C++

Modify the code so it prints the alphabet backwards and forwards using the next and prior pointers in the doubly linked list.

Answer should be the given code plus all modifications.

Code:

// LL.cpp : Defines the entry point for the console application. //

#include "stdafx.h" #include #include

using namespace std;

class node { public: char data; node* next; node(); };

node::node() {

}

int _tmain(int argc, _TCHAR* argv[]) { char s[] = "abcdefghijklmnopqrstuvwxyz";

node* head; node* temp; node* current;

head = new node; // create the head of the linked list head->data = s[0]; head->next = NULL; temp = head; // get ready for the loop - save the head in temp - you are going to change temp in the loop

for (size_t i = 1; i < strlen(s); i++) // create the rest of the linked list { current = new node; // make a new node current->data = s[i]; // set it's data member current->next = NULL; temp->next = current; // point to the new node temp = current; // make temp point to current node (for next time through) }

node* ptr = head; // set a ptr to head, then you are going to "increment" the pointer

while (ptr != NULL) { cout << ptr->data; // print out the linked list ptr = ptr->next; // increment the linked list }

cout << endl; system("pause"); return 0; }