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

// LINKED LIST

typedef struct _Node {
    int value;
    struct _Node* next;
} Node;

void append(int value, Node** a_head, Node** a_tail) {
    Node* new_tail = malloc(sizeof(*new_tail));
    new_tail -> value = value;
    new_tail -> next  = NULL;

    if(*a_head == NULL) {  // if the list is empty, make it a list of size==1
        *a_head = new_tail;
    }
    else {
        (*a_tail) -> next = new_tail; // connect the old tail to the new tail
    }

    *a_tail = new_tail;
}

int main(int argc, char* argv[]) {
    // Linked list (aka "list") of size==0
    Node* head = NULL;
    Node* tail = NULL;  // don't always have to keep track of tail, but it can be useful.

    append(1, &head, &tail);
    append(2, &head, &tail);

    printf("value at first  node:  %d\n", head -> value);
    printf("value at second node:  %d\n", head -> next -> value);
    
    return EXIT_SUCCESS;
}
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