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

struct node {
    int data;
    struct node *next;
};

struct list {
    struct node *head;
};

void listAppend(struct list *list, int value) {
    if (list == NULL) {
        return;
    }
    list->head = doListAppend(list->head, value);
}

struct node *doListAppend(struct node *node, int value) {
    if (node == NULL) {
        return newNode(value);
    }
    node->next = doListAppend(node->next, value);
    return node;
}

struct node *newNode(int value) {
    struct node *n = malloc(sizeof(struct node));
    n->data = value;
    n->next = NULL;
    return n;
}

void printList(struct list *list) {
    struct node *current = list->head;
    while (current != NULL) {
        printf("%d ", current->data);
        current = current->next;
    }
    printf("\n");
}

int main(void) {
    struct list *myList = malloc(sizeof(struct list));
    myList->head = NULL;
    listAppend(myList, 10);
    listAppend(myList, 20);
    listAppend(myList, 30);
    listAppend(myList, 40);
    printf("List contents: ");
    printList(myList);

    return 0;
}