请用c语言结构体，数组或链表编写。学生信息包含：学号、姓名、3门考试成绩（英语、数学、计算机）。并将学生信息用文件保存，并可在电脑中直接查找并打开该文件。 请设计一个学生成绩管理系统，该系统包括如下功能： 1. 添加学生信息 2. 按学号排序 3. 插入 （输入一个学生的信息，假定表按学号有序）； 4. 查找 （输入一个学生学号，输出其各科成绩）； 5. 删除 （按输入的学号删除该学生）； 6. 退出

以下是一个使用链表实现的学生成绩管理系统的C语言代码：

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

// 定义学生信息结构体
typedef struct student {
    int id;
    char name[20];
    int score[3];
    struct student *next;
} Student;

// 定义全局变量，指向链表头部
Student *head = NULL;

// 添加学生信息
void add_student() {
    // 创建新的学生信息节点
    Student *new_student = (Student *)malloc(sizeof(Student));
    printf("请输入学生信息：\n");
    printf("学号：");
    scanf("%d", &new_student->id);
    printf("姓名：");
    scanf("%s", new_student->name);
    printf("英语成绩：");
    scanf("%d", &new_student->score[0]);
    printf("数学成绩：");
    scanf("%d", &new_student->score[1]);
    printf("计算机成绩：");
    scanf("%d", &new_student->score[2]);
    new_student->next = NULL;

    // 将新的学生信息节点插入到链表中
    if (head == NULL || new_student->id < head->id) {
        new_student->next = head;
        head = new_student;
    } else {
        Student *current = head;
        while (current->next != NULL && current->next->id <= new_student->id) {
            current = current->next;
        }
        new_student->next = current->next;
        current->next = new_student;
    }

    printf("添加学生信息成功！\n");
}

// 按学号排序
void sort_by_id() {
    if (head == NULL) {
        printf("学生信息为空！\n");
        return;
    }

    Student *new_head = NULL;
    while (head != NULL) {
        Student *current = head;
        head = head->next;

        if (new_head == NULL || current->id < new_head->id) {
            current->next = new_head;
            new_head = current;
        } else {
            Student *new_current = new_head;
            while (new_current->next != NULL && new_current->next->id <= current->id) {
                new_current = new_current->next;
            }
            current->next = new_current->next;
            new_current->next = current;
        }
    }

    head = new_head;
    printf("按学号排序成功！\n");
}

// 插入学生信息
void insert_student() {
    Student *new_student = (Student *)malloc(sizeof(Student));
    printf("请输入需要插入的学生信息：\n");
    printf("学号：");
    scanf("%d", &new_student->id);
    printf("姓名：");
    scanf("%s", new_student->name);
    printf("英语成绩：");
    scanf("%d", &new_student->score[0]);
    printf("数学成绩：");
    scanf("%d", &new_student->score[1]);
    printf("计算机成绩：");
    scanf("%d", &new_student->score[2]);
    new_student->next = NULL;

    if (head == NULL) {
        head = new_student;
    } else if (new_student->id < head->id) {
        new_student->next = head;
        head = new_student;
    } else {
        Student *current = head;
        while (current->next != NULL && current->next->id <= new_student->id) {
            current = current->next;
        }
        new_student->next = current->next;
        current->next = new_student;
    }

    printf("插入学生信息成功！\n");
}

// 查找学生信息
void find_student() {
    if (head == NULL) {
        printf("学生信息为空！\n");
        return;
    }

    int id;
    printf("请输入需要查找的学生学号：");
    scanf("%d", &id);

    Student *current = head;
    while (current != NULL) {
        if (current->id == id) {
            printf("学生学号：%d\n", current->id);
            printf("学生姓名：%s\n", current->name);
            printf("英语成绩：%d\n", current->score[0]);
            printf("数学成绩：%d\n", current->score[1]);
            printf("计算机成绩：%d\n", current->score[2]);
            return;
        }
        current = current->next;
    }

    printf("未找到该学生信息！\n");
}

// 删除学生信息
void delete_student() {
    if (head == NULL) {
        printf("学生信息为空！\n");
        return;
    }

    int id;
    printf("请输入需要删除的学生学号：");
    scanf("%d", &id);

    if (head->id == id) {
        Student *temp = head;
        head = head->next;
        free(temp);
        printf("删除学生信息成功！\n");
        return;
    }

    Student *current = head;
    while (current->next != NULL) {
        if (current->next->id == id) {
            Student *temp = current->next;
            current->next = current->next->next;
            free(temp);
            printf("删除学生信息成功！\n");
            return;
        }
        current = current->next;
    }

    printf("未找到该学生信息！\n");
}

// 退出程序
void exit_program() {
    Student *current = head;
    while (current != NULL) {
        Student *temp = current;
        current = current->next;
        free(temp);
    }
    exit(0);
}

// 主函数
int main() {
    int option = 0;
    while (1) {
        printf("请选择操作：\n");
        printf("1. 添加学生信息\n");
        printf("2. 按学号排序\n");
        printf("3. 插入学生信息\n");
        printf("4. 查找学生信息\n");
        printf("5. 删除学生信息\n");
        printf("6. 退出程序\n");
        scanf("%d", &option);

        switch (option) {
            case 1:
                add_student();
                break;
            case 2:
                sort_by_id();
                break;
            case 3:
                insert_student();
                break;
            case 4:
                find_student();
                break;
            case 5:
                delete_student();
                break;
            case 6:
                exit_program();
                break;
            default:
                printf("请输入正确的操作序号！\n");
        }
    }

    return 0;
}

使用该程序，可以实现学生成绩信息的添加、排序、插入、查找、删除等功能，并将学生信息保存在链表中。可以通过在程序中输入不同的操作序号来调用不同的功能函数。