pvjc25/du6/list_ops.c

118 lines
3.0 KiB
C

#include <stdlib.h>
#include <stddef.h>
#include <stdbool.h> // pre bool
typedef int list_element_t;
typedef struct {
size_t length;
list_element_t elements[];
} list_t;
// ==== Deklarácie funkcií (tzv. prototypy) ====
list_t *new_list(size_t length, list_element_t default_value);
list_t *map_list(list_t *list, list_element_t (*map_fn)(list_element_t));
list_t *filter_list(list_t *list, bool (*filter_fn)(list_element_t));
list_element_t foldl_list(list_t *list, list_element_t initial, list_element_t (*fold_fn)(list_element_t, list_element_t));
list_element_t foldr_list(list_t *list, list_element_t initial, list_element_t (*fold_fn)(list_element_t, list_element_t));
list_t *reverse_list(list_t *list);
void delete_list(list_t *list);
// ==== Implementácie ====
list_t *new_list(size_t length, list_element_t default_value) {
list_t *list = malloc(sizeof(list_t) + length * sizeof(list_element_t));
if (list == NULL) {
return NULL;
}
list->length = length;
for (size_t i = 0; i < length; i++) {
list->elements[i] = default_value;
}
return list;
}
list_t *map_list(list_t *list, list_element_t (*map_fn)(list_element_t)) {
list_t *result = malloc(sizeof(list_t) + sizeof(list_element_t) * list->length);
if (result == NULL) {
return NULL;
}
result->length = list->length;
for (size_t i = 0; i < list->length; i++) {
result->elements[i] = map_fn(list->elements[i]);
}
return result;
}
list_t *filter_list(list_t *list, bool (*filter_fn)(list_element_t)) {
size_t count = 0;
for (size_t i = 0; i < list->length; i++) {
if (filter_fn(list->elements[i])) {
count++;
}
}
list_t *result = malloc(sizeof(list_t) + sizeof(list_element_t) * count);
if (result == NULL) {
return NULL;
}
result->length = count;
size_t index = 0;
for (size_t i = 0; i < list->length; i++) {
if (filter_fn(list->elements[i])) {
result->elements[index] = list->elements[i];
index++;
}
}
return result;
}
list_element_t foldl_list(list_t *list, list_element_t initial, list_element_t (*fold_fn)(list_element_t, list_element_t)) {
list_element_t acc = initial;
for (size_t i = 0; i < list->length; i++) {
acc = fold_fn(acc, list->elements[i]);
}
return acc;
}
list_element_t foldr_list(list_t *list, list_element_t initial, list_element_t (*fold_fn)(list_element_t, list_element_t)) {
list_element_t acc = initial;
for (size_t i = list->length; i > 0; i--) {
acc = fold_fn(list->elements[i - 1], acc);
}
return acc;
}
list_t *reverse_list(list_t *list) {
list_t *result = malloc(sizeof(list_t) + sizeof(list_element_t) * list->length);
if (result == NULL) {
return NULL;
}
result->length = list->length;
for (size_t i = 0; i < list->length; i++) {
result->elements[i] = list->elements[list->length - 1 - i];
}
return result;
}
void delete_list(list_t *list) {
free(list);
}