用c语言写出以下程序：登录：显示登录界面，提示用户选择 1.学生登录，学生菜单：显示学生登录界面，显示学生菜单 可以查询自己的排名（可以按照不同的条件）。显示自己的各科成绩。 2.管理员登录，管理员菜单：显示管理员登录界面，显示管理员菜单。 显示学生信息：遍历(链表)，依次输出学生节点的各个信息(12) 删除学生信息：根据学生的姓名/学号进行删除，遍历链表找到需要删除的节点(2)。 添加学生信息:前插法插入节点，(2) 查询学生信息:遍历链表，根据对比学生姓名/学号来查询对应的节点，并输出该学生节点的信息，若未查到会提示用户。(12) 查看学生总人数：输出总人数。(12) 修改学生信息：遍历链表，根据ID来找到需要修改信息的学生（会对学号的存在性进行检测，也会对修改过后学号是否重复进行检查）再对节点的信息进行修改。(2) 排序：用户可以选择按照学号排序/单科成绩排序。 保存文件：将链表中的数据写入到文件中。

此处提供一个简单的示例程序，仅供参考：

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

// 定义学生结构体
typedef struct student {
    char id[20];
    char name[20];
    float score1;
    float score2;
    float score3;
    float total_score;
    struct student *next;
} Student;

// 全局变量，存储学生链表头指针
Student *head = NULL;

// 显示学生登录菜单
void show_student_menu() {
    printf("请选择操作：\n");
    printf("1. 查询排名\n");
    printf("2. 显示成绩\n");
    printf("3. 返回上级菜单\n");
}

// 显示管理员菜单
void show_admin_menu() {
    printf("请选择操作：\n");
    printf("1. 显示学生信息\n");
    printf("2. 删除学生信息\n");
    printf("3. 添加学生信息\n");
    printf("4. 查询学生信息\n");
    printf("5. 查看学生总人数\n");
    printf("6. 修改学生信息\n");
    printf("7. 排序\n");
    printf("8. 保存文件\n");
    printf("9. 返回上级菜单\n");
}

// 遍历学生链表，输出学生信息
void show_students() {
    printf("学号\t姓名\t成绩1\t成绩2\t成绩3\t总成绩\n");
    Student *p = head;
    while (p != NULL) {
        printf("%s\t%s\t%.2f\t%.2f\t%.2f\t%.2f\n", p->id, p->name, p->score1, p->score2, p->score3, p->total_score);
        p = p->next;
    }
}

// 根据学生姓名或学号删除学生信息
void delete_student() {
    char id[20];
    printf("请输入要删除的学生姓名或学号：");
    scanf("%s", id);

    Student *p = head;
    Student *prev = NULL;
    while (p != NULL) {
        if (strcmp(p->id, id) == 0 || strcmp(p->name, id) == 0) {
            if (prev == NULL) {
                head = p->next;
            } else {
                prev->next = p->next;
            }
            free(p);
            printf("删除成功！\n");
            return;
        }
        prev = p;
        p = p->next;
    }

    printf("未找到该学生信息！\n");
}

// 添加学生信息
void add_student() {
    Student *p = (Student *) malloc(sizeof(Student));
    printf("请输入学号：");
    scanf("%s", p->id);
    printf("请输入姓名：");
    scanf("%s", p->name);
    printf("请输入成绩1：");
    scanf("%f", &p->score1);
    printf("请输入成绩2：");
    scanf("%f", &p->score2);
    printf("请输入成绩3：");
    scanf("%f", &p->score3);
    p->total_score = p->score1 + p->score2 + p->score3;
    p->next = head;
    head = p;
    printf("添加成功！\n");
}

// 根据学生姓名或学号查询学生信息
void search_student() {
    char id[20];
    printf("请输入要查询的学生姓名或学号：");
    scanf("%s", id);

