编写一段代码：录入每个学生的学号、姓名和各科成绩；分别计算每门课程及每个学生的总分和平均分；按照总分进行升序或者降序排序；按照学号升序排序；插入学生一条记录；按照姓名查找，并删除一条记录；查找并显示一条信息；输出每个学生的学号、姓名、各科成绩、总分和分均分

下面是一份基于C语言的简单学生成绩管理系统代码，包括了录入学生信息、计算总分和平均分、排序、插入、查找、删除和输出等功能。

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

#define MAX_STUDENT_NUM 100
#define MAX_NAME_LEN 20
#define MAX_SUBJECT_NUM 5

typedef struct {
    char id[10];
    char name[MAX_NAME_LEN];
    int score[MAX_SUBJECT_NUM];
    int total_score;
    float avg_score;
} Student;

Student students[MAX_STUDENT_NUM];
int student_count = 0;

int cmp_by_total_score_desc(const void *a, const void *b) {
    const Student *sa = (const Student *)a;
    const Student *sb = (const Student *)b;
    return sb->total_score - sa->total_score;
}

int cmp_by_total_score_asc(const void *a, const void *b) {
    const Student *sa = (const Student *)a;
    const Student *sb = (const Student *)b;
    return sa->total_score - sb->total_score;
}

int cmp_by_id_asc(const void *a, const void *b) {
    const Student *sa = (const Student *)a;
    const Student *sb = (const Student *)b;
    return strcmp(sa->id, sb->id);
}

int find_student_by_name(const char *name) {
    for (int i = 0; i < student_count; i++) {
        if (strcmp(students[i].name, name) == 0) {
            return i;
        }
    }
    return -1;
}

void add_student() {
    if (student_count >= MAX_STUDENT_NUM) {
        printf("Error: student list is full\n");
        return;
    }

    printf("Input student id: ");
    scanf("%s", students[student_count].id);
    printf("Input student name: ");
    scanf("%s", students[student_count].name);

    for (int i = 0; i < MAX_SUBJECT_NUM; i++) {
        printf("Input score of subject %d: ", i + 1);
        scanf("%d", &students[student_count].score[i]);
        students[student_count].total_score += students[student_count].score[i];
    }

    students[student_count].avg_score = (float)students[student_count].total_score / MAX_SUBJECT_NUM;
    student_count++;

    printf("Add student successfully\n");
}

void delete_student() {
    char name[MAX_NAME_LEN];
    printf("Input name of the student to be deleted: ");
    scanf("%s", name);

    int index = find_student_by_name(name);
    if (index == -1) {
        printf("Error: student not found\n");
        return;
    }

    for (int i = index; i < student_count - 1; i++) {
        students[i] = students[i + 1];
    }
    student_count--;

    printf("Delete student successfully\n");
}

void search_student() {
    char name[MAX_NAME_LEN];
    printf("Input name of the student to be searched: ");
    scanf("%s", name);

    int index = find_student_by_name(name);
    if (index == -1) {
        printf("Error: student not found\n");
        return;
    }

    printf("Student found:\n");
    printf("ID: %s\n", students[index].id);
    printf("Name: %s\n", students[index].name);
    for (int i = 0; i < MAX_SUBJECT_NUM; i++) {
        printf("Subject %d: %d\n", i + 1, students[index].score[i]);
    }
    printf("Total score: %d\n", students[index].total_score);
    printf("Average score: %.2f\n", students[index].avg_score);
}

void sort_by_total_score() {
    char order;
    printf("Sort by total score in ascending or descending order? (a/d): ");
    scanf(" %c", &order);

    if (order == 'a') {
        qsort(students, student_count, sizeof(Student), cmp_by_total_score_asc);
        printf("Sort by total score in ascending order successfully\n");
    }
    else if (order == 'd') {
        qsort(students, student_count, sizeof(Student), cmp_by_total_score_desc);
        printf("Sort by total score in descending order successfully\n");
    }
    else {
        printf("Error: invalid order\n");
    }
}

void sort_by_id() {
    qsort(students, student_count, sizeof(Student), cmp_by_id_asc);
    printf("Sort by ID in ascending order successfully\n");
}

void print_students() {
    printf("Students:\n");
    for (int i = 0; i < student_count; i++) {
        printf("ID: %s\n", students[i].id);
        printf("Name: %s\n", students[i].name);
        for (int j = 0; j < MAX_SUBJECT_NUM; j++) {
            printf("Subject %d: %d\n", j + 1, students[i].score[j]);
        }
        printf("Total score: %d\n", students[i].total_score);
        printf("Average score: %.2f\n", students[i].avg_score);
    }
}

void print_menu() {
    printf("\n");
    printf("1. Add a student\n");
    printf("2. Delete a student\n");
    printf("3. Search a student\n");
    printf("4. Sort by total score\n");
    printf("5. Sort by ID\n");
    printf("6. Print students\n");
    printf("0. Exit\n");
}

int main() {
    int choice;
    while (1) {
        print_menu();
        printf("Input your choice: ");
        scanf("%d", &choice);

        switch (choice) {
        case 0:
            printf("Goodbye!\n");
            return 0;
        case 1:
            add_student();
            break;
        case 2:
            delete_student();
            break;
        case 3:
            search_student();
            break;
        case 4:
            sort_by_total_score();
            break;
        case 5:
            sort_by_id();
            break;
        case 6:
            print_students();
            break;
        default:
            printf("Error: invalid choice\n");
            break;
        }
    }
}

注意，这只是一个简单的示例代码，实际的学生成绩管理系统可能需要更加完善和复杂的功能，也需要更加严谨和安全的数据处理和算法实现。如果你需要使用这个代码作为参考或者基础，请自行理解和修改，以符合你的具体需求和要求。