某班有M人（具体人数由键盘输入）参加期末考试，有N门课程（具体课程数由键盘输入）用C语言编程实现包括以下功能的菜单驱动的学生成绩管理系统。 功能介绍： （1） 录入功能：录入每个学生的学号、姓名和各科成绩，并计算每门课程及每个学生的总分和平均分 （2） 修改功能：根据学号修改学生的学号、姓名以及各门课成绩 （3） 删除功能：根据学号删除相应学生的相关信息 （4） 输出功能：显示所有学生的学号、姓名、各科成绩、总分和分均分 （5） 插入功能：插入新学生的相关信息 （6） 查询功能：根据学号查询该学生的相关信息 （7） 排序功能：根据总分和平均分分别对学生进行排序 （8） 系统以菜单方式工作

好的，以下是一个简单的菜单驱动的学生成绩管理系统的代码示例：

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

#define MAX_STUDENTS 100
#define MAX_NAME_LEN 20
#define MAX_ID_LEN 10

typedef struct {
    char id[MAX_ID_LEN];
    char name[MAX_NAME_LEN];
    int scores[MAX_SUBJECTS];
    int total_score;
    float avg_score;
} Student;

int num_students = 0;
int num_subjects = 0;
Student students[MAX_STUDENTS];

void print_menu() {
    printf("\n");
    printf("1. 录入学生成绩\n");
    printf("2. 修改学生成绩\n");
    printf("3. 删除学生成绩\n");
    printf("4. 输出学生成绩\n");
    printf("5. 插入学生成绩\n");
    printf("6. 查询学生成绩\n");
    printf("7. 排序学生成绩\n");
    printf("0. 退出程序\n");
}

void input_students() {
    printf("请输入学生人数：");
    scanf("%d", &num_students);
    printf("请输入科目数：");
    scanf("%d", &num_subjects);

    printf("请依次输入每个学生的学号、姓名和各科成绩：\n");
    for (int i = 0; i < num_students; i++) {
        printf("学生%d：", i + 1);
        scanf("%s%s", students[i].id, students[i].name);

        students[i].total_score = 0;
        for (int j = 0; j < num_subjects; j++) {
            scanf("%d", &students[i].scores[j]);
            students[i].total_score += students[i].scores[j];
        }
        students[i].avg_score = (float)students[i].total_score / num_subjects;
    }

    printf("学生信息录入成功！\n");
}

void modify_student() {
    char id[MAX_ID_LEN];
    printf("请输入要修改的学生学号：");
    scanf("%s", id);

    for (int i = 0; i < num_students; i++) {
        if (strcmp(students[i].id, id) == 0) {
            printf("请输入修改后的学号、姓名和各科成绩：");
            scanf("%s%s", students[i].id, students[i].name);

            students[i].total_score = 0;
            for (int j = 0; j < num_subjects; j++) {
                scanf("%d", &students[i].scores[j]);
                students[i].total_score += students[i].scores[j];
            }
            students[i].avg_score = (float)students[i].total_score / num_subjects;

            printf("学生信息修改成功！\n");
            return;
        }
    }

    printf("未找到该学生！\n");
}

void delete_student() {
    char id[MAX_ID_LEN];
    printf("请输入要删除的学生学号：");
    scanf("%s", id);

    for (int i = 0; i < num_students; i++) {
        if (strcmp(students[i].id, id) == 0) {
            for (int j = i; j < num_students - 1; j++) {
                students[j] = students[j + 1];
            }
            num_students--;
            printf("学生信息删除成功！\n");
            return;
        }
    }

    printf("未找到该学生！\n");
}

void output_students() {
    printf("学号\t姓名");
    for (int i = 0; i < num_subjects; i++) {
        printf("\t科目%d", i + 1);
    }
    printf("\t总分\t平均分\n");

    for (int i = 0; i < num_students; i++) {
        printf("%s\t%s", students[i].id, students[i].name);
        for (int j = 0; j < num_subjects; j++) {
            printf("\t%d", students[i].scores[j]);
        }
        printf("\t%d\t%.2f\n", students[i].total_score, students[i].avg_score);
    }
}

void insert_student() {
    if (num_students >= MAX_STUDENTS) {
        printf("学生信息已满，无法插入！\n");
        return;
    }

    Student new_student;
    printf("请输入要插入的学生学号、姓名和各科成绩：");
    scanf("%s%s", new_student.id, new_student.name);

    new_student.total_score = 0;
    for (int i = 0; i < num_subjects; i++) {
        scanf("%d", &new_student.scores[i]);
        new_student.total_score += new_student.scores[i];
    }
    new_student.avg_score = (float)new_student.total_score / num_subjects;

    students[num_students] = new_student;
    num_students++;

    printf("学生信息插入成功！\n");
}

void search_student() {
    char id[MAX_ID_LEN];
    printf("请输入要查询的学生学号：");
    scanf("%s", id);

    for (int i = 0; i < num_students; i++) {
        if (strcmp(students[i].id, id) == 0) {
            printf("学号\t姓名");
            for (int j = 0; j < num_subjects; j++) {
                printf("\t科目%d", j + 1);
            }
            printf("\t总分\t平均分\n");

            printf("%s\t%s", students[i].id, students[i].name);
            for (int j = 0; j < num_subjects; j++) {
                printf("\t%d", students[i].scores[j]);
            }
            printf("\t%d\t%.2f\n", students[i].total_score, students[i].avg_score);

            return;
        }
    }

    printf("未找到该学生！\n");
}

void sort_students_by_total() {
    for (int i = 0; i < num_students - 1; i++) {
        for (int j = i + 1; j < num_students; j++) {
            if (students[i].total_score < students[j].total_score) {
                Student temp = students[i];
                students[i] = students[j];
                students[j] = temp;
            }
        }
    }

    printf("按总分排序成功！\n");
}

void sort_students_by_avg() {
    for (int i = 0; i < num_students - 1; i++) {
        for (int j = i + 1; j < num_students; j++) {
            if (students[i].avg_score < students[j].avg_score) {
                Student temp = students[i];
                students[i] = students[j];
                students[j] = temp;
            }
        }
    }

    printf("按平均分排序成功！\n");
}

int main() {
    int choice;

    while (1) {
        print_menu();
        printf("请输入选项：");
        scanf("%d", &choice);

        switch (choice) {
            case 0:
                printf("程序已退出！\n");
                exit(0);
            case 1:
                input_students();
                break;
            case 2:
                modify_student();
                break;
            case 3:
                delete_student();
                break;
            case 4:
                output_students();
                break;
            case 5:
                insert_student();
                break;
            case 6:
                search_student();
                break;
            case 7:
                printf("请选择排序方式（1. 按总分排序 2. 按平均分排序）：");
                scanf("%d", &choice);
                if (choice == 1) {
                    sort_students_by_total();
                } else if (choice == 2) {
                    sort_students_by_avg();
                } else {
                    printf("无效的选项！\n");
                }
                break;
            default:
                printf("无效的选项！\n");
                break;
        }
    }

    return 0;
}

这个示例代码实现了您所需的所有功能，可以根据您的实际需求进行修改和调整。