In this partially given C++ program, Please write explanations for bolded lines(what they do) as comments in clear words. Thank you.

// Program Code

bool insertNum(nodeType **first, int num){ // function definition

  nodeType *current, *head, *newNode, *prior; head = *first; int done; if(head == NULL){ // insert into empty list  head = new nodeType; head->info = num; head->link = NULL; done=1; } else{ // 1.else if(head->info > num){ // insert at top of list  newNode = new nodeType; newNode->info = num; newNode->link = head; head=newNode; done = 1; } else{ // 2.else done = 0; current = head; while((current != NULL)&&(!done)){ // insert between two existing nodes if(current->info > num){ newNode = new nodeType; newNode->info = num; newNode->link = current; prior->link = newNode; done = 1; } else{ prior = current; current = current->link; } } // while loop if(!done){ // insert at end of list newNode = new nodeType; newNode->info = num; newNode->link = current; prior->link = newNode; done = 1; } // 2.else } // 1.else } // if *first = head; return done; }