#include <iostream>
#include <fstream>
#include <cstring>
using namespace std;

const int LINE_BUFFER_SIZE = 256;

struct CharLinkD {

CharLinkD *prev;
char c;
CharLinkD *next;

};

// detects if a word is a palindrome
void makeList(const char candidate[], CharLinkD* &head, CharLinkD* &tail) {

        // get the length of the c-string
        int len = strlen(candidate);


        CharLinkD* first = NULL;
        CharLinkD* temp = NULL;

        //make first link
        first = new CharLinkD;
        first->prev = NULL;
        first->next = NULL;
        first->c = candidate[0];

        //make head and tail point to it
        head = first;
        tail = first;

        //make the list

        for(int i = 1; i < len; i++)
        {
                //make a new link for each character left
                temp = new CharLinkD;

                //make a link that goes back to tail
                temp->prev = tail;

                //link forward is null
                temp->next=NULL;

                temp->c = candidate[i];

                //set up link backward to end of list
                tail->next = temp;

                //new tail is now last element
                tail = temp;
        }
}

bool isPalindrome(CharLinkD * head, CharLinkD * tail) {
        bool answer = true;

        //YOUR CODE HERE

        return answer;
}

// reads in the list of words
// prints out word if it is a palendrome
int main() {

        CharLinkD *head = NULL;
        CharLinkD *tail = NULL;

        // open a file for READING
        ifstream infile("words");

        // create a buffer to hold a line of text from the file
        char line[LINE_BUFFER_SIZE];

        // while not at the end of file
        while (!infile.eof()) {
                // get a line of the file into the buffer
                infile.getline(line, LINE_BUFFER_SIZE);


                makeList(line, head, tail);
                // use our function to check if it's a palindrome
                if (isPalindrome(head, tail)) {
                        cout << line << endl;
                }
        }
        infile.close();
}