写一个程序实现单链表的ADT

好的，以下是一个实现单链表的ADT的程序示例：

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

typedef struct Node {
    int data;
    struct Node *next;
} Node;

typedef struct List {
    Node *head;
    int size;
} List;

List *createList() {
    List *list = (List*)malloc(sizeof(List));
    list->head = NULL;
    list->size = 0;
    return list;
}

void add(List *list, int data) {
    Node *newNode = (Node*)malloc(sizeof(Node));
    newNode->data = data;
    newNode->next = NULL;
    if (list->head == NULL) {
        list->head = newNode;
    } else {
        Node *current = list->head;
        while (current->next != NULL) {
            current = current->next;
        }
        current->next = newNode;
    }
    list->size++;
}

void removeAt(List *list, int index) {
    if (index < 0 || index >= list->size) {
        printf("Invalid index\n");
        return;
    }
    Node *current = list->head;
    if (index == 0) {
        list->head = current->next;
        free(current);
    } else {
        Node *prev = NULL;
        int i;
        for (i = 0; i < index; i++) {
            prev = current;
            current = current->next;
        }
        prev->next = current->next;
        free(current);
    }
    list->size--;
}

int get(List *list, int index) {
    if (index < 0 || index >= list->size) {
        printf("Invalid index\n");
        return -1;
    }
    Node *current = list->head;
    int i;
    for (i = 0; i < index; i++) {
        current = current->next;
    }
    return current->data;
}

int main() {
    List *list = createList();
    add(list, 1);
    add(list, 2);
    add(list, 3);
    printf("%d\n", get(list, 1));
    removeAt(list, 1);
    printf("%d\n", get(list, 1));
    return 0;
}

这个程序实现了单链表的基本操作，包括创建链表、添加元素、删除元素、获取元素等。