帮我用C语言编程，要求如下：设计编写一个传统的小型学生信息管理系统。 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。

好的，以下是一个简单的学生信息管理系统的C语言代码，满足上述需求。其中，学生信息使用结构体数组存储，文件操作使用了fopen、fclose、fscanf等函数。

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

#define MAX_STUDENT_NUM 50  // 最大学生人数
#define FILE_NAME "student.txt"  // 学生信息文件名

// 学生信息结构体
typedef struct {
    char id[10];  // 学号
    char name[20];  // 姓名
    char gender[5];  // 性别
    char birth[15];  // 出生日期
    float score;  // 成绩
    char department[20];  // 所在系
} Student;

// 学生信息数组
Student students[MAX_STUDENT_NUM];
int student_num = 0;  // 学生数量

// 文件操作函数
int save_students() {
    FILE *fp = fopen(FILE_NAME, "w");
    if (fp == NULL) {
        printf("Failed to open file %s!\n", FILE_NAME);
        return 0;
    }
    for (int i = 0; i < student_num; i++) {
        fprintf(fp, "%s %s %s %s %f %s\n", students[i].id, students[i].name, students[i].gender, students[i].birth, students[i].score, students[i].department);
    }
    fclose(fp);
    return 1;
}

int load_students() {
    FILE *fp = fopen(FILE_NAME, "r");
    if (fp == NULL) {
        printf("Failed to open file %s!\n", FILE_NAME);
        return 0;
    }
    student_num = 0;
    while (fscanf(fp, "%s %s %s %s %f %s\n", students[student_num].id, students[student_num].name, students[student_num].gender, students[student_num].birth, &students[student_num].score, students[student_num].department) != EOF) {
        student_num++;
    }
    fclose(fp);
    return 1;
}

// 查询、统计、排序函数
void print_student(Student s) {
    printf("%s %s %s %s %.2f %s\n", s.id, s.name, s.gender, s.birth, s.score, s.department);
}

void print_all_students() {
    printf("*** All Students ***\n");
    for (int i = 0; i < student_num; i++) {
        print_student(students[i]);
    }
}

void query_student_by_name(char *name) {
    printf("*** Query Result ***\n");
    for (int i = 0; i < student_num; i++) {
        if (strcmp(students[i].name, name) == 0) {
            print_student(students[i]);
            return;
        }
    }
    printf("No student named %s found!\n", name);
}

void query_student_by_department(char *department) {
    printf("*** Query Result ***\n");
    int count = 0;
    for (int i = 0; i < student_num; i++) {
        if (strcmp(students[i].department, department) == 0) {
            print_student(students[i]);
            count++;
        }
    }
    printf("Total students in %s: %d\n", department, count);
}

void query_student_by_score(float min_score, float max_score) {
    printf("*** Query Result ***\n");
    int count = 0;
    for (int i = 0; i < student_num; i++) {
        if (students[i].score >= min_score && students[i].score <= max_score) {
            print_student(students[i]);
            count++;
        }
    }
    printf("Total students with score between %.2f and %.2f: %d\n", min_score, max_score, count);
}

void sort_students_by_score() {
    printf("*** Sorted Students ***\n");
    for (int i = 0; i < student_num; i++) {
        for (int j = i + 1; j < student_num; j++) {
            if (students[i].score < students[j].score) {
                Student temp = students[i];
                students[i] = students[j];
                students[j] = temp;
            }
        }
        print_student(students[i]);
    }
}

// 添加、修改、删除函数
void add_student(Student s) {
    if (student_num >= MAX_STUDENT_NUM) {
        printf("Max number of students reached!\n");
        return;
    }
    students[student_num] = s;
    student_num++;
    printf("Add student %s successfully!\n", s.name);
}

void modify_student(char *id, Student new_s) {
    for (int i = 0; i < student_num; i++) {
        if (strcmp(students[i].id, id) == 0) {
            students[i] = new_s;
            printf("Modify student %s successfully!\n", new_s.name);
            return;
        }
    }
    printf("No student with ID %s found!\n", id);
}

void delete_student(char *id) {
    for (int i = 0; i < student_num; i++) {
        if (strcmp(students[i].id, id) == 0) {
            for (int j = i + 1; j < student_num; j++) {
                students[j - 1] = students[j];
            }
            student_num--;
            printf("Delete student %s successfully!\n", students[i].name);
            return;
        }
    }
    printf("No student with ID %s found!\n", id);
}

// 主函数
int main() {
    load_students();
    while (1) {
        printf("=====================\n");
        printf("1. Add student\n");
        printf("2. Modify student\n");
        printf("3. Delete student\n");
        printf("4. Query student by name\n");
        printf("5. Query student by department\n");
        printf("6. Query student by score\n");
        printf("7. Sort students by score\n");
        printf("8. Print all students\n");
        printf("0. Exit\n");
        printf("=====================\n");
        int choice;
        scanf("%d", &choice);
        if (choice == 0) {
            save_students();
            printf("Goodbye!\n");
            break;
        } else if (choice == 1) {
            Student s;
            printf("Input student ID: ");
            scanf("%s", s.id);
            printf("Input student name: ");
            scanf("%s", s.name);
            printf("Input student gender: ");
            scanf("%s", s.gender);
            printf("Input student birth: ");
            scanf("%s", s.birth);
            printf("Input student score: ");
            scanf("%f", &s.score);
            printf("Input student department: ");
            scanf("%s", s.department);
            add_student(s);
        } else if (choice == 2) {
            char id[10];
            printf("Input student ID: ");
            scanf("%s", id);
            Student new_s;
            printf("Input new student name: ");
            scanf("%s", new_s.name);
            printf("Input new student gender: ");
            scanf("%s", new_s.gender);
            printf("Input new student birth: ");
            scanf("%s", new_s.birth);
            printf("Input new student score: ");
            scanf("%f", &new_s.score);
            printf("Input new student department: ");
            scanf("%s", new_s.department);
            modify_student(id, new_s);
        } else if (choice == 3) {
            char id[10];
            printf("Input student ID: ");
            scanf("%s", id);
            delete_student(id);
        } else if (choice == 4) {
            char name[20];
            printf("Input student name: ");
            scanf("%s", name);
            query_student_by_name(name);
        } else if (choice == 5) {
            char department[20];
            printf("Input department: ");
            scanf("%s", department);
            query_student_by_department(department);
        } else if (choice == 6) {
            float min_score, max_score;
            printf("Input min score: ");
            scanf("%f", &min_score);
            printf("Input max score: ");
            scanf("%f", &max_score);
            query_student_by_score(min_score, max_score);
        } else if (choice == 7) {
            sort_students_by_score();
        } else if (choice == 8) {
            print_all_students();
        } else {
            printf("Invalid choice!\n");
        }
    }
    return 0;
}