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

typedef struct _Node { // 16+ bytes
    char* value;        // 8 bytes
    struct _Node* next; // 8 bytes
} Node;

#define log_int(n) printf("%s == %d\n", #n, n)

void print_list(const Node* head) {
    // good code quality: using a for loop
    for (const Node* node = head; node != NULL; node = node->next) {
        printf("[\"%s\"]->", node->value);
    }
    printf("NULL\n");
}

void destroy_list(Node* head) {
    Node* node = head;
    while (node != NULL) {
        Node* next = node->next;
        // the value is assumed to be on the heap
        // if we have a mix of heap and not heap strings,
        // we would need an additional field to distinguish them
        free(node->value);
        free(node);
        node = next;
    }

}

void append(Node** a_head, Node** a_tail, char* value) {
    Node* new_node = malloc(sizeof(*new_node));
    *new_node = (Node) { .next = NULL, .value = value };

    if (*a_head == NULL) {
        // from size 0 to size 1
        *a_head = new_node;
    } else {
        // from size N to size N+1
        (*a_tail)->next = new_node;
    }
    *a_tail = new_node;
}

int get_size_of_list(const Node* head) {
    int size = 0;
    for (const Node* node = head; node != NULL; node = node->next) {
        size += 1;
    }
    return size;
}


char* copy_string(const char* original) {
    char* copy = malloc(sizeof(*copy) * (strlen(original) + 1));
    strcpy(copy, original);
    return copy;
}

int main(int argc, char* argv[]) {
    Node* head = NULL;
    Node* tail = NULL;
    print_list(head);

    append(&head, &tail, copy_string("One"));
    print_list(head);

    append(&head, &tail, copy_string("Two"));
    print_list(head);

    append(&head, &tail, copy_string("Three"));
    print_list(head);
    print_list(head->next);

    append(&head, &tail, copy_string("Hello"));
    append(&head, &tail, copy_string("Class"));
    append(&head, &tail, copy_string("This Is a Linked List"));
    append(&head, &tail, copy_string("With lots of nodes"));
    append(&head, &tail, copy_string("String"));
    append(&head, &tail, copy_string("I am running out of ideas"));
    print_list(head);
    log_int(get_size_of_list(head));
    log_int(get_size_of_list(head->next));

    destroy_list(head);

    return EXIT_SUCCESS;
}
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