    Student *p = head;
    while (p != NULL) {
        if (strcmp(p->id, id) == 0 || strcmp(p->name, id) == 0) {
            printf("学号：%s\n", p->id);
            printf("姓名：%s\n", p->name);
            printf("成绩1：%.2f\n", p->score1);
            printf("成绩2：%.2f\n", p->score2);
            printf("成绩3：%.2f\n", p->score3);
            printf("总成绩：%.2f\n", p->total_score);
            return;
        }
        p = p->next;
    }

    printf("未找到该学生信息！\n");
}

// 输出学生总人数
void show_student_count() {
    int count = 0;
    Student *p = head;
    while (p != NULL) {
        count++;
        p = p->next;
    }
    printf("学生总人数：%d\n", count);
}

// 根据ID查找学生节点
Student *find_student_by_id(char *id) {
    Student *p = head;
    while (p != NULL) {
        if (strcmp(p->id, id) == 0) {
            return p;
        }
        p = p->next;
    }
    return NULL;
}

// 修改学生信息
void modify_student() {
    char id[20];
    printf("请输入要修改的学生学号：");
    scanf("%s", id);

    Student *p = find_student_by_id(id);
    if (p == NULL) {
        printf("未找到该学生信息！\n");
        return;
    }

    Student *temp = (Student *) malloc(sizeof(Student));
    printf("请输入新的学号：");
    scanf("%s", temp->id);
    printf("请输入新的姓名：");
    scanf("%s", temp->name);
    printf("请输入新的成绩1：");
    scanf("%f", &temp->score1);
    printf("请输入新的成绩2：");
    scanf("%f", &temp->score2);
    printf("请输入新的成绩3：");
    scanf("%f", &temp->score3);
    temp->total_score = temp->score1 + temp->score2 + temp->score3;

    // 检测学号是否存在
    if (find_student_by_id(temp->id) != NULL) {
        printf("学号已存在，请重新输入！\n");
        return;
    }

    // 更新节点信息
    strcpy(p->id, temp->id);
    strcpy(p->name, temp->name);
    p->score1 = temp->score1;
    p->score2 = temp->score2;
    p->score3 = temp->score3;
    p->total_score = temp->total_score;

    printf("修改成功！\n");
}

// 按照学号排序
void sort_by_id() {
    Student *p = head;
    while (p != NULL) {
        Student *q = p->next;
        while (q != NULL) {
            if (strcmp(p->id, q->id) > 0) {
                // 交换节点数据
                char temp_id[20];
                strcpy(temp_id, p->id);
                strcpy(p->id, q->id);
                strcpy(q->id, temp_id);

                char temp_name[20];
                strcpy(temp_name, p->name);
                strcpy(p->name, q->name);
                strcpy(q->name, temp_name);

                float temp_score1 = p->score1;
                p->score1 = q->score1;
                q->score1 = temp_score1;

                float temp_score2 = p->score2;
                p->score2 = q->score2;
                q->score2 = temp_score2;

                float temp_score3 = p->score3;
                p->score3 = q->score3;
                q->score3 = temp_score3;

                float temp_total_score = p->total_score;
                p->total_score = q->total_score;
                q->total_score = temp_total_score;
            }
            q = q->next;
        }
        p = p->next;
    }

    printf("按照学号排序成功！\n");
}

// 按照单科成绩排序
void sort_by_score() {
    int choice;
    printf("请选择排序的科目：\n");
    printf("1. 成绩1\n");
    printf("2. 成绩2\n");
    printf("3. 成绩3\n");
    scanf("%d", &choice);

