courses[i].name, courses[i].num_students);
    }
}

void print_menu() { // 打印菜单
    printf("1. 录入学生的缺课记录\n");
    printf("2. 修改某个学生的缺课记录\n");
    printf("3. 查询某个学生的缺课情况\n");
    printf("4. 统计某段时间内，旷课学生姓名及旷课次数，按旷课次数由多到少排序\n");
    printf("5. 统计某段时间内，有学生旷课的课程及旷课人次，按旷课人次由多到少排序\n");
    printf("6. 退出\n");
}

int main() {
    struct School school;
    school.num_courses = 0;
    int choice;
    do {
        print_menu();
        printf("请选择操作：");
        scanf("%d", &choice);
        switch (choice) {
            case 1:
                add_absence_record(&school);
                break;
            case 2:
                modify_absence_record(&school);
                break;
            case 3:
                query_absences(&school);
                break;
            case 4:
                sort_students_by_absences(&school);
                break;
            case 5:
                sort_courses_by_absences(&school);
                break;
            case 6:
                printf("谢谢使用！\n");
                return 0;
            default:
                printf("无效的选择。\n");
        }
    } while (1);
}

这个考勤系统可以实现录入学生的缺课记录、修改某个学生的缺课记录、查询某个学生的缺课情况、统计某段时间内旷课学生姓名及旷课次数，以及统计某段时间内有学生旷课的课程及旷课人次，并且支持菜单方式工作。