find word in a text file

hey guys!
i'm a newbie in programming specifically text files.

i kinda need some help with this problem that i'm trying to solve
about text files. I'M NOT REALLY ASKING FOR A COMPLETE CODES.

problem:

i have a text file, let's call it "vocab.text", the text file contains
alphabetical words only.
then i have to create a program that reads the text file and
finds the longest word that has its REVERSE word.

example, i found the word "desserts" and its reversal word which is
"stressed", the 2 words should be the longest words,
the program should output both "desserts" & "stressed".

take note that both reversal words are in the text file "vocab.text",
the programs' job is only to find the longest reversed words like "desserts" & "stressed".



ANY ADVICE WOULD BE GREAT!
THANKS IN ADVANCE!


so far i have this code:

Code:

#include <iostream>
#include <fstream>
#include <string>

using namespace std;

int main ()
{
    string str, longest;
    
    ifstream textfile ("vocab.txt");
    
    if (textfile.is_open())
    {
        while (!textfile.eof())
        {
              getline (textfile,str);
                        
              reverse (str.begin(), str.end());
              
              if (str.size () > longest.size ())
              longest = str;
              
         }
         cout << longest <<endl;
         
         textfile.close();
    }
    
    else
    cout << "Unable to open file"<<endl; 

    system ("pause");
    return 0;
}

What output are you getting if any? What errors are you having?

the longest word in reverse.

actually the function of my program is to reverse all words in the file
but only output the longest word that has been reversed.

but what errors are you getting

For a given word in a file, after reversing the current word, you must determine whether its reversed word exists.

Like in your example if "desserts" is the current word , then the existence of "stressed" must be checked in the given file.If the reversed word exists and it is longer than the current maximum length, longest = current_word.

A brute force solution will take O(n^2) time(worst case), when all the words are distinct.

Originally Posted by rodrigorules

but what errors are you getting

i'm not getting any error, its just that my output is not
what it should be..

Originally Posted by zalezog

For a given word in a file, after reversing the current word, you must determine whether its reversed word exists.

Like in your example if "desserts" is the current word , then the existence of "stressed" must be checked in the given file.If the reversed word exists and it is longer than the current maximum length, longest = current_word.

A brute force solution will take O(n^2) time(worst case), when all the words are distinct.

you're right, but the thing is don't have a clear idea/s
of how to do it...
how do i find the longest word that has its reverse
word in the file??.like in my text file vocab.text, my program
should display "desserts and stressed" but i don't know how.
any advice?.please.

how can i close this post??