(8分，用链表实现对单生成睛进行样储，插人及显示功能. 学生包括工D和score属性。 结构体类型定义如下 struct grade int score cher 10L61 struct grade *next 红）写函教创建单向链表并存储学生成绩信息，有入TD和soore按退号隔开，先给入score后输人加，当score《0时链来创建宽成.并输出创建后的链表信息. <2）写函数实现在第r个结点后面插人一个新结点，并输出插入 新结点后的销表信息。 3）写函教释放链表所占内存空目 在上函教依次调用各函效即可

以下是实现要求的代码：

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

struct grade {
    int ID;
    int score;
    struct grade *next;
};

void create_list(struct grade **head) {
    int id, score;
    struct grade *new_node;
    *head = NULL;
    printf("Enter student ID and score (separated by space): ");
    scanf("%d %d", &id, &score);
    while (score >= 0) {
        new_node = (struct grade*)malloc(sizeof(struct grade));
        new_node->ID = id;
        new_node->score = score;
        new_node->next = *head;
        *head = new_node;
        printf("Enter student ID and score (separated by space): ");
        scanf("%d %d", &id, &score);
    }
}

void insert_node(struct grade **head, int pos) {
    struct grade *new_node, *ptr;
    int i;
    ptr = *head;
    for (i = 1; i < pos && ptr != NULL; i++) {
        ptr = ptr->next;
    }
    if (ptr == NULL) {
        printf("Cannot insert node at position %d\n", pos);
        return;
    }
    printf("Enter student ID and score (separated by space): ");
    new_node = (struct grade*)malloc(sizeof(struct grade));
    scanf("%d %d", &new_node->ID, &new_node->score);
    new_node->next = ptr->next;
    ptr->next = new_node;
}

void display_list(struct grade *head) {
    struct grade *ptr = head;
    while (ptr != NULL) {
        printf("ID: %d\tScore: %d\n", ptr->ID, ptr->score);
        ptr = ptr->next;
    }
}

void free_list(struct grade **head) {
    struct grade *ptr = *head;
    while (ptr != NULL) {
        *head = (*head)->next;
        free(ptr);
        ptr = *head;
    }
}

int main() {
    struct grade *head = NULL;
    int pos;
    create_list(&head);
    printf("Initial list:\n");
    display_list(head);
    printf("Enter position to insert new node: ");
    scanf("%d", &pos);
    insert_node(&head, pos);
    printf("List after insertion:\n");
    display_list(head);
    free_list(&head);
    return 0;
}

注：由于题目中没有规定 ID 的输入方式，所以这里采用了和 score 相同的方式，即在输入时用空格分隔。如果需要单独输入 ID，只需要稍作修改即可。