用c语言写一个成绩管理系统，要求用动态链表和注释

以下是一个简单的成绩管理系统的C语言代码，使用了动态链表来存储学生信息和成绩，并且添加了详细的注释解释程序的各个部分：

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

// 定义一个结构体来存储学生信息和成绩
struct student {
    char name[20];
    int score;
    struct student *next;
};

// 初始化链表头节点
struct student *head = NULL;

// 添加学生信息到链表中
void add_student() {
    struct student *new_student = (struct student*) malloc(sizeof(struct student));
    printf("请输入学生姓名：");
    scanf("%s", new_student->name);
    printf("请输入学生成绩：");
    scanf("%d", &new_student->score);
    new_student->next = head;
    head = new_student;
    printf("添加成功！\n");
}

// 删除指定学生信息
void delete_student() {
    char name[20];
    printf("请输入要删除的学生姓名：");
    scanf("%s", name);
    struct student *current_student = head;
    struct student *previous_student = NULL;
    while (current_student != NULL) {
        if (strcmp(current_student->name, name) == 0) {
            if (previous_student == NULL) {
                head = current_student->next;
            } else {
                previous_student->next = current_student->next;
            }
            free(current_student);
            printf("删除成功！\n");
            return;
        }
        previous_student = current_student;
        current_student = current_student->next;
    }
    printf("未找到该学生信息！\n");
}

// 修改指定学生信息
void modify_student() {
    char name[20];
    printf("请输入要修改的学生姓名：");
    scanf("%s", name);
    struct student *current_student = head;
    while (current_student != NULL) {
        if (strcmp(current_student->name, name) == 0) {
            printf("请输入新的学生成绩：");
            scanf("%d", &current_student->score);
            printf("修改成功！\n");
            return;
        }
        current_student = current_student->next;
    }
    printf("未找到该学生信息！\n");
}

// 查询指定学生信息
void query_student() {
    char name[20];
    printf("请输入要查询的学生姓名：");
    scanf("%s", name);
    struct student *current_student = head;
    while (current_student != NULL) {
        if (strcmp(current_student->name, name) == 0) {
            printf("学生姓名：%s，学生成绩：%d\n", current_student->name, current_student->score);
            return;
        }
        current_student = current_student->next;
    }
    printf("未找到该学生信息！\n");
}

// 展示所有学生信息
void show_all_students() {
    struct student *current_student = head;
    while (current_student != NULL) {
        printf("学生姓名：%s，学生成绩：%d\n", current_student->name, current_student->score);
        current_student = current_student->next;
    }
}

// 主函数
int main() {
    int choice;
    while (1) {
        printf("\n");
        printf("1. 添加学生信息\n");
        printf("2. 删除学生信息\n");
        printf("3. 修改学生信息\n");
        printf("4. 查询学生信息\n");
        printf("5. 展示所有学生信息\n");
        printf("6. 退出程序\n");
        printf("请输入您的选择：");
        scanf("%d", &choice);
        switch (choice) {
            case 1:
                add_student();
                break;
            case 2:
                delete_student();
                break;
            case 3:
                modify_student();
                break;
            case 4:
                query_student();
                break;
            case 5:
                show_all_students();
                break;
            case 6:
                exit(0);
            default:
                printf("选择有误，请重新输入！\n");
        }
    }
    return 0;
}

以上是一个简单的成绩管理系统的C语言代码，使用了动态链表来存储学生信息和成绩，并且添加了详细的注释解释程序的各个部分。