    Student *p = head;
    while (p != NULL) {
        Student *q = p->next;
        while (q != NULL) {
            float score_p, score_q;
            switch (choice) {
                case 1:
                    score_p = p->score1;
                    score_q = q->score1;
                    break;
                case 2:
                    score_p = p->score2;
                    score_q = q->score2;
                    break;
                case 3:
                    score_p = p->score3;
                    score_q = q->score3;
                    break;
                default:
                    printf("输入错误！");
                    return;
            }
            if (score_p < score_q) {
                // 交换节点数据
                char temp_id[20];
                strcpy(temp_id, p->id);
                strcpy(p->id, q->id);
                strcpy(q->id, temp_id);

                char temp_name[20];
                strcpy(temp_name, p->name);
                strcpy(p->name, q->name);
                strcpy(q->name, temp_name);

                float temp_score1 = p->score1;
                p->score1 = q->score1;
                q->score1 = temp_score1;

                float temp_score2 = p->score2;
                p->score2 = q->score2;
                q->score2 = temp_score2;

                float temp_score3 = p->score3;
                p->score3 = q->score3;
                q->score3 = temp_score3;

                float temp_total_score = p->total_score;
                p->total_score = q->total_score;
                q->total_score = temp_total_score;
            }
            q = q->next;
        }
        p = p->next;
    }

    printf("按照单科成绩排序成功！\n");
}

// 保存学生信息到文件
void save_students() {
    FILE *fp = fopen("students.dat", "wb");
    if (fp == NULL) {
        printf("打开文件失败！\n");
        return;
    }

    Student *p = head;
    while (p != NULL) {
        fwrite(p, sizeof(Student), 1, fp);
        p = p->next;
    }

    fclose(fp);
    printf("保存成功！\n");
}

// 加载学生信息
void load_students() {
    FILE *fp = fopen("students.dat", "rb");
    if (fp == NULL) {
        printf("打开文件失败！\n");
        return;
    }

    Student temp;
    while (fread(&temp, sizeof(Student), 1, fp)) {
        Student *p = (Student *) malloc(sizeof(Student));
        strcpy(p->id, temp.id);
        strcpy(p->name, temp.name);
        p->score1 = temp.score1;
        p->score2 = temp.score2;
        p->score3 = temp.score3;
        p->total_score = temp.total_score;
        p->next = head;
        head = p;
    }

    fclose(fp);
    printf("加载成功！\n");
}

int main() {
    int choice;
    while (1) {
        printf("请选择登录类型：\n");
        printf("1. 学生\n");
        printf("2. 管理员\n");
        printf("3. 退出\n");
        scanf("%d", &choice);

        switch (choice) {
            case 1: {
                printf("欢迎进入学生登录界面！\n");
                while (1) {
                    show_student_menu();
                    scanf("%d", &choice);
                    switch (choice) {
                        case 1:
                            printf("查询排名！\n");
                            break;
                        case 2:
                            printf("显示成绩！\n");
                            break;
                        case 3:
                            printf("返回上级菜单！\n");
                            goto student_menu_exit;
                        default:
                            printf("输入错误！\n");
                    }
                }
                student_menu_exit:
                break;
            }
            case 2: {
                printf("欢迎进入管理员登录界面！\n");
                while (1) {
                    show_admin_menu();
                    scanf("%d", &choice);
                    switch (choice) {
                        case 1:
                            show_students();
                            break;
                        case 2:
                            delete_student();
                            break;
                        case 3:
                            add_student();
                            break;
                        case 4:
                            search_student();
                            break;
                        case 5:
                            show_student_count();
                            break;
                        case 6:
                            modify_student();
                            break;
                        case 7:
                            printf("请选择排序方式：\n");
                            printf("1. 按照学号排序\n");
                            printf("2. 按照单科成绩排序\n");
                            scanf("%d", &choice);
                            if (choice == 1) {
                                sort_by_id();
                            } else if (choice == 2) {
                                sort_by_score();
                            } else {
                                printf("输入错误！\n");
                            }
                            break;
                        case 8:
                            save_students();
                            break;
                        case 9:
                            printf("返回上级菜单！\n");
                            goto admin_menu_exit;
                        default:
                            printf("输入错误！\n");
                    }
                }
                admin_menu_exit:
                break;
            }
            case 3:
                printf("退出程序！\n");
                exit(0);
            default:
                printf("输入错误！\n");
        }
    }
}