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

typedef struct _Node { // 12+ bytes
    int value;          // 4 bytes
    struct _Node* next; // 8 bytes
} Node;

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

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

void destroy_list(Node* top) {
    Node* node = top;
    while (node != NULL) {
        Node* next = node->next;
        free(node);
        node = next;
    }
}

// push_stack and pop_stack effectively makes this a queue
void push_stack(Node** a_top, int value) {
    Node* new_node = malloc(sizeof(*new_node));
    *new_node = (Node) { .next = NULL, .value = value };

    new_node->next = *a_top;
    *a_top = new_node;
}

Node* pop_stack(Node** a_top) {
    Node* node = *a_top;
    if (node == NULL) {
        return NULL;
    }
    *a_top = node->next;
    node->next = NULL;
    return node;
}

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

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

    push_stack(&top, 1);
    print_list(top);

    push_stack(&top, 2);
    print_list(top);

    push_stack(&top, 3);
    print_list(top);
    print_list(top->next);

    push_stack(&top, 343);
    push_stack(&top, 34);
    push_stack(&top, 6654);
    push_stack(&top, 545);
    push_stack(&top, 934);
    push_stack(&top, 49);
    print_list(top);
    log_int(get_size_of_list(top));
    log_int(get_size_of_list(top->next));

    Node* node = pop_stack(&top);
    print_list(top);
    print_list(node);
    destroy_list(node);

    node = pop_stack(&top);
    print_list(top);
    print_list(node);
    destroy_list(node);

    push_stack(&top, 1234);
    print_list(top);

    node = pop_stack(&top);
    print_list(top);
    print_list(node);
    destroy_list(node);

    destroy_list(top);

    return EXIT_SUCCESS;
}
/* vim: set tabstop=4 shiftwidth=4 fileencoding=utf-8 noexpandtab: */