C/Typy złożone: Różnice pomiędzy wersjami
Usunięta treść Dodana treść
m →Listy: = |
m →Implementacja listy: http://thradams.com/generator/linked_list.html |
||
Linia 515:
* w przypadku list dwukierunkowych - w strukturze el_listy znajduje się jeszcze pole, które wskazuje na element poprzedni
* w przypadku list cyklicznych - ostatni element wskazuje na pierwszy (nie rozróżnia się wtedy elementu pierwszego, ani ostatniego)
===Lista dwukierunkowa===
<syntaxhighlight lang="c">
//http://thradams.com/generator/linked_list.html
#include <stdlib.h>
#include <assert.h>
#include <errno.h>
struct book {
char* title;
struct book* next;
struct book* prev;
};
void book_destroy(struct book* book) {
/*remove if it is empty*/
free(book->title);
}
struct books {
struct book* head, *tail;
};
void books_insert_after(struct books* books, struct book* book, struct book* new_book)
{
assert(books != NULL);
assert(book != NULL);
assert(new_book != NULL);
assert(new_book->prev == NULL);
assert(new_book->next == NULL);
new_book->prev = book;
if (book->next == NULL) {
books->tail = new_book;
}
else {
new_book->next = book->next;
book->next->prev = new_book;
}
book->next = new_book;
}
void books_insert_before(struct books* books, struct book* book, struct book* new_book)
{
assert(books != NULL);
assert(book != NULL);
assert(new_book != NULL);
assert(new_book->prev == NULL);
assert(new_book->next == NULL);
new_book->next = book;
if (book->prev == NULL) {
books->head = new_book;
}
else {
new_book->prev = book->prev;
book->prev->next = new_book;
}
book->prev = new_book;
}
void books_remove(struct books* books, struct book* book)
{
assert(books != NULL);
assert(book != NULL);
if (book->prev == NULL)
books->head = book->next;
else
book->prev->next = book->next;
if (book->next == NULL)
books->tail = book->prev;
else
book->next->prev = book->prev;
book_destroy(book);
free(book);
}
void books_push_back(struct books* books, struct book* new_book)
{
assert(books != NULL);
assert(new_book != NULL);
assert(new_book->prev == NULL);
assert(new_book->next == NULL);
if (books->tail == NULL) {
books->head = new_book;
}
else {
new_book->prev = books->tail;
books->tail->next = new_book;
}
books->tail = new_book;
}
void books_push_front(struct books* books, struct book* new_book)
{
assert(books != NULL);
assert(new_book != NULL);
assert(new_book->prev == NULL);
assert(new_book->next == NULL);
if (books->head == NULL) {
books->tail = new_book;
}
else {
new_book->next = books->head;
books->head->prev = new_book;
}
books->head = new_book;
}
void books_destroy(struct books* books)
{
//pre condition
assert(books != NULL);
struct book* it = books->head;
while (it != NULL) {
struct book* next = it->next;
book_destroy(it);
free(it);
it = next;
}
}
int main(int argc, char* argv[])
{
struct books list = { 0 };
struct book* b1 = calloc(1, sizeof(struct book));
if (b1)
{
books_push_front(&list, b1);
}
books_destroy(&list);
}
</syntaxhighlight>
=Odnośniki=
| |||