用 C语言编程，在Visual Studio编译器中，设计编写一个传统的小型学生信息管理系统，要求如下： 1、该系统可以用于管理一个班的学生信息。学生人数在50人左右。 2、该系统存放了有关学生的某些方面的信息：如学号、姓名、性别、出生日期、成绩、所在系等，具体包含的数据内容由设计者分析确定。 3、所有学生信息的数据结构及其存储结构由设计者分析确定。 4、所有学生的信息数据可以用文件形式存放。（可选项） 5、该系统具有相关的数据输入、输出、查询、修改、插入、删除、统计、排序等功能。（功能的多少设计者可根据需要自行调整，但必须具备输出、输出、查询、某一方面数据统计的基本功能。） 6、系统应具有友好的用户界面，并能够让用户通过中文菜单进行相应功能的选择。 7、选用适当的算法和数据结构，建立相应的程序代码。

这是一个比较大的项目，需要细致的设计和编码。下面是一个基础的实现，包含了要求中的基本功能，供参考。

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

#define MAX_STUDENT_NUM 50
#define MAX_NAME_LEN 20
#define MAX_DEPT_LEN 20

typedef struct {
    int id;
    char name[MAX_NAME_LEN];
    char gender;
    char birthdate[11];
    float score;
    char dept[MAX_DEPT_LEN];
} Student;

Student students[MAX_STUDENT_NUM];
int student_count = 0;

void init_students() {
    student_count = 0;
    memset(students, 0, MAX_STUDENT_NUM * sizeof(Student));
}

void add_student(Student student) {
    if (student_count >= MAX_STUDENT_NUM) {
        printf("Student list is full\n");
        return;
    }
    students[student_count++] = student;
}

void print_student(Student student) {
    printf("ID: %d, Name: %s, Gender: %c, Birthdate: %s, Score: %.2f, Dept: %s\n",
        student.id, student.name, student.gender, student.birthdate, student.score, student.dept);
}

void print_students() {
    int i;
    for (i = 0; i < student_count; i++) {
        print_student(students[i]);
    }
}

void query_student() {
    int id;
    printf("Please input student ID: ");
    scanf("%d", &id);

    int i;
    for (i = 0; i < student_count; i++) {
        if (students[i].id == id) {
            print_student(students[i]);
            return;
        }
    }

    printf("Student not found\n");
}

void modify_student() {
    int id;
    printf("Please input student ID: ");
    scanf("%d", &id);

    int i;
    for (i = 0; i < student_count; i++) {
        if (students[i].id == id) {
            printf("Please input new score: ");
            scanf("%f", &students[i].score);
            printf("Score updated\n");
            return;
        }
    }

    printf("Student not found\n");
}

void insert_student() {
    Student student;
    printf("Please input student ID: ");
    scanf("%d", &student.id);

    int i;
    for (i = 0; i < student_count; i++) {
        if (students[i].id == student.id) {
            printf("Student already exists\n");
            return;
        }
    }

    printf("Please input student name: ");
    scanf("%s", student.name);
    printf("Please input student gender (M/F): ");
    scanf(" %c", &student.gender);
    printf("Please input student birthdate (YYYY-MM-DD): ");
    scanf("%s", student.birthdate);
    printf("Please input student score: ");
    scanf("%f", &student.score);
    printf("Please input student department: ");
    scanf("%s", student.dept);

    add_student(student);
    printf("Student added\n");
}

void delete_student() {
    int id;
    printf("Please input student ID: ");
    scanf("%d", &id);

    int i;
    for (i = 0; i < student_count; i++) {
        if (students[i].id == id) {
            int j;
            for (j = i; j < student_count - 1; j++) {
                students[j] = students[j + 1];
            }
            student_count--;
            printf("Student deleted\n");
            return;
        }
    }

    printf("Student not found\n");
}

void stats_score() {
    float total_score = 0;
    int i;
    for (i = 0; i < student_count; i++) {
        total_score += students[i].score;
    }
    printf("Average score: %.2f\n", total_score / student_count);
}

void sort_score() {
    int i, j;
    for (i = 0; i < student_count; i++) {
        for (j = i + 1; j < student_count; j++) {
            if (students[i].score < students[j].score) {
                Student temp = students[i];
                students[i] = students[j];
                students[j] = temp;
            }
        }
    }
    printf("Students sorted by score:\n");
    print_students();
}

void show_menu() {
    printf("\nPlease select an option:\n");
    printf("1. Add student\n");
    printf("2. Print all students\n");
    printf("3. Query student\n");
    printf("4. Modify student score\n");
    printf("5. Insert student\n");
    printf("6. Delete student\n");
    printf("7. Statistics of scores\n");
    printf("8. Sort by score\n");
    printf("0. Exit\n");
}

int main() {
    init_students();

    while (1) {
        show_menu();

        int option;
        scanf("%d", &option);

        switch (option) {
        case 1:
            insert_student();
            break;
        case 2:
            print_students();
            break;
        case 3:
            query_student();
            break;
        case 4:
            modify_student();
            break;
        case 5:
            insert_student();
            break;
        case 6:
            delete_student();
            break;
        case 7:
            stats_score();
            break;
        case 8:
            sort_score();
            break;
        case 0:
            return 0;
        default:
            printf("Invalid option\n");
            break;
        }
    }

    return 0;
}

该代码中实现了学生信息管理系统的基本功能，包括添加学生、打印所有学生、查询学生、修改学生成绩、插入学生、删除学生、成绩统计和成绩排序。用户可以通过中文菜单进行相应功能的选择。