Lets say, I have singly linkedlist with 5 elements in it. How will I resize the list if I delete an element with this specific situation -

My singly linkedlist is defined as 0->1->2->3->4, where these numbers are the index of the list. Suppose I have function, f() which return a pointer directly at index 2. From here, I want to delete 2 but don't know how to connect 1 to 3. How can I do that?

CodePudding user response：

For the case of a "singley-linked" list you will need to maintain the data-structure of for the "next" item in the list.

If in your case (it seems as though you are) constricted to use a function that returns a pointer to this link, then you can loop through and delete accordingly.

For example:

struct link *f(struct link *head) {
    // Do work...
    // is found struct link *target
    return target;
}

struct link *delete_link(struct link *head, struct link *target) {
    if (head == target) {
        struct link *tmp = head;
        struct link *new_head = tmp->next;
        return new_head;
    }

    struct link *curr = head;
    while (curr->next != target) {
        struct link *tmp = curr;
        curr = curr->next;
    }
    curr->next = target->next
    free(target);
    return head;
}

int main(int argc, char *argv[])
{
    struct link {
        // data
        struct link *next;
    };

    // Construct list....
    struct link *head = construct_list(1, 2, 3, 4);
    // Do stuff...
    struct link *target = f(list);
    // Found a deletion target...
    head = delete_link(target);
    return 0;
}