Lista Dinâmica Encadeada

#include <stdio.h>
#include <stdlib.h>

#define TRUE 1
#define FALSE 0

typedef struct ListaDE ListaDE;
typedef struct Item Item;

struct Item {
    int value;
    Item* next;
};

struct ListaDE {
    Item* item;
};

ListaDE* newListaDE();
int isEmpty(ListaDE* list);
int has(int value, ListaDE* list);
Item* get(int value, ListaDE* list);

void add(int value, ListaDE* list);
void delete(int value, ListaDE* list);
void print(ListaDE* list);
void freeList(ListaDE* list);

ListaDE* newListaDE()
{
    ListaDE* newList = malloc(sizeof(ListaDE));
    newList->item = NULL;

    return newList;
}

int isEmpty(ListaDE* list) {
    return list->item == NULL;
}

int has(int value, ListaDE* list)
{
    Item* item = list->item;

    while (item != NULL) {
        if (item->value == value)
            return TRUE;

        item = item->next;
    }

    return FALSE;
}

Item* get(int value, ListaDE* list)
{
    Item* item = list->item;

    while (item != NULL && item->value != value)
        item = item->next;

    return item;
}

void add(int value, ListaDE* list)
{
    if (has(value, list))
        return;

    Item* newItem = malloc(sizeof(Item));
    newItem->value = value;
    newItem->next = NULL;

    if (isEmpty(list)) {
        list->item = newItem;
        return;
    }

    Item *item = list->item;

    if (item->value > value)
    {
        newItem->next = item;
        list->item = newItem;
        return;
    }

    while (item->next != NULL && value > item->next->value)
        item = item->next;

    newItem->next = item->next;
    item->next = newItem;
}

void delete(int value, ListaDE* list)
{
    if (isEmpty(list) || !has(value, list))
        return;

    Item* item = list->item;

    if (item->value == value)
    {
        if (item->next == NULL)
        {
            list->item = NULL;
        }
        else
        {
            list->item = item->next;
        }

        free(item);
        return;
    }

    while(item->next != NULL && item->next->value != value)
        item = item->next;

    Item* itemToBeDeleted = item->next;

    item->next = itemToBeDeleted->next;

    free(itemToBeDeleted);
}

void print(ListaDE* list)
{
    Item* item = list->item;

    while (item != NULL) {
        printf("%d%c", item->value, (item->next == NULL) ? '\n' : ' ');
        item = item->next;
    }
}

void freeList(ListaDE* list)
{
    Item* item = list->item;

    while (item != NULL) {
        Item* next = item->next;

        free(item);
        item = next;
    }

    free(list);
}

int main()
{
    ListaDE* list = newListaDE();

    int value;

    char c;
    while (scanf("%c", &c) != EOF)
    {
        switch (c)
        {
            case 'I':
                scanf("%d", &value);

                add(value, list);
            break;

            case 'R':
                scanf("%d", &value);

                delete(value, list);
            break;

            case 'B':
                scanf("%d", &value);

                if (has(value, list))
                    printf("SIM\n");
                else
                    printf("NAO\n");
            break;

            case 'L':
                print(list);
            break;

            default:
            break;
        }
    }

    freeList(list);
    return 0;
}