Question

c++ please

Change InsertLast to be used on a double linked list instead of a single linked list. Use prev as the other pointer name.

bool LinkedList::InsertLast(int v) {
    if(size == 0) {
        return InsertFirst(v);
    }
    Node *tmp = new Node;
    if(tmp == NULL) return false;
    tmp->value=v;
    last->next=tmp;
    last = tmp;
    size++;
    if(size == 1){
        first = last;
    }
    return true;
}

Answer 1

Hi,

bool LinkedList::InsertLast(int v) {

if(size == 0) {

return InsertFirst(v);

}

Node *tmp = new Node;

if(tmp == NULL) return false;

//changes start here

tmp->value=v;

//doubly linked stores not only next but also previous node address

// last node address will become current node previous

tmp->prev=last;

//before insertion last->next value will be null

//now we are giving the newly created node address

last->next=tmp;

// tmp->next will be null and that's correct no need to change or revalue with NULL

last = tmp;

size++;

if(size == 1){

first = last;

}

return true;

}

Please comment below for any further clarification on the answer