int Queue_drop(Queue *q, const char *id) {
if (q->first != NULL) {
if (strcmp(q->first->id, id) == 0) {
Queue_dequeue(q);
return 1;
} else {
struct student* next_student = q->first;
struct student* last_student;
do {
if (strcmp(next_student->id, id) == 0) {
struct student* student_to_delete = next_student;
last_student->next = student_to_delete->next;
if (student_to_delete == q->last) {
q->last = last_student;
last_student->next = NULL;
}
free_student(student_to_delete);
return 1;
}
last_student = next_student;
next_student = next_student->next;
} while(next_student != NULL);
}
}
return 0;
}
/// Removes the first member of the queue, and releases all memory allocated for it.
/// \param q
/// \return 1, if something was removed; or 0 if nothing was removed, i.e., because the queue was already empty.
int Queue_dequeue(Queue *q) {
if (q->first != NULL) {
if (q->first == q->last) { // only one item in the queue
free_student(q->first);
q->first = NULL;
q->last = NULL;
} else { // more than one item
struct student* first_item = q->first;
q->first = first_item->next;
free_student(first_item);
}
return 1;
}
return 0;
}
void free_student_nulls(void *data)
{
if(data == NULL)
return;
free_student(data);
}