C++

Overload the == operator in UnorderedLinkedList that returns true when this list has exactly the same elements as the argument list regardless of order. Write a function called getKthElement that returns the element at position k given an integer k. Comment explaining your answer.

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*linkedList.h:

#ifndef H_LinkedListType #define H_LinkedListType #include #include using namespace std; //Definition of the node template struct nodeType { Type info; nodeType *link; }; template class linkedListIterator { public: linkedListIterator(); //Default constructor //Postcondition: current = NULL; linkedListIterator(nodeType *ptr); //Constructor with a parameter. //Postcondition: current = ptr; Type operator*(); //Function to overload the dereferencing operator *. //Postcondition: Returns the info contained in the node. linkedListIterator operator++(); //Overload the preincrement operator. //Postcondition: The iterator is advanced to the next node. bool operator==(const linkedListIterator& right) const; //Overload the equality operator. //Postcondition: Returns true if this iterator is equal to // the iterator specified by right, otherwise it returns // false. bool operator!=(const linkedListIterator& right) const; //Overload the not equal to operator. //Postcondition: Returns true if this iterator is not equal to // the iterator specified by right, otherwise it returns // false. private: nodeType *current; //pointer to point to the current //node in the linked list }; template linkedListIterator::linkedListIterator() { current = NULL; } template linkedListIterator:: linkedListIterator(nodeType *ptr) { current = ptr; } template Type linkedListIterator::operator*() { return current->info; } template linkedListIterator linkedListIterator::operator++() { current = current->link; return *this; } template bool linkedListIterator::operator== (const linkedListIterator& right) const { return (current == right.current); } template bool linkedListIterator::operator!= (const linkedListIterator& right) const { return (current != right.current); } //*********************************************************** // This class specifies the members to implement the basic // properties of a linked list. This is an abstract class. // We cannot instantiate an object of this class. //*********************************************************** template class linkedListType { public: const linkedListType& operator= (const linkedListType&); //Overload the assignment operator. void initializeList(); //Initialize the list to an empty state. //Postcondition: first = NULL, last = NULL, count = 0; bool isEmptyList() const; //Function to determine whether the list is empty. //Postcondition: Returns true if the list is empty, otherwise // it returns false. void print() const; //Function to output the data contained in each node. //Postcondition: none int length() const; //Function to return the number of nodes in the list. //Postcondition: The value of count is returned. void destroyList(); //Function to delete all the nodes from the list. //Postcondition: first = NULL, last = NULL, count = 0; Type front() const; //Function to return the first element of the list. //Precondition: The list must exist and must not be empty. //Postcondition: If the list is empty, the program terminates; // otherwise, the first element of the list is returned. Type back() const; //Function to return the last element of the list. //Precondition: The list must exist and must not be empty. //Postcondition: If the list is empty, the program // terminates; otherwise, the last // element of the list is returned. virtual bool search(const Type& searchItem) const = 0; //Function to determine whether searchItem is in the list. //Postcondition: Returns true if searchItem is in the list, // otherwise the value false is returned. virtual void insertFirst(const Type& newItem) = 0; //Function to insert newItem at the beginning of the list. //Postcondition: first points to the new list, newItem is // inserted at the beginning of the list, last points to // the last node in the list, and count is incremented by // 1. virtual void insertLast(const Type& newItem) = 0; //Function to insert newItem at the end of the list. //Postcondition: first points to the new list, newItem is // inserted at the end of the list, last points to the // last node in the list, and count is incremented by 1. virtual void deleteNode(const Type& deleteItem) = 0; //Function to delete deleteItem from the list. //Postcondition: If found, the node containing deleteItem is // deleted from the list. first points to the first node, // last points to the last node of the updated list, and // count is decremented by 1. linkedListIterator begin(); //Function to return an iterator at the beginning of the //linked list. //Postcondition: Returns an iterator such that current is set // to first. linkedListIterator end(); //Function to return an iterator one element past the //last element of the linked list. //Postcondition: Returns an iterator such that current is set // to NULL. linkedListType(); //default constructor //Initializes the list to an empty state. //Postcondition: first = NULL, last = NULL, count = 0; linkedListType(const linkedListType& otherList); //copy constructor ~linkedListType(); //destructor //Deletes all the nodes from the list. //Postcondition: The list object is destroyed. protected: int count; //variable to store the number of list elements // nodeType *first; //pointer to the first node of the list nodeType *last; //pointer to the last node of the list private: void copyList(const linkedListType& otherList); //Function to make a copy of otherList. //Postcondition: A copy of otherList is created and assigned // to this list. }; template bool linkedListType::isEmptyList() const { return (first == NULL); } template linkedListType::linkedListType() //default constructor { first = NULL; last = NULL; count = 0; } template void linkedListType::destroyList() { nodeType *temp; //pointer to deallocate the memory //occupied by the node while (first != NULL) //while there are nodes in the list { temp = first; //set temp to the current node first = first->link; //advance first to the next node delete temp; //deallocate the memory occupied by temp } last = NULL; //initialize last to NULL; first has already //been set to NULL by the while loop count = 0; } template void linkedListType::initializeList() { destroyList(); //if the list has any nodes, delete them } template void linkedListType::print() const { nodeType *current; //pointer to traverse the list current = first; //set current so that it points to //the first node while (current != NULL) //while more data to print { cout << current->info << " "; current = current->link; } }//end print template int linkedListType::length() const { return count; } //end length template Type linkedListType::front() const { assert(first != NULL); return first->info; //return the info of the first node }//end front template Type linkedListType::back() const { assert(last != NULL); return last->info; //return the info of the last node }//end back template linkedListIterator linkedListType::begin() { linkedListIterator temp(first); return temp; } template linkedListIterator linkedListType::end() { linkedListIterator temp(NULL); return temp; } template void linkedListType::copyList (const linkedListType& otherList) { nodeType *newNode; //pointer to create a node nodeType *current; //pointer to traverse the list if (first != NULL) //if the list is nonempty, make it empty destroyList(); if (otherList.first == NULL) //otherList is empty { first = NULL; last = NULL; count = 0; } else { current = otherList.first; //current points to the //list to be copied count = otherList.count; //copy the first node first = new nodeType; //create the node first->info = current->info; //copy the info first->link = NULL; //set the link field of //the node to NULL last = first; //make last point to the //first node current = current->link; //make current point to //the next node //copy the remaining list while (current != NULL) { newNode = new nodeType; //create a node newNode->info = current->info; //copy the info newNode->link = NULL; //set the link of //newNode to NULL last->link = newNode; //attach newNode after last last = newNode; //make last point to //the actual last node current = current->link; //make current point //to the next node }//end while }//end else }//end copyList template linkedListType::~linkedListType() //destructor { destroyList(); }//end destructor template linkedListType::linkedListType (const linkedListType& otherList) { first = NULL; copyList(otherList); }//end copy constructor //overload the assignment operator template const linkedListType& linkedListType::operator= (const linkedListType& otherList) { if (this != &otherList) //avoid self-copy { copyList(otherList); }//end else return *this; } #endif

