Explain the code (Do not use flowchart). See attached photo for the problem. It doesn't have to be long as long as you explain the important parts of the codeint removeHead() { if(!isEmpty()) { return remove_between(head->next); } return 0; } int removeTail() { if(!isEmpty()) { return remove_between(tail->prev); } return 0; } int add(int num) { addTail(num); return index; } int remove(int num) { node* currnode = head->next; int pos = 0; while(currnode != tail) { pos++; if(currnode->element == num) { remove_between(currnode); return pos; } else { currnode = currnode->next; } } return 0; } bool addAt(int num, int pos) { node* currnode; int count; bool start_from_head = true; if (pos > index/2) { start_from_head = false; } if (start_from_head) { // START FROM HEAD currnode = head->next; count = 0; while (currnode != NULL) { count++; if (count == pos) { add_between(num, currnode->prev, currnode); return true; } else { currnode = currnode->next; } } } else { // START FROM TAIL currnode = tail->prev; count = index + 1; while (currnode != NULL) { count--; if (count == pos - 1) { add_between(num, currnode, currnode->next); return true; } else { currnode = currnode->prev; } } } return false; } int removeAt(int pos) { node* currnode; int count; bool start_from_head = true; if (pos > index/2) { start_from_head = false; } if (start_from_head) { // START FROM HEAD currnode = head->next; count = 0; while (currnode != NULL) { count++; if (count == pos) { int elem = currnode->element; remove_between(currnode); return elem; } else { currnode = currnode->next; } } } else { // START FROM TAIL currnode = tail->prev; count = index + 1; while (currnode != NULL) { count--; if (count == pos) { int elem = currnode->element; remove_between(currnode); return elem; } else { currnode = currnode->prev; } } } return -1; } int removeAll(int num) { node* currnode = head->next; int count = 0; while(currnode != tail) { if(currnode->element == num) { count++; node* newcurrnode = currnode->next; remove_between(currnode); currnode = newcurrnode; } else { currnode = currnode->next; } } return count; } int contains(int num) { node* currnode = head->next; int pos = 0; while(currnode != NULL) { pos++; if(currnode->element == num) { return pos; } else { currnode = currnode->next; } } return 0; } int count(int num) { node* currnode = head->next; int ctr = 0; while(currnode != NULL) { if(currnode->element == num) { ctr++; } currnode = currnode->next; } return ctr; } bool move(int pos1, int pos2) { int elem = removeAt(pos1); if(elem == -1) { return false; } bool success = addAt(elem, pos2); if(!success) { addAt(elem, pos1); } return success; } bool isEmpty() { return index == 0; } void clear() { while(!isEmpty()){ removeHead(); } } bool addAt(int num, int pos) [remember the note)This method will add the integer num to the posth position ofthe list and returns true if the value of pos is valid.Performing addAt(20, 2) in the example list will add 20 at the2nd position and the linked list will now look like this: h + 1o+ 20 + 30 + 40 + 50 + t.When the value of pos is invalid i.e. greater than the size + 1 orless than one, return false.int removeAt(int pos) [remember the note]Removes the number in the posth position of the list andreturns the element removed.Performing removeAt(3) in the example list will remove the 3rdelement of the linked list and the updated list will be: h + 1O+ 30 + 50 +tWhen the value of pos is greater than the size or less than one,return -1.int removeAll(int num)Removes all instances of num in the linked list and returns thenumber of instances removed.In this list h + 10 10 20 + 30 + 10 +t, performingremoveAll(10) will remove all three 10's and the list will looklike this: 20 → 30. Then, it will return the number of instancesremoved, in this case, 3.int contains(int num)This will return the position of the first instance of the elementnum in the list. If num is not found, return 0. In the example,having the method contains(30) will return 2 as it is located inthe second position.int count (int num)This will return the count of the instances of the element numin the list. In the linked list in removeAll method, having themethod count(10) will return 3 as there are three 10's in thelinked list.