用c语言写出学院考勤管理系统

以下是一个简单的学院考勤管理系统C语言代码示例：

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

#define MAX_STUDENTS 100
#define MAX_NAME_LENGTH 50
#define MAX_ID_LENGTH 20

struct student {
    char name[MAX_NAME_LENGTH];
    char id[MAX_ID_LENGTH];
    int presence_count;
};

void add_student(struct student *students, int *student_count) {
    if (*student_count >= MAX_STUDENTS) {
        printf("The maximum number of students has been reached.\n");
        return;
    }
    struct student new_student;
    printf("Enter student name: ");
    scanf("%s", new_student.name);
    printf("Enter student ID: ");
    scanf("%s", new_student.id);
    new_student.presence_count = 0;
    students[*student_count] = new_student;
    (*student_count)++;
    printf("Student added successfully.\n");
}

void mark_presence(struct student *students, int student_count) {
    char id[MAX_ID_LENGTH];
    printf("Enter student ID: ");
    scanf("%s", id);
    for (int i = 0; i < student_count; i++) {
        if (strcmp(students[i].id, id) == 0) {
            students[i].presence_count++;
            printf("Presence marked for student %s.\n", students[i].name);
            return;
        }
    }
    printf("No student found with ID %s.\n", id);
}

void print_report(struct student *students, int student_count) {
    printf("Student ID\tName\tPresence Count\n");
    for (int i = 0; i < student_count; i++) {
        printf("%s\t%s\t%d\n", students[i].id, students[i].name, students[i].presence_count);
    }
}

int main() {
    struct student students[MAX_STUDENTS];
    int student_count = 0;
    int choice;
    while (1) {
        printf("\n1. Add student\n");
        printf("2. Mark presence\n");
        printf("3. Print report\n");
        printf("4. Exit\n");
        printf("Enter your choice: ");
        scanf("%d", &choice);
        switch (choice) {
            case 1:
                add_student(students, &student_count);
                break;
            case 2:
                mark_presence(students, student_count);
                break;
            case 3:
                print_report(students, student_count);
                break;
            case 4:
                exit(0);
            default:
                printf("Invalid choice.\n");
        }
    }
    return 0;
}

该程序实现了一个简单的学院考勤管理系统，可以添加学生、标记学生出席情况和打印出席报告。