1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 | #include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <assert.h>
typedef struct _Node {
int value;
struct _Node* next;
} Node;
void print_list(Node* head) {
for(Node* curr = head; curr != NULL; curr = curr -> next) {
printf("[%d]", curr -> value);
if(curr -> next != NULL) { // If curr is not the tail...
printf("→");
}
}
printf("\n");
}
void _append(int value, Node** a_head, Node** a_tail) {
// Allocate memory on heap for a new node.
Node* new_node = malloc(sizeof(*new_node));
// Initialize fields of the new node.
new_node -> value = value;
new_node -> next = NULL;
if(*a_head == NULL) { // If list is empty (size=0), initialize a list of size one.
assert(*a_tail == NULL);
// "Create a new list" meaning before this line, the head and tail (variables)
*a_head = new_node; // in the caller were set to NULL. We will now set them to
*a_tail = new_node; // the address of a real node on the heap.
} // Terminology note: "Initialize" means to assign the
else { // value to a variable for the first time.
(*a_tail) -> next = new_node; // Connect tail to new node. IOW: Set the '.next'
*a_tail = new_node; // field of the tail to the address of the new node.
}
}
int main(int argc, char* argv[]) {
Node* head = NULL;
Node* tail = head;
_append(5, &head, &tail);
_append(6, &head, &tail);
_append(7, &head, &tail);
for(int i = 0; i < 15; i++) {
_append(i, &head, &tail);
}
print_list(head);
return EXIT_SUCCESS;
}
/* vim: set tabstop=4 shiftwidth=4 fileencoding=utf-8 noexpandtab: */
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