diff --git a/array_backed_list.c b/array_backed_list.c index 31e1d84..66e53a2 100644 --- a/array_backed_list.c +++ b/array_backed_list.c @@ -1,9 +1,9 @@ /*---------------------------------------------------------- - * HTBLA-Leonding / Class: + * HTBLA-Leonding / Class: 2IHIF * --------------------------------------------------------- * Exercise Number: S04 * Title: Array backed List implementation - * Author: */;/* + * Author: Marc Tismonar * ---------------------------------------------------------- * Description: * Implementation of an array backed list. @@ -50,6 +50,9 @@ /** The implementation of list data: payload-buffer, capacity, size */ struct IntListData { + int* buffer; + int capacity; + int size; }; /* ===================================================================== */ @@ -60,6 +63,288 @@ struct IntListData { * Hint: memcpy may be used to copy all bytes(!) from the existing to the new buffer */ static void increase_buffer(IntList list, unsigned int additional_capacity) { + if (list->buffer == 0) { + list->buffer = alloc_mem(sizeof(int) * additional_capacity); + if (list->buffer != 0) { + list->capacity = additional_capacity; + } + } else { + int* new_buffer = alloc_mem(sizeof(int) * (list->capacity + additional_capacity)); + if (new_buffer != 0) { + for (int i = 0; i < list->size; i++) { + new_buffer[i] = list->buffer[i]; + } + + list->buffer = new_buffer; + list->capacity += additional_capacity; + } + } } /* ===================================================================== */ + +/** + * Obtains ('creates') and provides a 'new' list instance. + * Any list obtained via this function MUST be released using + * function `release_list()`. + * + * Note: This function does not make any assumptions + * about how list components, esp. nodes, are allocated. + * + * @return The list instance or 0, if no list could by instantiated. + */ +IntList list_obtain() { + IntList list = alloc_mem(sizeof(struct IntListData)); + if (list != 0) { + list->buffer = 0; + list->capacity = 0; + list->size = 0; + } + + return list; +} + +/** + * Releases a list that was obtained earlier via function `obtain_list`. + * Released lists MUST NOT be used anymore. + * + * Note: The implementation of this function does not make any assumptions + * about the allocation method of list elements, but MUST match the implementation + * of function `obtain_list` as its inverse function. + * + * @param p_list The pointer to the list to release. The value of the pointer + * is set to 0, if the list was successfully released, otherwise it is left untouched. + */ +void list_release(IntList* p_list) { + if (p_list != 0 && *p_list != 0) { + IntList list = *p_list; + if (list->buffer != 0) { + free_mem(list->buffer); + } + + free_mem(list); + *p_list = 0; + } +} + +/** + * Determines whether or not the given list is valid. + * + * @param list The list to evaluate. + * @return `True` if the list is valid, false otherwise. + */ +bool list_is_valid(IntList list) { + return list != 0; +} + +/** + * Determines whether or not the list contains at least one item. + * + * @param list The list to evaluate. + * @return `False` if the list contains one or more items, `true` otherwise. + */ +bool list_is_empty(IntList list) { + return !list_is_valid(list) || list->size == 0; +} + +/** + * Provides the number of values stored in the list. + * + * @param list The list to evaluate. + * @return The number of values the list contains. + */ +int list_get_size(IntList list) { + return list_is_valid(list) ? list->size : 0; +} + +/** + * Determines whether or not the list given list contains the queried value + * at least once. + * + * @param list The list to query. + * @param value The value. + * @return `True` if the list contains at least one instance of the value, + * `false ` otherwise. + */ +bool list_contains(IntList list, int value) { + if (list_is_valid(list)) { + for (int i = 0; i < list->size; i++) { + if (list->buffer[i] == value) { + return true; + } + } + } + + return false; +} + +/** + * Provides the value stored in the list at the given position. + * + * @param list The list from which the value shall be retrieved. + * @param index The zero-based position index of the value to retrieve. + * @return The value stored at the given position or 0, if the position + * is not available. + */ +int list_get_at(IntList list, unsigned int index) { + if (list_is_valid(list) && index < list->size) { + return