Question

Fill the code in list.cpp

app.cpp:

#include "list.hpp"

int main()

{

        LinkedList aList;

bool success = false;

        aList.evensFrontOddsEnd(3);

        aList.evensFrontOddsEnd(10);

        aList.evensFrontOddsEnd(6);

        aList.evensFrontOddsEnd(9);

        aList.evensFrontOddsEnd(17);

        aList.evensFrontOddsEnd(12);

        aList.printForward(); // output should be: 12 6 10 3 9 17

        aList.printBackward(); // output should be: 17 9 3 10 6 12

        success = aList.remove(17);

if(success)

cout << "17 Successfully Removed." << endl;

        success = aList.remove(10);

if(success)

cout << "10 Successfully Removed." << endl;

success = aList.remove(7); // 7 is not in the list, so success should be false.

if(!success)

cout << "7 is not in the list." << endl;

        success = aList.remove(12);

if(success)

cout << "12 Successfully Removed." << endl;

        aList.printForward(); // output should be: 6 3 9.

        aList.printBackward(); // output should be: 9 3 6.

aList.remove(3);

aList.remove(6);

aList.remove(9);

aList.printForward(); // The list is now empty, so your program should not crash.

aList.printBackward();

        return 0;

}

list.cpp:

#include "list.hpp"

// Implementation file for lab 6, CS162.

//put your implementation of LinkedList class here

// LinkedList constructor. Set head and tail to nullptr.

LinkedList::LinkedList() {

head = nullptr;

tail = nullptr;

}

// evensFrontOddsEnd method. You must add nodes with numbers that are even,

// (2, 4, 12, etc.) to the head and nodes with odd numbers to the tail.

// Suppose you use temp as a pointer and create a new node using temp. If head = nullptr,

// set head = tail = temp. Temp will be the first node. To add to the head,

// make head->prev point to temp, temp->next point to head, and head = temp.

// To add to the tail, make tail->next point to temp, temp->prev point to tail,

// and tail = temp. If you add to the head, make temp->prev = nullptr.

// If you add to the tail, then temp->next = nullptr.

void LinkedList::evensFrontOddsEnd(int val) {

}

// printForward method. Print the list in forward order. If the list is empty, return immediately.

// Otherwise, create a temporary pointer that starts at head,

// and then moves down the linked list: cur = head, while cur != nullptr, cur = cur->next.

void LinkedList::printForward() const {

}

// printBackward method. Print the list in reverse order. If the list is empty, return immediately.

// Otherwise, create a temporary pointer that starts at tail, and then moves up the linked list:

// cur = tail, while cur != nullptr, cur = cur->prev.

//

void LinkedList::printBackward() const {

}

// Place the remove method below. If the val argument is not found in the list, or if the list is

// empty, return false. Otherwise, create a temporary pointer, perhaps called cur.

// If the number to remove is the head, set cur = head, set head->next->prev = nullptr,

// head = head->next, then delete cur. You must check if head->next is not equal to nullptr first.

// If the number to remove is the tail, set cur = tail, set tail->prev->next = nullptr,

// tail = tail->prev, then delete cur. Check to see if tail->prev is not equal to nullptr first.

// Lastly, if the node is somewhere in the middle, then cur->prev->next = cur->next,

// cur->next->prev = cur->prev, and then delete cur.

// If you removed a node, return true.

bool LinkedList::remove(int val) {

}

list.hpp:

#ifndef LIST_H

#define LIST_H

#include <iostream>

using namespace std;

struct Node

{

int data;

Node * next;

Node * prev;

};

class LinkedList

{

private:

    Node * head, * tail;

public:

    LinkedList();

    void evensFrontOddsEnd(int val); // Add nodes with numbers even numbers to the front

// of the list. Add odds to the end of the list.

    bool remove(int val);

    void printForward() const; // print the list in forward order.

void printBackward() const; // print the list in reverse order.

};

#endif

Answer 1

#######################################
            list.cpp
#######################################
#include "list.hpp"

// Implementation file for lab 6, CS162.

//put your implementation of LinkedList class here

// LinkedList constructor. Set head and tail to nullptr.

