Qfyilyi

Edited
I have to remove from a LinkedList sequences which their sum equals to 5.

for example for this Linked list: {3,2, 1, 4, 10,3,3,2,1} I get {10, 3, 3, 2, 1}. I dont really know why it's like that, it should remove 3,2 also but it dosent.

void LinkedList::cleanFive(LinkedList& list)

{

head = list.GetHead();



Node* end = head;

Node* headd = head;

Node* flag = head;

Node* curr = head;



int sum = 0;





while (end) {

    sum += end->data;



    if (sum < 5) {

        end = end->next;

    }

    if (sum == 5) {

        end = end->next;

        headd = end;

        flag = headd;

        head = flag;

        sum = 0;

    }

    if (sum > 5) {

        flag = head;

        curr = end;

        end = end->next;

        sum = 0;

    }

}

}

curr = head;

end = head;

currprev = nullptr;



std::vector<Node*> flag;

while(end) {

     sum += end->data;

     if (sum < 5) {

         flag.push_back(end);

         end = end->next;

     }



     if (sum > 5) {

         currprev = curr;

         curr = curr->next;

         end = curr;

         sum = 0;

         empty_flag()

     }



     if (sum == 5) {

         curr = end->next;

         end = curr;

         sum = 0;

         delete_nodes_from_flag_from_linked_list()

         empty_flag()

     }

}

Here is a possible solution. flag is in this case a vector of nodes which are saved until the sum is proven to be 5 or greater as 5. With flag there are two operations which need to be made: empy_flag() - deletes all entries from the vector and delete_nodes_from_flag_from_linked_list() - that deletes the elements from flag from the linked list.

Code for delete_nodes_from_flag_from_linked_list() should be as follows:

auto it = flag.end();

it--;

Node* last = *it;



if (currprev)

    currprev->next = last->next;

else

    head = last->next



for (auto f : flag) 

    delete f;

where currprev is the element just before curr. You have to keep track of this element from the beginning, unless your linked list elements keep pointers to previous elements. I am updating the code from above. head is the start of the list.