Replace any word that starts with n F or a f with *

Question

Question: Write a program that reads a text file called "naughty.txt" and creates another file called "nice.txt" that is exactly the same, except for one thing: every word that begins with the letter F or f is replaced by a string of stars that are the same length as the removed word.

Note! Our univesity has their own libraries created that allow us to basically just use "library.h" and be able to code.

My Code:

#include "library.h"

struct mytype{string word;};

void replace(mytype array[], int size)
{
    ifstream fin("naughty.txt");
    if(fin.fail())
    {
        cout << "Error opening file "<< endl;
        exit(1);
    }
    else {
        while(!fin.eof())
        {
            for(int i = 0; i < size; i++)
            {
                if(array[i].word =="f" || array[i + 1].word == "F ")

Fixed Code:

#include "library.h"

struct mytype{string words;};

void read(mytype array[], int size)
{
    ifstream fin("naughty.txt.txt");
    if(fin.fail())
    {
        cout << "Input file didn't open." << endl;
    }

    else 
        {
            ofstream fout("nice.txt");
            for(int i = 0; i < size; i++)
                {
                    fin >> array[i].words;
                    if(array[i].words == "f" || array[i].words == "F") 
                        {
                            int length = array[i].words.length();
                            int j = 1;
                            while(j < length)
                            {
                                fout << "*";
                                j++;
                            }
                        }
                    fout << array[i].words;
                }
            }

}



void main()
{
    int size = 1000;
    mytype array[1000];
    read(array, size);
}

The problem is that my file called naughty.txt has this in it" We don't like fried pickles or fried anything."

My nice.txt file is outputting "wedon'tlikefriendpicklesorfriedanything"

Third Edit: #include "library.h"

struct mytype{string words;};

void read(mytype array[], int size)
{
    ifstream fin("naughty.txt");
    if(fin.fail())
    {
        cout << "Input file didn't open." << endl;
    }

    else 
        {
            ofstream fout("nice.txt");
            for(int i = 0; i < size; i++)
                {
                    fin >> array[i].words;
                    if(array[i].words[0] == 'f' || array[i].words[0] == 'F') 
                        {
                            int length = array[i].words.length();
                            int j = array[i].words.find_first_of("f" );
                            while(j < length)
                            {
                                fout << "*";
                                j++;
                            }
                        }

                    else if(i > 0){
                    fout << ' ';
                    fout << array[i].words << " ";}
                }
            }

}



void main()
{
    int size = 1000;
    mytype array[1000];
    read(array, size);
 }

Data in the file "nice.txt" is We don't like ***** fried pickles or anything ***** fried

Answer 1

                if(array[i].words == "f" || array[i].words == "F") 

This checks if the word is f or F rather than whether it starts with f or F.

Answer 2

Because you haven’t posted library.h the following example uses only standard libraries. I have added some comments to clarify the idea of char-by-char reading (not word-by-word as you expect):

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

int main(void)
{
    // open file streams
    ifstream fin; // input stream
    ofstream fout; // output stream
    char c; // bufer (just one character)
    bool word = false; // become true when new word is found
    bool replace = false; // become true when f-word is processed
    // open and check
    fin.open("naughty.txt", ifstream::in);
    if( !fin.is_open() )
    {
        cerr << "ERROR: Source file cannot be open!" << endl;
        return 1;
    }
    fout.open("nice.txt", ofstream::out);
    if( !fout.is_open() )
    {
        cerr << "ERROR: Destiation file cannot be open!" << endl;
        return 1;
    }
    // read and write until end of file reached or reading fail
    while (fin.get(c)) 
    {
        // check the read character for being not a letter (part of word)
        if( !isalpha(c) )   // consider changing condition to: if( isspace(c) ) 
        {   // it is lot a letter, so it is not a word and nothing to be changed
            word = false;
            replace = false; 
            // And just repeat this character
            fout.put(c);
        }
        else
        { // it is a letter, so it is a word
            if( !word ) // if it is a new word
            {
                word = true;
                // check the first letter
                if( c == 'F' || c == 'f' )
                {
                    replace = true; // now replasement is needed
                }
            }
            if( replace )
            {   // if replacement is needed
                fout.put('*');  
            }
            else
            {   // or just repeat the character
                fout.put(c);
            }
        }
    }
    // close files
    fin.close();
    fout.close();
}