I'm working on an assignment and I have to write a function that takes in a dynamically allocated array of strings and an index, and removes the element at that index. Using a sample main function provided to test the code, it crashes at the first call of the function, and I have no idea why. Here's my code.

int removeElement(ArrayList *list, int index)
{
    int i;

if(list != NULL && index < list->size)
{
    for(i = index; i < list->size - 1; i++)
    {
        free(list->array[i]);
        list->array[i] = malloc(sizeof(char) * (strlen(list->array[i + 1]) + 1));
        if(list->array[i] = NULL)
        {
            printf("Can't allocate memory. Returning 0.\n");
            return 0;
        }

        strcpy(list->array[i], list->array[i + 1]);
    }

    free(list->array[i]);
    list->array[i] = NULL;
    list->size--;
    return 1;
}

return 0;
};

I think it might be because the first string ("List of names") is larger than the second ("Sean"). But I'm still confused regarding to how it works.

有帮助吗?

解决方案

This is not a direct answer to your question, but you might as well just copy pointers instead of all these mallocs and strcpys:

int i;
if (list != NULL && index < list->size)
{
    free(list->array[index]);
    for (i=index; i<list->size-1; i++)
        list->array[i] = list->array[i+1];
    list->size--;
    return 1;
}

Or if you don't mind the order of the strings, then even better:

if (list != NULL && index < list->size)
{
    free(list->array[index]);
    if (index < list->size-1)
        list->array[index] = list->array[list->size-1];
    list->size--;
    return 1;
}
许可以下: CC-BY-SA归因
不隶属于 StackOverflow
scroll top