LinkedList::LinkedList() {

head = nullptr;

tail = nullptr;

}

// evensFrontOddsEnd method. You must add nodes with numbers that are even,
// (2, 4, 12, etc.) to the head and nodes with odd numbers to the tail.
// Suppose you use temp as a pointer and create a new node using temp. If head = nullptr,
// set head = tail = temp. Temp will be the first node. To add to the head,
// make head->prev point to temp, temp->next point to head, and head = temp.
// To add to the tail, make tail->next point to temp, temp->prev point to tail,
// and tail = temp. If you add to the head, make temp->prev = nullptr.
// If you add to the tail, then temp->next = nullptr.
void LinkedList::evensFrontOddsEnd(int val) {
        Node *temp = new Node;
        temp->data = val;
        temp->next = nullptr;
        temp->prev = nullptr;
        if(head == nullptr) {
                head = temp;
                tail = temp;
        } else if(val % 2 == 0) {
                temp->next = head;
                head->prev = temp;
                head = temp;
        } else {
                temp->prev = tail;
                tail->next = temp;
                tail = temp;
        }
}

// printForward method. Print the list in forward order. If the list is empty, return immediately.
// Otherwise, create a temporary pointer that starts at head,
// and then moves down the linked list: cur = head, while cur != nullptr, cur = cur->next.
void LinkedList::printForward() const {
        Node *tmp = head;
        while(tmp != nullptr) {
                cout << tmp->data << " ";
                tmp = tmp->next;
        }
        cout << endl;
}

// printBackward method. Print the list in reverse order. If the list is empty, return immediately.
// Otherwise, create a temporary pointer that starts at tail, and then moves up the linked list:
// cur = tail, while cur != nullptr, cur = cur->prev.
//
void LinkedList::printBackward() const {
        Node *tmp = tail;
        while(tmp != nullptr) {
                cout << tmp->data << " ";
                tmp = tmp->prev;
        }
        cout << endl;
}

// Place the remove method below. If the val argument is not found in the list, or if the list is
// empty, return false. Otherwise, create a temporary pointer, perhaps called cur.
// If the number to remove is the head, set cur = head, set head->next->prev = nullptr,
// head = head->next, then delete cur. You must check if head->next is not equal to nullptr first.
// If the number to remove is the tail, set cur = tail, set tail->prev->next = nullptr,
// tail = tail->prev, then delete cur. Check to see if tail->prev is not equal to nullptr first.
// Lastly, if the node is somewhere in the middle, then cur->prev->next = cur->next,
// cur->next->prev = cur->prev, and then delete cur.
// If you removed a node, return true.
bool LinkedList::remove(int val) {
        if(head == nullptr) {
                return false;
        }
        Node *cur = head;

        if(cur->data == val) {
                head = head->next;
                if(head != nullptr) {
                        head->prev = nullptr;
                } else {
                        tail = nullptr;
                }
                delete cur;
                return true;
        } else if(tail->data == val) {
                cur = tail;
                tail = tail->prev;
                if(tail != nullptr) {
                        tail->next = nullptr;
                } else {
                        head = nullptr;
                }
                delete cur;
                return true;
        } else {
                Node *prev = cur;
                cur = cur->next;
                while(cur != nullptr && cur->data != val) {
                        prev = cur;
                        cur = cur->next;
                }

                if(cur != nullptr) {
                        prev->next = cur->next;
                        cur->next->prev = prev;
                        delete cur;
                        return true;
                }
        }
        return false;
}



#######################################
            list.hpp
#######################################
#ifndef LIST_H
#define LIST_H

#include <iostream>

using namespace std;

struct Node

{

int data;

Node * next;

Node * prev;

};

class LinkedList

{

private:

    Node * head, * tail;

public:

    LinkedList();

    void evensFrontOddsEnd(int val); // Add nodes with numbers even numbers to the front

// of the list. Add odds to the end of the list.

    bool remove(int val);

    void printForward() const; // print the list in forward order.

void printBackward() const; // print the list in reverse order.

};



#endif




#######################################
            main.cpp
#######################################
#include "list.hpp"

int main()

{

        LinkedList aList;

bool success = false;

        aList.evensFrontOddsEnd(3);

        aList.evensFrontOddsEnd(10);

        aList.evensFrontOddsEnd(6);

        aList.evensFrontOddsEnd(9);

        aList.evensFrontOddsEnd(17);

        aList.evensFrontOddsEnd(12);

        aList.printForward(); // output should be: 12 6 10 3 9 17

        aList.printBackward(); // output should be: 17 9 3 10 6 12

        success = aList.remove(17);

if(success)

cout << "17 Successfully Removed." << endl;

        success = aList.remove(10);

if(success)

cout << "10 Successfully Removed." << endl;

success = aList.remove(7); // 7 is not in the list, so success should be false.

if(!success)

cout << "7 is not in the list." << endl;

        success = aList.remove(12);

if(success)

cout << "12 Successfully Removed." << endl;

        aList.printForward(); // output should be: 6 3 9.

        aList.printBackward(); // output should be: 9 3 6.

aList.remove(3);

aList.remove(6);

aList.remove(9);

aList.printForward(); // The list is now empty, so your program should not crash.

aList.printBackward();

        return 0;

}




Please upvote, as i have given the exact answer as asked in question. Still in case of any issues in code, let me know in comments. Thanks!