• bool move(int pos1, int pos2) [remember the note)This method will move the element at position post to theposition specified as pos2 and will return true if the move issuccessful. This will return false if either the specifiedpositions is invalid. In the example stated, operating themethod move(1, 3) will move the 1st element and shall nowbecome the 3rd element. The linked list shall now look like: h +> 30 + 40 + 10 + 50 +t Currently, we have implemented the addHead, add Tail, andget. You are to implement removeHead, and removeTail (youmay follow my code in my discussion) and you also have tocreate the following functions (for visual purposes of the detailexplanation, header and trailer sentinels are described as h andt respectively):IMPORTANT NOTE: For all the methods that has the posparameter ie. addAt, removeAt, move, make sure to accessthat specified position from whichever is nearer - the head orthe tail - similar to what we have done in the get method. I willbe looking at your code to see if you have taken this intoconsideration. Failure to do so will cut your score by 50% forthe said methods.Example DoublyLinkedList: h + 10 + 30 + 40 + 50 + tint add(int num)This will add the element num into the last element of thelinked list and return the position of the newly-addedelement. In the above example, having add(60) will return 5 asit is the fifth position in the list.int remove(int num)This will remove the first instance of the element and returnthe position of the removed element. In the above example,having remove(40) will return 3 as 40 was the third element inthe linked list before having removed. If the specified num isnot found, return 0.int removeTail()This method will remove the last element in your linked list andreturn the said element. If the list is empty, return 0. You canuse the existing methods.void isEmpty)This method will return true if the linked list is empty,otherwise return false.• void clear(0This method will empty your linked list. Effectively, this shouldand already has been called in your destructor (Le., the-LinkedList0 method) so that it will deallocate the nodescreated first before deallocating the linked list itself.

Answered: Image /qna-images/answer/db7bda19-e5bd-42ff-ae3a-d129d13ac856.jpg

Explain the code (Do not use flowchart). See attached photo for the problem. It doesn't have to be long as long as you explain the important parts of the code int removeHead() { if(!isEmpty()) { return remove_between(head->next); } return 0; } int removeTail() { if(!isEmpty()) { return remove_between(tail->prev); } return 0; } int add(int num) { addTail(num); return index; } int remove(int num) { node* currnode = head->next; int pos = 0; while(currnode != tail) { pos++; if(currnode->element == num) { remove_between(currnode); return pos; } else { currnode = currnode->next; } } return 0; } bool addAt(int num, int pos) { node* currnode; int count; bool start_from_head = true; if (pos > index/2) { start_from_head = false; } if (start_from_head) { // START FROM HEAD currnode = head->next; count = 0; while (currnode != NULL) { count++; if (count == pos) { add_between(num, currnode->prev, currnode); return true; } else { currnode = currnode->next; } } } else { // START FROM TAIL currnode = tail->prev; count = index + 1; while (currnode != NULL) { count--; if (count == pos - 1) { add_between(num, currnode, currnode->next); return true; } else { currnode = currnode->prev; } } } return false; } int removeAt(int pos) { node* currnode; int count; bool start_from_head = true; if (pos > index/2) { start_from_head = false; } if (start_from_head) { // START FROM HEAD currnode = head->next; count = 0; while (currnode != NULL) { count++; if (count == pos) { int elem = currnode->element; remove_between(currnode); return elem; } else { currnode = currnode->next; } } } else { // START FROM TAIL currnode = tail->prev; count = index + 1; while (currnode != NULL) { count--; if (count == pos) { int elem = currnode->element; remove_between(currnode); return elem; } else { currnode = currnode->prev; } } } return -1; } int removeAll(int num) { node* currnode = head->next; int count = 0; while(currnode != tail) { if(currnode->element == num) { count++; node* newcurrnode = currnode->next; remove_between(currnode); currnode = newcurrnode; } else { currnode = currnode->next; } } return count; } int contains(int num) { node* currnode = head->next; int pos = 0; while(currnode != NULL) { pos++; if(currnode->element == num) { return pos; } else { currnode = currnode->next; } } return 0; } int count(int num) { node* currnode = head->next; int ctr = 0; while(currnode != NULL) { if(currnode->element == num) { ctr++; } currnode = currnode->next; } return ctr; } bool move(int pos1, int pos2) { int elem = removeAt(pos1); if(elem == -1) { return false; } bool success = addAt(elem, pos2); if(!success) { addAt(elem, pos1); } return success; } bool isEmpty() { return index == 0; } void clear() { while(!isEmpty()){ removeHead(); } }