list->buffer[index]; + } + + return 0; +} + +/** + * Inserts the given value at the end of the given list. + * + * @param list The list to which the value shall be appended. + * @param value The value to append to the list. + */ +void list_insert(IntList list, int value) { + if (list_is_valid(list)) { + if (list->size >= list->capacity) { + increase_buffer(list, CAPACITY_INCREMENT); + } + + list->buffer[list->size] = value; + list->size++; + } +} + +/** + * Inserts the given value at the indexed position in a way the + * the inserted value is on that position. The index is + * - similar to arrays - zero-based. If the the list is shorter + * than the indexed position, the value is inserted at the end + * of the list. + * + * @param list The list into which the value shall be appended. + * @param index The position index of the value to insert. + * @param value The value to insert. + */ +void list_insert_at(IntList list, unsigned int index, int value) { + if (list_is_valid(list)) { + if (index >= list->size) { + list_insert(list, value); + } else { + if (list->size >= list->capacity) { + increase_buffer(list, CAPACITY_INCREMENT); + } + + for (int i = list->size; i > index; i--) { + list->buffer[i] = list->buffer[i - 1]; + } + + list->buffer[index] = value; + list->size++; + } + } +} + +/** + * Appends the `list_to_append` at the end of the given `list`. + * The appended list is empty afterwards, because all nodes of that list + * have been transferred to `list`. + * + * @param list The list that receives the other list. + * @param list_to_append The list that is appended to `list`. + */ +/* This function is not required in this assignment. */ +/* void list_append(IntList list, IntList list_to_append); */ + +/** + * Removes the first occurrance of `value` from the given list. + * If the list does not contain that value, the list shall not + * be modified. + * + * @param list The list from which the given value shall be removed. + * @param value The value to remove from the list. + */ +void list_remove(IntList list, int value) { + if (list_is_valid(list)) { + for (int i = 0; i < list->size; i++) { + if (list->buffer[i] == value) { + for (int j = i; j < list->size - 1; j++) { + list->buffer[j] = list->buffer[j + 1]; + } + + list->size--; + return; + } + } + } +} + +/** + * Removes all occurrances of `value` from the list. + * If the list does not contain that value, the list shall not + * be modified. + * + * @param list The list from which all occurrances of `value` shall be removed. + * @param value The `value` to remove throughout the list. + */ +void list_remove_all(IntList list, int value) { + if (list_is_valid(list)) { + for (int i = 0; i < list->size; i++) { + if (list->buffer[i] == value) { + for (int j = i; j < list->size - 1; j++) { + list->buffer[j] = list->buffer[j + 1]; + } + + list->size--; + i--; + } + } + } +} + +/** + * Removes the value at the indexed position from the given list + * and provides that value. If the list does not have a value + * at that position, the list remains unmodified. + * + * @param list The list from which the value at the given index shall be returned. + * @param index The zero-based index of the value to return. + * @return The removed value or 0 in case of errors. + */ +int list_remove_at(IntList list, unsigned int index) { + if (list_is_valid(list) && index < list->size) { + int value = list->buffer[index]; + for (int i = index; i < list->size - 1; i++) { + list->buffer[i] = list->buffer[i + 1]; + } + + list->size--; + return value; + } + + return 0; +} + +/** + * Swaps the values at the given indexes, so that value at fst_idx becomes + * the value at snd_idx and vice versa. The invocation is ignored, if the + * list is invalid or at least one of the given indexes is out of range. + * + * @param list The list to manipulate + * @param fst_idx The index of the first item to swap. + * @param snd_idx The index of the second item to swap. + */ +void list_swap(IntList list, unsigned int fst_idx, unsigned int snd_idx) { + if (list_is_valid(list) && fst_idx < list->size && snd_idx < list->size) { + int temp = list->buffer[fst_idx]; + list->buffer[fst_idx] = list->buffer[snd_idx]; + list->buffer[snd_idx] = temp; + } +} + +/** + * Clears the given list by removing all values from the list. + * + * @param list The list to clear. + */ +void list_clear(IntList list) { + if (list_is_valid(list)) { + list->size = 0; + } +} \ No newline at end of file