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*unorderedLinkedList.h:

#ifndef H_UnorderedLinkedList #define H_UnorderedLinkedList #include "linkedList.h" using namespace std; template class unorderedLinkedList: public linkedListType { public: bool search(const Type& searchItem) const; //Function to determine whether searchItem is in the list. //Postcondition: Returns true if searchItem is in the list, // otherwise the value false is returned. void insertFirst(const Type& newItem); //Function to insert newItem at the beginning of the list. //Postcondition: first points to the new list, newItem is // inserted at the beginning of the list, last points to // the last node, and count is incremented by 1. // void insertLast(const Type& newItem); //Function to insert newItem at the end of the list. //Postcondition: first points to the new list, newItem is // inserted at the end of the list, last points to the // last node, and count is incremented by 1. void deleteNode(const Type& deleteItem); //Function to delete deleteItem from the list. //Postcondition: If found, the node containing deleteItem // is deleted from the list. first points to the first // node, last points to the last node of the updated // list, and count is decremented by 1. }; template bool unorderedLinkedList:: search(const Type& searchItem) const { nodeType *current; //pointer to traverse the list bool found = false; current = first; //set current to point to the first //node in the list while (current != NULL && !found) //search the list if (current->info == searchItem) //searchItem is found found = true; else current = current->link; //make current point to //the next node return found; }//end search template void unorderedLinkedList::insertFirst(const Type& newItem) { nodeType *newNode; //pointer to create the new node newNode = new nodeType; //create the new node newNode->info = newItem; //store the new item in the node newNode->link = first; //insert newNode before first first = newNode; //make first point to the //actual first node count++; //increment count if (last == NULL) //if the list was empty, newNode is also //the last node in the list last = newNode; }//end insertFirst template void unorderedLinkedList::insertLast(const Type& newItem) { nodeType *newNode; //pointer to create the new node newNode = new nodeType; //create the new node newNode->info = newItem; //store the new item in the node newNode->link = NULL; //set the link field of newNode //to NULL if (first == NULL) //if the list is empty, newNode is //both the first and last node { first = newNode; last = newNode; count++; //increment count } else //the list is not empty, insert newNode after last { last->link = newNode; //insert newNode after last last = newNode; //make last point to the actual //last node in the list count++; //increment count } }//end insertLast template void unorderedLinkedList::deleteNode(const Type& deleteItem) { nodeType *current; //pointer to traverse the list nodeType *trailCurrent; //pointer just before current bool found; if (first == NULL) //Case 1; the list is empty. cout << "Cannot delete from an empty list." << endl; else { if (first->info == deleteItem) //Case 2 { current = first; first = first->link; count--; if (first == NULL) //the list has only one node last = NULL; delete current; } else //search the list for the node with the given info { found = false; trailCurrent = first; //set trailCurrent to point //to the first node current = first->link; //set current to point to //the second node while (current != NULL && !found) { if (current->info != deleteItem) { trailCurrent = current; current = current-> link; } else found = true; }//end while if (found) //Case 3; if found, delete the node { trailCurrent->link = current->link; count--; if (last == current) //node to be deleted //was the last node last = trailCurrent; //update the value //of last delete current; //delete the node from the list } else cout << "The item to be deleted is not in " << "the list." << endl; }//end else }//end else }//end deleteNode #endif