bool mySetIsIn(MySet set, MySetElement element) {
if (set == NULL || element == NULL) {
return false;
}
for (MySetNode iterator = set->head; iterator != NULL; iterator = iterator->next) {
if (set->compareElements(iterator->element, element) == 0) {
return true;
}
}
return false;
}
MySetElement mySetExtract(MySet set, MySetElement element) {
if (set == NULL || !mySetIsIn(set, element)) {
return NULL;
}
assert(set->head != NULL);
MySetElement result;
MySetNode node; // node we want to deallocate
if (set->compareElements(set->head->element, element) == 0) {
// pop front
result = set->head->element;
node = set->head;
// extracting
set->head = set->head->next;
} else {
MySetNode position;
for (position = set->head;
position->next != NULL && set->compareElements(position->next->element, element) != 0;
position = position->next);
assert(position->next != NULL && set->compareElements(position->next->element, element) == 0);
result = position->next->element;
if (position->next->next == NULL) {
node = position->next;
// extracting
position->next = NULL;
} else {
position = position->next;
node = position->next;
// extracting
assert(position->next != NULL);
position->element = position->next->element;
position->next = position->next->next;
}
}
free(node);
return result;
}
MySetResult mySetAdd(MySet set, MySetElement element) {
if (set == NULL || element == NULL) {
return MY_SET_NULL_ARGUMENT;
}
if (mySetIsIn(set, element)) {
return MY_SET_ITEM_ALREADY_EXISTS;
}
// Create new node
MySetNode node;
MY_SET_ALLOCATION(MySetNode_t, node, MY_SET_OUT_OF_MEMORY);
if (NULL == (node->element = set->copyElement(element))) {
free(node);
return MY_SET_OUT_OF_MEMORY;
}
if (set->head == NULL || set->compareElements(set->head->element, element) > 0) {
//need to push front
node->next = set->head;
set->head = node;
} else {
assert(set->head != NULL);
assert(set->compareElements(set->head->element, element) < 0);
// find last position where element is lower then ours or last element
MySetNode position;
for (position = set->head;
position->next != NULL &&
set->compareElements(position->next->element, element) < 0;
position = position->next);
assert(position != NULL);
assert(position->next == NULL || set->compareElements(position->next->element, element) > 0);
// insert after position
node->next = position->next;
position->next = node;
}
return MY_SET_SUCCESS;
}
