Input/output files help.

[Jake Jung]

I'm sorry this is a little long.. but please help if you can.
Here is my code.
When I am opening a txt file and transferring its content into a different selected txt file, it always have one "word" too many. Any ideas?

#include <iostream>
#include <vector>
#include <fstream>
#include <string>
#include <algorithm>


using namespace std;

//bool duplicate;
void filter(vector < string > & filter_vector, string word)
{
	bool copy = false;

	for(int i = 0; i < filter_vector.size(); i++)
	{

		if(word == filter_vector[i])

		{
			copy = true;
		}
	}

	if(copy == false)
	{
		filter_vector.push_back(word);

	}
}

//open file;
int main()
{
	cout << "Please enter the file name: ";
	string file;
	getline(cin, file);
	ifstream in_file;
	in_file.open(file.c_str());

	if(in_file.fail())
	{
		cout << "the file \"" << file << "\" cannot be found." << endl;

		return main() ;
	}
	else
	{

		cout << "the file \"" << file << "\" is now opened." << endl;
	}

	vector<string> word2;
	string word;

	while(in_file >> word)
	{
		filter(word2, word);
	}



	sort(word2.begin()+1, word2.end());

	ofstream out_file;

	string out;
	cout << "Enter your output file name: ";
	getline(cin, out);

	out_file.open(out.c_str());

	out_file << word2.size() << endl;

	for(int i = 1; i < word2.size(); i++)
	{
		out_file << word2[i] << endl;
	}

	system("pause");
	return 0;
}

[MiiNiPaa]

for(int i = 1; i < word2.size(); i++)
Indexes starts from 0: for(int i = 0; i < word2.size(); i++)
Even better:

for(auto x: word2)
    out_file << x << endl;

Some notes:
1) Latest standart version can take strings instead of c-strings as arguments almost everywhere.
2) You can tell which file to open in constructor
Combining both:

cout << "Please enter the file name: ";
string file;
getline(cin, file);
ifstream in_file(file);

3)return main() ;
Do not do that. Ever. Do not call main().